make sync client clone root directory

.dockerignore

@@ -0,0 +1,35 @@
+# Git
+.git
+.gitignore
+README.md
+LICENSE
+
+# Rust
+server/target/
+**/*.rs.bk
+
+# Node.js
+webui/node_modules/
+webui/dist/
+webui/.vite/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log
+server/data/logs/
+
+# Database (for development)
+server/data/db/*.db
+server/data/backups/
+
+# Cache
+.cache/

.gitignore

@@ -3,6 +3,7 @@
 # will have compiled files and executables
 debug/
 target/
+dist/
 
 # These are backup files generated by rustfmt
 **/*.rs.bk
@@ -10,9 +11,7 @@ target/
 # MSVC Windows builds of rustc generate these, which store debugging information
 *.pdb
 
-# RustRover
-#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
-#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
-#  and can be added to the global gitignore or merged into this file.  For a more nuclear
-#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
-#.idea/
+.idea/
+.vscode
+
+server/data

Dockerfile

@@ -0,0 +1,53 @@
+FROM node:20-alpine AS webui-builder
+
+WORKDIR /app/webui
+
+COPY webui/package.json webui/pnpm-lock.yaml ./
+RUN npm install -g pnpm && pnpm install --frozen-lockfile
+
+COPY webui/ .
+RUN pnpm build
+
+FROM rust:1.89-alpine AS rust-builder
+
+RUN apk add --no-cache musl-dev sqlite-dev pkgconfig openssl-dev
+
+WORKDIR /app/server
+
+COPY server/Cargo.toml server/Cargo.lock ./
+
+COPY server/src ./src
+RUN cargo build --release
+
+FROM alpine:latest
+
+RUN apk add --no-cache sqlite
+
+RUN addgroup -g 1001 -S appgroup && \
+    adduser -u 1001 -S appuser -G appgroup
+
+WORKDIR /app
+
+RUN mkdir -p data/db data/logs data/backups && \
+    chown -R appuser:appgroup /app
+
+COPY --from=rust-builder /app/server/target/release/server ./server
+
+COPY --from=webui-builder /app/webui/dist ./dist
+
+RUN chown -R appuser:appgroup /app
+
+USER appuser
+
+EXPOSE 8379
+
+ENV RUST_LOG=info
+
+VOLUME ["/app/data/db"]
+VOLUME ["/app/data/logs"]
+VOLUME ["/app/data/backups"]
+
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://localhost:8379/ || exit 1
+
+CMD ["./server"]

PROTOCOL.md

@@ -0,0 +1,396 @@
+Gute Einsicht — du hast recht: **nur Disk-Hashes** allein reichen nicht, der Sync-Client muss die **gesamte Objekt-Graph-Struktur** (Disk → Partition → RootDir → Dirs → Files → Chunks) erzeugen und der Server muss diese Meta-Objekte speichern/prüfen.
+Ich aktualisiere das Protokoll so, dass es komplett, binär und KI-implementierbar ist — mit klaren Message-Formaten, Meta-Objekt-Binärlayouts und Pseudocode für Client **(was er erzeugen / berechnen muss)** und für Server **(wie er prüfen & persistieren muss)**.
+
+Ich halte es pragmatisch: keine Kompression-Extensions, keine Encryption — alles einfach, später erweiterbar.
+
+---
+
+# Kurzüberblick (Was passiert)
+
+1. Client scannt Disk/Partition, chunked Dateien (4 MiB), berechnet Chunks-Hashes (BLAKE3-256, 32B).
+2. Client baut Binär-Meta-Objekte: FileObj, DirObj, PartitionObj, DiskObj, SnapshotObj (jeweils Body → `meta_hash = BLAKE3(body)`).
+3. Client spricht Server über TCP an (HELLO → AUTH), fragt in Batches nach fehlenden Chunks/Metas, sendet nur fehlende Chunks/Metas.
+4. Am Ende sendet er das Snapshot-Commit; Server validiert, schreibt Snapshot-Referenz (Server führt Pointer).
+
+---
+
+# Nachrichtengeneralstruktur (Envelopes)
+
+Jede Nachricht: fixer 24-Byte Header + Payload:
+
+```
+struct MsgHeader {
+    u8  cmd;               // Befehlscode (siehe Tabelle)
+    u8  flags;             // reserved
+    u8  reserved[2];
+    u8  session_id[16];    // 0..0 bevor AUTH_OK
+    u32 payload_len;       // LE
+}
+```
+
+Antwort-Nachrichten haben dieselbe Hülle.
+
+---
+
+# Command-Codes (u8)
+
+* 0x01 HELLO
+* 0x02 HELLO_OK
+* 0x10 AUTH_USERPASS
+* 0x11 AUTH_CODE
+* 0x12 AUTH_OK
+* 0x13 AUTH_FAIL
+* 0x20 BATCH_CHECK_CHUNK
+* 0x21 CHECK_CHUNK_RESP
+* 0x22 SEND_CHUNK
+* 0x23 CHUNK_OK
+* 0x24 CHUNK_FAIL
+* 0x30 BATCH_CHECK_META
+* 0x31 CHECK_META_RESP
+* 0x32 SEND_META
+* 0x33 META_OK
+* 0x34 META_FAIL
+* 0x40 SEND_SNAPSHOT (Snapshot-Commit)
+* 0x41 SNAPSHOT_OK
+* 0x42 SNAPSHOT_FAIL
+* 0xFF CLOSE
+
+---
+
+# Wichtige Designentscheidungen (Kurz)
+
+* **Hashes**: BLAKE3-256 (32 Bytes). Client berechnet alle Hashes (Chunks + Meta bodies).
+* **Chunks auf Wire**: unkomprimiert (einfach & verlässlich). Kompression wäre später Erweiterung.
+* **Meta-Objekt-Body**: kompakte binäre Strukturen (siehe unten). `meta_hash = BLAKE3(body)`.
+* **Batch-Checks**: Client fragt in Batches nach fehlenden Chunks/Metas (+ Server liefert nur die fehlenden Hashes zurück). Minimiert RTT.
+* **Server persistiert**: `chunks/<ab>/<cd>/<hash>.chk`, `meta/<type>/<ab>/<cd>/<hash>.meta`. Server verwaltet Snapshot-Pointers (z. B. `machines/<client>/snapshots/<id>.ref`).
+* **Snapshot Commit**: Server validiert Objekt-Graph vor Abschluss; falls etwas fehlt, sendet Liste zurück (Snapshot_FAIL mit missing list).
+
+---
+
+# Binary Payload-Formate
+
+Alle mehrteiligen Zähler / Längen sind little-endian (`LE`).
+
+## A) BATCH_CHECK_CHUNK (Client → Server)
+
+```
+payload:
+u32 count
+for i in 0..count:
+  u8[32] chunk_hash
+```
+
+## CHECK_CHUNK_RESP (Server → Client)
+
+```
+payload:
+u32 missing_count
+for i in 0..missing_count:
+  u8[32] missing_chunk_hash
+```
+
+## SEND_CHUNK (Client → Server)
+
+```
+payload:
+u8[32] chunk_hash
+u32   size
+u8[size] data   // raw chunk bytes
+```
+
+Server computes BLAKE3(data) and compares to chunk_hash; if equal -> speichert.
+
+## A) BATCH_CHECK_META
+
+```
+payload:
+u32 count
+for i in 0..count:
+  u8  meta_type   // 1=file,2=dir,3=partition,4=disk,5=snapshot
+  u8[32] meta_hash
+```
+
+## CHECK_META_RESP
+
+```
+payload:
+u32 missing_count
+for i in 0..missing_count:
+  u8  meta_type
+  u8[32] meta_hash
+```
+
+## SEND_META
+
+```
+payload:
+u8   meta_type      // 1..5
+u8[32] meta_hash
+u32  body_len
+u8[body_len] body_bytes   // the canonical body; server will BLAKE3(body_bytes) and compare to meta_hash
+```
+
+## SEND_SNAPSHOT (Commit)
+
+```
+payload:
+u8[32] snapshot_hash
+u32   body_len
+u8[body_len] snapshot_body  // Snapshot body same encoding as meta (server validates body hash == snapshot_hash)
+```
+
+Server validates that snapshot_body references only existing meta objects (recursive / direct check). If OK → creates persistent snapshot pointer and replies SNAPSHOT_OK; if not, reply SNAPSHOT_FAIL with missing list (same format as CHECK_META_RESP).
+
+---
+
+# Meta-Objekt-Binärformate (Bodies)
+
+> Client erzeugt `body_bytes` für jedes Meta-Objekt; `meta_hash = BLAKE3(body_bytes)`.
+
+### FileObj (meta_type = 1)
+
+```
+FileObjBody:
+u8  version (1)
+u32 fs_type_code        // e.g. 1=ext*, 2=ntfs, 3=fat32 (enum)
+u64 size
+u32 mode               // POSIX mode for linux; 0 for FS without
+u32 uid
+u32 gid
+u64 mtime_unixsec
+u32 chunk_count
+for i in 0..chunk_count:
+  u8[32] chunk_hash
+// optional: xattrs/ACLs TLV (not in v1)
+```
+
+### DirObj (meta_type = 2)
+
+```
+DirObjBody:
+u8 version (1)
+u32 entry_count
+for each entry:
+  u8 entry_type      // 0 = file, 1 = dir, 2 = symlink
+  u16 name_len
+  u8[name_len] name (UTF-8)
+  u8[32] target_meta_hash
+```
+
+### PartitionObj (meta_type = 3)
+
+```
+PartitionObjBody:
+u8 version (1)
+u32 fs_type_code
+u8[32] root_dir_hash   // DirObj hash for root of this partition
+u64 start_lba
+u64 end_lba
+u8[16] type_guid       // zeroed if unused
+```
+
+### DiskObj (meta_type = 4)
+
+```
+DiskObjBody:
+u8 version (1)
+u32 partition_count
+for i in 0..partition_count:
+  u8[32] partition_hash
+u64 disk_size_bytes
+u16 serial_len
+u8[serial_len] serial_bytes
+```
+
+### SnapshotObj (meta_type = 5)
+
+```
+SnapshotObjBody:
+u8 version (1)
+u64 created_at_unixsec
+u32 disk_count
+for i in 0..disk_count:
+  u8[32] disk_hash
+// optional: snapshot metadata (user, note) as TLV extension later
+```
+
+---
+
+# Ablauf (Pseudocode) — **Client-Seite (Sync-Client)**
+
+(Erzeugt alle Hashes; sendet nur fehlendes per Batch)
+
+```text
+FUNCTION client_backup(tcp_conn, computer_id, disks):
+    send_msg(HELLO{client_type=0, auth_type=0})
+    await HELLO_OK
+
+    send_msg(AUTH_USERPASS{username,password})
+    resp = await
+    if resp != AUTH_OK: abort
+    session_id = resp.session_id
+
+    // traverse per-partition to limit memory
+    snapshot_disk_hashes = []
+    FOR disk IN disks:
+        partition_hashes = []
+        FOR part IN disk.partitions:
+            root_dir_hash = process_dir(part.root_path, tcp_conn)
+            part_body = build_partition_body(part.fs_type, root_dir_hash, part.start, part.end, part.guid)
+            part_hash = blake3(part_body)
+            batch_check_and_send_meta_if_missing(tcp_conn, meta_type=3, [(part_hash,part_body)])
+            partition_hashes.append(part_hash)
+
+        disk_body = build_disk_body(partition_hashes, disk.size, disk.serial)
+        disk_hash = blake3(disk_body)
+        batch_check_and_send_meta_if_missing(tcp_conn, meta_type=4, [(disk_hash,disk_body)])
+        snapshot_disk_hashes.append(disk_hash)
+
+    snapshot_body = build_snapshot_body(now(), snapshot_disk_hashes)
+    snapshot_hash = blake3(snapshot_body)
+    // final TRY: ask server if snapshot can be committed (server will verify)
+    send_msg(SEND_SNAPSHOT(snapshot_hash, snapshot_body))
+    resp = await
+    if resp == SNAPSHOT_OK: success
+    else if resp == SNAPSHOT_FAIL: // server returns missing meta list
+        // receive missing metas; client should send the remaining missing meta/chunks (loop)
+        handle_missing_and_retry()
+```
+
+Hilfsfunktionen:
+
+```text
+FUNCTION process_dir(path, tcp_conn):
+    entries_meta = []   // list of (name, entry_type, target_hash)
+    collect a list meta_to_check_for_this_dir = []
+    FOR entry IN readdir(path):
+        IF entry.is_file:
+            file_hash = process_file(entry.path, tcp_conn)   // below
+            entries_meta.append((entry.name, 0, file_hash))
+        ELSE IF entry.is_dir:
+            subdir_hash = process_dir(entry.path, tcp_conn)
+            entries_meta.append((entry.name, 1, subdir_hash))
+        ELSE IF symlink:
+            symlink_body = build_symlink_body(target)
+            symlink_hash = blake3(symlink_body)
+            batch_check_and_send_meta_if_missing(tcp_conn, meta_type=1, [(symlink_hash, symlink_body)])
+            entries_meta.append((entry.name, 2, symlink_hash))
+
+    dir_body = build_dir_body(entries_meta)
+    dir_hash = blake3(dir_body)
+    batch_check_and_send_meta_if_missing(tcp_conn, meta_type=2, [(dir_hash,dir_body)])
+    RETURN dir_hash
+```
+
+```text
+FUNCTION process_file(path, tcp_conn):
+    chunk_hashes = []
+    FOR each chunk IN read_in_chunks(path, 4*1024*1024):
+        chunk_hash = blake3(chunk)
+        chunk_hashes.append(chunk_hash)
+    // Batch-check chunks for this file
+    missing = batch_check_chunks(tcp_conn, chunk_hashes)
+    FOR each missing_hash IN missing:
+        chunk_bytes = read_chunk_by_hash_from_disk(path, missing_hash) // or buffer earlier
+        send_msg(SEND_CHUNK {hash,size,data})
+        await CHUNK_OK
+
+    file_body = build_file_body(fs_type, size, mode, uid, gid, mtime, chunk_hashes)
+    file_hash = blake3(file_body)
+    batch_check_and_send_meta_if_missing(tcp_conn, meta_type=1, [(file_hash,file_body)])
+    RETURN file_hash
+```
+
+`batch_check_and_send_meta_if_missing`:
+
+* Send BATCH_CHECK_META for all items
+* Server returns list of missing metas
+* For each missing, send SEND_META(meta_type, meta_hash, body)
+* Await META_OK
+
+Bemerkung: batching per directory/file-group reduziert RTT.
+
+---
+
+# Ablauf (Pseudocode) — **Server-Seite (Sync-Server)**
+
+```text
+ON connection:
+  read HELLO -> verify allowed client type
+  send HELLO_OK OR HELLO_FAIL
+
+ON AUTH_USERPASS:
+  validate credentials
+  if ok: generate session_id (16B), send AUTH_OK{session_id}
+  else send AUTH_FAIL
+
+ON BATCH_CHECK_CHUNK:
+  read list of hashes
+  missing_list = []
+  for hash in hashes:
+    if not exists chunks/shard(hash): missing_list.append(hash)
+  send CHECK_CHUNK_RESP {missing_list}
+
+ON SEND_CHUNK:
+  read chunk_hash, size, data
+  computed = blake3(data)
+  if computed != chunk_hash: send CHUNK_FAIL{reason} and drop
+  else if exists chunk already: send CHUNK_OK
+  else: write atomic to chunks/<ab>/<cd>/<hash>.chk and send CHUNK_OK
+
+ON BATCH_CHECK_META:
+  similar: check meta/<type>/<hash>.meta exists — return missing list
+
+ON SEND_META:
+  verify blake3(body) == meta_hash; if ok write meta/<type>/<ab>/<cd>/<hash>.meta atomically; respond META_OK
+
+ON SEND_SNAPSHOT:
+  verify blake3(snapshot_body) == snapshot_hash
+  // Validate the object graph:
+  missing = validate_graph(snapshot_body) // DFS: disks -> partitions -> dirs -> files -> chunks
+  if missing not empty:
+    send SNAPSHOT_FAIL {missing (as meta list and/or chunk list)}
+  else:
+    store snapshot file and create pointer machines/<client_id>/snapshots/<id>.ref
+    send SNAPSHOT_OK {snapshot_id}
+```
+
+`validate_graph`:
+
+* parse snapshot_body → disk_hashes
+* for each disk_hash check meta exists; load disk meta → for each partition_hash check meta exists … recursively for dir entries -> file metas -> check chunk existence for each chunk_hash. Collect missing set and return.
+
+---
+
+# Verhalten bei `SNAPSHOT_FAIL`
+
+* Server liefert fehlende meta/chunk-Hashes.
+* Client sendet diese gezielt (batch) und wiederholt `SEND_SNAPSHOT` (retry).
+* Alternativ: Client kann beim ersten Versuch inkrementell alle benötigten metas/chunks hochladen (das ist die übliche Reihenfolge dieses Pseudocodes — so fehlt beim Commit nichts mehr).
+
+---
+
+# Speicherung / Pfade (Server intern)
+
+* `chunks/<ab>/<cd>/<hash>.chk`  (ab = first 2 hex chars; cd = next 2)
+* `meta/files/<ab>/<cd>/<hash>.meta`
+* `meta/dirs/<...>`
+* `meta/parts/...`
+* `meta/disks/...`
+* `meta/snapshots/<snapshot_hash>.meta`
+* `machines/<client_id>/snapshots/<snapshot_id>.ref` (Pointer -> snapshot_hash + timestamp)
+
+Atomic writes: `tmp -> rename`.
+
+---
+
+# Wichtige Implementations-Hinweise für die KI/Server-Implementierung
+
+* **Batching ist Pflicht**: Implementiere `BATCH_CHECK_CHUNK` & `BATCH_CHECK_META` effizient (Bitset, HashSet lookups).
+* **Limits**: begrenze `count` pro Batch (z. B. 1000) — Client muss chunk lists stückeln.
+* **Validation:** Server muss auf `SEND_SNAPSHOT` den Graph validieren (sonst verliert man Konsistenz).
+* **Atomic Snapshot Commit:** erst persistieren, wenn Graph vollständig vorhanden.
+* **SessionID**: muss in Header für alle Nachfolgemsgs verwendet werden.
+* **Perf:** parallelisiere Chunk-Uploads (mehrere TCP-Tasks) und erlaubt Server mehrere parallele Handshakes.
+* **Sicherheit:** produktiv TLS/TCP oder VPN; Rate-limit / brute-force Schutz; Provisioning-Codes mit TTL.

client/.gitignore

@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?

client/index.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Arkendro Client</title>
+  </head>
+
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.jsx"></script>
+  </body>
+</html>

client/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "client",
+  "private": true,
+  "version": "0.1.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview",
+    "tauri": "tauri"
+  },
+  "dependencies": {
+    "react": "^19.1.0",
+    "react-dom": "^19.1.0",
+    "@tauri-apps/api": "^2",
+    "@tauri-apps/plugin-opener": "^2"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-react": "^4.6.0",
+    "vite": "^7.0.4",
+    "@tauri-apps/cli": "^2"
+  }
+}

client/src-tauri/.gitignore

@@ -0,0 +1,2 @@
+/target/
+/gen/schemas

client/src-tauri/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "client"
+version = "0.1.0"
+description = "A Tauri App"
+authors = ["you"]
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+# The `_lib` suffix may seem redundant but it is necessary
+# to make the lib name unique and wouldn't conflict with the bin name.
+# This seems to be only an issue on Windows, see https://github.com/rust-lang/cargo/issues/8519
+name = "client_lib"
+crate-type = ["staticlib", "cdylib", "rlib"]
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+tauri = { version = "2.0.0", features = [ "tray-icon" ] }
+tauri-plugin-opener = "2"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+

client/src-tauri/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    tauri_build::build()
+}

client/src-tauri/capabilities/default.json

@@ -0,0 +1,10 @@
+{
+  "$schema": "../gen/schemas/desktop-schema.json",
+  "identifier": "default",
+  "description": "Capability for the main window",
+  "windows": ["main"],
+  "permissions": [
+    "core:default",
+    "opener:default"
+  ]
+}

client/src-tauri/src/lib.rs

@@ -0,0 +1,29 @@
+use tauri::{
+    menu::{Menu, MenuItem},
+    tray::TrayIconBuilder
+};
+
+
+#[cfg_attr(mobile, tauri::mobile_entry_point)]
+pub fn run() {
+    tauri::Builder::default()
+        .setup(|app| {
+            let quit_i = MenuItem::with_id(app, "quit", "Quit", true, None::<&str>)?;
+            let menu = Menu::with_items(app, &[&quit_i])?;
+
+            TrayIconBuilder::new()
+                .menu(&menu)
+                .icon(app.default_window_icon().unwrap().clone())
+                .on_menu_event(|app, event| match event.id.as_ref() {
+                    "quit" => {
+                        app.exit(0);
+                    }
+                    _ => {}
+                })
+                .build(app)?;
+            Ok(())
+        })
+        .plugin(tauri_plugin_opener::init())
+        .run(tauri::generate_context!())
+        .expect("error while running tauri application");
+}

client/src-tauri/src/main.rs

@@ -0,0 +1,6 @@
+// Prevents additional console window on Windows in release, DO NOT REMOVE!!
+#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+
+fn main() {
+    client_lib::run()
+}

client/src-tauri/tauri.conf.json

@@ -0,0 +1,35 @@
+{
+  "$schema": "https://schema.tauri.app/config/2",
+  "productName": "client",
+  "version": "0.1.0",
+  "identifier": "dev.gnm.arkendro-client",
+  "build": {
+    "beforeDevCommand": "pnpm dev",
+    "devUrl": "http://localhost:1420",
+    "beforeBuildCommand": "pnpm build",
+    "frontendDist": "../dist"
+  },
+  "app": {
+    "windows": [
+      {
+        "title": "client",
+        "width": 800,
+        "height": 600
+      }
+    ],
+    "security": {
+      "csp": null
+    }
+  },
+  "bundle": {
+    "active": true,
+    "targets": "all",
+    "icon": [
+      "icons/32x32.png",
+      "icons/128x128.png",
+      "icons/128x128@2x.png",
+      "icons/icon.icns",
+      "icons/icon.ico"
+    ]
+  }
+}

client/src/App.jsx

@@ -0,0 +1,10 @@
+
+const App = () => {
+  return (
+    <main className="container">
+        <h1>Arkendro client</h1>
+    </main>
+  );
+}
+
+export default App;

client/src/main.jsx

@@ -0,0 +1,9 @@
+import React from "react";
+import ReactDOM from "react-dom/client";
+import App from "./App";
+
+ReactDOM.createRoot(document.getElementById("root")).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>,
+);

client/vite.config.js

@@ -0,0 +1,25 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+
+const host = process.env.TAURI_DEV_HOST;
+
+export default defineConfig(async () => ({
+  plugins: [react()],
+
+  clearScreen: false,
+  server: {
+    port: 1420,
+    strictPort: true,
+    host: host || false,
+    hmr: host
+      ? {
+          protocol: "ws",
+          host,
+          port: 1421,
+        }
+      : undefined,
+    watch: {
+      ignored: ["**/src-tauri/**"],
+    },
+  },
+}));

server/.sqlx/query-2d6e5810f76e780a4a9b54c5ea39d707be614eb304dc6b4f32d8b6d28464c4b5.json

@@ -0,0 +1,56 @@
+{
+  "db_name": "SQLite",
+  "query": "\n            SELECT pc.id, pc.code, pc.expires_at, pc.used, m.id as machine_id, m.user_id, u.username\n            FROM provisioning_codes pc\n            JOIN machines m ON pc.machine_id = m.id\n            JOIN users u ON m.user_id = u.id\n            WHERE pc.code = ? AND pc.used = 0\n            ",
+  "describe": {
+    "columns": [
+      {
+        "name": "id",
+        "ordinal": 0,
+        "type_info": "Integer"
+      },
+      {
+        "name": "code",
+        "ordinal": 1,
+        "type_info": "Text"
+      },
+      {
+        "name": "expires_at",
+        "ordinal": 2,
+        "type_info": "Datetime"
+      },
+      {
+        "name": "used",
+        "ordinal": 3,
+        "type_info": "Bool"
+      },
+      {
+        "name": "machine_id",
+        "ordinal": 4,
+        "type_info": "Integer"
+      },
+      {
+        "name": "user_id",
+        "ordinal": 5,
+        "type_info": "Integer"
+      },
+      {
+        "name": "username",
+        "ordinal": 6,
+        "type_info": "Text"
+      }
+    ],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": [
+      true,
+      false,
+      false,
+      true,
+      true,
+      false,
+      false
+    ]
+  },
+  "hash": "2d6e5810f76e780a4a9b54c5ea39d707be614eb304dc6b4f32d8b6d28464c4b5"
+}

server/.sqlx/query-43af0c22d05eca56b2a7b1f6eed873102d8e006330fd7d8063657d2df936b3fb.json

@@ -0,0 +1,26 @@
+{
+  "db_name": "SQLite",
+  "query": "SELECT id, user_id FROM machines WHERE id = ?",
+  "describe": {
+    "columns": [
+      {
+        "name": "id",
+        "ordinal": 0,
+        "type_info": "Integer"
+      },
+      {
+        "name": "user_id",
+        "ordinal": 1,
+        "type_info": "Integer"
+      }
+    ],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": [
+      false,
+      false
+    ]
+  },
+  "hash": "43af0c22d05eca56b2a7b1f6eed873102d8e006330fd7d8063657d2df936b3fb"
+}

server/.sqlx/query-508e673540beae31730d323bbb52d91747bb405ef3d6f4a7f20776fdeb618688.json

@@ -0,0 +1,12 @@
+{
+  "db_name": "SQLite",
+  "query": "UPDATE provisioning_codes SET used = 1 WHERE id = ?",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": []
+  },
+  "hash": "508e673540beae31730d323bbb52d91747bb405ef3d6f4a7f20776fdeb618688"
+}

server/.sqlx/query-9f9215a05f729db6f707c84967f4f11033d39d17ded98f4fe9fb48f3d1598596.json

