feat: enhance user registration and authentication flow, improve attachment handling, and strengthen security measures

src/handlers/accounts.ts

@@ -27,12 +27,6 @@ export async function handleRegister(request: Request, env: Env): Promise<Respon
     return errorResponse(message, 400);
   }
 
-  // Check if already registered
-  const isRegistered = await storage.isRegistered();
-  if (isRegistered) {
-    return errorResponse('Registration is closed', 403);
-  }
-
   let body: {
     email?: string;
     name?: string;
@@ -88,7 +82,11 @@ export async function handleRegister(request: Request, env: Env): Promise<Respon
     updatedAt: new Date().toISOString(),
   };
 
-  await storage.saveUser(user);
+  const created = await storage.createFirstUser(user);
+  if (!created) {
+    return errorResponse('Registration is closed', 403);
+  }
+
   await storage.setRegistered();
 
   return jsonResponse({ success: true }, 200);
@@ -200,6 +198,7 @@ export async function handleGetRevisionDate(request: Request, env: Env, userId:
 // POST /api/accounts/verify-password
 export async function handleVerifyPassword(request: Request, env: Env, userId: string): Promise<Response> {
   const storage = new StorageService(env.DB);
+  const auth = new AuthService(env);
   const user = await storage.getUserById(userId);
 
   if (!user) {
@@ -217,7 +216,8 @@ export async function handleVerifyPassword(request: Request, env: Env, userId: s
     return errorResponse('masterPasswordHash is required', 400);
   }
 
-  if (body.masterPasswordHash !== user.masterPasswordHash) {
+  const valid = await auth.verifyPassword(body.masterPasswordHash, user.masterPasswordHash);
+  if (!valid) {
     return errorResponse('Invalid password', 400);
   }
 

src/handlers/attachments.ts

@@ -1,4 +1,4 @@
-import { Env, Attachment } from '../types';
+import { Env, Attachment, DEFAULT_DEV_SECRET } from '../types';
 import { StorageService } from '../services/storage';
 import { jsonResponse, errorResponse } from '../utils/response';
 import { generateUUID } from '../utils/uuid';
@@ -210,6 +210,11 @@ export async function handlePublicDownloadAttachment(
   cipherId: string,
   attachmentId: string
 ): Promise<Response> {
+  const secret = (env.JWT_SECRET || '').trim();
+  if (!secret || secret.length < 32 || secret === DEFAULT_DEV_SECRET) {
+    return errorResponse('Server configuration error', 500);
+  }
+
   const url = new URL(request.url);
   const token = url.searchParams.get('token');
 

src/handlers/ciphers.ts

@@ -68,10 +68,12 @@ export async function handleGetCiphers(request: Request, env: Env, userId: strin
     ? ciphers 
     : ciphers.filter(c => !c.deletedAt);
 
+  const attachmentsByCipher = await storage.getAttachmentsByCipherIds(filteredCiphers.map(c => c.id));
+
   // Get attachments for all ciphers
   const cipherResponses = [];
   for (const cipher of filteredCiphers) {
-    const attachments = await storage.getAttachmentsByCipher(cipher.id);
+    const attachments = attachmentsByCipher.get(cipher.id) || [];
     cipherResponses.push(cipherToResponse(cipher, attachments));
   }
 

src/handlers/identity.ts

@@ -32,12 +32,7 @@ export async function handleToken(request: Request, env: Env): Promise<Response>
       return identityErrorResponse('Email and password are required', 'invalid_request', 400);
     }
 
-    const user = await storage.getUser(email);
+    // Check login lockout before user lookup to reduce user-enumeration signal
-    if (!user) {
-      return identityErrorResponse('Username or password is incorrect. Try again', 'invalid_grant', 400);
-    }
-
-    // Check if login is rate limited (only after confirming user exists)
     const loginCheck = await rateLimit.checkLoginAttempt(email);
     if (!loginCheck.allowed) {
       return identityErrorResponse(
@@ -47,6 +42,12 @@ export async function handleToken(request: Request, env: Env): Promise<Response>
       );
     }
 
