Add token encryption service and Wix token rotation support

backend/routers/v1/social_proxy.py

@@ -1,182 +0,0 @@
-from __future__ import annotations
-
-import json
-from datetime import datetime, timezone
-from typing import Optional
-from urllib.parse import urlencode
-
-from fastapi import APIRouter, Depends, HTTPException, Query
-from fastapi.responses import RedirectResponse
-from loguru import logger
-from sqlalchemy import text
-from sqlalchemy.orm import Session
-
-from services.database import get_db
-
-router = APIRouter(prefix="/v1/social-proxy", tags=["social-proxy"])
-
-
-def _utc_now_iso() -> str:
-    return datetime.now(timezone.utc).isoformat()
-
-
-def _ensure_tables(db: Session) -> None:
-    # Keep this router backward-compatible on tenant DBs without migrations.
-    db.execute(text("""
-        CREATE TABLE IF NOT EXISTS oauth_nonce_sessions (
-            id INTEGER PRIMARY KEY AUTOINCREMENT,
-            state TEXT NOT NULL UNIQUE,
-            nonce TEXT NOT NULL,
-            user_id TEXT NOT NULL,
-            platform TEXT NOT NULL,
-            channel_id INTEGER,
-            consumed_at TEXT,
-            expires_at TEXT,
-            created_at TEXT NOT NULL
-        )
-    """))
-    db.execute(text("""
-        CREATE TABLE IF NOT EXISTS social_channels (
-            id INTEGER PRIMARY KEY AUTOINCREMENT,
-            user_id TEXT NOT NULL,
-            platform TEXT NOT NULL,
-            platform_account_id TEXT NOT NULL,
-            token_bundle TEXT NOT NULL,
-            token_version INTEGER NOT NULL DEFAULT 1,
-            publication_linkage TEXT,
-            is_connected INTEGER NOT NULL DEFAULT 1,
-            created_at TEXT NOT NULL,
-            updated_at TEXT NOT NULL,
-            UNIQUE(platform, platform_account_id)
-        )
-    """))
-
-
-def _build_redirect(base_url: str, code: str, message: str, channel_id: Optional[int] = None) -> RedirectResponse:
-    params = {"code": code, "message": message}
-    if channel_id is not None:
-        params["channel_id"] = str(channel_id)
-    return RedirectResponse(url=f"{base_url}?{urlencode(params)}", status_code=303)
-
-
-@router.get("/oauth/callback")
-def oauth_callback(
-    state: str = Query(...),
-    platform: str = Query(...),
-    account_id: str = Query(...),
-    token_bundle: str = Query(..., description="Serialized token payload"),
-    ui_redirect: str = Query("/dashboard/connections"),
-    db: Session = Depends(get_db),
-):
-    """Consume OAuth callback, bind to user/platform, and upsert social channel connection."""
-    _ensure_tables(db)
-
-    record = db.execute(
-        text("""
-            SELECT id, nonce, user_id, platform, channel_id, consumed_at, expires_at
-            FROM oauth_nonce_sessions WHERE state = :state
-        """),
-        {"state": state},
-    ).mappings().first()
-
-    if not record:
-        return _build_redirect(ui_redirect, "invalid_state", "Missing OAuth session")
-
-    if record["consumed_at"] is not None:
-        return _build_redirect(ui_redirect, "state_reused", "OAuth state already consumed")
-
-    if record["platform"] != platform:
-        return _build_redirect(ui_redirect, "platform_mismatch", "Platform mismatch")
-
-    if record["expires_at"] and record["expires_at"] < _utc_now_iso():
-        return _build_redirect(ui_redirect, "state_expired", "OAuth session expired")
-
-    user_id = record["user_id"]
-
-    # Validate token payload is JSON.
-    try:
-        parsed_bundle = json.loads(token_bundle)
-    except json.JSONDecodeError as exc:
-        raise HTTPException(status_code=400, detail="Invalid token_bundle JSON") from exc
-
-    now = _utc_now_iso()
-
-    existing = db.execute(
-        text("""
-            SELECT id, publication_linkage, token_version
-            FROM social_channels
-            WHERE platform = :platform AND platform_account_id = :account_id
-        """),
-        {"platform": platform, "account_id": account_id},
-    ).mappings().first()
-
-    if existing:
-        # Reconnect path: preserve publication linkage and bump token version.
-        db.execute(
-            text("""
-                UPDATE social_channels
-                SET user_id = :user_id,
-                    token_bundle = :token_bundle,
-                    token_version = :token_version,
-                    is_connected = 1,
-                    updated_at = :updated_at
-                WHERE id = :id
-            """),
-            {
-                "id": existing["id"],
-                "user_id": user_id,
-                "token_bundle": json.dumps(parsed_bundle),
-                "token_version": int(existing["token_version"] or 0) + 1,
-                "updated_at": now,
-            },
-        )
-        channel_id = existing["id"]
-        result_code = "reconnected"
-        result_message = "Channel reconnected"
-    else:
-        db.execute(
-            text("""
-                INSERT INTO social_channels (
-                    user_id, platform, platform_account_id, token_bundle,
-                    token_version, publication_linkage, is_connected, created_at, updated_at
-                ) VALUES (
-                    :user_id, :platform, :account_id, :token_bundle,
-                    1, :publication_linkage, 1, :created_at, :updated_at
-                )
-            """),
-            {
-                "user_id": user_id,
-                "platform": platform,
-                "account_id": account_id,
-                "token_bundle": json.dumps(parsed_bundle),
-                "publication_linkage": None,
-                "created_at": now,
-                "updated_at": now,
-            },
-        )
-        channel_id = db.execute(text("SELECT last_insert_rowid()")).scalar_one()
-        result_code = "connected"
-        result_message = "Channel connected"
-
-    # Bind callback session to concrete channel/user/platform and mark consumed.
-    db.execute(
-        text("""
-            UPDATE oauth_nonce_sessions
-            SET consumed_at = :consumed_at,
-                channel_id = :channel_id,
-                user_id = :user_id,
-                platform = :platform
-            WHERE id = :id
-        """),
-        {
-            "id": record["id"],
-            "consumed_at": now,
-            "channel_id": channel_id,
-            "user_id": user_id,
-            "platform": platform,
-        },
-    )
-
-    db.commit()
-    logger.info(f"OAuth callback complete user={user_id} platform={platform} channel_id={channel_id}")
-    return _build_redirect(ui_redirect, result_code, result_message, channel_id)