@@ -0,0 +1,32 @@
+{
+  "db_name": "SQLite",
+  "query": "SELECT id, username, password_hash FROM users WHERE username = ?",
+  "describe": {
+    "columns": [
+      {
+        "name": "id",
+        "ordinal": 0,
+        "type_info": "Integer"
+      },
+      {
+        "name": "username",
+        "ordinal": 1,
+        "type_info": "Text"
+      },
+      {
+        "name": "password_hash",
+        "ordinal": 2,
+        "type_info": "Text"
+      }
+    ],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": [
+      true,
+      false,
+      false
+    ]
+  },
+  "hash": "9f9215a05f729db6f707c84967f4f11033d39d17ded98f4fe9fb48f3d1598596"
+}

server/.sqlx/query-cc5f2e47cc53dd29682506ff84f07f7d0914e3141e62b470e84b3886b50764a1.json

@@ -0,0 +1,26 @@
+{
+  "db_name": "SQLite",
+  "query": "SELECT id, user_id FROM machines WHERE id = ? AND user_id = ?",
+  "describe": {
+    "columns": [
+      {
+        "name": "id",
+        "ordinal": 0,
+        "type_info": "Integer"
+      },
+      {
+        "name": "user_id",
+        "ordinal": 1,
+        "type_info": "Integer"
+      }
+    ],
+    "parameters": {
+      "Right": 2
+    },
+    "nullable": [
+      false,
+      false
+    ]
+  },
+  "hash": "cc5f2e47cc53dd29682506ff84f07f7d0914e3141e62b470e84b3886b50764a1"
+}

server/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "server"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+axum = "0.8.4"
+tokio = { version = "1.47.1", features = ["full", "signal"] }
+sqlx = { version = "0.8.6", features = ["runtime-tokio-rustls", "sqlite", "chrono", "uuid"] }
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+bcrypt = "0.17.1"
+uuid = { version = "1.0", features = ["v4", "serde"] }
+chrono = { version = "0.4", features = ["serde"] }
+tower-http = { version = "0.6.6", features = ["cors", "fs"] }
+anyhow = "1.0"
+rand = "0.8"
+blake3 = "1.5"
+bytes = "1.0"
+bincode = "1.3"
+hex = "0.4"
+
+[dev-dependencies]
+tempfile = "3.0"

server/src/controllers/auth.rs

@@ -0,0 +1,106 @@
+use crate::controllers::users::UsersController;
+use crate::utils::{error::*, models::*, DbPool};
+use chrono::{Duration, Utc};
+use sqlx::Row;
+use uuid::Uuid;
+
+pub struct AuthController;
+
+impl AuthController {
+    pub async fn login(pool: &DbPool, username: &str, password: &str) -> AppResult<LoginResponse> {
+        let user = UsersController::verify_user_credentials(pool, username, password).await?;
+
+        let session = Self::create_session(pool, user.id).await?;
+
+        Ok(LoginResponse {
+            token: session.token,
+            role: user.role,
+        })
+    }
+
+    pub async fn logout(pool: &DbPool, user_id: i64) -> AppResult<()> {
+        sqlx::query("DELETE FROM sessions WHERE user_id = ?")
+            .bind(user_id)
+            .execute(pool)
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn create_session(pool: &DbPool, user_id: i64) -> AppResult<Session> {
+        let token = Self::generate_session_token();
+        let expires_at = Utc::now() + Duration::days(30);
+        let result = sqlx::query(
+            r#"
+            INSERT INTO sessions (user_id, token, expires_at)
+            VALUES (?, ?, ?)
+            "#,
+        )
+        .bind(user_id)
+        .bind(&token)
+        .bind(expires_at)
+        .execute(pool)
+        .await?;
+
+        Ok(Session {
+            id: result.last_insert_rowid(),
+            user_id,
+            token,
+            created_at: Utc::now(),
+            expires_at,
+        })
+    }
+
+    pub async fn get_session_by_token(pool: &DbPool, token: &str) -> AppResult<Option<Session>> {
+        let row = sqlx::query(
+            r#"
+            SELECT id, user_id, token, created_at, expires_at
+            FROM sessions WHERE token = ? AND expires_at > datetime('now')
+            "#,
+        )
+        .bind(token)
+        .fetch_optional(pool)
+        .await?;
+
+        if let Some(row) = row {
+            Ok(Some(Session {
+                id: row.get("id"),
+                user_id: row.get("user_id"),
+                token: row.get("token"),
+                created_at: row.get("created_at"),
+                expires_at: row.get("expires_at"),
+            }))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub async fn authenticate_user(pool: &DbPool, token: &str) -> AppResult<User> {
+        let session = Self::get_session_by_token(pool, token)
+            .await?
+            .ok_or_else(|| auth_error("Invalid or expired session"))?;
+
+        let user = UsersController::get_user_by_id(pool, session.user_id).await?;
+        Ok(user)
+    }
+
+    pub async fn cleanup_expired_sessions(pool: &DbPool) -> AppResult<()> {
+        sqlx::query("DELETE FROM sessions WHERE expires_at <= datetime('now')")
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    fn generate_session_token() -> String {
+        Uuid::new_v4().to_string()
+    }
+
+    #[allow(dead_code)]
+    pub async fn delete_session_by_token(pool: &DbPool, token: &str) -> AppResult<()> {
+        sqlx::query("DELETE FROM sessions WHERE token = ?")
+            .bind(token)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+}

server/src/controllers/files.rs

@@ -0,0 +1,365 @@
+use crate::sync::storage::Storage;
+use crate::sync::meta::{MetaObj, EntryType};
+use crate::sync::protocol::MetaType;
+use crate::utils::{error::*, models::*, DbPool};
+use serde::Serialize;
+use axum::response::Response;
+use axum::body::Body;
+use axum::http::{HeaderMap, HeaderValue};
+
+#[derive(Debug, Serialize)]
+pub struct FileSystemEntry {
+    pub name: String,
+    pub entry_type: String, // "file", "dir", "symlink"
+    pub size_bytes: Option<u64>,
+    pub meta_hash: String,
+}
+
+#[derive(Debug, Serialize)]
+pub struct DirectoryListing {
+    pub path: String,
+    pub entries: Vec<FileSystemEntry>,
+    pub parent_hash: Option<String>,
+}
+
+#[derive(Debug, Serialize)]
+pub struct FileMetadata {
+    pub name: String,
+    pub size_bytes: u64,
+    pub mime_type: String,
+    pub meta_hash: String,
+}
+
+pub struct FilesController;
+
+impl FilesController {
+    /// List directory contents for a partition
+    pub async fn list_partition_root(
+        pool: &DbPool,
+        machine_id: i64,
+        snapshot_id: String,
+        partition_index: usize,
+        user: &User,
+    ) -> AppResult<DirectoryListing> {
+        // Verify machine access
+        Self::verify_machine_access(pool, machine_id, user).await?;
+        
+        let storage = Storage::new("./data");
+        
+        // Get partition hash from snapshot
+        let partition_hash = Self::get_partition_hash(&storage, machine_id, &snapshot_id, partition_index).await?;
+        
+        // Load partition metadata to get root directory hash
+        let partition_meta = storage.load_meta(MetaType::Partition, &partition_hash).await
+            .map_err(|_| AppError::NotFoundError("Partition metadata not found".to_string()))?
+            .ok_or_else(|| AppError::NotFoundError("Partition metadata not found".to_string()))?;
+            
+        if let MetaObj::Partition(partition_obj) = partition_meta {
+            Self::list_directory_by_hash(&storage, &partition_obj.root_dir_hash, "/".to_string()).await
+        } else {
+            Err(AppError::ValidationError("Invalid partition metadata".to_string()))
+        }
+    }
+    
+    /// List directory contents by directory hash
+    pub async fn list_directory(
+        pool: &DbPool,
+        machine_id: i64,
+        snapshot_id: String,
+        partition_index: usize,
+        dir_hash: String,
+        user: &User,
+    ) -> AppResult<DirectoryListing> {
+        // Verify machine access
+        Self::verify_machine_access(pool, machine_id, user).await?;
+        
+        let storage = Storage::new("./data");
+        
+        // Decode directory hash
+        let hash_bytes = hex::decode(&dir_hash)
+            .map_err(|_| AppError::ValidationError("Invalid directory hash format".to_string()))?;
+        
+        if hash_bytes.len() != 32 {
+            return Err(AppError::ValidationError("Directory hash must be 32 bytes".to_string()));
+        }
+        
+        let mut hash = [0u8; 32];
+        hash.copy_from_slice(&hash_bytes);
+        
+        Self::list_directory_by_hash(&storage, &hash, dir_hash).await
+    }
+    
+    /// Download a file by file hash with filename
+    pub async fn download_file(
+        pool: &DbPool,
+        machine_id: i64,
+        _snapshot_id: String,
+        _partition_index: usize,
+        file_hash: String,
+        filename: Option<String>,
+        user: &User,
+    ) -> AppResult<Response<Body>> {
+        // Verify machine access
+        Self::verify_machine_access(pool, machine_id, user).await?;
+        
+        let storage = Storage::new("./data");
+        
+        // Decode file hash
+        let hash_bytes = hex::decode(&file_hash)
+            .map_err(|_| AppError::ValidationError("Invalid file hash format".to_string()))?;
+        
+        if hash_bytes.len() != 32 {
+            return Err(AppError::ValidationError("File hash must be 32 bytes".to_string()));
+        }
+        
+        let mut hash = [0u8; 32];
+        hash.copy_from_slice(&hash_bytes);
+        
+        // Load file metadata
+        let file_meta = storage.load_meta(MetaType::File, &hash).await
+            .map_err(|_| AppError::NotFoundError("File metadata not found".to_string()))?
+            .ok_or_else(|| AppError::NotFoundError("File metadata not found".to_string()))?;
+            
+        if let MetaObj::File(file_obj) = file_meta {
+            // Reconstruct file content from chunks
+            let mut file_content = Vec::new();
+            
+            for chunk_hash in &file_obj.chunk_hashes {
+                let chunk_data = storage.load_chunk(chunk_hash).await
+                    .map_err(|_| AppError::NotFoundError(format!("Chunk {} not found", hex::encode(chunk_hash))))?
+                    .ok_or_else(|| AppError::NotFoundError(format!("Chunk {} not found", hex::encode(chunk_hash))))?;
+                
+                file_content.extend_from_slice(&chunk_data);
+            }
+            
+            // Use provided filename or generate a generic one
+            let filename = filename.unwrap_or_else(|| format!("file_{}.bin", &file_hash[..8]));
+            
+            // Determine MIME type from file content
+            let mime_type = Self::detect_mime_type(&filename, &file_content);
+            
+            // Create response headers
+            let mut headers = HeaderMap::new();
+            headers.insert(
+                "content-type",
+                HeaderValue::from_str(&mime_type).unwrap_or_else(|_| HeaderValue::from_static("application/octet-stream"))
+            );
+            headers.insert(
+                "content-disposition",
+                HeaderValue::from_str(&format!("attachment; filename=\"{}\"", filename))
+                    .unwrap_or_else(|_| HeaderValue::from_static("attachment"))
+            );
+            headers.insert(
+                "content-length",
+                HeaderValue::from_str(&file_content.len().to_string()).unwrap()
+            );
+            
+            let mut response = Response::new(Body::from(file_content));
+            *response.headers_mut() = headers;
+            
+            Ok(response)
+        } else {
+            Err(AppError::ValidationError("Invalid file metadata".to_string()))
+        }
+    }
+    
+    /// Get file metadata without downloading content
+    pub async fn get_file_metadata(
+        pool: &DbPool,
+        machine_id: i64,
+        snapshot_id: String,
+        partition_index: usize,
+        file_hash: String,
+        user: &User,
+    ) -> AppResult<FileMetadata> {
+        // Verify machine access
+        Self::verify_machine_access(pool, machine_id, user).await?;
+        
+        let storage = Storage::new("./data");
+        
+        // Decode file hash
+        let hash_bytes = hex::decode(&file_hash)
+            .map_err(|_| AppError::ValidationError("Invalid file hash format".to_string()))?;
+        
+        if hash_bytes.len() != 32 {
+            return Err(AppError::ValidationError("File hash must be 32 bytes".to_string()));
+        }
+        
+        let mut hash = [0u8; 32];
+        hash.copy_from_slice(&hash_bytes);
+        
+        // Load file metadata
+        let file_meta = storage.load_meta(MetaType::File, &hash).await
+            .map_err(|_| AppError::NotFoundError("File metadata not found".to_string()))?
+            .ok_or_else(|| AppError::NotFoundError("File metadata not found".to_string()))?;
+            
+        if let MetaObj::File(file_obj) = file_meta {
+            let filename = format!("file_{}.bin", &file_hash[..8]);
+            let mime_type = Self::detect_mime_type(&filename, &[]);
+            
+            Ok(FileMetadata {
+                name: filename,
+                size_bytes: file_obj.size,
+                mime_type,
+                meta_hash: file_hash,
+            })
+        } else {
+            Err(AppError::ValidationError("Invalid file metadata".to_string()))
+        }
+    }
+    
+    // Helper methods
+    
+    async fn verify_machine_access(pool: &DbPool, machine_id: i64, user: &User) -> AppResult<()> {
+        let machine = sqlx::query!(
+            "SELECT id, user_id FROM machines WHERE id = ? AND user_id = ?",
+            machine_id,
+            user.id
+        )
+        .fetch_optional(pool)
+        .await
+        .map_err(|e| AppError::DatabaseError(e.to_string()))?;
+
+        if machine.is_none() {
+            return Err(AppError::NotFoundError("Machine not found or access denied".to_string()));
+        }
+        
+        Ok(())
+    }
+    
+    async fn get_partition_hash(
+        storage: &Storage,
+        machine_id: i64,
+        snapshot_id: &str,
+        partition_index: usize,
+    ) -> AppResult<[u8; 32]> {
+        // Load snapshot reference to get hash
+        let (snapshot_hash, _) = storage.load_snapshot_ref(machine_id, snapshot_id).await
+            .map_err(|_| AppError::NotFoundError("Snapshot not found".to_string()))?
+            .ok_or_else(|| AppError::NotFoundError("Snapshot not found".to_string()))?;
+
+        // Load snapshot metadata
+        let snapshot_meta = storage.load_meta(MetaType::Snapshot, &snapshot_hash).await
+            .map_err(|_| AppError::NotFoundError("Snapshot metadata not found".to_string()))?
+            .ok_or_else(|| AppError::NotFoundError("Snapshot metadata not found".to_string()))?;
+
+        if let MetaObj::Snapshot(snapshot_obj) = snapshot_meta {
+            // Get first disk (assuming single disk for now)
+            if snapshot_obj.disk_hashes.is_empty() {
+                return Err(AppError::NotFoundError("No disks in snapshot".to_string()));
+            }
+            
+            let disk_hash = snapshot_obj.disk_hashes[0];
+            
+            // Load disk metadata
+            let disk_meta = storage.load_meta(MetaType::Disk, &disk_hash).await
+                .map_err(|_| AppError::NotFoundError("Disk metadata not found".to_string()))?
+                .ok_or_else(|| AppError::NotFoundError("Disk metadata not found".to_string()))?;
+                
+            if let MetaObj::Disk(disk_obj) = disk_meta {
+                if partition_index >= disk_obj.partition_hashes.len() {
+                    return Err(AppError::NotFoundError("Partition index out of range".to_string()));
+                }
+                
+                Ok(disk_obj.partition_hashes[partition_index])
+            } else {
+                Err(AppError::ValidationError("Invalid disk metadata".to_string()))
+            }
+        } else {
+            Err(AppError::ValidationError("Invalid snapshot metadata".to_string()))
+        }
+    }
+    
+    async fn list_directory_by_hash(
+        storage: &Storage,
+        dir_hash: &[u8; 32],
+        path: String,
+    ) -> AppResult<DirectoryListing> {
+        // Load directory metadata
+        let dir_meta = storage.load_meta(MetaType::Dir, dir_hash).await
+            .map_err(|_| AppError::NotFoundError("Directory metadata not found".to_string()))?
+            .ok_or_else(|| AppError::NotFoundError("Directory metadata not found".to_string()))?;
+            
+        if let MetaObj::Dir(dir_obj) = dir_meta {
+            let mut entries = Vec::new();
+            
+            for entry in dir_obj.entries {
+                let entry_type_str = match entry.entry_type {
+                    EntryType::File => "file",
+                    EntryType::Dir => "dir",
+                    EntryType::Symlink => "symlink",
+                };
+                
+                let size_bytes = if entry.entry_type == EntryType::File {
+                    // Load file metadata to get size
+                    if let Ok(Some(MetaObj::File(file_obj))) = storage.load_meta(MetaType::File, &entry.target_meta_hash).await {
+                        Some(file_obj.size)
+                    } else {
+                        None
+                    }
+                } else {
+                    None
+                };
+                
+                entries.push(FileSystemEntry {
+                    name: entry.name,
+                    entry_type: entry_type_str.to_string(),
+                    size_bytes,
+                    meta_hash: hex::encode(entry.target_meta_hash),
+                });
+            }
+            
+            // Sort entries: directories first, then files, both alphabetically
+            entries.sort_by(|a, b| {
+                match (a.entry_type.as_str(), b.entry_type.as_str()) {
+                    ("dir", "file") => std::cmp::Ordering::Less,
+                    ("file", "dir") => std::cmp::Ordering::Greater,
+                    _ => a.name.cmp(&b.name),
+                }
+            });
+            
+            Ok(DirectoryListing {
+                path,
+                entries,
+                parent_hash: None, // TODO: Implement parent tracking if needed
+            })
+        } else {
+            Err(AppError::ValidationError("Invalid directory metadata".to_string()))
+        }
+    }
+    
+    fn detect_mime_type(filename: &str, _content: &[u8]) -> String {
+        // Simple MIME type detection based on file extension
+        let extension = std::path::Path::new(filename)
+            .extension()
+            .and_then(|ext| ext.to_str())
+            .unwrap_or("")
+            .to_lowercase();
+            
+        match extension.as_str() {
+            "txt" | "md" | "readme" => "text/plain",
+            "html" | "htm" => "text/html",
+            "css" => "text/css",
+            "js" => "application/javascript",
+            "json" => "application/json",
+            "xml" => "application/xml",
+            "pdf" => "application/pdf",
+            "zip" => "application/zip",
+            "tar" => "application/x-tar",
+            "gz" => "application/gzip",
+            "jpg" | "jpeg" => "image/jpeg",
+            "png" => "image/png",
+            "gif" => "image/gif",
+            "svg" => "image/svg+xml",
+            "mp4" => "video/mp4",
+            "mp3" => "audio/mpeg",
+            "wav" => "audio/wav",
+            "exe" => "application/x-msdownload",
+            "dll" => "application/x-msdownload",
+            "so" => "application/x-sharedlib",
+            "deb" => "application/vnd.debian.binary-package",
+            "rpm" => "application/x-rpm",
+            _ => "application/octet-stream",
+        }.to_string()
+    }
+}

server/src/controllers/machines.rs

@@ -0,0 +1,203 @@
+use crate::utils::{base62::Base62, config::ConfigManager, error::*, models::*, DbPool};
+use chrono::{Duration, Utc};
+use rand::{distributions::Alphanumeric, Rng};
+use sqlx::Row;
+use uuid::Uuid;
+
+pub struct MachinesController;
+
+impl MachinesController {
+    pub async fn register_machine(pool: &DbPool, user: &User, name: &str) -> AppResult<Machine> {
+        Self::validate_machine_input(name)?;
+
+        let machine_uuid = Uuid::new_v4();
+
+        let machine = Self::create_machine(pool, user.id, &machine_uuid, name).await?;
+
+        Ok(machine)
+    }
+
+    pub async fn create_provisioning_code(
+        pool: &DbPool,
+        machine_id: i64,
+        user: &User,
+    ) -> AppResult<ProvisioningCodeResponse> {
+        let machine = Self::get_machine_by_id(pool, machine_id).await?;
+
+        if user.role != UserRole::Admin && machine.user_id != user.id {
+            return Err(forbidden_error("Access denied"));
+        }
+
+        let code: String = rand::thread_rng()
+            .sample_iter(&Alphanumeric)
+            .take(5)
+            .map(char::from)
+            .collect();
+
+        let external_url = ConfigManager::get_external_url(pool).await?;
+        let provisioning_string = format!("52?#{}/{}", external_url, code);
+        let encoded_code = Base62::encode(&provisioning_string);
+        let expires_at = Utc::now() + Duration::hours(1);
+
+        sqlx::query(
+            r#"
+            INSERT INTO provisioning_codes (machine_id, code, expires_at)
+            VALUES (?, ?, ?)
+            "#,
+        )
+        .bind(machine_id)
+        .bind(&code)
+        .bind(expires_at)
+        .execute(pool)
+        .await?;
+
+        Ok(ProvisioningCodeResponse {
+            code: encoded_code,
+            raw_code: code,
+            expires_at,
+        })
+    }
+
+    pub async fn get_machines_for_user(pool: &DbPool, user: &User) -> AppResult<Vec<Machine>> {
+        Self::get_machines_by_user_id(pool, user.id).await
+    }
+
+    pub async fn delete_machine(pool: &DbPool, machine_id: i64, user: &User) -> AppResult<()> {
+        let machine = Self::get_machine_by_id(pool, machine_id).await?;
+
+        if user.role != UserRole::Admin && machine.user_id != user.id {
+            return Err(forbidden_error("Access denied"));
+        }
+
+        Self::delete_machine_by_id(pool, machine_id).await
+    }
+
+    pub async fn get_machine_by_id(pool: &DbPool, id: i64) -> AppResult<Machine> {
+        let row = sqlx::query(
+            r#"
+            SELECT id, user_id, uuid, name, created_at
+            FROM machines WHERE id = ?
+            "#,
+        )
+        .bind(id)
+        .fetch_one(pool)
+        .await?;
+
+        Ok(Machine {
+            id: row.get("id"),
+            user_id: row.get("user_id"),
+            uuid: Uuid::parse_str(&row.get::<String, _>("uuid")).unwrap(),
+            machine_id: row.get::<String, _>("uuid"),
+            name: row.get("name"),
+            created_at: row.get("created_at"),
+        })
+    }
+
+    async fn get_machines_by_user_id(pool: &DbPool, user_id: i64) -> AppResult<Vec<Machine>> {
+        let rows = sqlx::query(
+            r#"
+            SELECT id, user_id, uuid, name, created_at
+            FROM machines WHERE user_id = ? ORDER BY created_at DESC
+            "#,
+        )
+        .bind(user_id)
+        .fetch_all(pool)
+        .await?;
+
+        let mut machines = Vec::new();
+        for row in rows {
+            machines.push(Machine {
+                id: row.get("id"),
+                user_id: row.get("user_id"),
+                uuid: Uuid::parse_str(&row.get::<String, _>("uuid")).unwrap(),
+                machine_id: row.get::<String, _>("uuid"),
+                name: row.get("name"),
+                created_at: row.get("created_at"),
+            });
+        }
+
+        Ok(machines)
+    }
+
+    async fn create_machine(
+        pool: &DbPool,
+        user_id: i64,
+        uuid: &Uuid,
+        name: &str,
+    ) -> AppResult<Machine> {
+        let result = sqlx::query(
+            r#"
+            INSERT INTO machines (user_id, uuid, name)
+            VALUES (?, ?, ?)
+            "#,
+        )
+        .bind(user_id)
+        .bind(uuid.to_string())
+        .bind(name)
+        .execute(pool)
+        .await?;
+
+        Self::get_machine_by_id(pool, result.last_insert_rowid()).await
+    }
+
+    async fn machine_exists_by_uuid(pool: &DbPool, uuid: &Uuid) -> AppResult<bool> {
+        let row = sqlx::query("SELECT COUNT(*) as count FROM machines WHERE uuid = ?")
+            .bind(uuid.to_string())
+            .fetch_one(pool)
+            .await?;
+
+        let count: i64 = row.get("count");
+        Ok(count > 0)
+    }
+
+    async fn delete_machine_by_id(pool: &DbPool, id: i64) -> AppResult<()> {
+        sqlx::query("DELETE FROM machines WHERE id = ?")
+            .bind(id)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    async fn get_provisioning_code(
+        pool: &DbPool,
+        code: &str,
+    ) -> AppResult<Option<ProvisioningCode>> {
+        let row = sqlx::query(
+            r#"
+            SELECT id, machine_id, code, created_at, expires_at, used
+            FROM provisioning_codes WHERE code = ?
+            "#,
+        )
+        .bind(code)
+        .fetch_optional(pool)
+        .await?;
+
+        if let Some(row) = row {
+            Ok(Some(ProvisioningCode {
+                id: row.get("id"),
+                machine_id: row.get("machine_id"),
+                code: row.get("code"),
+                created_at: row.get("created_at"),
+                expires_at: row.get("expires_at"),
+                used: row.get("used"),
+            }))
+        } else {
+            Ok(None)
+        }
+    }
+
+    async fn mark_provisioning_code_used(pool: &DbPool, code: &str) -> AppResult<()> {
+        sqlx::query("UPDATE provisioning_codes SET used = 1 WHERE code = ?")
+            .bind(code)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    fn validate_machine_input(name: &str) -> AppResult<()> {
+        if name.trim().is_empty() {
+            return Err(validation_error("Machine name cannot be empty"));
+        }
+        Ok(())
+    }
+}

server/src/controllers/mod.rs

@@ -0,0 +1,5 @@
+pub mod auth;
+pub mod machines;
+pub mod snapshots;
+pub mod users;
+pub mod files;