+    const user = await storage.getUser(email);
+    if (!user) {
+      await rateLimit.recordFailedLogin(email);
+      return identityErrorResponse('Username or password is incorrect. Try again', 'invalid_grant', 400);
+    }
+
     const valid = await auth.verifyPassword(passwordHash, user.masterPasswordHash);
     if (!valid) {
       // Record failed login attempt

src/handlers/sync.ts

@@ -14,6 +14,7 @@ export async function handleSync(request: Request, env: Env, userId: string): Pr
 
   const ciphers = await storage.getAllCiphers(userId);
   const folders = await storage.getAllFolders(userId);
+  const attachmentsByCipher = await storage.getAttachmentsByCipherIds(ciphers.map(c => c.id));
 
   // Build profile response
   const profile: ProfileResponse = {
@@ -43,7 +44,7 @@ export async function handleSync(request: Request, env: Env, userId: string): Pr
   // Build cipher responses with attachments
   const cipherResponses: CipherResponse[] = [];
   for (const cipher of ciphers) {
-    const attachments = await storage.getAttachmentsByCipher(cipher.id);
+    const attachments = attachmentsByCipher.get(cipher.id) || [];
     cipherResponses.push(cipherToResponse(cipher, attachments));
   }
 

src/router.ts

@@ -1,4 +1,4 @@
-import { Env } from './types';
+import { Env, DEFAULT_DEV_SECRET } from './types';
 import { AuthService } from './services/auth';
 import { RateLimitService, getClientIdentifier } from './services/ratelimit';
 import { handleCors, errorResponse, jsonResponse } from './utils/response';
@@ -184,7 +184,7 @@ export async function handleRequest(request: Request, env: Env): Promise<Respons
 
     // If JWT_SECRET is not safely configured, block any other endpoints.
     const secret = (env.JWT_SECRET || '').trim();
-    if (!secret || secret.length < 32) {
+    if (!secret || secret.length < 32 || secret === DEFAULT_DEV_SECRET) {
       return errorResponse('Server configuration error: JWT_SECRET is not set or too weak', 500);
     }
 

src/services/auth.ts

@@ -11,9 +11,15 @@ export class AuthService {
 
   // Verify password hash (compare with stored hash)
   async verifyPassword(inputHash: string, storedHash: string): Promise<boolean> {
-    // In Bitwarden, the client sends the password hash directly
+    const input = new TextEncoder().encode(inputHash);
-    // We compare the hashes
+    const stored = new TextEncoder().encode(storedHash);
-    return inputHash === storedHash;
+    if (input.length !== stored.length) return false;
+
+    let diff = 0;
+    for (let i = 0; i < input.length; i++) {
+      diff |= input[i] ^ stored[i];
+    }
+    return diff === 0;
   }
 
   // Generate access token

src/services/storage.ts

@@ -9,6 +9,17 @@ import { User, Cipher, Folder, Attachment } from '../types';
 export class StorageService {
   constructor(private db: D1Database) {}
 
+  private async sha256Hex(input: string): Promise<string> {
+    const bytes = new TextEncoder().encode(input);
+    const digest = await crypto.subtle.digest('SHA-256', bytes);
+    return Array.from(new Uint8Array(digest)).map(b => b.toString(16).padStart(2, '0')).join('');
+  }
+
+  private async refreshTokenKey(token: string): Promise<string> {
+    const digest = await this.sha256Hex(token);
+    return `sha256:${digest}`;
+  }
+
   // --- Database initialization ---
   // Idempotent auto-init for environments where D1 migrations have not been applied
   // (e.g. one-click deploy). Mirrors the schema in migrations/0001_init.sql —
@@ -245,6 +256,35 @@ CREATE INDEX IF NOT EXISTS idx_api_rate_window ON api_rate_limits(window_start);
       .run();
   }
 
+  async createFirstUser(user: User): Promise<boolean> {
+    const email = user.email.toLowerCase();
+    const result = await this.db
+      .prepare(
+        'INSERT INTO users(id, email, name, master_password_hash, key, private_key, public_key, kdf_type, kdf_iterations, kdf_memory, kdf_parallelism, security_stamp, created_at, updated_at) ' +
+        'SELECT ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ? ' +
+        'WHERE NOT EXISTS (SELECT 1 FROM users LIMIT 1)'
+      )
+      .bind(
+        user.id,
+        email,
+        user.name,
+        user.masterPasswordHash,
+        user.key,
+        user.privateKey,
+        user.publicKey,
+        user.kdfType,
+        user.kdfIterations,
+        user.kdfMemory ?? null,
+        user.kdfParallelism ?? null,
+        user.securityStamp,
+        user.createdAt,
+        user.updatedAt
+      )
+      .run();
+
+    return (result.meta.changes ?? 0) > 0;
+  }
+
   // --- Ciphers ---
 
   async getCipher(id: string): Promise<Cipher | null> {
@@ -412,6 +452,36 @@ CREATE INDEX IF NOT EXISTS idx_api_rate_window ON api_rate_limits(window_start);
     }));
   }
 