backend/services/integrations/wix_oauth.py

@@ -9,26 +9,27 @@ from typing import Optional, Dict, Any, List
 from datetime import datetime, timedelta
 from loguru import logger
 
-
 from services.database import get_user_db_path
+from services.token_crypto_service import TokenCryptoService
+
 
 class WixOAuthService:
     """Manages Wix OAuth2 authentication flow and token storage."""
-    
+
     def __init__(self, db_path: Optional[str] = None):
         self.db_path = db_path
-    
+        self.token_crypto = TokenCryptoService()
+
     def _get_db_path(self, user_id: str) -> str:
         if self.db_path:
             return self.db_path
         return get_user_db_path(user_id)
-    
+
     def _init_db(self, user_id: str):
         """Initialize database tables for OAuth tokens."""
         db_path = self._get_db_path(user_id)
-        # Ensure directory exists
         os.makedirs(os.path.dirname(db_path), exist_ok=True)
-        
+
         with sqlite3.connect(db_path) as conn:
             cursor = conn.cursor()
             cursor.execute('''
@@ -45,168 +46,133 @@ class WixOAuthService:
                     member_id TEXT,
                     created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                     updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-                    is_active BOOLEAN DEFAULT TRUE
+                    is_active BOOLEAN DEFAULT TRUE,
+                    token_key_version TEXT,
+                    token_key_reference TEXT
                 )
             ''')
+            for column_name, column_def in [
+                ("token_key_version", "TEXT"),
+                ("token_key_reference", "TEXT"),
+            ]:
+                try:
+                    cursor.execute(f"ALTER TABLE wix_oauth_tokens ADD COLUMN {column_name} {column_def}")
+                except sqlite3.OperationalError:
+                    pass
             conn.commit()
-    
-    def store_tokens(
-        self,
-        user_id: str,
-        access_token: str,
-        refresh_token: Optional[str] = None,
-        expires_in: Optional[int] = None,
-        token_type: str = 'bearer',
-        scope: Optional[str] = None,
-        site_id: Optional[str] = None,
-        member_id: Optional[str] = None
-    ) -> bool:
-        """
-        Store Wix OAuth tokens in the database.
-        
-        Args:
-            user_id: User ID (Clerk string)
-            access_token: Access token from Wix
-            refresh_token: Optional refresh token
-            expires_in: Optional expiration time in seconds
-            token_type: Token type (default: 'bearer')
-            scope: Optional OAuth scope
-            site_id: Optional Wix site ID
-            member_id: Optional Wix member ID
-            
-        Returns:
-            True if tokens were stored successfully
-        """
+
+    def store_tokens(self, user_id: str, access_token: str, refresh_token: Optional[str] = None,
+                     expires_in: Optional[int] = None, token_type: str = 'bearer', scope: Optional[str] = None,
+                     site_id: Optional[str] = None, member_id: Optional[str] = None) -> bool:
         try:
-            # Ensure DB is initialized for this user
             self._init_db(user_id)
             db_path = self._get_db_path(user_id)
-            
-            expires_at = None
-            if expires_in:
-                expires_at = datetime.now() + timedelta(seconds=expires_in)
-            
+            expires_at = datetime.now() + timedelta(seconds=expires_in) if expires_in else None
+            encrypted_access_token, encrypted_refresh_token = self.token_crypto.encrypt_pair(access_token, refresh_token)
+
             with sqlite3.connect(db_path) as conn:
                 cursor = conn.cursor()
                 cursor.execute('''
-                    INSERT INTO wix_oauth_tokens 
-                    (user_id, access_token, refresh_token, token_type, expires_at, expires_in, scope, site_id, member_id)