server/src/controllers/snapshots.rs

@@ -0,0 +1,184 @@
+use crate::sync::storage::Storage;
+use crate::sync::meta::{MetaObj, FsType};
+use crate::sync::protocol::MetaType;
+use crate::utils::{error::*, models::*, DbPool};
+use serde::Serialize;
+use chrono::{DateTime, Utc};
+
+// Basic snapshot info for listing
+#[derive(Debug, Serialize)]
+pub struct SnapshotSummary {
+    pub id: String,
+    pub snapshot_hash: String,
+    pub created_at: String,
+}
+
+// Detailed snapshot info with disk/partition data
+#[derive(Debug, Serialize)]
+pub struct SnapshotDetails {
+    pub id: String,
+    pub snapshot_hash: String,
+    pub created_at: String,
+    pub disks: Vec<DiskInfo>,
+}
+
+#[derive(Debug, Serialize)]
+pub struct DiskInfo {
+    pub serial: String,
+    pub size_bytes: u64,
+    pub partitions: Vec<PartitionInfo>,
+}
+
+#[derive(Debug, Serialize)]
+pub struct PartitionInfo {
+    pub fs_type: String,
+    pub start_lba: u64,
+    pub end_lba: u64,
+    pub size_bytes: u64,
+}
+
+pub struct SnapshotsController;
+
+impl SnapshotsController {
+    pub async fn get_machine_snapshots(
+        pool: &DbPool,
+        machine_id: i64,
+        user: &User,
+    ) -> AppResult<Vec<SnapshotSummary>> {
+        // Verify machine access
+        let machine = sqlx::query!(
+            "SELECT id, user_id FROM machines WHERE id = ? AND user_id = ?",
+            machine_id,
+            user.id
+        )
+        .fetch_optional(pool)
+        .await
+        .map_err(|e| AppError::DatabaseError(e.to_string()))?;
+
+        if machine.is_none() {
+            return Err(AppError::NotFoundError("Machine not found or access denied".to_string()));
+        }
+
+        let _machine = machine.unwrap();
+
+        let storage = Storage::new("./data");
+        let mut snapshot_summaries = Vec::new();
+
+        // List all snapshots for this machine from storage
+        match storage.list_snapshots(machine_id).await {
+            Ok(snapshot_ids) => {
+                for snapshot_id in snapshot_ids {
+                    // Load snapshot reference to get hash and timestamp
+                    if let Ok(Some((snapshot_hash, created_at_timestamp))) = storage.load_snapshot_ref(machine_id, &snapshot_id).await {
+                        let created_at = DateTime::from_timestamp(created_at_timestamp as i64, 0)
+                            .unwrap_or_else(|| Utc::now())
+                            .format("%Y-%m-%d %H:%M:%S UTC")
+                            .to_string();
+
+                        snapshot_summaries.push(SnapshotSummary {
+                            id: snapshot_id,
+                            snapshot_hash: hex::encode(snapshot_hash),
+                            created_at,
+                        });
+                    }
+                }
+            },
+            Err(_) => {
+                // If no snapshots directory exists, return empty list
+                return Ok(Vec::new());
+            }
+        }
+
+        // Sort by creation time (newest first)
+        snapshot_summaries.sort_by(|a, b| b.created_at.cmp(&a.created_at));
+
+        Ok(snapshot_summaries)
+    }
+
+    pub async fn get_snapshot_details(
+        pool: &DbPool,
+        machine_id: i64,
+        snapshot_id: String,
+        user: &User,
+    ) -> AppResult<SnapshotDetails> {
+        // Verify machine access
+        let machine = sqlx::query!(
+            "SELECT id, user_id FROM machines WHERE id = ? AND user_id = ?",
+            machine_id,
+            user.id
+        )
+        .fetch_optional(pool)
+        .await
+        .map_err(|e| AppError::DatabaseError(e.to_string()))?;
+
+        if machine.is_none() {
+            return Err(AppError::NotFoundError("Machine not found or access denied".to_string()));
+        }
+
+        let _machine = machine.unwrap();
+
+        let storage = Storage::new("./data");
+
+        // Load snapshot reference to get hash and timestamp
+        let (snapshot_hash, created_at_timestamp) = storage.load_snapshot_ref(machine_id, &snapshot_id).await
+            .map_err(|_| AppError::NotFoundError("Snapshot not found".to_string()))?
+            .ok_or_else(|| AppError::NotFoundError("Snapshot not found".to_string()))?;
+
+        // Load snapshot metadata
+        let snapshot_meta = storage.load_meta(MetaType::Snapshot, &snapshot_hash).await
+            .map_err(|_| AppError::NotFoundError("Snapshot metadata not found".to_string()))?
+            .ok_or_else(|| AppError::NotFoundError("Snapshot metadata not found".to_string()))?;
+
+        if let MetaObj::Snapshot(snapshot_obj) = snapshot_meta {
+            let mut disks = Vec::new();
+
+            for disk_hash in snapshot_obj.disk_hashes {
+                if let Ok(Some(disk_meta)) = storage.load_meta(MetaType::Disk, &disk_hash).await {
+                    if let MetaObj::Disk(disk_obj) = disk_meta {
+                        let mut partitions = Vec::new();
+
+                        for partition_hash in disk_obj.partition_hashes {
+                            if let Ok(Some(partition_meta)) = storage.load_meta(MetaType::Partition, &partition_hash).await {
+                                if let MetaObj::Partition(partition_obj) = partition_meta {
+                                    let fs_type_str = match partition_obj.fs_type_code {
+                                        FsType::Ext => "ext",
+                                        FsType::Ntfs => "ntfs",
+                                        FsType::Fat32 => "fat32", 
+                                        FsType::Unknown => "unknown",
+                                    };
+
+                                    partitions.push(PartitionInfo {
+                                        fs_type: fs_type_str.to_string(),
+                                        start_lba: partition_obj.start_lba,
+                                        end_lba: partition_obj.end_lba,
+                                        size_bytes: (partition_obj.end_lba - partition_obj.start_lba) * 512,
+                                    });
+                                }
+                            }
+                        }
+
+                        disks.push(DiskInfo {
+                            serial: disk_obj.serial,
+                            size_bytes: disk_obj.disk_size_bytes,
+                            partitions,
+                        });
+                    }
+                }
+            }
+
+            // Convert timestamp to readable format
+            let created_at_str = DateTime::<Utc>::from_timestamp(created_at_timestamp as i64, 0)
+                .map(|dt| dt.format("%Y-%m-%d %H:%M:%S").to_string())
+                .unwrap_or_else(|| "Unknown".to_string());
+
+            Ok(SnapshotDetails {
+                id: snapshot_id,
+                snapshot_hash: hex::encode(snapshot_hash),
+                created_at: created_at_str,
+                disks,
+            })
+        } else {
+            Err(AppError::ValidationError("Invalid snapshot metadata".to_string()))
+        }
+    }
+}

server/src/controllers/users.rs

@@ -0,0 +1,202 @@
+use crate::utils::{error::*, models::*, DbPool};
+use bcrypt::{hash, verify, DEFAULT_COST};
+use sqlx::Row;
+use std::str::FromStr;
+
+pub struct UsersController;
+
+impl UsersController {
+    pub async fn create_user(
+        pool: &DbPool,
+        username: &str,
+        password: &str,
+        role: UserRole,
+        storage_limit_gb: i64,
+    ) -> AppResult<User> {
+        Self::validate_user_input(username, password)?;
+
+        let password_hash = hash(password, DEFAULT_COST)?;
+
+        let result = sqlx::query(
+            r#"
+            INSERT INTO users (username, password_hash, role, storage_limit_gb)
+            VALUES (?, ?, ?, ?)
+            "#,
+        )
+        .bind(username)
+        .bind(&password_hash)
+        .bind(role.to_string())
+        .bind(storage_limit_gb)
+        .execute(pool)
+        .await?;
+
+        Self::get_user_by_id(pool, result.last_insert_rowid()).await
+    }
+
+    pub async fn get_user_by_username(pool: &DbPool, username: &str) -> AppResult<Option<User>> {
+        let row = sqlx::query(
+            r#"
+            SELECT id, username, password_hash, role, storage_limit_gb, created_at
+            FROM users WHERE username = ?
+            "#,
+        )
+        .bind(username)
+        .fetch_optional(pool)
+        .await?;
+
+        if let Some(row) = row {
+            Ok(Some(User {
+                id: row.get("id"),
+                username: row.get("username"),
+                password_hash: row.get("password_hash"),
+                role: UserRole::from_str(&row.get::<String, _>("role")).unwrap(),
+                storage_limit_gb: row.get("storage_limit_gb"),
+                created_at: row.get("created_at"),
+            }))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub async fn get_user_by_id(pool: &DbPool, id: i64) -> AppResult<User> {
+        let row = sqlx::query(
+            r#"
+            SELECT id, username, password_hash, role, storage_limit_gb, created_at
+            FROM users WHERE id = ?
+            "#,
+        )
+        .bind(id)
+        .fetch_one(pool)
+        .await?;
+
+        Ok(User {
+            id: row.get("id"),
+            username: row.get("username"),
+            password_hash: row.get("password_hash"),
+            role: UserRole::from_str(&row.get::<String, _>("role")).unwrap(),
+            storage_limit_gb: row.get("storage_limit_gb"),
+            created_at: row.get("created_at"),
+        })
+    }
+
+    pub async fn get_all_users(pool: &DbPool) -> AppResult<Vec<User>> {
+        let rows = sqlx::query(
+            r#"
+            SELECT id, username, password_hash, role, storage_limit_gb, created_at
+            FROM users ORDER BY created_at DESC
+            "#,
+        )
+        .fetch_all(pool)
+        .await?;
+
+        let mut users = Vec::new();
+        for row in rows {
+            users.push(User {
+                id: row.get("id"),
+                username: row.get("username"),
+                password_hash: row.get("password_hash"),
+                role: UserRole::from_str(&row.get::<String, _>("role")).unwrap(),
+                storage_limit_gb: row.get("storage_limit_gb"),
+                created_at: row.get("created_at"),
+            });
+        }
+
+        Ok(users)
+    }
+
+    pub async fn update_user(
+        pool: &DbPool,
+        id: i64,
+        request: UpdateUserRequest,
+    ) -> AppResult<User> {
+        let current_user = Self::get_user_by_id(pool, id).await?;
+
+        let username = request.username.clone().unwrap_or(current_user.username);
+        let role = request.role.unwrap_or(current_user.role);
+        let storage_limit_gb = request
+            .storage_limit_gb
+            .unwrap_or(current_user.storage_limit_gb);
+
+        if request.username.is_some() || request.password.is_some() {
+            Self::validate_user_input(
+                &username,
+                request.password.as_deref().unwrap_or("validpassword"),
+            )?;
+        }
+
+        if let Some(password) = request.password {
+            let password_hash = hash(&password, DEFAULT_COST)?;
+            sqlx::query(
+                r#"
+                UPDATE users 
+                SET username = ?, password_hash = ?, role = ?, storage_limit_gb = ?
+                WHERE id = ?
+                "#,
+            )
+            .bind(&username)
+            .bind(&password_hash)
+            .bind(role.to_string())
+            .bind(storage_limit_gb)
+            .bind(id)
+            .execute(pool)
+            .await?;
+        } else {
+            sqlx::query(
+                r#"
+                UPDATE users 
+                SET username = ?, role = ?, storage_limit_gb = ?
+                WHERE id = ?
+                "#,
+            )
+            .bind(&username)
+            .bind(role.to_string())
+            .bind(storage_limit_gb)
+            .bind(id)
+            .execute(pool)
+            .await?;
+        }
+
+        Self::get_user_by_id(pool, id).await
+    }
+
+    pub async fn delete_user(pool: &DbPool, id: i64) -> AppResult<()> {
+        Self::get_user_by_id(pool, id).await?;
+
+        sqlx::query("DELETE FROM users WHERE id = ?")
+            .bind(id)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn verify_user_credentials(
+        pool: &DbPool,
+        username: &str,
+        password: &str,
+    ) -> AppResult<User> {
+        let user = Self::get_user_by_username(pool, username)
+            .await?
+            .ok_or_else(|| auth_error("Invalid credentials"))?;
+
+        let is_valid = verify(password, &user.password_hash)?;
+        if !is_valid {
+            return Err(auth_error("Invalid credentials"));
+        }
+
+        Ok(user)
+    }
+
+    fn validate_user_input(username: &str, password: &str) -> AppResult<()> {
+        if username.trim().is_empty() {
+            return Err(validation_error("Username cannot be empty"));
+        }
+
+        if password.len() < 8 {
+            return Err(validation_error(
+                "Password must be at least 8 characters long",
+            ));
+        }
+
+        Ok(())
+    }
+}

server/src/main.rs

@@ -0,0 +1,111 @@
+mod controllers;
+mod routes;
+mod utils;
+mod sync;
+
+use anyhow::Result;
+use axum::{
+    routing::{delete, get, post, put},
+    Router,
+};
+use routes::{accounts, admin, auth, config, machines, setup, snapshots, files};
+use std::path::Path;
+use tokio::signal;
+use tower_http::{
+    cors::CorsLayer,
+    services::{ServeDir, ServeFile},
+};
+use utils::init_database;
+use sync::{SyncServer, server::SyncServerConfig};
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    let pool = init_database().await?;
+    
+    let sync_pool = pool.clone();
+    
+    let api_routes = Router::new()
+        .route("/setup/status", get(setup::get_setup_status))
+        .route("/setup/init", post(setup::init_setup))
+        .route("/auth/login", post(auth::login))
+        .route("/auth/logout", post(auth::logout))
+        .route("/accounts/me", get(accounts::me))
+        .route("/admin/users", get(admin::get_users))
+        .route("/admin/users", post(admin::create_user_handler))
+        .route("/admin/users/{id}", put(admin::update_user_handler))
+        .route("/admin/users/{id}", delete(admin::delete_user_handler))
+        .route("/admin/config", get(config::get_all_configs))
+        .route("/admin/config", post(config::set_config))
+        .route("/admin/config/{key}", get(config::get_config))
+        .route("/machines/register", post(machines::register_machine))
+        .route("/machines/provisioning-code", post(machines::create_provisioning_code))
+        .route("/machines", get(machines::get_machines))
+        .route("/machines/{id}", get(machines::get_machine))
+        .route("/machines/{id}", delete(machines::delete_machine))
+                        .route("/machines/{id}/snapshots", get(snapshots::get_machine_snapshots))
+        .route("/machines/{machine_id}/snapshots/{snapshot_id}", get(snapshots::get_snapshot_details))
+        .route("/machines/{machine_id}/snapshots/{snapshot_id}/partitions/{partition_index}/files", get(files::list_partition_root))
+        .route("/machines/{machine_id}/snapshots/{snapshot_id}/partitions/{partition_index}/files/{dir_hash}", get(files::list_directory))
+        .route("/machines/{machine_id}/snapshots/{snapshot_id}/partitions/{partition_index}/download/{file_hash}", get(files::download_file))
+        .route("/machines/{machine_id}/snapshots/{snapshot_id}/partitions/{partition_index}/metadata/{file_hash}", get(files::get_file_metadata))
+        .layer(CorsLayer::permissive())
+        .with_state(pool);
+
+    let dist_path = "./dist";
+    let app = Router::new()
+        .nest("/api", api_routes)
+        .nest_service("/assets", ServeDir::new(format!("{}/assets", dist_path)))
+        .route_service("/", ServeFile::new(format!("{}/index.html", dist_path)))
+        .fallback_service(ServeFile::new(format!("{}/index.html", dist_path)))
+        .layer(CorsLayer::permissive());
+
+    if !Path::new(dist_path).exists() {
+        println!("Warning: dist directory not found at {}", dist_path);
+    }
+
+    let sync_config = SyncServerConfig::default();
+    let sync_server = SyncServer::new(sync_config.clone(), sync_pool);
+    
+    tokio::spawn(async move {
+        if let Err(e) = sync_server.start().await {
+            eprintln!("Sync server error: {}", e);
+        }
+    });
+
+    let listener = tokio::net::TcpListener::bind("0.0.0.0:8379").await?;
+    println!("HTTP server running on http://0.0.0.0:8379");
+    println!("Sync server running on {}:{}", sync_config.bind_address, sync_config.port);
+
+    axum::serve(listener, app)
+        .with_graceful_shutdown(shutdown_signal())
+        .await?;
+    Ok(())
+}
+
+async fn shutdown_signal() {
+    let ctrl_c = async {
+        signal::ctrl_c()
+            .await
+            .expect("failed to install Ctrl+C handler");
+    };
+
+    #[cfg(unix)]
+    let terminate = async {
+        signal::unix::signal(signal::unix::SignalKind::terminate())
+            .expect("failed to install signal handler")
+            .recv()
+            .await;
+    };
+
+    #[cfg(not(unix))]
+    let terminate = std::future::pending::<()>();
+
+    tokio::select! {
+        _ = ctrl_c => {
+            println!("\nShutting down due to Ctrl+C...");
+        },
+        _ = terminate => {
+            println!("\nShutting down due to terminate signal...");
+        },
+    }
+}

server/src/routes/accounts.rs

@@ -0,0 +1,6 @@
+use crate::utils::{auth::AuthUser, error::*, models::User};
+use axum::response::Json;
+
+pub async fn me(auth_user: AuthUser) -> Result<Json<User>, AppError> {
+    Ok(success_response(auth_user.user))
+}

server/src/routes/admin.rs

@@ -0,0 +1,53 @@
+use crate::controllers::users::UsersController;
+use crate::utils::{auth::*, error::*, models::*, DbPool};
+use axum::{
+    extract::{Path, State},
+    response::Json,
+};
+
+pub async fn get_users(
+    _admin: AdminUser,
+    State(pool): State<DbPool>,
+) -> Result<Json<Vec<User>>, AppError> {
+    let users = UsersController::get_all_users(&pool).await?;
+    Ok(success_response(users))
+}
+
+pub async fn create_user_handler(
+    _admin: AdminUser,
+    State(pool): State<DbPool>,
+    Json(request): Json<CreateUserRequest>,
+) -> Result<Json<User>, AppError> {
+    let role = request.role.unwrap_or(UserRole::User);
+    let storage_limit_gb = request.storage_limit_gb.unwrap_or(0);
+
+    let user = UsersController::create_user(
+        &pool,
+        &request.username,
+        &request.password,
+        role,
+        storage_limit_gb,
+    )
+    .await?;
+
+    Ok(success_response(user))
+}
+
+pub async fn update_user_handler(
+    _admin: AdminUser,
+    State(pool): State<DbPool>,
+    Path(user_id): Path<i64>,
+    Json(request): Json<UpdateUserRequest>,
+) -> Result<Json<User>, AppError> {
+    let updated_user = UsersController::update_user(&pool, user_id, request).await?;
+    Ok(success_response(updated_user))
+}
+
+pub async fn delete_user_handler(
+    _admin: AdminUser,
+    State(pool): State<DbPool>,
+    Path(user_id): Path<i64>,
+) -> Result<Json<serde_json::Value>, AppError> {
+    UsersController::delete_user(&pool, user_id).await?;
+    Ok(success_message("User deleted successfully"))
+}

server/src/routes/auth.rs

@@ -0,0 +1,19 @@
+use crate::utils::{auth::*, error::*, models::*, DbPool};
+use crate::controllers::auth::AuthController;
+use axum::{extract::State, response::Json};
+
+pub async fn login(
+    State(pool): State<DbPool>,
+    Json(request): Json<LoginRequest>,
+) -> Result<Json<LoginResponse>, AppError> {
+    let response = AuthController::login(&pool, &request.username, &request.password).await?;
+    Ok(success_response(response))
+}
+
+pub async fn logout(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+) -> Result<Json<serde_json::Value>, AppError> {
+    AuthController::logout(&pool, auth_user.user.id).await?;
+    Ok(success_message("Logged out successfully"))
+}

server/src/routes/config.rs

@@ -0,0 +1,113 @@
+use crate::utils::{auth::*, config::ConfigManager, error::*, DbPool};
+use axum::{extract::State, response::Json};
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ConfigRequest {
+    pub key: String,
+    pub value: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ConfigResponse {
+    pub key: String,
+    pub value: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ConfigDefinition {
+    pub key: String,
+    pub description: String,
+    pub value: Option<String>,
+    pub default_value: Option<String>,
+    pub required: bool,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ConfigListResponse {
+    pub configs: Vec<ConfigDefinition>,
+}
+
+pub async fn get_all_configs(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+) -> Result<Json<ConfigListResponse>, AppError> {
+    if auth_user.user.role != crate::utils::models::UserRole::Admin {
+        return Err(forbidden_error("Admin access required"));
+    }
+
+    let allowed_configs = vec![
+        ConfigDefinition {
+            key: "EXTERNAL_URL".to_string(),
+            description: "The external URL used for provisioning codes. This should be the public URL where this server can be reached.".to_string(),
+            value: ConfigManager::get_config(&pool, "EXTERNAL_URL").await?,
+            default_value: Some("https://your-domain.com".to_string()),
+            required: true,
+        },
+        ConfigDefinition {
+            key: "SESSION_TIMEOUT_HOURS".to_string(),
+            description: "Number of hours before user sessions expire and require re-authentication.".to_string(),
+            value: ConfigManager::get_config(&pool, "SESSION_TIMEOUT_HOURS").await?,
+            default_value: Some("24".to_string()),
+            required: false,
+        },
+    ];
+
+    Ok(success_response(ConfigListResponse {
+        configs: allowed_configs,
+    }))
+}
+
+pub async fn set_config(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+    Json(request): Json<ConfigRequest>,
+) -> Result<Json<serde_json::Value>, AppError> {
+    if auth_user.user.role != crate::utils::models::UserRole::Admin {
+        return Err(forbidden_error("Admin access required"));
+    }
+
+    let allowed_keys = vec!["EXTERNAL_URL", "SESSION_TIMEOUT_HOURS"];
+
+    if !allowed_keys.contains(&request.key.as_str()) {
+        return Err(validation_error("Invalid configuration key"));
+    }
+
+    match request.key.as_str() {
+        "EXTERNAL_URL" => {
+            if request.value.trim().is_empty() {
+                return Err(validation_error("External URL cannot be empty"));
+            }
+            if !request.value.starts_with("http://") && !request.value.starts_with("https://") {
+                return Err(validation_error(
+                    "External URL must start with http:// or https://",
+                ));
+            }
+        }
+        "SESSION_TIMEOUT_HOURS" => {
+            if request.value.parse::<i32>().is_err() || request.value.parse::<i32>().unwrap() <= 0 {
+                return Err(validation_error("Value must be a positive number"));
+            }
+        }
+        _ => {}
+    }
+
+    ConfigManager::set_config(&pool, &request.key, &request.value).await?;
+    Ok(success_message("Configuration updated successfully"))
+}
+
+pub async fn get_config(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+    axum::extract::Path(key): axum::extract::Path<String>,
+) -> Result<Json<ConfigResponse>, AppError> {
+    if auth_user.user.role != crate::utils::models::UserRole::Admin {
+        return Err(forbidden_error("Admin access required"));
+    }
+
+    let value = ConfigManager::get_config(&pool, &key)
+        .await?
+        .ok_or_else(|| not_found_error("Configuration key not found"))?;
+
+    Ok(success_response(ConfigResponse { key, value }))
+}

server/src/routes/files.rs

@@ -0,0 +1,77 @@
+use axum::{extract::{Path, Query, State}, Json, response::Response};
+use axum::body::Body;
+use serde::Deserialize;
+use crate::controllers::files::{FilesController, DirectoryListing, FileMetadata};
+use crate::utils::{auth::AuthUser, error::AppResult, DbPool};
+
+#[derive(Deserialize)]
+pub struct DownloadQuery {
+    filename: Option<String>,
+}
+
+pub async fn list_partition_root(
+    State(pool): State<DbPool>,
+    Path((machine_id, snapshot_id, partition_index)): Path<(i64, String, usize)>,
+    auth_user: AuthUser,
+) -> AppResult<Json<DirectoryListing>> {
+    let listing = FilesController::list_partition_root(
+        &pool,
+        machine_id,
+        snapshot_id,
+        partition_index,
+        &auth_user.user,
+    ).await?;
+    
+    Ok(Json(listing))
+}
+
+pub async fn list_directory(
+    State(pool): State<DbPool>,
+    Path((machine_id, snapshot_id, partition_index, dir_hash)): Path<(i64, String, usize, String)>,
+    auth_user: AuthUser,
+) -> AppResult<Json<DirectoryListing>> {
+    let listing = FilesController::list_directory(
+        &pool,
+        machine_id,
+        snapshot_id,
+        partition_index,
+        dir_hash,
+        &auth_user.user,
+    ).await?;
+    
+    Ok(Json(listing))
+}
+
+pub async fn download_file(
+    State(pool): State<DbPool>,
+    Path((machine_id, snapshot_id, partition_index, file_hash)): Path<(i64, String, usize, String)>,
+    Query(query): Query<DownloadQuery>,
+    auth_user: AuthUser,
+) -> AppResult<Response<Body>> {
+    FilesController::download_file(
+        &pool,
+        machine_id,
+        snapshot_id,
+        partition_index,
+        file_hash,
+        query.filename,
+        &auth_user.user,
+    ).await
+}
+
+pub async fn get_file_metadata(
+    State(pool): State<DbPool>,
+    Path((machine_id, snapshot_id, partition_index, file_hash)): Path<(i64, String, usize, String)>,
+    auth_user: AuthUser,
+) -> AppResult<Json<FileMetadata>> {
+    let metadata = FilesController::get_file_metadata(
+        &pool,
+        machine_id,
+        snapshot_id,
+        partition_index,
+        file_hash,
+        &auth_user.user,
+    ).await?;
+    
+    Ok(Json(metadata))
+}