+  async getAttachmentsByCipherIds(cipherIds: string[]): Promise<Map<string, Attachment[]>> {
+    const grouped = new Map<string, Attachment[]>();
+    if (cipherIds.length === 0) return grouped;
+
+    const placeholders = cipherIds.map(() => '?').join(',');
+    const res = await this.db
+      .prepare(`SELECT id, cipher_id, file_name, size, size_name, key FROM attachments WHERE cipher_id IN (${placeholders})`)
+      .bind(...cipherIds)
+      .all<any>();
+
+    for (const row of (res.results || [])) {
+      const item: Attachment = {
+        id: row.id,
+        cipherId: row.cipher_id,
+        fileName: row.file_name,
+        size: row.size,
+        sizeName: row.size_name,
+        key: row.key,
+      };
+      const list = grouped.get(item.cipherId);
+      if (list) {
+        list.push(item);
+      } else {
+        grouped.set(item.cipherId, [item]);
+      }
+    }
+
+    return grouped;
+  }
+
   async addAttachmentToCipher(cipherId: string, attachmentId: string): Promise<void> {
     // Kept for API compatibility; no-op because attachments table already links cipher_id.
     // We still validate that the attachment exists and belongs to cipher.
@@ -441,20 +511,39 @@ CREATE INDEX IF NOT EXISTS idx_api_rate_window ON api_rate_limits(window_start);
 
   async saveRefreshToken(token: string, userId: string, expiresAtMs?: number): Promise<void> {
     const expiresAt = expiresAtMs ?? (Date.now() + 30 * 24 * 60 * 60 * 1000);
+    const tokenKey = await this.refreshTokenKey(token);
     await this.db.prepare(
       'INSERT INTO refresh_tokens(token, user_id, expires_at) VALUES(?, ?, ?) ' +
       'ON CONFLICT(token) DO UPDATE SET user_id=excluded.user_id, expires_at=excluded.expires_at'
     )
-      .bind(token, userId, expiresAt)
+      .bind(tokenKey, userId, expiresAt)
       .run();
   }
 
   async getRefreshTokenUserId(token: string): Promise<string | null> {
     const now = Date.now();
-    const row = await this.db.prepare('SELECT user_id, expires_at FROM refresh_tokens WHERE token = ?')
+    const tokenKey = await this.refreshTokenKey(token);
-      .bind(token)
+
+    let row = await this.db.prepare('SELECT user_id, expires_at FROM refresh_tokens WHERE token = ?')
+      .bind(tokenKey)
       .first<{ user_id: string; expires_at: number }>();
 
+    if (!row) {
+      const legacyRow = await this.db.prepare('SELECT user_id, expires_at FROM refresh_tokens WHERE token = ?')
+        .bind(token)
+        .first<{ user_id: string; expires_at: number }>();
+
+      if (legacyRow) {
+        if (legacyRow.expires_at && legacyRow.expires_at < now) {
+          await this.deleteRefreshToken(token);
+          return null;
+        }
+        await this.saveRefreshToken(token, legacyRow.user_id, legacyRow.expires_at);
+        await this.db.prepare('DELETE FROM refresh_tokens WHERE token = ?').bind(token).run();
+        return legacyRow.user_id;
+      }
+    }
+
     if (!row) return null;
     if (row.expires_at && row.expires_at < now) {
       await this.deleteRefreshToken(token);
@@ -464,7 +553,9 @@ CREATE INDEX IF NOT EXISTS idx_api_rate_window ON api_rate_limits(window_start);
   }
 
   async deleteRefreshToken(token: string): Promise<void> {
+    const tokenKey = await this.refreshTokenKey(token);
     await this.db.prepare('DELETE FROM refresh_tokens WHERE token = ?').bind(token).run();
+    await this.db.prepare('DELETE FROM refresh_tokens WHERE token = ?').bind(tokenKey).run();
   }
 
   // --- Revision dates ---