-                    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
-                ''', (user_id, access_token, refresh_token, token_type, expires_at, expires_in, scope, site_id, member_id))
+                    INSERT INTO wix_oauth_tokens
+                    (user_id, access_token, refresh_token, token_type, expires_at, expires_in, scope, site_id, member_id, token_key_version, token_key_reference)
+                    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+                ''', (
+                    user_id,
+                    encrypted_access_token,
+                    encrypted_refresh_token,
+                    token_type,
+                    expires_at,
+                    expires_in,
+                    scope,
+                    site_id,
+                    member_id,
+                    self.token_crypto.key_version,
+                    self.token_crypto.key_reference,
+                ))
                 conn.commit()
-                logger.info(f"Wix OAuth: Token inserted into database for user {user_id}")
-            
+                logger.info(f"Wix OAuth: Encrypted token stored for user {user_id}")
             return True
-            
         except Exception as e:
             logger.error(f"Error storing Wix tokens for user {user_id}: {e}")
             return False
-    
+
     def get_user_tokens(self, user_id: str) -> List[Dict[str, Any]]:
-        """Get all active Wix tokens for a user."""
+        """Get all active Wix token rows (encrypted values)."""
         try:
-            # Ensure database tables exist to prevent 'no such table' errors
             self._init_db(user_id)
-            
             db_path = self._get_db_path(user_id)
             if not os.path.exists(db_path):
                 return []
-                
+
             with sqlite3.connect(db_path) as conn:
                 cursor = conn.cursor()
                 cursor.execute('''
-                    SELECT id, access_token, refresh_token, token_type, expires_at, expires_in, scope, site_id, member_id, created_at
+                    SELECT id, access_token, refresh_token, token_type, expires_at, expires_in, scope, site_id, member_id, created_at, token_key_version, token_key_reference
                     FROM wix_oauth_tokens
                     WHERE user_id = ? AND is_active = TRUE AND (expires_at IS NULL OR expires_at > datetime('now'))
                     ORDER BY created_at DESC
                 ''', (user_id,))
-                
-                tokens = []
-                for row in cursor.fetchall():
-                    tokens.append({
-                        "id": row[0],
-                        "access_token": row[1],
-                        "refresh_token": row[2],
-                        "token_type": row[3],
-                        "expires_at": row[4],
-                        "expires_in": row[5],
-                        "scope": row[6],
-                        "site_id": row[7],
-                        "member_id": row[8],
-                        "created_at": row[9]
-                    })
-                
-                return tokens
-                
+
+                return [{
+                    "id": row[0], "access_token": row[1], "refresh_token": row[2], "token_type": row[3],
+                    "expires_at": row[4], "expires_in": row[5], "scope": row[6], "site_id": row[7],
+                    "member_id": row[8], "created_at": row[9], "token_key_version": row[10],
+                    "token_key_reference": row[11]
+                } for row in cursor.fetchall()]
         except Exception as e:
             logger.error(f"Error getting Wix tokens for user {user_id}: {e}")
             return []
-    
-    def get_user_token_status(self, user_id: str) -> Dict[str, Any]:
-        """Get detailed token status for a user including expired tokens."""
-        try:
-            # Ensure database tables exist to prevent 'no such table' errors
-            self._init_db(user_id)
 