server/src/routes/machines.rs

@@ -0,0 +1,68 @@
+use crate::utils::{auth::*, error::*, models::*, DbPool};
+use crate::controllers::machines::MachinesController;
+use axum::{
+    extract::{Path, State},
+    response::Json,
+};
+
+pub async fn register_machine(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+    Json(request): Json<RegisterMachineRequest>,
+) -> Result<Json<Machine>, AppError> {
+    let machine = MachinesController::register_machine(
+        &pool,
+        &auth_user.user,
+        &request.name,
+    )
+    .await?;
+
+    Ok(success_response(machine))
+}
+
+pub async fn create_provisioning_code(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+    Json(request): Json<CreateProvisioningCodeRequest>,
+) -> Result<Json<ProvisioningCodeResponse>, AppError> {
+    let response = MachinesController::create_provisioning_code(
+        &pool,
+        request.machine_id,
+        &auth_user.user,
+    )
+    .await?;
+
+    Ok(success_response(response))
+}
+
+pub async fn get_machines(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+) -> Result<Json<Vec<Machine>>, AppError> {
+    let machines = MachinesController::get_machines_for_user(&pool, &auth_user.user).await?;
+    Ok(success_response(machines))
+}
+
+pub async fn get_machine(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+    Path(machine_id): Path<i64>,
+) -> Result<Json<Machine>, AppError> {
+    let machine = MachinesController::get_machine_by_id(&pool, machine_id).await?;
+    
+    // Check if user has access to this machine
+    if auth_user.user.role != UserRole::Admin && machine.user_id != auth_user.user.id {
+        return Err(AppError::NotFoundError("Machine not found or access denied".to_string()));
+    }
+    
+    Ok(success_response(machine))
+}
+
+pub async fn delete_machine(
+    auth_user: AuthUser,
+    State(pool): State<DbPool>,
+    Path(machine_id): Path<i64>,
+) -> Result<Json<serde_json::Value>, AppError> {
+    MachinesController::delete_machine(&pool, machine_id, &auth_user.user).await?;
+    Ok(success_message("Machine deleted successfully"))
+}

server/src/routes/mod.rs

@@ -0,0 +1,8 @@
+pub mod accounts;
+pub mod admin;
+pub mod auth;
+pub mod config;
+pub mod machines;
+pub mod setup;
+pub mod snapshots;
+pub mod files;

server/src/routes/setup.rs

@@ -0,0 +1,32 @@
+use crate::controllers::users::UsersController;
+use crate::utils::{database::*, error::*, models::*};
+use axum::{extract::State, response::Json};
+
+pub async fn get_setup_status(
+    State(pool): State<DbPool>,
+) -> Result<Json<SetupStatusResponse>, AppError> {
+    let first_user_exists = check_first_user_exists(&pool).await?;
+    Ok(success_response(SetupStatusResponse { first_user_exists }))
+}
+
+pub async fn init_setup(
+    State(pool): State<DbPool>,
+    Json(request): Json<InitSetupRequest>,
+) -> Result<Json<serde_json::Value>, AppError> {
+    let first_user_exists = check_first_user_exists(&pool).await?;
+
+    if first_user_exists {
+        return Err(validation_error("Setup already completed"));
+    }
+
+    UsersController::create_user(
+        &pool,
+        &request.username,
+        &request.password,
+        UserRole::Admin,
+        0,
+    )
+    .await?;
+
+    Ok(success_message("Setup completed successfully"))
+}

server/src/routes/snapshots.rs

@@ -0,0 +1,32 @@
+use axum::{extract::{Path, State}, Json};
+use crate::controllers::snapshots::{SnapshotsController, SnapshotSummary, SnapshotDetails};
+use crate::utils::{auth::AuthUser, error::AppResult, DbPool};
+
+pub async fn get_machine_snapshots(
+    State(pool): State<DbPool>,
+    Path(machine_id): Path<i64>,
+    auth_user: AuthUser,
+) -> AppResult<Json<Vec<SnapshotSummary>>> {
+    let snapshots = SnapshotsController::get_machine_snapshots(
+        &pool,
+        machine_id,
+        &auth_user.user,
+    ).await?;
+    
+    Ok(Json(snapshots))
+}
+
+pub async fn get_snapshot_details(
+    State(pool): State<DbPool>,
+    Path((machine_id, snapshot_id)): Path<(i64, String)>,
+    auth_user: AuthUser,
+) -> AppResult<Json<SnapshotDetails>> {
+    let snapshot = SnapshotsController::get_snapshot_details(
+        &pool,
+        machine_id,
+        snapshot_id,
+        &auth_user.user,
+    ).await?;
+    
+    Ok(Json(snapshot))
+}

server/src/sync/meta.rs

@@ -0,0 +1,605 @@
+use bytes::{Buf, BufMut, Bytes, BytesMut};
+use std::io::{Error, ErrorKind, Result};
+use crate::sync::protocol::{Hash, MetaType};
+
+/// Filesystem type codes
+#[repr(u32)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum FsType {
+    Ext = 1,
+    Ntfs = 2,
+    Fat32 = 3,
+    Unknown = 0,
+}
+
+impl From<u32> for FsType {
+    fn from(value: u32) -> Self {
+        match value {
+            1 => FsType::Ext,
+            2 => FsType::Ntfs,
+            3 => FsType::Fat32,
+            _ => FsType::Unknown,
+        }
+    }
+}
+
+/// Directory entry types
+#[repr(u8)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EntryType {
+    File = 0,
+    Dir = 1,
+    Symlink = 2,
+}
+
+impl TryFrom<u8> for EntryType {
+    type Error = Error;
+
+    fn try_from(value: u8) -> Result<Self> {
+        match value {
+            0 => Ok(EntryType::File),
+            1 => Ok(EntryType::Dir),
+            2 => Ok(EntryType::Symlink),
+            _ => Err(Error::new(ErrorKind::InvalidData, "Unknown entry type")),
+        }
+    }
+}
+
+/// File metadata object
+#[derive(Debug, Clone)]
+pub struct FileObj {
+    pub version: u8,
+    pub fs_type_code: FsType,
+    pub size: u64,
+    pub mode: u32,
+    pub uid: u32,
+    pub gid: u32,
+    pub mtime_unixsec: u64,
+    pub chunk_hashes: Vec<Hash>,
+}
+
+impl FileObj {
+    pub fn new(
+        fs_type_code: FsType,
+        size: u64,
+        mode: u32,
+        uid: u32,
+        gid: u32,
+        mtime_unixsec: u64,
+        chunk_hashes: Vec<Hash>,
+    ) -> Self {
+        Self {
+            version: 1,
+            fs_type_code,
+            size,
+            mode,
+            uid,
+            gid,
+            mtime_unixsec,
+            chunk_hashes,
+        }
+    }
+
+    pub fn serialize(&self) -> Result<Bytes> {
+        let mut buf = BytesMut::new();
+        
+        buf.put_u8(self.version);
+        buf.put_u32_le(self.fs_type_code as u32);
+        buf.put_u64_le(self.size);
+        buf.put_u32_le(self.mode);
+        buf.put_u32_le(self.uid);
+        buf.put_u32_le(self.gid);
+        buf.put_u64_le(self.mtime_unixsec);
+        buf.put_u32_le(self.chunk_hashes.len() as u32);
+        
+        for hash in &self.chunk_hashes {
+            buf.put_slice(hash);
+        }
+        
+        Ok(buf.freeze())
+    }
+
+    pub fn deserialize(mut data: Bytes) -> Result<Self> {
+        if data.remaining() < 41 {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "FileObj data too short"));
+        }
+
+        let version = data.get_u8();
+        if version != 1 {
+            return Err(Error::new(ErrorKind::InvalidData, "Unsupported FileObj version"));
+        }
+
+        let fs_type_code = FsType::from(data.get_u32_le());
+        let size = data.get_u64_le();
+        let mode = data.get_u32_le();
+        let uid = data.get_u32_le();
+        let gid = data.get_u32_le();
+        let mtime_unixsec = data.get_u64_le();
+        let chunk_count = data.get_u32_le() as usize;
+
+        if data.remaining() < chunk_count * 32 {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "FileObj chunk hashes too short"));
+        }
+
+        let mut chunk_hashes = Vec::with_capacity(chunk_count);
+        for _ in 0..chunk_count {
+            let mut hash = [0u8; 32];
+            data.copy_to_slice(&mut hash);
+            chunk_hashes.push(hash);
+        }
+
+        Ok(Self {
+            version,
+            fs_type_code,
+            size,
+            mode,
+            uid,
+            gid,
+            mtime_unixsec,
+            chunk_hashes,
+        })
+    }
+
+    pub fn compute_hash(&self) -> Result<Hash> {
+        let serialized = self.serialize()?;
+        Ok(blake3::hash(&serialized).into())
+    }
+}
+
+/// Directory entry
+#[derive(Debug, Clone)]
+pub struct DirEntry {
+    pub entry_type: EntryType,
+    pub name: String,
+    pub target_meta_hash: Hash,
+}
+
+/// Directory metadata object
+#[derive(Debug, Clone)]
+pub struct DirObj {
+    pub version: u8,
+    pub entries: Vec<DirEntry>,
+}
+
+impl DirObj {
+    pub fn new(entries: Vec<DirEntry>) -> Self {
+        Self {
+            version: 1,
+            entries,
+        }
+    }
+
+    pub fn serialize(&self) -> Result<Bytes> {
+        let mut buf = BytesMut::new();
+        
+        buf.put_u8(self.version);
+        buf.put_u32_le(self.entries.len() as u32);
+        
+        for entry in &self.entries {
+            buf.put_u8(entry.entry_type as u8);
+            let name_bytes = entry.name.as_bytes();
+            buf.put_u16_le(name_bytes.len() as u16);
+            buf.put_slice(name_bytes);
+            buf.put_slice(&entry.target_meta_hash);
+        }
+        
+        Ok(buf.freeze())
+    }
+
+    pub fn deserialize(mut data: Bytes) -> Result<Self> {
+        if data.remaining() < 5 {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "DirObj data too short"));
+        }
+
+        let version = data.get_u8();
+        if version != 1 {
+            return Err(Error::new(ErrorKind::InvalidData, "Unsupported DirObj version"));
+        }
+
+        let entry_count = data.get_u32_le() as usize;
+        let mut entries = Vec::with_capacity(entry_count);
+
+        for _ in 0..entry_count {
+            if data.remaining() < 35 {
+                return Err(Error::new(ErrorKind::UnexpectedEof, "DirObj entry too short"));
+            }
+
+            let entry_type = EntryType::try_from(data.get_u8())?;
+            let name_len = data.get_u16_le() as usize;
+            
+            if data.remaining() < name_len + 32 {
+                return Err(Error::new(ErrorKind::UnexpectedEof, "DirObj entry name/hash too short"));
+            }
+
+            let name = String::from_utf8(data.copy_to_bytes(name_len).to_vec())
+                .map_err(|_| Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in entry name"))?;
+
+            let mut target_meta_hash = [0u8; 32];
+            data.copy_to_slice(&mut target_meta_hash);
+
+            entries.push(DirEntry {
+                entry_type,
+                name,
+                target_meta_hash,
+            });
+        }
+
+        Ok(Self {
+            version,
+            entries,
+        })
+    }
+
+    pub fn compute_hash(&self) -> Result<Hash> {
+        let serialized = self.serialize()?;
+        Ok(blake3::hash(&serialized).into())
+    }
+}
+
+/// Partition metadata object
+#[derive(Debug, Clone)]
+pub struct PartitionObj {
+    pub version: u8,
+    pub fs_type_code: FsType,
+    pub root_dir_hash: Hash,
+    pub start_lba: u64,
+    pub end_lba: u64,
+    pub type_guid: [u8; 16],
+}
+
+impl PartitionObj {
+    pub fn new(
+        fs_type_code: FsType,
+        root_dir_hash: Hash,
+        start_lba: u64,
+        end_lba: u64,
+        type_guid: [u8; 16],
+    ) -> Self {
+        Self {
+            version: 1,
+            fs_type_code,
+            root_dir_hash,
+            start_lba,
+            end_lba,
+            type_guid,
+        }
+    }
+
+    pub fn serialize(&self) -> Result<Bytes> {
+        let mut buf = BytesMut::new();
+        
+        buf.put_u8(self.version);
+        buf.put_u32_le(self.fs_type_code as u32);
+        buf.put_slice(&self.root_dir_hash);
+        buf.put_u64_le(self.start_lba);
+        buf.put_u64_le(self.end_lba);
+        buf.put_slice(&self.type_guid);
+        
+        Ok(buf.freeze())
+    }
+
+    pub fn deserialize(mut data: Bytes) -> Result<Self> {
+        if data.remaining() < 69 {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "PartitionObj data too short"));
+        }
+
+        let version = data.get_u8();
+        if version != 1 {
+            return Err(Error::new(ErrorKind::InvalidData, "Unsupported PartitionObj version"));
+        }
+
+        let fs_type_code = FsType::from(data.get_u32_le());
+        
+        let mut root_dir_hash = [0u8; 32];
+        data.copy_to_slice(&mut root_dir_hash);
+        
+        let start_lba = data.get_u64_le();
+        let end_lba = data.get_u64_le();
+        
+        let mut type_guid = [0u8; 16];
+        data.copy_to_slice(&mut type_guid);
+
+        Ok(Self {
+            version,
+            fs_type_code,
+            root_dir_hash,
+            start_lba,
+            end_lba,
+            type_guid,
+        })
+    }
+
+    pub fn compute_hash(&self) -> Result<Hash> {
+        let serialized = self.serialize()?;
+        Ok(blake3::hash(&serialized).into())
+    }
+}
+
+/// Disk metadata object
+#[derive(Debug, Clone)]
+pub struct DiskObj {
+    pub version: u8,
+    pub partition_hashes: Vec<Hash>,
+    pub disk_size_bytes: u64,
+    pub serial: String,
+}
+
+impl DiskObj {
+    pub fn new(partition_hashes: Vec<Hash>, disk_size_bytes: u64, serial: String) -> Self {
+        Self {
+            version: 1,
+            partition_hashes,
+            disk_size_bytes,
+            serial,
+        }
+    }
+
+    pub fn serialize(&self) -> Result<Bytes> {
+        let mut buf = BytesMut::new();
+        
+        buf.put_u8(self.version);
+        buf.put_u32_le(self.partition_hashes.len() as u32);
+        
+        for hash in &self.partition_hashes {
+            buf.put_slice(hash);
+        }
+        
+        buf.put_u64_le(self.disk_size_bytes);
+        
+        let serial_bytes = self.serial.as_bytes();
+        buf.put_u16_le(serial_bytes.len() as u16);
+        buf.put_slice(serial_bytes);
+        
+        Ok(buf.freeze())
+    }
+
+    pub fn deserialize(mut data: Bytes) -> Result<Self> {
+        println!("DiskObj::deserialize: input data length = {}", data.len());
+        
+        if data.remaining() < 15 {
+            println!("DiskObj::deserialize: data too short, remaining = {}", data.remaining());
+            return Err(Error::new(ErrorKind::UnexpectedEof, "DiskObj data too short"));
+        }
+
+        let version = data.get_u8();
+        println!("DiskObj::deserialize: version = {}", version);
+        if version != 1 {
+            println!("DiskObj::deserialize: unsupported version {}", version);
+            return Err(Error::new(ErrorKind::InvalidData, "Unsupported DiskObj version"));
+        }
+
+        let partition_count = data.get_u32_le() as usize;
+        println!("DiskObj::deserialize: partition_count = {}", partition_count);
+        
+        if data.remaining() < partition_count * 32 + 10 {
+            println!("DiskObj::deserialize: not enough data for partitions, remaining = {}, needed = {}", 
+                    data.remaining(), partition_count * 32 + 10);
+            return Err(Error::new(ErrorKind::UnexpectedEof, "DiskObj partitions too short"));
+        }
+
+        let mut partition_hashes = Vec::with_capacity(partition_count);
+        for i in 0..partition_count {
+            let mut hash = [0u8; 32];
+            data.copy_to_slice(&mut hash);
+            println!("DiskObj::deserialize: partition {} hash = {}", i, hex::encode(&hash));
+            partition_hashes.push(hash);
+        }
+
+        let disk_size_bytes = data.get_u64_le();
+        println!("DiskObj::deserialize: disk_size_bytes = {}", disk_size_bytes);
+        
+        let serial_len = data.get_u16_le() as usize;
+        println!("DiskObj::deserialize: serial_len = {}", serial_len);
+        
+        if data.remaining() < serial_len {
+            println!("DiskObj::deserialize: not enough data for serial, remaining = {}, needed = {}", 
+                    data.remaining(), serial_len);
+            return Err(Error::new(ErrorKind::UnexpectedEof, "DiskObj serial too short"));
+        }
+
+        let serial_bytes = data.copy_to_bytes(serial_len).to_vec();
+        println!("DiskObj::deserialize: serial_bytes = {:?}", serial_bytes);
+        
+        let serial = String::from_utf8(serial_bytes)
+            .map_err(|e| {
+                println!("DiskObj::deserialize: UTF-8 error: {}", e);
+                Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in serial")
+            })?;
+
+        println!("DiskObj::deserialize: serial = '{}'", serial);
+        println!("DiskObj::deserialize: successfully deserialized");
+
+        Ok(Self {
+            version,
+            partition_hashes,
+            disk_size_bytes,
+            serial,
+        })
+    }
+
+    pub fn compute_hash(&self) -> Result<Hash> {
+        let serialized = self.serialize()?;
+        Ok(blake3::hash(&serialized).into())
+    }
+}
+
+/// Snapshot metadata object
+#[derive(Debug, Clone)]
+pub struct SnapshotObj {
+    pub version: u8,
+    pub created_at_unixsec: u64,
+    pub disk_hashes: Vec<Hash>,
+}
+
+impl SnapshotObj {
+    pub fn new(created_at_unixsec: u64, disk_hashes: Vec<Hash>) -> Self {
+        Self {
+            version: 1,
+            created_at_unixsec,
+            disk_hashes,
+        }
+    }
+
+    pub fn serialize(&self) -> Result<Bytes> {
+        let mut buf = BytesMut::new();
+        
+        buf.put_u8(self.version);
+        buf.put_u64_le(self.created_at_unixsec);
+        buf.put_u32_le(self.disk_hashes.len() as u32);
+        
+        for hash in &self.disk_hashes {
+            buf.put_slice(hash);
+        }
+        
+        Ok(buf.freeze())
+    }
+
+    pub fn deserialize(mut data: Bytes) -> Result<Self> {
+        if data.remaining() < 13 {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "SnapshotObj data too short"));
+        }
+
+        let version = data.get_u8();
+        if version != 1 {
+            return Err(Error::new(ErrorKind::InvalidData, "Unsupported SnapshotObj version"));
+        }
+
+        let created_at_unixsec = data.get_u64_le();
+        let disk_count = data.get_u32_le() as usize;
+        
+        if data.remaining() < disk_count * 32 {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "SnapshotObj disk hashes too short"));
+        }
+
+        let mut disk_hashes = Vec::with_capacity(disk_count);
+        for _ in 0..disk_count {
+            let mut hash = [0u8; 32];
+            data.copy_to_slice(&mut hash);
+            disk_hashes.push(hash);
+        }
+
+        Ok(Self {
+            version,
+            created_at_unixsec,
+            disk_hashes,
+        })
+    }
+
+    pub fn compute_hash(&self) -> Result<Hash> {
+        let serialized = self.serialize()?;
+        Ok(blake3::hash(&serialized).into())
+    }
+}
+
+/// Meta object wrapper
+#[derive(Debug, Clone)]
+pub enum MetaObj {
+    File(FileObj),
+    Dir(DirObj),
+    Partition(PartitionObj),
+    Disk(DiskObj),
+    Snapshot(SnapshotObj),
+}
+
+impl MetaObj {
+    pub fn meta_type(&self) -> MetaType {
+        match self {
+            MetaObj::File(_) => MetaType::File,
+            MetaObj::Dir(_) => MetaType::Dir,
+            MetaObj::Partition(_) => MetaType::Partition,
+            MetaObj::Disk(_) => MetaType::Disk,
+            MetaObj::Snapshot(_) => MetaType::Snapshot,
+        }
+    }
+
+    pub fn serialize(&self) -> Result<Bytes> {
+        match self {
+            MetaObj::File(obj) => obj.serialize(),
+            MetaObj::Dir(obj) => obj.serialize(),
+            MetaObj::Partition(obj) => obj.serialize(),
+            MetaObj::Disk(obj) => obj.serialize(),
+            MetaObj::Snapshot(obj) => obj.serialize(),
+        }
+    }
+
+    pub fn deserialize(meta_type: MetaType, data: Bytes) -> Result<Self> {
+        match meta_type {
+            MetaType::File => Ok(MetaObj::File(FileObj::deserialize(data)?)),
+            MetaType::Dir => Ok(MetaObj::Dir(DirObj::deserialize(data)?)),
+            MetaType::Partition => Ok(MetaObj::Partition(PartitionObj::deserialize(data)?)),
+            MetaType::Disk => Ok(MetaObj::Disk(DiskObj::deserialize(data)?)),
+            MetaType::Snapshot => Ok(MetaObj::Snapshot(SnapshotObj::deserialize(data)?)),
+        }
+    }
+
+    pub fn compute_hash(&self) -> Result<Hash> {
+        match self {
+            MetaObj::File(obj) => obj.compute_hash(),
+            MetaObj::Dir(obj) => obj.compute_hash(),
+            MetaObj::Partition(obj) => obj.compute_hash(),
+            MetaObj::Disk(obj) => obj.compute_hash(),
+            MetaObj::Snapshot(obj) => obj.compute_hash(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_file_obj_serialization() {
+        let obj = FileObj::new(
+            FsType::Ext,
+            1024,
+            0o644,
+            1000,
+            1000,
+            1234567890,
+            vec![[1; 32], [2; 32]],
+        );
+
+        let serialized = obj.serialize().unwrap();
+        let deserialized = FileObj::deserialize(serialized).unwrap();
+
+        assert_eq!(obj.fs_type_code, deserialized.fs_type_code);
+        assert_eq!(obj.size, deserialized.size);
+        assert_eq!(obj.chunk_hashes, deserialized.chunk_hashes);
+    }
+
+    #[test]
+    fn test_dir_obj_serialization() {
+        let entries = vec![
+            DirEntry {
+                entry_type: EntryType::File,
+                name: "test.txt".to_string(),
+                target_meta_hash: [1; 32],
+            },
+            DirEntry {
+                entry_type: EntryType::Dir,
+                name: "subdir".to_string(),
+                target_meta_hash: [2; 32],
+            },
+        ];
+
+        let obj = DirObj::new(entries);
+        let serialized = obj.serialize().unwrap();
+        let deserialized = DirObj::deserialize(serialized).unwrap();
+
+        assert_eq!(obj.entries.len(), deserialized.entries.len());
+        assert_eq!(obj.entries[0].name, deserialized.entries[0].name);
+        assert_eq!(obj.entries[1].entry_type, deserialized.entries[1].entry_type);
+    }
+
+    #[test]
+    fn test_hash_computation() {
+        let obj = FileObj::new(FsType::Ext, 1024, 0o644, 1000, 1000, 1234567890, vec![]);
+        let hash1 = obj.compute_hash().unwrap();
+        let hash2 = obj.compute_hash().unwrap();
+        assert_eq!(hash1, hash2);
+
+        let obj2 = FileObj::new(FsType::Ext, 1025, 0o644, 1000, 1000, 1234567890, vec![]);
+        let hash3 = obj2.compute_hash().unwrap();
+        assert_ne!(hash1, hash3);
+    }
+}

server/src/sync/mod.rs

@@ -0,0 +1,8 @@
+pub mod protocol;
+pub mod server;
+pub mod storage;
+pub mod session;
+pub mod meta;
+pub mod validation;
+
+pub use server::SyncServer;

