feat(auth): implement secure password authentication

- Replace plaintext password comparison with bcrypt verification
- Hash passwords before database storage in registration
- Validate bcrypt hashes during login to reject legacy plaintext
- Update password change and reset flows with proper hashing
- Add legacy password detection for security enforcement

services/auth/auth.service.ts

@@ -4,6 +4,7 @@ import { EmailVerificationService } from './emailVerification.service';
 import { databaseService } from '../database';
 import { logger } from '../logging';
 import { tokenService } from './token.service';
+import { hashPassword, verifyPassword, isBcryptHash } from './password.service';
 
 const emailVerificationService = new EmailVerificationService();
 
@@ -22,9 +23,11 @@ const authService = {
       }
 
       // Create user with password
+      const passwordToPersist = await hashPassword(password);
+
       const user = await databaseService.createUserWithPassword(
         email,
-        password,
+        passwordToPersist,
         username
       );
 
@@ -80,14 +83,21 @@ const authService = {
       throw new Error('Email verification required');
     }
 
-    // Simple password verification (in production, use bcrypt)
-    logger.auth.login('Comparing passwords', {
-      inputPassword: input.password,
-      storedPassword: user.password,
-      match: user.password === input.password,
+    if (!isBcryptHash(user.password)) {
+      logger.auth.error('Stored password is not hashed; rejecting login');
+      throw new Error('Invalid credentials');
+    }
+
+    const hasValidPassword = await verifyPassword(
+      input.password,
+      user.password
+    );
+
+    logger.auth.login('Password comparison result', {
+      hasValidPassword,
     });
 
-    if (user.password !== input.password) {
+    if (!hasValidPassword) {
       logger.auth.error('Password mismatch');
       throw new Error('Invalid credentials');
     }
@@ -162,8 +172,16 @@ const authService = {
       throw new Error('Cannot change password for OAuth accounts');
     }
 
-    // Verify current password
-    if (user.password !== currentPassword) {
+    if (!isBcryptHash(user.password)) {
+      throw new Error('Password needs to be reset before it can be changed');
+    }
+
+    const currentPasswordMatches = await verifyPassword(
+      currentPassword,
+      user.password
+    );
+
+    if (!currentPasswordMatches) {
       throw new Error('Current password is incorrect');
     }
 
@@ -175,7 +193,7 @@ const authService = {
     // Update user with new password (this should be hashed before calling)
     const updatedUser = await databaseService.updateUser({
       ...user,
-      password: newPassword,
+      password: await hashPassword(newPassword),
     });
 
     return {
@@ -249,10 +267,11 @@ const authService = {
       throw new Error('User not found');
     }
 
-    // Update user with new password (this should be hashed before calling)
+    const hashedPassword = await hashPassword(newPassword);
+
     const updatedUser = await databaseService.updateUser({
       ...user,
-      password: newPassword,
+      password: hashedPassword,
     });
 
     // Remove used token