+    def get_user_tokens_decrypted(self, user_id: str) -> List[Dict[str, Any]]:
+        """Decrypt tokens for integration managers and token refresh routines."""
+        decrypted = []
+        for token in self.get_user_tokens(user_id):
+            token_copy = dict(token)
+            token_copy["access_token"] = self.token_crypto.decrypt_token(token_copy.get("access_token"))
+            token_copy["refresh_token"] = self.token_crypto.decrypt_token(token_copy.get("refresh_token"))
+            decrypted.append(token_copy)
+        return decrypted
+
+    def get_user_token_status(self, user_id: str) -> Dict[str, Any]:
+        try:
+            self._init_db(user_id)
             db_path = self._get_db_path(user_id)
             if not os.path.exists(db_path):
-                return {
-                    "has_tokens": False,
-                    "has_active_tokens": False,
-                    "has_expired_tokens": False,
-                    "active_tokens": [],
-                    "expired_tokens": [],
-                    "total_tokens": 0,
-                    "last_token_date": None
-                }
+                return {"has_tokens": False, "has_active_tokens": False, "has_expired_tokens": False,
+                        "active_tokens": [], "expired_tokens": [], "total_tokens": 0, "last_token_date": None}
 
             with sqlite3.connect(db_path) as conn:
                 cursor = conn.cursor()
-                
-                # Get all tokens (active and expired)
                 cursor.execute('''
-                    SELECT id, access_token, refresh_token, token_type, expires_at, expires_in, scope, site_id, member_id, created_at, is_active
+                    SELECT id, access_token, refresh_token, token_type, expires_at, expires_in, scope, site_id, member_id,
+                           created_at, is_active, token_key_version, token_key_reference
                     FROM wix_oauth_tokens
                     WHERE user_id = ?
                     ORDER BY created_at DESC
                 ''', (user_id,))
-                
-                all_tokens = []
-                active_tokens = []
-                expired_tokens = []
-                
+
+                all_tokens, active_tokens, expired_tokens = [], [], []
                 for row in cursor.fetchall():
                     token_data = {
-                        "id": row[0],
-                        "access_token": row[1],
-                        "refresh_token": row[2],
-                        "token_type": row[3],
-                        "expires_at": row[4],
-                        "expires_in": row[5],
-                        "scope": row[6],
-                        "site_id": row[7],
-                        "member_id": row[8],
-                        "created_at": row[9],
-                        "is_active": bool(row[10])
+                        "id": row[0], "access_token": row[1], "refresh_token": row[2], "token_type": row[3],
+                        "expires_at": row[4], "expires_in": row[5], "scope": row[6], "site_id": row[7],
+                        "member_id": row[8], "created_at": row[9], "is_active": bool(row[10]),
+                        "token_key_version": row[11], "token_key_reference": row[12]
                     }
                     all_tokens.append(token_data)
-                    
-                    # Determine expiry using robust parsing and is_active flag
+
                     is_active_flag = bool(row[10])
                     not_expired = False
                     try:
                         expires_at_val = row[4]
                         if expires_at_val:
-                            # First try Python parsing
                             try:
                                 dt = datetime.fromisoformat(expires_at_val) if isinstance(expires_at_val, str) else expires_at_val
                                 not_expired = dt > datetime.now()
                             except Exception:
-                                # Fallback to SQLite comparison
                                 cursor.execute("SELECT datetime('now') < ?", (expires_at_val,))
                                 not_expired = cursor.fetchone()[0] == 1
                         else:
-                            # No expiry stored => consider not expired
                             not_expired = True
                     except Exception:
                         not_expired = False
@@ -215,7 +181,7 @@ class WixOAuthService:
                         active_tokens.append(token_data)
                     else:
                         expired_tokens.append(token_data)
-                
+
                 return {
                     "has_tokens": len(all_tokens) > 0,
                     "has_active_tokens": len(active_tokens) > 0,
@@ -225,81 +191,101 @@ class WixOAuthService:
                     "total_tokens": len(all_tokens),
                     "last_token_date": all_tokens[0]["created_at"] if all_tokens else None
                 }
-                
         except Exception as e:
             logger.error(f"Error getting Wix token status for user {user_id}: {e}")
-            return {
-                "has_tokens": False,
-                "has_active_tokens": False,
-                "has_expired_tokens": False,
-                "active_tokens": [],
-                "expired_tokens": [],
-                "total_tokens": 0,
-                "last_token_date": None,
-                "error": str(e)
-            }
-    
-    def update_tokens(
-        self,
-        user_id: str,
-        access_token: str,
-        refresh_token: Optional[str] = None,
-        expires_in: Optional[int] = None
-    ) -> bool:
-        """Update tokens for a user (e.g., after refresh)."""
+            return {"has_tokens": False, "has_active_tokens": False, "has_expired_tokens": False,
+                    "active_tokens": [], "expired_tokens": [], "total_tokens": 0, "last_token_date": None, "error": str(e)}
+
+    def update_tokens(self, user_id: str, access_token: str, refresh_token: Optional[str] = None,
+                      expires_in: Optional[int] = None) -> bool:
         try:
-            # Ensure DB initialized for this user
             self._init_db(user_id)
             db_path = self._get_db_path(user_id)
+            expires_at = datetime.now() + timedelta(seconds=expires_in) if expires_in else None
+            encrypted_access_token = self.token_crypto.encrypt_token(access_token)
+            encrypted_refresh_token = self.token_crypto.encrypt_token(refresh_token) if refresh_token else None
 