server/src/sync/protocol.rs

@@ -0,0 +1,620 @@
+use bytes::{Buf, BufMut, Bytes, BytesMut};
+use std::io::{Error, ErrorKind, Result};
+
+/// Command codes for the sync protocol
+#[repr(u8)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Command {
+    Hello = 0x01,
+    HelloOk = 0x02,
+    AuthUserPass = 0x10,
+    AuthCode = 0x11,
+    AuthOk = 0x12,
+    AuthFail = 0x13,
+    BatchCheckChunk = 0x20,
+    CheckChunkResp = 0x21,
+    SendChunk = 0x22,
+    ChunkOk = 0x23,
+    ChunkFail = 0x24,
+    BatchCheckMeta = 0x30,
+    CheckMetaResp = 0x31,
+    SendMeta = 0x32,
+    MetaOk = 0x33,
+    MetaFail = 0x34,
+    SendSnapshot = 0x40,
+    SnapshotOk = 0x41,
+    SnapshotFail = 0x42,
+    Close = 0xFF,
+}
+
+impl TryFrom<u8> for Command {
+    type Error = Error;
+
+    fn try_from(value: u8) -> Result<Self> {
+        match value {
+            0x01 => Ok(Command::Hello),
+            0x02 => Ok(Command::HelloOk),
+            0x10 => Ok(Command::AuthUserPass),
+            0x11 => Ok(Command::AuthCode),
+            0x12 => Ok(Command::AuthOk),
+            0x13 => Ok(Command::AuthFail),
+            0x20 => Ok(Command::BatchCheckChunk),
+            0x21 => Ok(Command::CheckChunkResp),
+            0x22 => Ok(Command::SendChunk),
+            0x23 => Ok(Command::ChunkOk),
+            0x24 => Ok(Command::ChunkFail),
+            0x30 => Ok(Command::BatchCheckMeta),
+            0x31 => Ok(Command::CheckMetaResp),
+            0x32 => Ok(Command::SendMeta),
+            0x33 => Ok(Command::MetaOk),
+            0x34 => Ok(Command::MetaFail),
+            0x40 => Ok(Command::SendSnapshot),
+            0x41 => Ok(Command::SnapshotOk),
+            0x42 => Ok(Command::SnapshotFail),
+            0xFF => Ok(Command::Close),
+            _ => Err(Error::new(ErrorKind::InvalidData, "Unknown command code")),
+        }
+    }
+}
+
+/// Message header structure (24 bytes fixed)
+#[derive(Debug, Clone)]
+pub struct MessageHeader {
+    pub cmd: Command,
+    pub flags: u8,
+    pub reserved: [u8; 2],
+    pub session_id: [u8; 16],
+    pub payload_len: u32,
+}
+
+impl MessageHeader {
+    pub const SIZE: usize = 24;
+
+    pub fn new(cmd: Command, session_id: [u8; 16], payload_len: u32) -> Self {
+        Self {
+            cmd,
+            flags: 0,
+            reserved: [0; 2],
+            session_id,
+            payload_len,
+        }
+    }
+
+    pub fn serialize(&self) -> [u8; Self::SIZE] {
+        let mut buf = [0u8; Self::SIZE];
+        buf[0] = self.cmd as u8;
+        buf[1] = self.flags;
+        buf[2..4].copy_from_slice(&self.reserved);
+        buf[4..20].copy_from_slice(&self.session_id);
+        buf[20..24].copy_from_slice(&self.payload_len.to_le_bytes());
+        buf
+    }
+
+    pub fn deserialize(buf: &[u8]) -> Result<Self> {
+        if buf.len() < Self::SIZE {
+            return Err(Error::new(ErrorKind::UnexpectedEof, "Header too short"));
+        }
+
+        let cmd = Command::try_from(buf[0])?;
+        let flags = buf[1];
+        let reserved = [buf[2], buf[3]];
+        let mut session_id = [0u8; 16];
+        session_id.copy_from_slice(&buf[4..20]);
+        let payload_len = u32::from_le_bytes([buf[20], buf[21], buf[22], buf[23]]);
+
+        Ok(Self {
+            cmd,
+            flags,
+            reserved,
+            session_id,
+            payload_len,
+        })
+    }
+}
+
+/// A 32-byte BLAKE3 hash
+pub type Hash = [u8; 32];
+
+/// Meta object types
+#[repr(u8)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum MetaType {
+    File = 1,
+    Dir = 2,
+    Partition = 3,
+    Disk = 4,
+    Snapshot = 5,
+}
+
+impl TryFrom<u8> for MetaType {
+    type Error = Error;
+
+    fn try_from(value: u8) -> Result<Self> {
+        match value {
+            1 => Ok(MetaType::File),
+            2 => Ok(MetaType::Dir),
+            3 => Ok(MetaType::Partition),
+            4 => Ok(MetaType::Disk),
+            5 => Ok(MetaType::Snapshot),
+            _ => Err(Error::new(ErrorKind::InvalidData, "Unknown meta type")),
+        }
+    }
+}
+
+/// Protocol message types
+#[derive(Debug, Clone)]
+pub enum Message {
+    Hello {
+        client_type: u8,
+        auth_type: u8,
+    },
+    HelloOk,
+    AuthUserPass {
+        username: String,
+        password: String,
+        machine_id: i64,
+    },
+    AuthCode {
+        code: String,
+    },
+    AuthOk {
+        session_id: [u8; 16],
+    },
+    AuthFail {
+        reason: String,
+    },
+    BatchCheckChunk {
+        hashes: Vec<Hash>,
+    },
+    CheckChunkResp {
+        missing_hashes: Vec<Hash>,
+    },
+    SendChunk {
+        hash: Hash,
+        data: Bytes,
+    },
+    ChunkOk,
+    ChunkFail {
+        reason: String,
+    },
+    BatchCheckMeta {
+        items: Vec<(MetaType, Hash)>,
+    },
+    CheckMetaResp {
+        missing_items: Vec<(MetaType, Hash)>,
+    },
+    SendMeta {
+        meta_type: MetaType,
+        meta_hash: Hash,
+        body: Bytes,
+    },
+    MetaOk,
+    MetaFail {
+        reason: String,
+    },
+    SendSnapshot {
+        snapshot_hash: Hash,
+        body: Bytes,
+    },
+    SnapshotOk {
+        snapshot_id: String,
+    },
+    SnapshotFail {
+        missing_chunks: Vec<Hash>,
+        missing_metas: Vec<(MetaType, Hash)>,
+    },
+    Close,
+}
+
+impl Message {
+    /// Serialize message payload to bytes
+    pub fn serialize_payload(&self) -> Result<Bytes> {
+        let mut buf = BytesMut::new();
+
+        match self {
+            Message::Hello { client_type, auth_type } => {
+                buf.put_u8(*client_type);
+                buf.put_u8(*auth_type);
+            }
+            Message::HelloOk => {
+                // No payload
+            }
+            Message::AuthUserPass { username, password, machine_id } => {
+                let username_bytes = username.as_bytes();
+                let password_bytes = password.as_bytes();
+                buf.put_u16_le(username_bytes.len() as u16);
+                buf.put_slice(username_bytes);
+                buf.put_u16_le(password_bytes.len() as u16);
+                buf.put_slice(password_bytes);
+                buf.put_i64_le(*machine_id);
+            }
+            Message::AuthCode { code } => {
+                let code_bytes = code.as_bytes();
+                buf.put_u16_le(code_bytes.len() as u16);
+                buf.put_slice(code_bytes);
+            }
+            Message::AuthOk { session_id } => {
+                buf.put_slice(session_id);
+            }
+            Message::AuthFail { reason } => {
+                let reason_bytes = reason.as_bytes();
+                buf.put_u16_le(reason_bytes.len() as u16);
+                buf.put_slice(reason_bytes);
+            }
+            Message::BatchCheckChunk { hashes } => {
+                buf.put_u32_le(hashes.len() as u32);
+                for hash in hashes {
+                    buf.put_slice(hash);
+                }
+            }
+            Message::CheckChunkResp { missing_hashes } => {
+                buf.put_u32_le(missing_hashes.len() as u32);
+                for hash in missing_hashes {
+                    buf.put_slice(hash);
+                }
+            }
+            Message::SendChunk { hash, data } => {
+                buf.put_slice(hash);
+                buf.put_u32_le(data.len() as u32);
+                buf.put_slice(data);
+            }
+            Message::ChunkOk => {
+                // No payload
+            }
+            Message::ChunkFail { reason } => {
+                let reason_bytes = reason.as_bytes();
+                buf.put_u16_le(reason_bytes.len() as u16);
+                buf.put_slice(reason_bytes);
+            }
+            Message::BatchCheckMeta { items } => {
+                buf.put_u32_le(items.len() as u32);
+                for (meta_type, hash) in items {
+                    buf.put_u8(*meta_type as u8);
+                    buf.put_slice(hash);
+                }
+            }
+            Message::CheckMetaResp { missing_items } => {
+                buf.put_u32_le(missing_items.len() as u32);
+                for (meta_type, hash) in missing_items {
+                    buf.put_u8(*meta_type as u8);
+                    buf.put_slice(hash);
+                }
+            }
+            Message::SendMeta { meta_type, meta_hash, body } => {
+                buf.put_u8(*meta_type as u8);
+                buf.put_slice(meta_hash);
+                buf.put_u32_le(body.len() as u32);
+                buf.put_slice(body);
+            }
+            Message::MetaOk => {
+                // No payload
+            }
+            Message::MetaFail { reason } => {
+                let reason_bytes = reason.as_bytes();
+                buf.put_u16_le(reason_bytes.len() as u16);
+                buf.put_slice(reason_bytes);
+            }
+            Message::SendSnapshot { snapshot_hash, body } => {
+                buf.put_slice(snapshot_hash);
+                buf.put_u32_le(body.len() as u32);
+                buf.put_slice(body);
+            }
+            Message::SnapshotOk { snapshot_id } => {
+                let id_bytes = snapshot_id.as_bytes();
+                buf.put_u16_le(id_bytes.len() as u16);
+                buf.put_slice(id_bytes);
+            }
+            Message::SnapshotFail { missing_chunks, missing_metas } => {
+                buf.put_u32_le(missing_chunks.len() as u32);
+                for hash in missing_chunks {
+                    buf.put_slice(hash);
+                }
+                buf.put_u32_le(missing_metas.len() as u32);
+                for (meta_type, hash) in missing_metas {
+                    buf.put_u8(*meta_type as u8);
+                    buf.put_slice(hash);
+                }
+            }
+            Message::Close => {
+                // No payload
+            }
+        }
+
+        Ok(buf.freeze())
+    }
+
+    /// Deserialize message payload from bytes
+    pub fn deserialize_payload(cmd: Command, mut payload: Bytes) -> Result<Self> {
+        match cmd {
+            Command::Hello => {
+                if payload.remaining() < 2 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "Hello payload too short"));
+                }
+                let client_type = payload.get_u8();
+                let auth_type = payload.get_u8();
+                Ok(Message::Hello { client_type, auth_type })
+            }
+            Command::HelloOk => Ok(Message::HelloOk),
+            Command::AuthUserPass => {
+                if payload.remaining() < 12 { // 4 bytes for lengths + at least 8 bytes for machine_id
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "AuthUserPass payload too short"));
+                }
+                let username_len = payload.get_u16_le() as usize;
+                if payload.remaining() < username_len + 10 { // 2 bytes for password len + 8 bytes for machine_id
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "AuthUserPass username too short"));
+                }
+                let username = String::from_utf8(payload.copy_to_bytes(username_len).to_vec())
+                    .map_err(|_| Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in username"))?;
+                let password_len = payload.get_u16_le() as usize;
+                if payload.remaining() < password_len + 8 { // 8 bytes for machine_id
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "AuthUserPass password too short"));
+                }
+                let password = String::from_utf8(payload.copy_to_bytes(password_len).to_vec())
+                    .map_err(|_| Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in password"))?;
+                let machine_id = payload.get_i64_le();
+                Ok(Message::AuthUserPass { username, password, machine_id })
+            }
+            Command::AuthCode => {
+                if payload.remaining() < 2 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "AuthCode payload too short"));
+                }
+                let code_len = payload.get_u16_le() as usize;
+                if payload.remaining() < code_len {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "AuthCode code too short"));
+                }
+                let code = String::from_utf8(payload.copy_to_bytes(code_len).to_vec())
+                    .map_err(|_| Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in code"))?;
+                Ok(Message::AuthCode { code })
+            }
+            Command::AuthOk => {
+                if payload.remaining() < 16 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "AuthOk payload too short"));
+                }
+                let mut session_id = [0u8; 16];
+                payload.copy_to_slice(&mut session_id);
+                Ok(Message::AuthOk { session_id })
+            }
+            Command::AuthFail => {
+                if payload.remaining() < 2 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "AuthFail payload too short"));
+                }
+                let reason_len = payload.get_u16_le() as usize;
+                if payload.remaining() < reason_len {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "AuthFail reason too short"));
+                }
+                let reason = String::from_utf8(payload.copy_to_bytes(reason_len).to_vec())
+                    .map_err(|_| Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in reason"))?;
+                Ok(Message::AuthFail { reason })
+            }
+            Command::BatchCheckChunk => {
+                if payload.remaining() < 4 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "BatchCheckChunk payload too short"));
+                }
+                let count = payload.get_u32_le() as usize;
+                if payload.remaining() < count * 32 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "BatchCheckChunk hashes too short"));
+                }
+                let mut hashes = Vec::with_capacity(count);
+                for _ in 0..count {
+                    let mut hash = [0u8; 32];
+                    payload.copy_to_slice(&mut hash);
+                    hashes.push(hash);
+                }
+                Ok(Message::BatchCheckChunk { hashes })
+            }
+            Command::CheckChunkResp => {
+                if payload.remaining() < 4 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "CheckChunkResp payload too short"));
+                }
+                let count = payload.get_u32_le() as usize;
+                if payload.remaining() < count * 32 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "CheckChunkResp hashes too short"));
+                }
+                let mut missing_hashes = Vec::with_capacity(count);
+                for _ in 0..count {
+                    let mut hash = [0u8; 32];
+                    payload.copy_to_slice(&mut hash);
+                    missing_hashes.push(hash);
+                }
+                Ok(Message::CheckChunkResp { missing_hashes })
+            }
+            Command::SendChunk => {
+                if payload.remaining() < 36 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SendChunk payload too short"));
+                }
+                let mut hash = [0u8; 32];
+                payload.copy_to_slice(&mut hash);
+                let size = payload.get_u32_le() as usize;
+                if payload.remaining() < size {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SendChunk data too short"));
+                }
+                let data = payload.copy_to_bytes(size);
+                Ok(Message::SendChunk { hash, data })
+            }
+            Command::ChunkOk => Ok(Message::ChunkOk),
+            Command::ChunkFail => {
+                if payload.remaining() < 2 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "ChunkFail payload too short"));
+                }
+                let reason_len = payload.get_u16_le() as usize;
+                if payload.remaining() < reason_len {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "ChunkFail reason too short"));
+                }
+                let reason = String::from_utf8(payload.copy_to_bytes(reason_len).to_vec())
+                    .map_err(|_| Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in reason"))?;
+                Ok(Message::ChunkFail { reason })
+            }
+            Command::BatchCheckMeta => {
+                if payload.remaining() < 4 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "BatchCheckMeta payload too short"));
+                }
+                let count = payload.get_u32_le() as usize;
+                if payload.remaining() < count * 33 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "BatchCheckMeta items too short"));
+                }
+                let mut items = Vec::with_capacity(count);
+                for _ in 0..count {
+                    let meta_type = MetaType::try_from(payload.get_u8())?;
+                    let mut hash = [0u8; 32];
+                    payload.copy_to_slice(&mut hash);
+                    items.push((meta_type, hash));
+                }
+                Ok(Message::BatchCheckMeta { items })
+            }
+            Command::CheckMetaResp => {
+                if payload.remaining() < 4 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "CheckMetaResp payload too short"));
+                }
+                let count = payload.get_u32_le() as usize;
+                if payload.remaining() < count * 33 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "CheckMetaResp items too short"));
+                }
+                let mut missing_items = Vec::with_capacity(count);
+                for _ in 0..count {
+                    let meta_type = MetaType::try_from(payload.get_u8())?;
+                    let mut hash = [0u8; 32];
+                    payload.copy_to_slice(&mut hash);
+                    missing_items.push((meta_type, hash));
+                }
+                Ok(Message::CheckMetaResp { missing_items })
+            }
+            Command::SendMeta => {
+                if payload.remaining() < 37 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SendMeta payload too short"));
+                }
+                let meta_type = MetaType::try_from(payload.get_u8())?;
+                let mut meta_hash = [0u8; 32];
+                payload.copy_to_slice(&mut meta_hash);
+                let body_len = payload.get_u32_le() as usize;
+                if payload.remaining() < body_len {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SendMeta body too short"));
+                }
+                let body = payload.copy_to_bytes(body_len);
+                Ok(Message::SendMeta { meta_type, meta_hash, body })
+            }
+            Command::MetaOk => Ok(Message::MetaOk),
+            Command::MetaFail => {
+                if payload.remaining() < 2 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "MetaFail payload too short"));
+                }
+                let reason_len = payload.get_u16_le() as usize;
+                if payload.remaining() < reason_len {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "MetaFail reason too short"));
+                }
+                let reason = String::from_utf8(payload.copy_to_bytes(reason_len).to_vec())
+                    .map_err(|_| Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in reason"))?;
+                Ok(Message::MetaFail { reason })
+            }
+            Command::SendSnapshot => {
+                if payload.remaining() < 36 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SendSnapshot payload too short"));
+                }
+                let mut snapshot_hash = [0u8; 32];
+                payload.copy_to_slice(&mut snapshot_hash);
+                let body_len = payload.get_u32_le() as usize;
+                if payload.remaining() < body_len {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SendSnapshot body too short"));
+                }
+                let body = payload.copy_to_bytes(body_len);
+                Ok(Message::SendSnapshot { snapshot_hash, body })
+            }
+            Command::SnapshotOk => {
+                if payload.remaining() < 2 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SnapshotOk payload too short"));
+                }
+                let id_len = payload.get_u16_le() as usize;
+                if payload.remaining() < id_len {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SnapshotOk id too short"));
+                }
+                let snapshot_id = String::from_utf8(payload.copy_to_bytes(id_len).to_vec())
+                    .map_err(|_| Error::new(ErrorKind::InvalidData, "Invalid UTF-8 in snapshot_id"))?;
+                Ok(Message::SnapshotOk { snapshot_id })
+            }
+            Command::SnapshotFail => {
+                if payload.remaining() < 8 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SnapshotFail payload too short"));
+                }
+                let chunk_count = payload.get_u32_le() as usize;
+                if payload.remaining() < chunk_count * 32 + 4 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SnapshotFail chunks too short"));
+                }
+                let mut missing_chunks = Vec::with_capacity(chunk_count);
+                for _ in 0..chunk_count {
+                    let mut hash = [0u8; 32];
+                    payload.copy_to_slice(&mut hash);
+                    missing_chunks.push(hash);
+                }
+                let meta_count = payload.get_u32_le() as usize;
+                if payload.remaining() < meta_count * 33 {
+                    return Err(Error::new(ErrorKind::UnexpectedEof, "SnapshotFail metas too short"));
+                }
+                let mut missing_metas = Vec::with_capacity(meta_count);
+                for _ in 0..meta_count {
+                    let meta_type = MetaType::try_from(payload.get_u8())?;
+                    let mut hash = [0u8; 32];
+                    payload.copy_to_slice(&mut hash);
+                    missing_metas.push((meta_type, hash));
+                }
+                Ok(Message::SnapshotFail { missing_chunks, missing_metas })
+            }
+            Command::Close => Ok(Message::Close),
+        }
+    }
+
+    /// Get the command for this message
+    pub fn command(&self) -> Command {
+        match self {
+            Message::Hello { .. } => Command::Hello,
+            Message::HelloOk => Command::HelloOk,
+            Message::AuthUserPass { .. } => Command::AuthUserPass,
+            Message::AuthCode { .. } => Command::AuthCode,
+            Message::AuthOk { .. } => Command::AuthOk,
+            Message::AuthFail { .. } => Command::AuthFail,
+            Message::BatchCheckChunk { .. } => Command::BatchCheckChunk,
+            Message::CheckChunkResp { .. } => Command::CheckChunkResp,
+            Message::SendChunk { .. } => Command::SendChunk,
+            Message::ChunkOk => Command::ChunkOk,
+            Message::ChunkFail { .. } => Command::ChunkFail,
+            Message::BatchCheckMeta { .. } => Command::BatchCheckMeta,
+            Message::CheckMetaResp { .. } => Command::CheckMetaResp,
+            Message::SendMeta { .. } => Command::SendMeta,
+            Message::MetaOk => Command::MetaOk,
+            Message::MetaFail { .. } => Command::MetaFail,
+            Message::SendSnapshot { .. } => Command::SendSnapshot,
+            Message::SnapshotOk { .. } => Command::SnapshotOk,
+            Message::SnapshotFail { .. } => Command::SnapshotFail,
+            Message::Close => Command::Close,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_header_serialization() {
+        let header = MessageHeader::new(Command::Hello, [1; 16], 42);
+        let serialized = header.serialize();
+        let deserialized = MessageHeader::deserialize(&serialized).unwrap();
+        
+        assert_eq!(deserialized.cmd, Command::Hello);
+        assert_eq!(deserialized.session_id, [1; 16]);
+        assert_eq!(deserialized.payload_len, 42);
+    }
+
+    #[test]
+    fn test_hello_message() {
+        let msg = Message::Hello { client_type: 1, auth_type: 2 };
+        let payload = msg.serialize_payload().unwrap();
+        let deserialized = Message::deserialize_payload(Command::Hello, payload).unwrap();
+        
+        match deserialized {
+            Message::Hello { client_type, auth_type } => {
+                assert_eq!(client_type, 1);
+                assert_eq!(auth_type, 2);
+            }
+            _ => panic!("Wrong message type"),
+        }
+    }
+}

server/src/sync/server.rs

@@ -0,0 +1,468 @@
+use anyhow::{Context, Result};
+use bytes::Bytes;
+use sqlx::SqlitePool;
+use std::sync::Arc;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::{TcpListener, TcpStream};
+use uuid::Uuid;
+
+use crate::sync::protocol::{Command, Message, MessageHeader, MetaType};
+use crate::sync::session::{SessionManager, session_cleanup_task};
+use crate::sync::storage::Storage;
+use crate::sync::validation::SnapshotValidator;
+
+/// Configuration for the sync server
+#[derive(Debug, Clone)]
+pub struct SyncServerConfig {
+    pub bind_address: String,
+    pub port: u16,
+    pub data_dir: String,
+    pub max_connections: usize,
+    pub chunk_size_limit: usize,
+    pub meta_size_limit: usize,
+    pub batch_limit: usize,
+}
+
+impl Default for SyncServerConfig {
+    fn default() -> Self {
+        Self {
+            bind_address: "0.0.0.0".to_string(),
+            port: 8380,
+            data_dir: "./data".to_string(),
+            max_connections: 100,
+            chunk_size_limit: 4 * 1024 * 1024, // 4 MiB
+            meta_size_limit: 1024 * 1024,      // 1 MiB
+            batch_limit: 1000,
+        }
+    }
+}
+
+/// Main sync server
+pub struct SyncServer {
+    config: SyncServerConfig,
+    storage: Storage,
+    session_manager: Arc<SessionManager>,
+    validator: SnapshotValidator,
+}
+
+impl SyncServer {
+    pub fn new(config: SyncServerConfig, db_pool: SqlitePool) -> Self {
+        let storage = Storage::new(&config.data_dir);
+        let session_manager = Arc::new(SessionManager::new(db_pool));
+        let validator = SnapshotValidator::new(storage.clone());
+
+        Self {
+            config,
+            storage,
+            session_manager,
+            validator,
+        }
+    }
+
+    /// Start the sync server
+    pub async fn start(&self) -> Result<()> {
+        // Initialize storage
+        self.storage.init().await
+            .context("Failed to initialize storage")?;
+
+        let bind_addr = format!("{}:{}", self.config.bind_address, self.config.port);
+        let listener = TcpListener::bind(&bind_addr).await
+            .with_context(|| format!("Failed to bind to {}", bind_addr))?;
+
+        println!("Sync server listening on {}", bind_addr);
+
+        // Start session cleanup task
+        let session_manager_clone = Arc::clone(&self.session_manager);
+        tokio::spawn(async move {
+            session_cleanup_task(session_manager_clone).await;
+        });
+
+        // Accept connections
+        loop {
+            match listener.accept().await {
+                Ok((stream, addr)) => {
+                    println!("New sync connection from {}", addr);
+                    
+                    let handler = ConnectionHandler::new(
+                        stream,
+                        self.storage.clone(),
+                        Arc::clone(&self.session_manager),
+                        self.validator.clone(),
+                        self.config.clone(),
+                    );
+
+                    tokio::spawn(async move {
+                        if let Err(e) = handler.handle().await {
+                            eprintln!("Connection error from {}: {}", addr, e);
+                        }
+                    });
+                }
+                Err(e) => {
+                    eprintln!("Failed to accept connection: {}", e);
+                }
+            }
+        }
+    }
+}
+
+/// Connection handler for individual sync clients
+struct ConnectionHandler {
+    stream: TcpStream,
+    storage: Storage,
+    session_manager: Arc<SessionManager>,
+    validator: SnapshotValidator,
+    config: SyncServerConfig,
+    session_id: Option<[u8; 16]>,
+    machine_id: Option<i64>,
+}
+
+impl ConnectionHandler {
+    fn new(
+        stream: TcpStream,
+        storage: Storage,
+        session_manager: Arc<SessionManager>,
+        validator: SnapshotValidator,
+        config: SyncServerConfig,
+    ) -> Self {
+        Self {
+            stream,
+            storage,
+            session_manager,
+            validator,
+            config,
+            session_id: None,
+            machine_id: None,
+        }
+    }
+
+    /// Handle the connection
+    async fn handle(mut self) -> Result<()> {
+        loop {
+            // Read message header
+            let header = self.read_header().await?;
+            
+            // Read payload with appropriate size limit based on command type
+            let payload = if header.payload_len > 0 {
+                self.read_payload(header.cmd, header.payload_len).await?
+            } else {
+                Bytes::new()
+            };
+
+            // Parse message
+            let message = Message::deserialize_payload(header.cmd, payload)
+                .context("Failed to deserialize message")?;
+
+            // Handle message
+            let response = self.handle_message(message).await?;
+            
+            // Send response
+            if let Some(response_msg) = response {
+                self.send_message(response_msg).await?;
+            }
+
+            // Close connection if requested
+            if header.cmd == Command::Close {
+                break;
+            }
+        }
+
+        // Clean up session
+        if let Some(session_id) = self.session_id {
+            self.session_manager.remove_session(&session_id).await;
+        }
+
+        Ok(())
+    }
+
+    /// Read message header
+    async fn read_header(&mut self) -> Result<MessageHeader> {
+        let mut header_buf = [0u8; MessageHeader::SIZE];
+        self.stream.read_exact(&mut header_buf).await
+            .context("Failed to read message header")?;
+        
+        MessageHeader::deserialize(&header_buf)
+            .context("Failed to parse message header")
+    }
+
+    /// Read message payload with appropriate size limit based on command type
+    async fn read_payload(&mut self, cmd: Command, len: u32) -> Result<Bytes> {
+        // Use different size limits based on command type
+        let size_limit = match cmd {
+            Command::SendChunk => self.config.chunk_size_limit,
+            _ => self.config.meta_size_limit,
+        };
+        
+        if len as usize > size_limit {
+            return Err(anyhow::anyhow!("Payload too large: {} bytes", len));
+        }
+
+        let mut payload_buf = vec![0u8; len as usize];
+        self.stream.read_exact(&mut payload_buf).await
+            .context("Failed to read message payload")?;
+        
+        Ok(Bytes::from(payload_buf))
+    }
+
+    /// Send a message
+    async fn send_message(&mut self, message: Message) -> Result<()> {
+        let session_id = self.session_id.unwrap_or([0u8; 16]);
+        let payload = message.serialize_payload()?;
+        
+        let header = MessageHeader::new(message.command(), session_id, payload.len() as u32);
+        let header_bytes = header.serialize();
+
+        self.stream.write_all(&header_bytes).await
+            .context("Failed to write message header")?;
+        
+        if !payload.is_empty() {
+            self.stream.write_all(&payload).await
+                .context("Failed to write message payload")?;
+        }
+
+        self.stream.flush().await
+            .context("Failed to flush stream")?;
+
+        Ok(())
+    }
+
+    /// Handle a received message
+    async fn handle_message(&mut self, message: Message) -> Result<Option<Message>> {
+        match message {
+            Message::Hello { client_type: _, auth_type: _ } => {
+                Ok(Some(Message::HelloOk))
+            }
+
+            Message::AuthUserPass { username, password, machine_id } => {
+                match self.session_manager.authenticate_userpass(&username, &password, machine_id).await {
+                    Ok(session) => {
+                        self.session_id = Some(session.session_id);
+                        self.machine_id = Some(session.machine_id);
+                        Ok(Some(Message::AuthOk { session_id: session.session_id }))
+                    }
+                    Err(e) => {
+                        Ok(Some(Message::AuthFail { reason: e.to_string() }))
+                    }
+                }
+            }
+
+            Message::AuthCode { code } => {
+                match self.session_manager.authenticate_code(&code).await {
+                    Ok(session) => {
+                        self.session_id = Some(session.session_id);
+                        self.machine_id = Some(session.machine_id);
+                        Ok(Some(Message::AuthOk { session_id: session.session_id }))
+                    }
+                    Err(e) => {
+                        Ok(Some(Message::AuthFail { reason: e.to_string() }))
+                    }
+                }
+            }
+
+            Message::BatchCheckChunk { hashes } => {
+                self.require_auth()?;
+                
+                if hashes.len() > self.config.batch_limit {
+                    return Err(anyhow::anyhow!("Batch size exceeds limit: {}", hashes.len()));
+                }
+
+                let missing_hashes = self.validator.validate_chunk_batch(&hashes).await?;
+                Ok(Some(Message::CheckChunkResp { missing_hashes }))
+            }
+
+            Message::SendChunk { hash, data } => {
+                self.require_auth()?;
+                
+                if data.len() > self.config.chunk_size_limit {
+                    return Ok(Some(Message::ChunkFail { 
+                        reason: format!("Chunk too large: {} bytes", data.len()) 
+                    }));
+                }
+
+                match self.storage.store_chunk(&hash, &data).await {
+                    Ok(()) => Ok(Some(Message::ChunkOk)),
+                    Err(e) => Ok(Some(Message::ChunkFail { reason: e.to_string() })),
+                }
+            }
+
+            Message::BatchCheckMeta { items } => {
+                self.require_auth()?;
+                
+                if items.len() > self.config.batch_limit {
+                    return Err(anyhow::anyhow!("Batch size exceeds limit: {}", items.len()));
+                }
+
+                let missing_items = self.validator.validate_meta_batch(&items).await?;
+                Ok(Some(Message::CheckMetaResp { missing_items }))
+            }
+
+            Message::SendMeta { meta_type, meta_hash, body } => {
+                self.require_auth()?;
+                
+                if body.len() > self.config.meta_size_limit {
+                    return Ok(Some(Message::MetaFail { 
+                        reason: format!("Meta object too large: {} bytes", body.len()) 
+                    }));
+                }
+
+                match self.storage.store_meta(meta_type, &meta_hash, &body).await {
+                    Ok(()) => Ok(Some(Message::MetaOk)),
+                    Err(e) => Ok(Some(Message::MetaFail { reason: e.to_string() })),
+                }
+            }
+
+            Message::SendSnapshot { snapshot_hash, body } => {
+                self.require_auth()?;
+                
+                if body.len() > self.config.meta_size_limit {
+                    println!("Snapshot rejected: size limit exceeded ({} > {})", body.len(), self.config.meta_size_limit);
+                    return Ok(Some(Message::SnapshotFail { 
+                        missing_chunks: vec![],
+                        missing_metas: vec![],
+                    }));
+                }
+
+                println!("Validating snapshot hash: {}", hex::encode(&snapshot_hash));
+
+                // Validate snapshot
+                match self.validator.validate_snapshot(&snapshot_hash, &body).await {
+                    Ok(validation_result) => {
+                        println!("Validation result - is_valid: {}, missing_chunks: {}, missing_metas: {}", 
+                                validation_result.is_valid, 
+                                validation_result.missing_chunks.len(), 
+                                validation_result.missing_metas.len());
+                        
+                        if validation_result.is_valid {
+                            // Store snapshot meta
+                            if let Err(e) = self.storage.store_meta(MetaType::Snapshot, &snapshot_hash, &body).await {
+                                println!("Failed to store snapshot meta: {}", e);
+                                return Ok(Some(Message::SnapshotFail { 
+                                    missing_chunks: vec![],
+                                    missing_metas: vec![],
+                                }));
+                            }
+
+                            // Create snapshot reference
+                            let snapshot_id = Uuid::new_v4().to_string();
+                            let machine_id = *self.machine_id.as_ref().unwrap();
+                            let created_at = chrono::Utc::now().timestamp() as u64;
+
+                            println!("Creating snapshot reference: machine_id={}, snapshot_id={}", machine_id, snapshot_id);
+
+                            if let Err(e) = self.storage.store_snapshot_ref(
+                                machine_id, 
+                                &snapshot_id, 
+                                &snapshot_hash, 
+                                created_at
+                            ).await {
+                                println!("Failed to store snapshot reference: {}", e);
+                                return Ok(Some(Message::SnapshotFail { 
+                                    missing_chunks: vec![],
+                                    missing_metas: vec![],
+                                }));
+                            }
+
+                            println!("Snapshot successfully stored with ID: {}", snapshot_id);
+                            Ok(Some(Message::SnapshotOk { snapshot_id }))
+                        } else {
+                            println!("Snapshot validation failed - returning missing items");
+                            Ok(Some(Message::SnapshotFail {
+                                missing_chunks: validation_result.missing_chunks,
+                                missing_metas: validation_result.missing_metas,
+                            }))
+                        }
+                    }
+                    Err(e) => {
+                        println!("Snapshot validation error: {}", e);
+                        Ok(Some(Message::SnapshotFail { 
+                            missing_chunks: vec![],
+                            missing_metas: vec![],
+                        }))
+                    }
+                }
+            }
+
+            Message::Close => {
+                Ok(None) // No response needed
+            }
+
+            // These are response messages that shouldn't be received by the server
+            Message::HelloOk | Message::AuthOk { .. } | Message::AuthFail { .. } |
+            Message::CheckChunkResp { .. } | Message::ChunkOk | Message::ChunkFail { .. } |
+            Message::CheckMetaResp { .. } | Message::MetaOk | Message::MetaFail { .. } |
+            Message::SnapshotOk { .. } | Message::SnapshotFail { .. } => {
+                Err(anyhow::anyhow!("Unexpected response message from client"))
+            }
+        }
+    }
+
+    /// Require authentication for protected operations
+    fn require_auth(&self) -> Result<()> {
+        if self.session_id.is_none() {
+            return Err(anyhow::anyhow!("Authentication required"));
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile::TempDir;
+    use sqlx::sqlite::SqlitePoolOptions;
+
+    async fn setup_test_server() -> (SyncServer, TempDir) {
+        let temp_dir = TempDir::new().unwrap();
+        
+        let pool = SqlitePoolOptions::new()
+            .connect(":memory:")
+            .await
+            .unwrap();
+
+        // Create required tables
+        sqlx::query!(
+            r#"
+            CREATE TABLE users (
+                id INTEGER PRIMARY KEY,
+                username TEXT UNIQUE NOT NULL,
+                password_hash TEXT NOT NULL,
+                active INTEGER DEFAULT 1
+            )
+            "#
+        )
+        .execute(&pool)
+        .await
+        .unwrap();
+
+        sqlx::query!(
+            r#"
+            CREATE TABLE provisioning_codes (
+                id INTEGER PRIMARY KEY,
+                code TEXT UNIQUE NOT NULL,
+                created_by INTEGER NOT NULL,
+                expires_at TEXT NOT NULL,
+                used INTEGER DEFAULT 0,
+                used_at TEXT,
+                FOREIGN KEY (created_by) REFERENCES users (id)
+            )
+            "#
+        )
+        .execute(&pool)
+        .await
+        .unwrap();
+
+        let config = SyncServerConfig {
+            data_dir: temp_dir.path().to_string_lossy().to_string(),
+            ..Default::default()
+        };
+
+        (SyncServer::new(config, pool), temp_dir)
+    }
+
+    #[tokio::test]
+    async fn test_server_creation() {
+        let (server, _temp_dir) = setup_test_server().await;
+        
+        // Initialize storage to verify everything works
+        server.storage.init().await.unwrap();
+    }
+}

server/src/sync/session.rs

@@ -0,0 +1,343 @@
+use anyhow::{Context, Result};
+use rand::RngCore;
+use sqlx::SqlitePool;
+use std::collections::HashMap;
+use std::sync::Arc;
+use tokio::sync::RwLock;
+
+/// Session information
+#[derive(Debug, Clone)]
+pub struct Session {
+    pub session_id: [u8; 16],
+    pub machine_id: i64,
+    pub user_id: i64,
+    pub created_at: chrono::DateTime<chrono::Utc>,
+}
+
+/// Session manager for sync connections
+#[derive(Debug)]
+pub struct SessionManager {
+    sessions: Arc<RwLock<HashMap<[u8; 16], Session>>>,
+    db_pool: SqlitePool,
+}
+
+impl SessionManager {
+    pub fn new(db_pool: SqlitePool) -> Self {
+        Self {
+            sessions: Arc::new(RwLock::new(HashMap::new())),
+            db_pool,
+        }
+    }
+
+    /// Get database pool reference
+    pub fn get_db_pool(&self) -> &SqlitePool {
+        &self.db_pool
+    }
+
+    /// Generate a new session ID
+    fn generate_session_id() -> [u8; 16] {
+        let mut session_id = [0u8; 16];
+        rand::thread_rng().fill_bytes(&mut session_id);
+        session_id
+    }
+
+    /// Authenticate with username/password and validate machine ownership
+    pub async fn authenticate_userpass(&self, username: &str, password: &str, machine_id: i64) -> Result<Session> {
+        // Query user from database
+        let user = sqlx::query!(
+            "SELECT id, username, password_hash FROM users WHERE username = ?",
+            username
+        )
+        .fetch_optional(&self.db_pool)
+        .await
+        .context("Failed to query user")?;
+
+        let user = user.ok_or_else(|| anyhow::anyhow!("Invalid credentials"))?;
+
+        // Verify password
+        if !bcrypt::verify(password, &user.password_hash)
+            .context("Failed to verify password")? {
+            return Err(anyhow::anyhow!("Invalid credentials"));
+        }
+
+        let user_id = user.id.unwrap_or(0) as i64;
+
+        // Validate machine ownership
+        let machine = sqlx::query!(
+            "SELECT id, user_id FROM machines WHERE id = ?",
+            machine_id
+        )
+        .fetch_optional(&self.db_pool)
+        .await
+        .context("Failed to query machine")?;
+
+        let machine = machine.ok_or_else(|| anyhow::anyhow!("Machine not found"))?;
+        
+        let machine_user_id = machine.user_id;
+        if machine_user_id != user_id {
+            return Err(anyhow::anyhow!("Machine does not belong to user"));
+        }
+
+        // Create session with machine ID
+        let session_id = Self::generate_session_id();
+        let machine_id = machine.id; // Use database ID
+        let session = Session {
+            session_id,
+            machine_id,
+            user_id,
+            created_at: chrono::Utc::now(),
+        };
+
+        // Store session
+        let mut sessions = self.sessions.write().await;
+        sessions.insert(session_id, session.clone());
+
+        Ok(session)
+    }
+
+    /// Authenticate with provisioning code
+    pub async fn authenticate_code(&self, code: &str) -> Result<Session> {
+        // Query provisioning code from database
+        let provisioning_code = sqlx::query!(
+            r#"
+            SELECT pc.id, pc.code, pc.expires_at, pc.used, m.id as machine_id, m.user_id, u.username
+            FROM provisioning_codes pc
+            JOIN machines m ON pc.machine_id = m.id
+            JOIN users u ON m.user_id = u.id
+            WHERE pc.code = ? AND pc.used = 0
+            "#,
+            code
+        )
+        .fetch_optional(&self.db_pool)
+        .await
+        .context("Failed to query provisioning code")?;
+
+        let provisioning_code = provisioning_code
+            .ok_or_else(|| anyhow::anyhow!("Invalid or used provisioning code"))?;
+
+        // Check if code is expired
+        let expires_at: chrono::DateTime<chrono::Utc> = chrono::DateTime::from_naive_utc_and_offset(
+            provisioning_code.expires_at, 
+            chrono::Utc
+        );
+
+        if chrono::Utc::now() > expires_at {
+            return Err(anyhow::anyhow!("Provisioning code expired"));
+        }
+
+        // Mark code as used
+        sqlx::query!(
+            "UPDATE provisioning_codes SET used = 1 WHERE id = ?",
+            provisioning_code.id
+        )
+        .execute(&self.db_pool)
+        .await
+        .context("Failed to mark provisioning code as used")?;
+
+        // Create session
+        let session_id = Self::generate_session_id();
+        let machine_id = provisioning_code.machine_id.expect("Machine ID should not be null"); // Use machine ID from database
+        let session = Session {
+            session_id,
+            machine_id,
+            user_id: provisioning_code.user_id as i64,
+            created_at: chrono::Utc::now(),
+        };
+
+        // Store session
+        let mut sessions = self.sessions.write().await;
+        sessions.insert(session_id, session.clone());
+
+        Ok(session)
+    }
+
+    /// Get session by session ID
+    pub async fn get_session(&self, session_id: &[u8; 16]) -> Option<Session> {
+        let sessions = self.sessions.read().await;
+        sessions.get(session_id).cloned()
+    }
+
+    /// Validate session and return associated machine ID
+    pub async fn validate_session(&self, session_id: &[u8; 16]) -> Result<i64> {
+        let session = self.get_session(session_id).await
+            .ok_or_else(|| anyhow::anyhow!("Invalid session"))?;
+
+        // Check if session is too old (24 hours)
+        let session_age = chrono::Utc::now() - session.created_at;
+        if session_age > chrono::Duration::hours(24) {
+            // Remove expired session
+            let mut sessions = self.sessions.write().await;
+            sessions.remove(session_id);
+            return Err(anyhow::anyhow!("Session expired"));
+        }
+
+        Ok(session.machine_id)
+    }
+
+    /// Remove session
+    pub async fn remove_session(&self, session_id: &[u8; 16]) {
+        let mut sessions = self.sessions.write().await;
+        sessions.remove(session_id);
+    }
+
+    /// Clean up expired sessions
+    pub async fn cleanup_expired_sessions(&self) {
+        let mut sessions = self.sessions.write().await;
+        let now = chrono::Utc::now();
+        
+        sessions.retain(|_, session| {
+            let age = now - session.created_at;
+            age <= chrono::Duration::hours(24)
+        });
+    }
+
+    /// Get active session count
+    pub async fn active_session_count(&self) -> usize {
+        let sessions = self.sessions.read().await;
+        sessions.len()
+    }
+
+    /// List active sessions
+    pub async fn list_active_sessions(&self) -> Vec<Session> {
+        let sessions = self.sessions.read().await;
+        sessions.values().cloned().collect()
+    }
+}
+
+/// Periodic cleanup task for expired sessions
+pub async fn session_cleanup_task(session_manager: Arc<SessionManager>) {
+    let mut interval = tokio::time::interval(tokio::time::Duration::from_secs(3600)); // Every hour
+    
+    loop {
+        interval.tick().await;
+        session_manager.cleanup_expired_sessions().await;
+        println!("Cleaned up expired sync sessions. Active sessions: {}", 
+                session_manager.active_session_count().await);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use sqlx::sqlite::SqlitePoolOptions;
+
+    async fn setup_test_db() -> SqlitePool {
+        let pool = SqlitePoolOptions::new()
+            .connect(":memory:")
+            .await
+            .unwrap();
+
+        // Create tables
+        sqlx::query!(
+            r#"
+            CREATE TABLE users (
+                id INTEGER PRIMARY KEY,
+                username TEXT UNIQUE NOT NULL,
+                password_hash TEXT NOT NULL,
+                active INTEGER DEFAULT 1
+            )
+            "#
+        )
+        .execute(&pool)
+        .await
+        .unwrap();
+
+        sqlx::query!(
+            r#"
+            CREATE TABLE provisioning_codes (
+                id INTEGER PRIMARY KEY,
+                code TEXT UNIQUE NOT NULL,
+                created_by INTEGER NOT NULL,
+                expires_at TEXT NOT NULL,
+                used INTEGER DEFAULT 0,
+                used_at TEXT,
+                FOREIGN KEY (created_by) REFERENCES users (id)
+            )
+            "#
+        )
+        .execute(&pool)
+        .await
+        .unwrap();
+
+        // Insert test user
+        let password_hash = bcrypt::hash("password123", bcrypt::DEFAULT_COST).unwrap();
+        sqlx::query!(
+            "INSERT INTO users (username, password_hash) VALUES (?, ?)",
+            "testuser",
+            password_hash
+        )
+        .execute(&pool)
+        .await
+        .unwrap();
+
+        pool
+    }
+
+    #[tokio::test]
+    async fn test_authenticate_userpass() {
+        let pool = setup_test_db().await;
+        let session_manager = SessionManager::new(pool);
+
+        let session = session_manager
+            .authenticate_userpass("testuser", "password123")
+            .await
+            .unwrap();
+
+        assert_eq!(session.user_id, 1);
+        assert!(!session.machine_id.is_empty());
+    }
+
+    #[tokio::test]
+    async fn test_authenticate_userpass_invalid() {
+        let pool = setup_test_db().await;
+        let session_manager = SessionManager::new(pool);
+
+        let result = session_manager
+            .authenticate_userpass("testuser", "wrongpassword")
+            .await;
+
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_session_validation() {
+        let pool = setup_test_db().await;
+        let session_manager = SessionManager::new(pool);
+
+        let session = session_manager
+            .authenticate_userpass("testuser", "password123")
+            .await
+            .unwrap();
+
+        let machine_id = session_manager
+            .validate_session(&session.session_id)
+            .await
+            .unwrap();
+
+        assert_eq!(machine_id, session.machine_id);
+    }
+
+    #[tokio::test]
+    async fn test_session_cleanup() {
+        let pool = setup_test_db().await;
+        let session_manager = SessionManager::new(pool);
+
+        let session = session_manager
+            .authenticate_userpass("testuser", "password123")
+            .await
+            .unwrap();
+
+        assert_eq!(session_manager.active_session_count().await, 1);
+
+        // Manually expire the session
+        {
+            let mut sessions = session_manager.sessions.write().await;
+            if let Some(mut session) = sessions.get_mut(&session.session_id) {
+                session.created_at = chrono::Utc::now() - chrono::Duration::hours(25);
+            }
+        }
+
+        session_manager.cleanup_expired_sessions().await;
+        assert_eq!(session_manager.active_session_count().await, 0);
+    }
+}

server/src/sync/storage.rs

@@ -0,0 +1,406 @@
+use anyhow::{Context, Result};
+use bytes::Bytes;
+use std::collections::HashSet;
+use std::path::{Path, PathBuf};
+use tokio::fs;
+use crate::sync::protocol::{Hash, MetaType};
+use crate::sync::meta::MetaObj;
+
+/// Storage backend for chunks and metadata objects
+#[derive(Debug, Clone)]
+pub struct Storage {
+    data_dir: PathBuf,
+}
+
+impl Storage {
+    pub fn new<P: AsRef<Path>>(data_dir: P) -> Self {
+        Self {
+            data_dir: data_dir.as_ref().to_path_buf(),
+        }
+    }
+
+    /// Initialize storage directories
+    pub async fn init(&self) -> Result<()> {
+        let chunks_dir = self.data_dir.join("sync").join("chunks");
+        let meta_dir = self.data_dir.join("sync").join("meta");
+        let machines_dir = self.data_dir.join("sync").join("machines");
+
+        fs::create_dir_all(&chunks_dir).await
+            .context("Failed to create chunks directory")?;
+        
+        fs::create_dir_all(&meta_dir).await
+            .context("Failed to create meta directory")?;
+
+        fs::create_dir_all(&machines_dir).await
+            .context("Failed to create machines directory")?;
+
+        // Create subdirectories for each meta type
+        for meta_type in &["files", "dirs", "partitions", "disks", "snapshots"] {
+            fs::create_dir_all(meta_dir.join(meta_type)).await
+                .with_context(|| format!("Failed to create meta/{} directory", meta_type))?;
+        }
+
+        Ok(())
+    }
+
+    /// Get chunk storage path for a hash
+    fn chunk_path(&self, hash: &Hash) -> PathBuf {
+        let hex = hex::encode(hash);
+        let ab = &hex[0..2];
+        let cd = &hex[2..4];
+        let filename = format!("{}.chk", hex);
+        
+        self.data_dir
+            .join("sync")
+            .join("chunks")
+            .join(ab)
+            .join(cd)
+            .join(filename)
+    }
+
+    /// Get meta storage path for a hash and type
+    fn meta_path(&self, meta_type: MetaType, hash: &Hash) -> PathBuf {
+        let hex = hex::encode(hash);
+        let ab = &hex[0..2];
+        let cd = &hex[2..4];
+        let filename = format!("{}.meta", hex);
+        
+        let type_dir = match meta_type {
+            MetaType::File => "files",
+            MetaType::Dir => "dirs", 
+            MetaType::Partition => "partitions",
+            MetaType::Disk => "disks",
+            MetaType::Snapshot => "snapshots",
+        };
+        
+        self.data_dir
+            .join("sync")
+            .join("meta")
+            .join(type_dir)
+            .join(ab)
+            .join(cd)
+            .join(filename)
+    }
+
+    /// Check if a chunk exists
+    pub async fn chunk_exists(&self, hash: &Hash) -> bool {
+        let path = self.chunk_path(hash);
+        path.exists()
+    }
+
+    /// Check if multiple chunks exist
+    pub async fn chunks_exist(&self, hashes: &[Hash]) -> Result<HashSet<Hash>> {
+        let mut existing = HashSet::new();
+        
+        for hash in hashes {
+            if self.chunk_exists(hash).await {
+                existing.insert(*hash);
+            }
+        }
+        
+        Ok(existing)
+    }
+
+    /// Store a chunk
+    pub async fn store_chunk(&self, hash: &Hash, data: &[u8]) -> Result<()> {
+        // Verify hash
+        let computed_hash = blake3::hash(data);
+        if computed_hash.as_bytes() != hash {
+            return Err(anyhow::anyhow!("Chunk hash mismatch"));
+        }
+
+        let path = self.chunk_path(hash);
+        
+        // Create parent directories
+        if let Some(parent) = path.parent() {
+            fs::create_dir_all(parent).await
+                .context("Failed to create chunk directory")?;
+        }
+
+        // Write to temporary file first, then rename (atomic write)
+        let temp_path = path.with_extension("tmp");
+        fs::write(&temp_path, data).await
+            .context("Failed to write chunk to temporary file")?;
+        
+        fs::rename(&temp_path, &path).await
+            .context("Failed to rename chunk file")?;
+
+        Ok(())
+    }
+
+    /// Load a chunk
+    pub async fn load_chunk(&self, hash: &Hash) -> Result<Option<Bytes>> {
+        let path = self.chunk_path(hash);
+        
+        if !path.exists() {
+            return Ok(None);
+        }
+
+        let data = fs::read(&path).await
+            .context("Failed to read chunk file")?;
+        
+        // Verify hash
+        let computed_hash = blake3::hash(&data);
+        if computed_hash.as_bytes() != hash {
+            return Err(anyhow::anyhow!("Stored chunk hash mismatch"));
+        }
+
+        Ok(Some(Bytes::from(data)))
+    }
+
+    /// Check if a meta object exists
+    pub async fn meta_exists(&self, meta_type: MetaType, hash: &Hash) -> bool {
+        let path = self.meta_path(meta_type, hash);
+        path.exists()
+    }
+
+    /// Check if multiple meta objects exist
+    pub async fn metas_exist(&self, items: &[(MetaType, Hash)]) -> Result<HashSet<(MetaType, Hash)>> {
+        let mut existing = HashSet::new();
+        
+        for &(meta_type, hash) in items {
+            if self.meta_exists(meta_type, &hash).await {
+                existing.insert((meta_type, hash));
+            }
+        }
+        
+        Ok(existing)
+    }
+
+    /// Store a meta object
+    pub async fn store_meta(&self, meta_type: MetaType, hash: &Hash, body: &[u8]) -> Result<()> {
+        // Verify hash
+        let computed_hash = blake3::hash(body);
+        if computed_hash.as_bytes() != hash {
+            return Err(anyhow::anyhow!("Meta object hash mismatch"));
+        }
+
+        let path = self.meta_path(meta_type, hash);
+        
+        // Create parent directories
+        if let Some(parent) = path.parent() {
+            fs::create_dir_all(parent).await
+                .context("Failed to create meta directory")?;
+        }
+
+        // Write to temporary file first, then rename (atomic write)
+        let temp_path = path.with_extension("tmp");
+        fs::write(&temp_path, body).await
+            .context("Failed to write meta to temporary file")?;
+        
+        fs::rename(&temp_path, &path).await
+            .context("Failed to rename meta file")?;
+
+        Ok(())
+    }
+
+    /// Load a meta object
+    pub async fn load_meta(&self, meta_type: MetaType, hash: &Hash) -> Result<Option<MetaObj>> {
+        let path = self.meta_path(meta_type, hash);
+        
+        if !path.exists() {
+            println!("Meta file does not exist: {:?}", path);
+            return Ok(None);
+        }
+
+        println!("Reading meta file: {:?}", path);
+        let data = fs::read(&path).await
+            .context("Failed to read meta file")?;
+        
+        println!("Read {} bytes from meta file", data.len());
+        
+        // Verify hash
+        let computed_hash = blake3::hash(&data);
+        if computed_hash.as_bytes() != hash {
+            println!("Hash mismatch: expected {}, got {}", hex::encode(hash), hex::encode(computed_hash.as_bytes()));
+            return Err(anyhow::anyhow!("Stored meta object hash mismatch"));
+        }
+
+        println!("Hash verified, deserializing {:?} object", meta_type);
+        let meta_obj = MetaObj::deserialize(meta_type, Bytes::from(data))
+            .context("Failed to deserialize meta object")?;
+
+        println!("Successfully deserialized meta object");
+        Ok(Some(meta_obj))
+    }
+
+    /// Get snapshot storage path for a machine
+    fn snapshot_ref_path(&self, machine_id: i64, snapshot_id: &str) -> PathBuf {
+        self.data_dir
+            .join("sync")
+            .join("machines")
+            .join(machine_id.to_string())
+            .join("snapshots")
+            .join(format!("{}.ref", snapshot_id))
+    }
+
+    /// Store a snapshot reference
+    pub async fn store_snapshot_ref(
+        &self, 
+        machine_id: i64, 
+        snapshot_id: &str, 
+        snapshot_hash: &Hash,
+        created_at: u64
+    ) -> Result<()> {
+        let path = self.snapshot_ref_path(machine_id, snapshot_id);
+        
+        // Create parent directories
+        if let Some(parent) = path.parent() {
+            fs::create_dir_all(parent).await
+                .context("Failed to create snapshot reference directory")?;
+        }
+
+        // Create snapshot reference content
+        let content = format!("{}:{}", hex::encode(snapshot_hash), created_at);
+        
+        // Write to temporary file first, then rename (atomic write)
+        let temp_path = path.with_extension("tmp");
+        fs::write(&temp_path, content).await
+            .context("Failed to write snapshot reference to temporary file")?;
+        
+        fs::rename(&temp_path, &path).await
+            .context("Failed to rename snapshot reference file")?;
+
+        Ok(())
+    }
+
+    /// Load a snapshot reference
+    pub async fn load_snapshot_ref(&self, machine_id: i64, snapshot_id: &str) -> Result<Option<(Hash, u64)>> {
+        let path = self.snapshot_ref_path(machine_id, snapshot_id);
+        
+        if !path.exists() {
+            return Ok(None);
+        }
+
+        let content = fs::read_to_string(&path).await
+            .context("Failed to read snapshot reference file")?;
+        
+        let parts: Vec<&str> = content.trim().split(':').collect();
+        if parts.len() != 2 {
+            return Err(anyhow::anyhow!("Invalid snapshot reference format"));
+        }
+
+        let snapshot_hash: Hash = hex::decode(parts[0])
+            .context("Failed to decode snapshot hash")?
+            .try_into()
+            .map_err(|_| anyhow::anyhow!("Invalid snapshot hash length"))?;
+        
+        let created_at: u64 = parts[1].parse()
+            .context("Failed to parse snapshot timestamp")?;
+
+        Ok(Some((snapshot_hash, created_at)))
+    }
+
+    /// List snapshots for a machine
+    pub async fn list_snapshots(&self, machine_id: i64) -> Result<Vec<String>> {
+        let snapshots_dir = self.data_dir
+            .join("sync")
+            .join("machines")
+            .join(machine_id.to_string())
+            .join("snapshots");
+
+        if !snapshots_dir.exists() {
+            return Ok(Vec::new());
+        }
+
+        let mut entries = fs::read_dir(&snapshots_dir).await
+            .context("Failed to read snapshots directory")?;
+
+        let mut snapshots = Vec::new();
+        while let Some(entry) = entries.next_entry().await
+            .context("Failed to read snapshot entry")? {
+            
+            if let Some(file_name) = entry.file_name().to_str() {
+                if file_name.ends_with(".ref") {
+                    let snapshot_id = file_name.trim_end_matches(".ref");
+                    snapshots.push(snapshot_id.to_string());
+                }
+            }
+        }
+
+        snapshots.sort();
+        Ok(snapshots)
+    }
+
+    /// Delete old snapshots, keeping only the latest N
+    pub async fn cleanup_snapshots(&self, machine_id: i64, keep_count: usize) -> Result<()> {
+        let mut snapshots = self.list_snapshots(machine_id).await?;
+        
+        if snapshots.len() <= keep_count {
+            return Ok(());
+        }
+
+        snapshots.sort();
+        snapshots.reverse(); // Most recent first
+        
+        // Delete older snapshots
+        for snapshot_id in snapshots.iter().skip(keep_count) {
+            let path = self.snapshot_ref_path(machine_id, snapshot_id);
+            if path.exists() {
+                fs::remove_file(&path).await
+                    .with_context(|| format!("Failed to delete snapshot {}", snapshot_id))?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+/// Add hex crate to dependencies
+use hex;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile::TempDir;
+
+    #[tokio::test]
+    async fn test_storage_init() {
+        let temp_dir = TempDir::new().unwrap();
+        let storage = Storage::new(temp_dir.path());
+        storage.init().await.unwrap();
+
+        assert!(temp_dir.path().join("sync/chunks").exists());
+        assert!(temp_dir.path().join("sync/meta/files").exists());
+        assert!(temp_dir.path().join("sync/machines").exists());
+    }
+
+    #[tokio::test]
+    async fn test_chunk_storage() {
+        let temp_dir = TempDir::new().unwrap();
+        let storage = Storage::new(temp_dir.path());
+        storage.init().await.unwrap();
+
+        let data = b"test chunk data";
+        let hash = blake3::hash(data).into();
+
+        // Store chunk
+        storage.store_chunk(&hash, data).await.unwrap();
+        assert!(storage.chunk_exists(&hash).await);
+
+        // Load chunk
+        let loaded = storage.load_chunk(&hash).await.unwrap().unwrap();
+        assert_eq!(loaded.as_ref(), data);
+    }
+
+    #[tokio::test]
+    async fn test_snapshot_ref_storage() {
+        let temp_dir = TempDir::new().unwrap();
+        let storage = Storage::new(temp_dir.path());
+        storage.init().await.unwrap();
+
+        let machine_id = 123i64;
+        let snapshot_id = "snapshot-001";
+        let snapshot_hash = [1u8; 32];
+        let created_at = 1234567890;
+
+        storage.store_snapshot_ref(machine_id, snapshot_id, &snapshot_hash, created_at)
+            .await.unwrap();
+
+        let loaded = storage.load_snapshot_ref(machine_id, snapshot_id)
+            .await.unwrap().unwrap();
+
+        assert_eq!(loaded.0, snapshot_hash);
+        assert_eq!(loaded.1, created_at);
+    }
+}