-            expires_at = None
-            if expires_in:
-                expires_at = datetime.now() + timedelta(seconds=expires_in)
-            
             with sqlite3.connect(db_path) as conn:
                 cursor = conn.cursor()
                 if refresh_token:
                     cursor.execute('''
-                        UPDATE wix_oauth_tokens 
-                        SET access_token = ?, refresh_token = ?, expires_at = ?, expires_in = ?, 
-                            is_active = TRUE, updated_at = datetime('now')
-                        WHERE user_id = ? AND refresh_token = ?
-                    ''', (access_token, refresh_token, expires_at, expires_in, user_id, refresh_token))
+                        UPDATE wix_oauth_tokens
+                        SET access_token = ?, refresh_token = ?, expires_at = ?, expires_in = ?,
+                            is_active = TRUE, updated_at = datetime('now'), token_key_version = ?, token_key_reference = ?
+                        WHERE user_id = ? AND (refresh_token = ? OR refresh_token = ?)
+                    ''', (encrypted_access_token, encrypted_refresh_token, expires_at, expires_in,
+                          self.token_crypto.key_version, self.token_crypto.key_reference,
+                          user_id, encrypted_refresh_token, refresh_token))
                 else:
                     cursor.execute('''
-                        UPDATE wix_oauth_tokens 
-                        SET access_token = ?, expires_at = ?, expires_in = ?, 
-                            is_active = TRUE, updated_at = datetime('now')
+                        UPDATE wix_oauth_tokens
+                        SET access_token = ?, expires_at = ?, expires_in = ?,
+                            is_active = TRUE, updated_at = datetime('now'), token_key_version = ?, token_key_reference = ?
                         WHERE user_id = ? AND id = (SELECT id FROM wix_oauth_tokens WHERE user_id = ? ORDER BY created_at DESC LIMIT 1)
-                    ''', (access_token, expires_at, expires_in, user_id, user_id))
+                    ''', (encrypted_access_token, expires_at, expires_in,
+                          self.token_crypto.key_version, self.token_crypto.key_reference, user_id, user_id))
                 conn.commit()
-                logger.info(f"Wix OAuth: Tokens updated for user {user_id}")
-            
+                logger.info(f"Wix OAuth: Encrypted tokens updated for user {user_id}")
             return True
-            
         except Exception as e:
             logger.error(f"Error updating Wix tokens for user {user_id}: {e}")
             return False
-    
+
+    def rotate_token_encryption(self, user_id: str, batch_size: int = 100) -> Dict[str, int]:
+        """Re-encrypt existing token rows in batches for key rotation."""
+        self._init_db(user_id)
+        db_path = self._get_db_path(user_id)
+        rotated, skipped, last_id = 0, 0, 0
+        with sqlite3.connect(db_path) as conn:
+            cursor = conn.cursor()
+            while True:
+                cursor.execute('''
+                    SELECT id, access_token, refresh_token
+                    FROM wix_oauth_tokens
+                    WHERE user_id = ? AND id > ?
+                    ORDER BY id ASC
+                    LIMIT ?
+                ''', (user_id, last_id, batch_size))
+                rows = cursor.fetchall()
+                if not rows:
+                    break
+
+                for row_id, enc_access, enc_refresh in rows:
+                    last_id = row_id
+                    try:
+                        plain_access = self.token_crypto.decrypt_token(enc_access)
+                        plain_refresh = self.token_crypto.decrypt_token(enc_refresh) if enc_refresh else None
+                    except Exception:
+                        skipped += 1
+                        continue
+
+                    new_access, new_refresh = self.token_crypto.encrypt_pair(plain_access, plain_refresh)
+                    cursor.execute('''
+                        UPDATE wix_oauth_tokens
+                        SET access_token = ?, refresh_token = ?, token_key_version = ?, token_key_reference = ?, updated_at = datetime('now')
+                        WHERE id = ?
+                    ''', (new_access, new_refresh, self.token_crypto.key_version, self.token_crypto.key_reference, row_id))
+                    rotated += 1
+            conn.commit()
+
+        logger.info(f"Wix OAuth: Encryption rotation complete for user {user_id}; rotated={rotated}, skipped={skipped}")
+        return {"rotated": rotated, "skipped": skipped}
+
     def revoke_token(self, user_id: str, token_id: int) -> bool:
-        """Revoke a Wix OAuth token."""
         try:
             db_path = self._get_db_path(user_id)
             with sqlite3.connect(db_path) as conn:
                 cursor = conn.cursor()
                 cursor.execute('''
-                    UPDATE wix_oauth_tokens 
+                    UPDATE wix_oauth_tokens
                     SET is_active = FALSE, updated_at = datetime('now')
                     WHERE user_id = ? AND id = ?
                 ''', (user_id, token_id))
                 conn.commit()
-                
                 if cursor.rowcount > 0:
                     logger.info(f"Wix token {token_id} revoked for user {user_id}")
                     return True
                 return False
-                
         except Exception as e:
             logger.error(f"Error revoking Wix token: {e}")
             return False
-