server/src/sync/validation.rs

@@ -0,0 +1,235 @@
+use anyhow::{Context, Result};
+use std::collections::{HashSet, VecDeque};
+use crate::sync::protocol::{Hash, MetaType};
+use crate::sync::storage::Storage;
+use crate::sync::meta::{MetaObj, SnapshotObj, EntryType};
+
+/// Validation result for snapshot commits
+#[derive(Debug, Clone)]
+pub struct ValidationResult {
+    pub is_valid: bool,
+    pub missing_chunks: Vec<Hash>,
+    pub missing_metas: Vec<(MetaType, Hash)>,
+}
+
+impl ValidationResult {
+    pub fn valid() -> Self {
+        Self {
+            is_valid: true,
+            missing_chunks: Vec::new(),
+            missing_metas: Vec::new(),
+        }
+    }
+
+    pub fn invalid(missing_chunks: Vec<Hash>, missing_metas: Vec<(MetaType, Hash)>) -> Self {
+        Self {
+            is_valid: false,
+            missing_chunks,
+            missing_metas,
+        }
+    }
+
+    pub fn has_missing(&self) -> bool {
+        !self.missing_chunks.is_empty() || !self.missing_metas.is_empty()
+    }
+}
+
+/// Validator for snapshot object graphs
+#[derive(Clone)]
+pub struct SnapshotValidator {
+    storage: Storage,
+}
+
+impl SnapshotValidator {
+    pub fn new(storage: Storage) -> Self {
+        Self { storage }
+    }
+
+    /// Validate a complete snapshot object graph using BFS only
+    pub async fn validate_snapshot(&self, snapshot_hash: &Hash, snapshot_body: &[u8]) -> Result<ValidationResult> {
+        // Use the BFS implementation
+        self.validate_snapshot_bfs(snapshot_hash, snapshot_body).await
+    }
+
+    /// Validate a batch of meta objects (for incremental validation)
+    pub async fn validate_meta_batch(&self, metas: &[(MetaType, Hash)]) -> Result<Vec<(MetaType, Hash)>> {
+        let mut missing = Vec::new();
+        
+        for &(meta_type, hash) in metas {
+            if !self.storage.meta_exists(meta_type, &hash).await {
+                missing.push((meta_type, hash));
+            }
+        }
+        
+        Ok(missing)
+    }
+
+    /// Validate a batch of chunks (for incremental validation)
+    pub async fn validate_chunk_batch(&self, chunks: &[Hash]) -> Result<Vec<Hash>> {
+        let mut missing = Vec::new();
+        
+        for &hash in chunks {
+            if !self.storage.chunk_exists(&hash).await {
+                missing.push(hash);
+            }
+        }
+        
+        Ok(missing)
+    }
+
+    /// Perform a breadth-first validation (useful for large snapshots)
+    pub async fn validate_snapshot_bfs(&self, snapshot_hash: &Hash, snapshot_body: &[u8]) -> Result<ValidationResult> {
+        // Verify snapshot hash
+        let computed_hash = blake3::hash(snapshot_body);
+        if computed_hash.as_bytes() != snapshot_hash {
+            return Err(anyhow::anyhow!("Snapshot hash mismatch"));
+        }
+
+        // Parse snapshot object
+        let snapshot_obj = SnapshotObj::deserialize(bytes::Bytes::from(snapshot_body.to_vec()))
+            .context("Failed to deserialize snapshot object")?;
+
+        let mut missing_chunks = Vec::new();
+        let mut missing_metas = Vec::new();
+        let mut visited_metas = HashSet::new();
+        let mut queue = VecDeque::new();
+
+        // Initialize queue with disk hashes
+        for disk_hash in &snapshot_obj.disk_hashes {
+            queue.push_back((MetaType::Disk, *disk_hash));
+        }
+
+        // BFS traversal
+        while let Some((meta_type, hash)) = queue.pop_front() {
+            let meta_key = (meta_type, hash);
+            
+            if visited_metas.contains(&meta_key) {
+                continue;
+            }
+            visited_metas.insert(meta_key);
+
+            // Check if meta exists
+            if !self.storage.meta_exists(meta_type, &hash).await {
+                println!("Missing metadata: {:?} hash {}", meta_type, hex::encode(&hash));
+                missing_metas.push((meta_type, hash));
+                continue; // Skip loading if missing
+            }
+
+            // Load and process meta object
+            println!("Loading metadata: {:?} hash {}", meta_type, hex::encode(&hash));
+            if let Some(meta_obj) = self.storage.load_meta(meta_type, &hash).await
+                .context("Failed to load meta object")? {
+                
+                match meta_obj {
+                    MetaObj::Disk(disk) => {
+                        for partition_hash in &disk.partition_hashes {
+                            queue.push_back((MetaType::Partition, *partition_hash));
+                        }
+                    }
+                    MetaObj::Partition(partition) => {
+                        queue.push_back((MetaType::Dir, partition.root_dir_hash));
+                    }
+                    MetaObj::Dir(dir) => {
+                        for entry in &dir.entries {
+                            match entry.entry_type {
+                                EntryType::File | EntryType::Symlink => {
+                                    queue.push_back((MetaType::File, entry.target_meta_hash));
+                                }
+                                EntryType::Dir => {
+                                    queue.push_back((MetaType::Dir, entry.target_meta_hash));
+                                }
+                            }
+                        }
+                    }
+                    MetaObj::File(file) => {
+                        // Check chunk dependencies
+                        for chunk_hash in &file.chunk_hashes {
+                            if !self.storage.chunk_exists(chunk_hash).await {
+                                missing_chunks.push(*chunk_hash);
+                            }
+                        }
+                    }
+                    MetaObj::Snapshot(_) => {
+                        // Snapshots shouldn't be nested
+                        return Err(anyhow::anyhow!("Unexpected nested snapshot object"));
+                    }
+                }
+            }
+        }
+
+        if missing_chunks.is_empty() && missing_metas.is_empty() {
+            Ok(ValidationResult::valid())
+        } else {
+            Ok(ValidationResult::invalid(missing_chunks, missing_metas))
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile::TempDir;
+    use crate::sync::meta::*;
+
+    async fn setup_test_storage() -> Storage {
+        let temp_dir = TempDir::new().unwrap();
+        let storage = Storage::new(temp_dir.path());
+        storage.init().await.unwrap();
+        storage
+    }
+
+    #[tokio::test]
+    async fn test_validate_empty_snapshot() {
+        let storage = setup_test_storage().await;
+        let validator = SnapshotValidator::new(storage);
+
+        let snapshot = SnapshotObj::new(1234567890, vec![]);
+        let snapshot_body = snapshot.serialize().unwrap();
+        let snapshot_hash = snapshot.compute_hash().unwrap();
+
+        let result = validator.validate_snapshot(&snapshot_hash, &snapshot_body)
+            .await.unwrap();
+
+        assert!(result.is_valid);
+        assert!(result.missing_chunks.is_empty());
+        assert!(result.missing_metas.is_empty());
+    }
+
+    #[tokio::test]
+    async fn test_validate_missing_disk() {
+        let storage = setup_test_storage().await;
+        let validator = SnapshotValidator::new(storage);
+
+        let missing_disk_hash = [1u8; 32];
+        let snapshot = SnapshotObj::new(1234567890, vec![missing_disk_hash]);
+        let snapshot_body = snapshot.serialize().unwrap();
+        let snapshot_hash = snapshot.compute_hash().unwrap();
+
+        let result = validator.validate_snapshot(&snapshot_hash, &snapshot_body)
+            .await.unwrap();
+
+        assert!(!result.is_valid);
+        assert!(result.missing_chunks.is_empty());
+        assert_eq!(result.missing_metas.len(), 1);
+        assert_eq!(result.missing_metas[0], (MetaType::Disk, missing_disk_hash));
+    }
+
+    #[tokio::test]
+    async fn test_validate_chunk_batch() {
+        let storage = setup_test_storage().await;
+        let validator = SnapshotValidator::new(storage);
+
+        let chunk_data = b"test chunk";
+        let chunk_hash = blake3::hash(chunk_data).into();
+        let missing_hash = [1u8; 32];
+
+        // Store one chunk
+        storage.store_chunk(&chunk_hash, chunk_data).await.unwrap();
+
+        let chunks = vec![chunk_hash, missing_hash];
+        let missing = validator.validate_chunk_batch(&chunks).await.unwrap();
+
+        assert_eq!(missing.len(), 1);
+        assert_eq!(missing[0], missing_hash);
+    }
+}

server/src/utils/auth.rs

@@ -0,0 +1,63 @@
+use crate::controllers::auth::AuthController;
+use crate::utils::{models::*, DbPool};
+use axum::{
+    extract::FromRequestParts,
+    http::{header::AUTHORIZATION, request::Parts, StatusCode},
+};
+
+#[derive(Clone)]
+pub struct AuthUser {
+    pub user: User,
+}
+
+impl FromRequestParts<DbPool> for AuthUser {
+    type Rejection = StatusCode;
+
+    async fn from_request_parts(
+        parts: &mut Parts,
+        state: &DbPool,
+    ) -> Result<Self, Self::Rejection> {
+        let auth_header = parts
+            .headers
+            .get(AUTHORIZATION)
+            .and_then(|header| header.to_str().ok())
+            .ok_or(StatusCode::UNAUTHORIZED)?;
+
+        if !auth_header.starts_with("Bearer ") {
+            return Err(StatusCode::UNAUTHORIZED);
+        }
+
+        let token = &auth_header[7..];
+
+        let user = AuthController::authenticate_user(state, token)
+            .await
+            .map_err(|_| StatusCode::UNAUTHORIZED)?;
+
+        Ok(AuthUser { user })
+    }
+}
+
+#[derive(Clone)]
+pub struct AdminUser {
+    #[allow(dead_code)]
+    pub user: User,
+}
+
+impl FromRequestParts<DbPool> for AdminUser {
+    type Rejection = StatusCode;
+
+    async fn from_request_parts(
+        parts: &mut Parts,
+        state: &DbPool,
+    ) -> Result<Self, Self::Rejection> {
+        let auth_user = AuthUser::from_request_parts(parts, state).await?;
+
+        if auth_user.user.role != UserRole::Admin {
+            return Err(StatusCode::FORBIDDEN);
+        }
+
+        Ok(AdminUser {
+            user: auth_user.user,
+        })
+    }
+}

server/src/utils/base62.rs

@@ -0,0 +1,108 @@
+const CHARS: &str = "rYTSJ96O2ntiEBkuwQq0vdslyfI8Ph51bpae3LgHoFZAxj7WmzUNCGXcR4MDKV";
+
+pub struct Base62;
+
+impl Base62 {
+    pub fn encode(input: &str) -> String {
+        if input.is_empty() {
+            return String::new();
+        }
+
+        let bytes = input.as_bytes();
+        let alphabet_chars: Vec<char> = CHARS.chars().collect();
+
+        let mut number = bytes.iter().fold(String::from("0"), |acc, &byte| {
+            Self::multiply_and_add(&acc, 256, byte as u32)
+        });
+
+        if number == "0" {
+            return "0".to_string();
+        }
+
+        let mut result = String::new();
+        while number != "0" {
+            let (new_number, remainder) = Self::divide_by(&number, 62);
+            result.push(alphabet_chars[remainder as usize]);
+            number = new_number;
+        }
+
+        result.chars().rev().collect()
+    }
+
+    pub fn decode(encoded: &str) -> Option<String> {
+        if encoded.is_empty() {
+            return Some(String::new());
+        }
+
+        let char_to_value: std::collections::HashMap<char, u32> = CHARS
+            .chars()
+            .enumerate()
+            .map(|(i, c)| (c, i as u32))
+            .collect();
+
+        let mut number = String::from("0");
+        for c in encoded.chars() {
+            let value = *char_to_value.get(&c)?;
+            number = Self::multiply_and_add(&number, 62, value);
+        }
+
+        if number == "0" {
+            return Some(String::new());
+        }
+
+        let mut bytes = Vec::new();
+        while number != "0" {
+            let (new_number, remainder) = Self::divide_by(&number, 256);
+            bytes.push(remainder as u8);
+            number = new_number;
+        }
+
+        bytes.reverse();
+        String::from_utf8(bytes).ok()
+    }
+
+    fn multiply_and_add(num_str: &str, base: u32, add: u32) -> String {
+        let mut result = Vec::new();
+        let mut carry = add;
+
+        for c in num_str.chars().rev() {
+            let digit = c.to_digit(10).unwrap_or(0);
+            let product = digit * base + carry;
+            result.push((product % 10).to_string());
+            carry = product / 10;
+        }
+
+        while carry > 0 {
+            result.push((carry % 10).to_string());
+            carry /= 10;
+        }
+
+        if result.is_empty() {
+            "0".to_string()
+        } else {
+            result.into_iter().rev().collect()
+        }
+    }
+
+    fn divide_by(num_str: &str, base: u32) -> (String, u32) {
+        let mut quotient = String::new();
+        let mut remainder = 0u32;
+
+        for c in num_str.chars() {
+            let digit = c.to_digit(10).unwrap_or(0);
+            let current = remainder * 10 + digit;
+            let q = current / base;
+            remainder = current % base;
+
+            if !quotient.is_empty() || q > 0 {
+                quotient.push_str(&q.to_string());
+            }
+        }
+
+        if quotient.is_empty() {
+            quotient = "0".to_string();
+        }
+
+        (quotient, remainder)
+    }
+}

server/src/utils/config.rs

@@ -0,0 +1,44 @@
+use crate::utils::{error::*, DbPool};
+use sqlx::Row;
+
+pub struct ConfigManager;
+
+impl ConfigManager {
+    pub async fn get_config(pool: &DbPool, key: &str) -> AppResult<Option<String>> {
+        let row = sqlx::query("SELECT value FROM config WHERE key = ?")
+            .bind(key)
+            .fetch_optional(pool)
+            .await?;
+
+        if let Some(row) = row {
+            Ok(Some(row.get("value")))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub async fn set_config(pool: &DbPool, key: &str, value: &str) -> AppResult<()> {
+        sqlx::query(
+            r#"
+            INSERT INTO config (key, value, updated_at)
+            VALUES (?, ?, CURRENT_TIMESTAMP)
+            ON CONFLICT(key) DO UPDATE SET
+                value = excluded.value,
+                updated_at = CURRENT_TIMESTAMP
+            "#,
+        )
+        .bind(key)
+        .bind(value)
+        .execute(pool)
+        .await?;
+
+        Ok(())
+    }
+
+    pub async fn get_external_url(pool: &DbPool) -> AppResult<String> {
+        match Self::get_config(pool, "EXTERNAL_URL").await? {
+            Some(url) => Ok(url),
+            None => Err(internal_error("EXTERNAL_URL not configured")),
+        }
+    }
+}

server/src/utils/database.rs

@@ -0,0 +1,124 @@
+use crate::utils::{ensure_data_directories, get_database_path, AppResult};
+use sqlx::{sqlite::SqlitePool, Pool, Row, Sqlite};
+use std::path::Path;
+
+pub type DbPool = Pool<Sqlite>;
+
+pub async fn init_database() -> AppResult<DbPool> {
+    ensure_data_directories()?;
+
+    let db_path = get_database_path()?;
+
+    if !Path::new(&db_path).exists() {
+        std::fs::File::create(&db_path)?;
+    }
+
+    let database_url = format!("sqlite://{}", db_path);
+
+    let pool = SqlitePool::connect(&database_url).await?;
+
+    run_migrations(&pool).await?;
+
+    Ok(pool)
+}
+
+async fn run_migrations(pool: &DbPool) -> AppResult<()> {
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS users (
+            id            INTEGER PRIMARY KEY AUTOINCREMENT,
+            username      TEXT UNIQUE NOT NULL,
+            password_hash TEXT NOT NULL,
+            role          TEXT CHECK(role IN ('admin','user')) NOT NULL,
+            storage_limit_gb INTEGER NOT NULL DEFAULT 0,
+            created_at    DATETIME DEFAULT CURRENT_TIMESTAMP
+        )
+        "#,
+    )
+    .execute(pool)
+    .await?;
+
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS sessions (
+            id            INTEGER PRIMARY KEY AUTOINCREMENT,
+            user_id       INTEGER NOT NULL,
+            token         TEXT UNIQUE NOT NULL,
+            created_at    DATETIME DEFAULT CURRENT_TIMESTAMP,
+            expires_at    DATETIME NOT NULL,
+            FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE
+        )
+        "#,
+    )
+    .execute(pool)
+    .await?;
+
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS machines (
+            id            INTEGER PRIMARY KEY AUTOINCREMENT,
+            user_id       INTEGER NOT NULL,
+            uuid          TEXT UNIQUE NOT NULL,
+            name          TEXT NOT NULL,
+            created_at    DATETIME DEFAULT CURRENT_TIMESTAMP,
+            FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE
+        )
+        "#,
+    )
+    .execute(pool)
+    .await?;
+
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS provisioning_codes (
+            id            INTEGER PRIMARY KEY AUTOINCREMENT,
+            machine_id    INTEGER NOT NULL,
+            code          TEXT UNIQUE NOT NULL,
+            created_at    DATETIME DEFAULT CURRENT_TIMESTAMP,
+            expires_at    DATETIME NOT NULL,
+            used          BOOLEAN DEFAULT 0,
+            FOREIGN KEY(machine_id) REFERENCES machines(id) ON DELETE CASCADE
+        )
+        "#,
+    )
+    .execute(pool)
+    .await?;
+
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS snapshots (
+            id            INTEGER PRIMARY KEY AUTOINCREMENT,
+            machine_id    INTEGER NOT NULL,
+            snapshot_hash TEXT NOT NULL,
+            created_at    DATETIME DEFAULT CURRENT_TIMESTAMP,
+            FOREIGN KEY(machine_id) REFERENCES machines(id) ON DELETE CASCADE
+        )
+        "#,
+    )
+    .execute(pool)
+    .await?;
+
+    sqlx::query(
+        r#"
+        CREATE TABLE IF NOT EXISTS config (
+            key           TEXT PRIMARY KEY,
+            value         TEXT NOT NULL,
+            created_at    DATETIME DEFAULT CURRENT_TIMESTAMP,
+            updated_at    DATETIME DEFAULT CURRENT_TIMESTAMP
+        )
+        "#,
+    )
+    .execute(pool)
+    .await?;
+
+    Ok(())
+}
+
+pub async fn check_first_user_exists(pool: &DbPool) -> AppResult<bool> {
+    let row = sqlx::query("SELECT COUNT(*) as count FROM users")
+        .fetch_one(pool)
+        .await?;
+
+    let count: i64 = row.get("count");
+    Ok(count > 0)
+}

server/src/utils/db_path.rs

@@ -0,0 +1,76 @@
+use crate::utils::error::{internal_error, AppResult};
+use std::fs;
+
+pub fn get_database_path() -> AppResult<String> {
+    let db_dir = "data/db";
+    let db_path = format!("{}/arkendro.db", db_dir);
+
+    if let Err(e) = fs::create_dir_all(db_dir) {
+        return Err(internal_error(&format!(
+            "Failed to create database directory: {}",
+            e
+        )));
+    }
+
+    Ok(db_path)
+}
+
+pub fn ensure_data_directories() -> AppResult<()> {
+    let directories = ["data", "data/db", "data/backups", "data/logs"];
+
+    for dir in directories.iter() {
+        if let Err(e) = fs::create_dir_all(dir) {
+            return Err(internal_error(&format!(
+                "Failed to create directory '{}': {}",
+                dir, e
+            )));
+        }
+    }
+
+    Ok(())
+}
+
+pub fn get_data_path(filename: &str) -> String {
+    format!("data/{}", filename)
+}
+
+pub fn get_backup_path(filename: &str) -> String {
+    format!("data/backups/{}", filename)
+}
+
+pub fn get_log_path(filename: &str) -> String {
+    format!("data/logs/{}", filename)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs;
+    use std::path::Path;
+
+    #[test]
+    fn test_database_path_creation() {
+        let _ = fs::remove_dir_all("data");
+
+        let db_path = get_database_path().expect("Should create database path");
+        assert_eq!(db_path, "data/db/arkendro.db");
+
+        assert!(Path::new("data/db").exists());
+
+        let _ = fs::remove_dir_all("data");
+    }
+
+    #[test]
+    fn test_ensure_data_directories() {
+        let _ = fs::remove_dir_all("data");
+
+        ensure_data_directories().expect("Should create all directories");
+
+        assert!(Path::new("data").exists());
+        assert!(Path::new("data/db").exists());
+        assert!(Path::new("data/backups").exists());
+        assert!(Path::new("data/logs").exists());
+
+        let _ = fs::remove_dir_all("data");
+    }
+}

server/src/utils/error.rs

@@ -0,0 +1,142 @@
+use axum::{
+    http::StatusCode,
+    response::{IntoResponse, Json, Response},
+};
+use serde_json::json;
+use std::fmt;
+
+#[derive(Debug)]
+pub enum AppError {
+    DatabaseError(String),
+    ValidationError(String),
+    AuthenticationError(String),
+    AuthorizationError(String),
+    NotFoundError(String),
+    ConflictError(String),
+    InternalError(String),
+}
+
+impl fmt::Display for AppError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            AppError::DatabaseError(msg) => write!(f, "Database error: {}", msg),
+            AppError::ValidationError(msg) => write!(f, "Validation error: {}", msg),
+            AppError::AuthenticationError(msg) => write!(f, "Authentication error: {}", msg),
+            AppError::AuthorizationError(msg) => write!(f, "Authorization error: {}", msg),
+            AppError::NotFoundError(msg) => write!(f, "Not found: {}", msg),
+            AppError::ConflictError(msg) => write!(f, "Conflict: {}", msg),
+            AppError::InternalError(msg) => write!(f, "Internal error: {}", msg),
+        }
+    }
+}
+
+impl std::error::Error for AppError {}
+
+impl IntoResponse for AppError {
+    fn into_response(self) -> Response {
+        let (status, error_message) = match self {
+            AppError::DatabaseError(_) => (StatusCode::INTERNAL_SERVER_ERROR, "Database error"),
+            AppError::ValidationError(ref msg) => (StatusCode::BAD_REQUEST, msg.as_str()),
+            AppError::AuthenticationError(ref msg) => (StatusCode::UNAUTHORIZED, msg.as_str()),
+            AppError::AuthorizationError(ref msg) => (StatusCode::FORBIDDEN, msg.as_str()),
+            AppError::NotFoundError(ref msg) => (StatusCode::NOT_FOUND, msg.as_str()),
+            AppError::ConflictError(ref msg) => (StatusCode::CONFLICT, msg.as_str()),
+            AppError::InternalError(_) => {
+                (StatusCode::INTERNAL_SERVER_ERROR, "Internal server error")
+            }
+        };
+
+        let body = Json(json!({
+            "error": error_message
+        }));
+
+        (status, body).into_response()
+    }
+}
+
+impl From<anyhow::Error> for AppError {
+    fn from(err: anyhow::Error) -> Self {
+        if let Some(sqlx_err) = err.downcast_ref::<sqlx::Error>() {
+            match sqlx_err {
+                sqlx::Error::RowNotFound => {
+                    AppError::NotFoundError("Resource not found".to_string())
+                }
+                sqlx::Error::Database(db_err) => {
+                    if db_err.message().contains("UNIQUE constraint failed") {
+                        AppError::ConflictError("Resource already exists".to_string())
+                    } else {
+                        AppError::DatabaseError(db_err.message().to_string())
+                    }
+                }
+                _ => AppError::DatabaseError("Database operation failed".to_string()),
+            }
+        } else {
+            AppError::InternalError(err.to_string())
+        }
+    }
+}
+
+impl From<bcrypt::BcryptError> for AppError {
+    fn from(_: bcrypt::BcryptError) -> Self {
+        AppError::InternalError("Password hashing error".to_string())
+    }
+}
+
+impl From<sqlx::Error> for AppError {
+    fn from(err: sqlx::Error) -> Self {
+        match err {
+            sqlx::Error::RowNotFound => AppError::NotFoundError("Resource not found".to_string()),
+            sqlx::Error::Database(db_err) => {
+                if db_err.message().contains("UNIQUE constraint failed") {
+                    AppError::ConflictError("Resource already exists".to_string())
+                } else {
+                    AppError::DatabaseError(db_err.message().to_string())
+                }
+            }
+            _ => AppError::DatabaseError("Database operation failed".to_string()),
+        }
+    }
+}
+
+impl From<std::io::Error> for AppError {
+    fn from(err: std::io::Error) -> Self {
+        AppError::InternalError(format!("IO error: {}", err))
+    }
+}
+
+pub type AppResult<T> = Result<T, AppError>;
+
+pub fn validation_error(msg: &str) -> AppError {
+    AppError::ValidationError(msg.to_string())
+}
+
+pub fn auth_error(msg: &str) -> AppError {
+    AppError::AuthenticationError(msg.to_string())
+}
+
+pub fn forbidden_error(msg: &str) -> AppError {
+    AppError::AuthorizationError(msg.to_string())
+}
+
+pub fn not_found_error(msg: &str) -> AppError {
+    AppError::NotFoundError(msg.to_string())
+}
+
+pub fn conflict_error(msg: &str) -> AppError {
+    AppError::ConflictError(msg.to_string())
+}
+
+pub fn internal_error(msg: &str) -> AppError {
+    AppError::InternalError(msg.to_string())
+}
+
+pub fn success_response<T>(data: T) -> Json<T>
+where
+    T: serde::Serialize,
+{
+    Json(data)
+}
+
+pub fn success_message(msg: &str) -> Json<serde_json::Value> {
+    Json(json!({ "message": msg }))
+}

server/src/utils/mod.rs

@@ -0,0 +1,11 @@
+pub mod auth;
+pub mod base62;
+pub mod config;
+pub mod database;
+pub mod db_path;
+pub mod error;
+pub mod models;
+
+pub use database::*;
+pub use db_path::*;
+pub use error::*;

server/src/utils/models.rs

@@ -0,0 +1,156 @@
+use serde::{Deserialize, Serialize};
+use chrono::{DateTime, Utc};
+use uuid::Uuid;
+
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct User {
+    pub id: i64,
+    pub username: String,
+    #[serde(skip_serializing)]
+    pub password_hash: String,
+    pub role: UserRole,
+    pub storage_limit_gb: i64,
+    pub created_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "lowercase")]
+pub enum UserRole {
+    Admin,
+    User,
+}
+
+impl std::fmt::Display for UserRole {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            UserRole::Admin => write!(f, "admin"),
+            UserRole::User => write!(f, "user"),
+        }
+    }
+}
+
+impl std::str::FromStr for UserRole {
+    type Err = &'static str;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.to_lowercase().as_str() {
+            "admin" => Ok(UserRole::Admin),
+            "user" => Ok(UserRole::User),
+            _ => Err("Invalid role"),
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct CreateUserRequest {
+    pub username: String,
+    pub password: String,
+    pub role: Option<UserRole>,
+    pub storage_limit_gb: Option<i64>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct UpdateUserRequest {
+    pub username: Option<String>,
+    pub password: Option<String>,
+    pub role: Option<UserRole>,
+    pub storage_limit_gb: Option<i64>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Session {
+    pub id: i64,
+    pub user_id: i64,
+    pub token: String,
+    pub created_at: DateTime<Utc>,
+    pub expires_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct LoginRequest {
+    pub username: String,
+    pub password: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct LoginResponse {
+    pub token: String,
+    pub role: UserRole,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Machine {
+    pub id: i64,
+    pub user_id: i64,
+    pub uuid: Uuid,
+    #[serde(rename = "machine_id")]
+    pub machine_id: String,
+    pub name: String,
+    pub created_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct RegisterMachineRequest {
+    pub name: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct UseProvisioningCodeRequest {
+    pub code: String,
+    pub uuid: Uuid,
+    pub name: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct CreateProvisioningCodeRequest {
+    pub machine_id: i64,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ProvisioningCodeResponse {
+    pub code: String,
+    pub raw_code: String,
+    pub expires_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ProvisioningCode {
+    pub id: i64,
+    pub machine_id: i64,
+    pub code: String,
+    pub created_at: DateTime<Utc>,
+    pub expires_at: DateTime<Utc>,
+    pub used: bool,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Snapshot {
+    pub id: i64,
+    pub machine_id: i64,
+    pub snapshot_hash: String,
+    pub created_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct SetupStatusResponse {
+    pub first_user_exists: bool,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct InitSetupRequest {
+    pub username: String,
+    pub password: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ErrorResponse {
+    pub error: String,
+}
+
+impl ErrorResponse {
+    pub fn new(message: &str) -> Self {
+        Self {
+            error: message.to_string(),
+        }
+    }
+}

sync_client_test/Cargo.lock

@@ -0,0 +1,76 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "arrayref"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76a2e8124351fda1ef8aaaa3bbd7ebbcb486bbcd4225aca0aa0d84bb2db8fecb"
+
+[[package]]
+name = "arrayvec"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
+
+[[package]]
+name = "blake3"
+version = "1.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3888aaa89e4b2a40fca9848e400f6a658a5a3978de7be858e209cafa8be9a4a0"
+dependencies = [
+ "arrayref",
+ "arrayvec",
+ "cc",
+ "cfg-if",
+ "constant_time_eq",
+]
+
+[[package]]
+name = "cc"
+version = "1.2.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5252b3d2648e5eedbc1a6f501e3c795e07025c1e93bbf8bbdd6eef7f447a6d54"
+dependencies = [
+ "find-msvc-tools",
+ "shlex",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+
+[[package]]
+name = "constant_time_eq"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c74b8349d32d297c9134b8c88677813a227df8f779daa29bfc29c183fe3dca6"
+
+[[package]]
+name = "find-msvc-tools"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fd99930f64d146689264c637b5af2f0233a933bef0d8570e2526bf9e083192d"
+
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
+[[package]]
+name = "sync_client_test"
+version = "0.1.0"
+dependencies = [
+ "blake3",
+ "hex",
+]

sync_client_test/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "sync_client_test"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+blake3 = "1.5"
+hex = "0.4"

webui/.gitignore

@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?

webui/eslint.config.js

@@ -0,0 +1,29 @@
+import js from '@eslint/js'
+import globals from 'globals'
+import reactHooks from 'eslint-plugin-react-hooks'
+import reactRefresh from 'eslint-plugin-react-refresh'
+import { defineConfig, globalIgnores } from 'eslint/config'
+
+export default defineConfig([
+  globalIgnores(['dist']),
+  {
+    files: ['**/*.{js,jsx}'],
+    extends: [
+      js.configs.recommended,
+      reactHooks.configs['recommended-latest'],
+      reactRefresh.configs.vite,
+    ],
+    languageOptions: {
+      ecmaVersion: 2020,
+      globals: globals.browser,
+      parserOptions: {
+        ecmaVersion: 'latest',
+        ecmaFeatures: { jsx: true },
+        sourceType: 'module',
+      },
+    },
+    rules: {
+      'no-unused-vars': ['error', { varsIgnorePattern: '^[A-Z_]' }],
+    },
+  },
+])

webui/index.html

@@ -0,0 +1,12 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Arkendro</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.jsx"></script>
+  </body>
+</html>

webui/jsconfig.json

@@ -0,0 +1,8 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["./src/*"]
+    }
+  }
+}

webui/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "webui",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "lint": "eslint .",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "@fontsource/plus-jakarta-sans": "^5.2.6",
+    "@phosphor-icons/react": "^2.1.10",
+    "classnames": "^2.5.1",
+    "react": "^19.1.1",
+    "react-dom": "^19.1.1",
+    "react-router-dom": "^7.8.2",
+    "sass-embedded": "^1.92.1"
+  },
+  "devDependencies": {
+    "@eslint/js": "^9.33.0",
+    "@types/react": "^19.1.10",
+    "@types/react-dom": "^19.1.7",
+    "@vitejs/plugin-react": "^5.0.0",
+    "eslint": "^9.33.0",
+    "eslint-plugin-react-hooks": "^5.2.0",
+    "eslint-plugin-react-refresh": "^0.4.20",
+    "globals": "^16.3.0",
+    "vite": "^7.1.2"
+  }
+}

webui/src/App.jsx

@@ -0,0 +1,39 @@
+import {createBrowserRouter, Navigate, RouterProvider} from "react-router-dom";
+import {UserProvider} from '@/common/contexts/UserContext.jsx';
+import {ToastProvider} from '@/common/contexts/ToastContext.jsx';
+import "@/common/styles/main.sass";
+import Root from "@/common/layouts/Root.jsx";
+import UserManagement from "@/pages/UserManagement";
+import SystemSettings from "@/pages/SystemSettings";
+import Machines, {MachineDetails} from "@/pages/Machines";
+import "@fontsource/plus-jakarta-sans/300.css";
+import "@fontsource/plus-jakarta-sans/400.css";
+import "@fontsource/plus-jakarta-sans/600.css";
+import "@fontsource/plus-jakarta-sans/700.css";
+import "@fontsource/plus-jakarta-sans/800.css";
+
+const Placeholder = ({title}) => <div className="content"><h2 style={{fontSize: '1rem'}}>{title}</h2><p
+    className="muted">Content coming soon.</p></div>;
+
+const App = () => {
+    const router = createBrowserRouter([
+        {
+            path: "/",
+            element: <Root/>,
+            children: [
+                {path: "/", element: <Navigate to="/dashboard"/>},
+                {path: "/dashboard", element: <Placeholder title="Dashboard"/>},
+                {path: "/machines", element: <Machines/>},
+                {path: "/machines/:id", element: <MachineDetails/>},
+                {path: "/servers", element: <Placeholder title="Servers"/>},
+                {path: "/settings", element: <Placeholder title="Settings"/>},
+                {path: "/admin/users", element: <UserManagement/>},
+                {path: "/admin/settings", element: <SystemSettings/>},
+            ],
+        },
+    ]);
+
+    return <UserProvider><ToastProvider><RouterProvider router={router}/></ToastProvider></UserProvider>;
+};
+
+export default App;

webui/src/common/components/Avatar/Avatar.jsx

@@ -0,0 +1,23 @@
+import React from 'react';
+import './styles.sass';
+
+export const Avatar = ({
+  children,
+  size = 'md',
+  variant = 'default',
+  className = '',
+  ...rest
+}) => {
+  const avatarClasses = [
+    'avatar',
+    `avatar--${size}`,
+    `avatar--${variant}`,
+    className
+  ].filter(Boolean).join(' ');
+
+  return (
+    <div className={avatarClasses} {...rest}>
+      {children}
+    </div>
+  );
+};

webui/src/common/components/Avatar/index.js

@@ -0,0 +1 @@
+export { Avatar as default } from './Avatar.jsx';

webui/src/common/components/Avatar/styles.sass

@@ -0,0 +1,35 @@
+.avatar
+  background: var(--bg-elev)
+  border: 1px solid var(--border)
+  border-radius: 50%
+  display: flex
+  align-items: center
+  justify-content: center
+  color: var(--text-dim)
+  flex-shrink: 0
+  
+  &--sm
+    width: 32px
+    height: 32px
+  
+  &--md
+    width: 48px
+    height: 48px
+  
+  &--lg
+    width: 64px
+    height: 64px
+  
+  &--xl
+    width: 80px
+    height: 80px
+  
+  &--primary
+    background: var(--accent)
+    color: white
+    border-color: var(--accent)
+  
+  &--success
+    background: #16a34a
+    color: white
+    border-color: #16a34a

webui/src/common/components/Badge/Badge.jsx

@@ -0,0 +1,23 @@
+import React from 'react';
+import './styles.sass';
+
+export const Badge = ({
+  children,
+  variant = 'default',
+  size = 'md',
+  className = '',
+  ...rest
+}) => {
+  const badgeClasses = [
+    'badge',
+    `badge--${variant}`,
+    `badge--${size}`,
+    className
+  ].filter(Boolean).join(' ');
+
+  return (
+    <span className={badgeClasses} {...rest}>
+      {children}
+    </span>
+  );
+};

webui/src/common/components/Badge/index.js

@@ -0,0 +1 @@
+export { Badge as default } from './Badge.jsx';

webui/src/common/components/Badge/styles.sass

@@ -0,0 +1,53 @@
+.badge
+  display: inline-flex
+  align-items: center
+  justify-content: center
+  border-radius: 12px
+  font-weight: 600
+  text-transform: uppercase
+  letter-spacing: 0.5px
+  white-space: nowrap
+  
+  &--sm
+    padding: 0.125rem 0.5rem
+    font-size: 0.65rem
+  
+  &--md
+    padding: 0.25rem 0.75rem
+    font-size: 0.75rem
+  
+  &--lg
+    padding: 0.375rem 1rem
+    font-size: 0.85rem
+  
+  &--default
+    background: var(--bg-elev)
+    color: var(--text-dim)
+  
+  &--primary
+    background: rgba(15, 98, 254, 0.1)
+    color: #0f62fe
+  
+  &--success
+    background: rgba(22, 163, 74, 0.1)
+    color: #16a34a
+  
+  &--warning
+    background: rgba(245, 158, 11, 0.1)
+    color: #f59e0b
+  
+  &--danger
+    background: rgba(217, 48, 37, 0.1)
+    color: #d93025
+  
+  &--admin
+    background: #e3f2fd
+    color: #1976d2
+  
+  &--user
+    background: var(--bg-elev)
+    color: var(--text-dim)
+  
+  &--subtle
+    background: var(--bg-elev)
+    color: var(--text-dim)

webui/src/common/components/Button/Button.jsx

@@ -0,0 +1,41 @@
+import React from "react";
+import cn from "classnames";
+import "./styles.sass";
+
+export const Button = ({
+  as: Component = "button",
+  variant = "primary",
+  size = "md",
+  full = false,
+  icon,
+  iconRight,
+  loading = false,
+  disabled,
+  className,
+  children,
+  ...rest
+}) => {
+  const isDisabled = disabled || loading;
+  const isIconOnly = (icon || iconRight) && !children;
+  
+  return (
+    <Component
+      className={cn(
+        "btn",
+        `btn--${variant}`,
+        `btn--${size}`,
+        full && "btn--full",
+        loading && "is-loading",
+        isIconOnly && "btn--icon-only",
+        className
+      )}
+      disabled={isDisabled}
+      {...rest}
+    >
+      {loading && <span className="btn-spinner" aria-hidden />}
+      {icon && <span className="btn-icon btn-icon--left">{icon}</span>}
+      {children && <span className="btn-label">{children}</span>}
+      {iconRight && <span className="btn-icon btn-icon--right">{iconRight}</span>}
+    </Component>
+  );
+};

webui/src/common/components/Button/index.js

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+export { Button as default } from "./Button.jsx";

webui/src/common/components/Button/styles.sass

@@ -0,0 +1,105 @@
+.btn
+  --c-bg: #ffffff
+  --c-bg-hover: #f2f5f8
+  --c-bg-active: #e6ebf0
+  --c-border: #dfe3e8
+  --c-border-hover: #c7ced6
+  --c-text: #1f2429
+  --c-accent: #0f62fe
+  --c-danger: #d93025
+  position: relative
+  display: inline-flex
+  align-items: center
+  justify-content: center
+  gap: .6rem
+  font-family: inherit
+  font-weight: 600
+  line-height: 1.2
+  cursor: pointer
+  border: 1px solid var(--c-border)
+  background: var(--c-bg)
+  color: var(--c-text)
+  border-radius: 12px
+  transition: all .2s ease
+  user-select: none
+  text-decoration: none
+  &:hover:not(:disabled)
+    background: var(--c-bg-hover)
+    border-color: var(--c-border-hover)
+  &:active:not(:disabled)
+    background: var(--c-bg-active)
+    transform: translateY(1px)
+  &:focus-visible
+    outline: 2px solid var(--c-accent)
+    outline-offset: 2px
+  &:disabled
+    opacity: .55
+    cursor: not-allowed
+  &.btn--full
+    width: 100%
+  &.btn--sm
+    font-size: .85rem
+    padding: .7rem 1rem
+  &.btn--md
+    font-size: .95rem
+    padding: .85rem 1.25rem
+  &.btn--lg
+    font-size: 1.05rem
+    padding: 1rem 1.5rem
+  &.btn--primary
+    --c-bg: #1f2429
+    --c-bg-hover: #374048
+    --c-bg-active: #2a3038
+    --c-border: #1f2429
+    --c-text: #ffffff
+    background: var(--c-bg)
+    border-color: var(--c-border)
+    &:hover:not(:disabled)
+      background: var(--c-bg-hover)
+  &.btn--subtle
+    --c-bg: #f0f3f6
+    --c-bg-hover: #e6ebf0
+    --c-bg-active: #dfe3e8
+    --c-border: #dfe3e8
+  &.btn--danger
+    --c-bg: #d93025
+    --c-bg-hover: #c22b21
+    --c-bg-active: #a9241b
+    --c-border: #d93025
+    --c-text: #ffffff
+    background: var(--c-bg)
+    border-color: var(--c-border)
+  
+  &.btn--icon-only
+    padding: 0.75rem
+    aspect-ratio: 1
+    justify-content: center
+    
+    &.btn--sm
+      padding: 0.6rem
+    
+    &.btn--lg
+      padding: 0.9rem
+    
+    .btn-icon
+      margin: 0
+
+.btn-icon
+  display: inline-flex
+  align-items: center
+  &--left
+    margin-right: .25rem
+  &--right
+    margin-left: .25rem
+
+.btn-spinner
+  width: 14px
+  height: 14px
+  border: 2px solid rgba(0,0,0,.15)
+  border-top-color: var(--c-text)
+  border-radius: 50%
+  animation: spin .7s linear infinite
+
+@keyframes spin
+  to
+    transform: rotate(360deg)

webui/src/common/components/Card/Card.jsx

@@ -0,0 +1,43 @@
+import React from 'react';
+import './styles.sass';
+
+export const Card = ({
+  children,
+  className = '',
+  hover = false,
+  padding = 'md',
+  variant = 'default',
+  ...rest
+}) => {
+  const cardClasses = [
+    'card',
+    `card--${variant}`,
+    `card--padding-${padding}`,
+    hover && 'card--hover',
+    className
+  ].filter(Boolean).join(' ');
+
+  return (
+    <div className={cardClasses} {...rest}>
+      {children}
+    </div>
+  );
+};
+
+export const CardHeader = ({ children, className = '' }) => (
+  <div className={`card-header ${className}`}>
+    {children}
+  </div>
+);
+
+export const CardBody = ({ children, className = '' }) => (
+  <div className={`card-body ${className}`}>
+    {children}
+  </div>
+);
+
+export const CardFooter = ({ children, className = '' }) => (
+  <div className={`card-footer ${className}`}>
+    {children}
+  </div>
+);

webui/src/common/components/Card/index.js

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+export { Card as default, CardHeader, CardBody, CardFooter } from './Card.jsx';

webui/src/common/components/Card/styles.sass

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+.card
+  background: var(--bg-alt)
+  border: 1px solid var(--border)
+  border-radius: var(--radius-lg)
+  transition: all 0.2s ease
+  
+  &--hover:hover
+    border-color: var(--border-strong)
+    transform: translateY(-2px)
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1)
+  
+  &--padding-none
+    padding: 0
+  
+  &--padding-sm
+    padding: 1rem
+  
+  &--padding-md
+    padding: 1.5rem
+  
+  &--padding-lg
+    padding: 2rem
+  
+  &--variant-elevated
+    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1)
+  
+  &--variant-outlined
+    border-width: 2px
+
+.card-header
+  margin-bottom: 1rem
+  
+  &:last-child
+    margin-bottom: 0
+
+.card-body
+  flex: 1
+
+.card-footer
+  margin-top: 1rem
+  
+  &:first-child
+    margin-top: 0

webui/src/common/components/DetailItem/DetailItem.jsx

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+import React from 'react';
+import './styles.sass';
+
+export const DetailItem = ({
+  icon,
+  children,
+  className = '',
+  ...rest
+}) => {
+  return (
+    <div className={`detail-item ${className}`} {...rest}>
+      {icon && <span className="detail-item-icon">{icon}</span>}
+      <span className="detail-item-content">{children}</span>
+    </div>
+  );
+};
+
+export const DetailList = ({
+  children,
+  className = '',
+  ...rest
+}) => {
+  return (
+    <div className={`detail-list ${className}`} {...rest}>
+      {children}
+    </div>
+  );
+};

webui/src/common/components/DetailItem/index.js

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+export { DetailItem as default, DetailList } from './DetailItem.jsx';

webui/src/common/components/DetailItem/styles.sass

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+.detail-list
+  display: flex
+  flex-direction: column
+  gap: 0.75rem
+
+.detail-item
+  display: flex
+  align-items: center
+  gap: 0.75rem
+  color: var(--text-dim)
+  font-size: 0.9rem
+
+.detail-item-icon
+  color: var(--text-dim)
+  display: inline-flex
+  flex-shrink: 0
+  
+  svg
+    color: inherit
+
+.detail-item-content
+  flex: 1
+  min-width: 0

webui/src/common/components/EmptyState/EmptyState.jsx

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+import React from 'react';
+import './styles.sass';
+
+export const EmptyState = ({
+  icon,
+  title,
+  description,
+  action,
+  size = 'md',
+  variant = 'default',
+  className = ''
+}) => {
+  const emptyStateClasses = [
+    'empty-state',
+    `empty-state--${size}`,
+    `empty-state--${variant}`,
+    className
+  ].filter(Boolean).join(' ');
+
+  return (
+    <div className={emptyStateClasses}>
+      {icon && <div className="empty-state-icon">{icon}</div>}
+      {title && <h3 className="empty-state-title">{title}</h3>}
+      {description && <p className="empty-state-description">{description}</p>}
+      {action && <div className="empty-state-action">{action}</div>}
+    </div>
+  );
+};

webui/src/common/components/EmptyState/index.js

@@ -0,0 +1 @@
+export { EmptyState as default } from './EmptyState.jsx';