backend/services/token_crypto_service.py

@@ -0,0 +1,69 @@
+"""Service for encrypting/decrypting integration tokens with key version metadata."""
+
+import base64
+import hashlib
+import os
+from typing import Optional, Tuple
+
+from cryptography.fernet import Fernet, InvalidToken
+from loguru import logger
+
+
+class TokenCryptoService:
+    """Token encryption/decryption service with key version support."""
+
+    ENV_KEY = "ALWRITY_TOKEN_ENCRYPTION_KEY"
+    ENV_KEY_VERSION = "ALWRITY_TOKEN_KEY_VERSION"
+
+    def __init__(self):
+        raw_key = os.getenv(self.ENV_KEY, "")
+        if raw_key:
+            self._fernet_key = self._normalize_key(raw_key)
+        else:
+            self._fernet_key = self._derive_dev_key()
+        self._fernet = Fernet(self._fernet_key)
+        self._key_version = os.getenv(self.ENV_KEY_VERSION, "v1")
+        self._key_reference = self._fingerprint(self._fernet_key)
+
+    @property
+    def key_version(self) -> str:
+        return self._key_version
+
+    @property
+    def key_reference(self) -> str:
+        return self._key_reference
+
+    def encrypt_token(self, token: Optional[str]) -> Optional[str]:
+        if token is None:
+            return None
+        return self._fernet.encrypt(token.encode("utf-8")).decode("utf-8")
+
+    def decrypt_token(self, encrypted_token: Optional[str]) -> Optional[str]:
+        if encrypted_token is None:
+            return None
+        try:
+            return self._fernet.decrypt(encrypted_token.encode("utf-8")).decode("utf-8")
+        except InvalidToken:
+            logger.error("Token decryption failed due to invalid token/key")
+            raise
+
+    def encrypt_pair(self, access_token: str, refresh_token: Optional[str]) -> Tuple[str, Optional[str]]:
+        return self.encrypt_token(access_token), self.encrypt_token(refresh_token)
+
+    @staticmethod
+    def _normalize_key(raw_key: str) -> bytes:
+        raw_key = raw_key.strip()
+        if len(raw_key) == 44 and raw_key.endswith("="):
+            return raw_key.encode("utf-8")
+        digest = hashlib.sha256(raw_key.encode("utf-8")).digest()
+        return base64.urlsafe_b64encode(digest)
+
+    @staticmethod
+    def _derive_dev_key() -> bytes:
+        seed = "alwrity-local-token-key"
+        digest = hashlib.sha256(seed.encode("utf-8")).digest()
+        return base64.urlsafe_b64encode(digest)
+
+    @staticmethod
+    def _fingerprint(key: bytes) -> str:
+        return hashlib.sha256(key).hexdigest()[:16]