feat: Implement hashed admin password support and centralize password logic

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

app/app.py

@@ -16,6 +16,7 @@ import json
 import hashlib
 import os
 import sqlite3
+import binascii
 from datetime import datetime
 from typing import Dict, List, Optional
 
@@ -223,6 +224,34 @@ def read_exif_datetimes(file_bytes: bytes):
         pass
     return created, modified
 
+
+def _hash_password(pw: str) -> str:
+    """Return PBKDF2-SHA256 hash of a password."""
+    try:
+        if not pw:
+            return ""
+        salt = os.urandom(16)
+        iterations = 200_000
+        dk = hashlib.pbkdf2_hmac('sha256', pw.encode('utf-8'), salt, iterations)
+        return f"pbkdf2_sha256${iterations}${binascii.hexlify(salt).decode()}${binascii.hexlify(dk).decode()}"
+    except Exception:
+        return ""
+
+def _verify_password(stored: str, pw: Optional[str]) -> bool:
+    """Verify a password against a PBKDF2-SHA256 hash."""
+    if not pw or not stored:
+        return False
+    try:
+        algo, iter_s, salt_hex, hash_hex = stored.split("$")
+        if algo != 'pbkdf2_sha256':
+            return False
+        iterations = int(iter_s)
+        salt = binascii.unhexlify(salt_hex)
+        dk = hashlib.pbkdf2_hmac('sha256', pw.encode('utf-8'), salt, iterations)
+        return binascii.hexlify(dk).decode() == hash_hex
+    except Exception:
+        return False
+
 def get_or_create_album_dir(album_name: str) -> str:
     """Get or create a directory for an album. Returns the path."""
     if not album_name or not isinstance(album_name, str):
@@ -858,7 +887,14 @@ async def api_login(request: Request) -> JSONResponse:
     if not email or not password:
         return JSONResponse({"error": "missing_credentials"}, status_code=400)
 
-    if email == "admin" and password == SETTINGS.admin_password:
+    stored_password = SETTINGS.admin_password
+    password_ok = False
+    if stored_password.startswith("pbkdf2_sha256$"):
+        password_ok = _verify_password(stored_password, password)
+    else:
+        password_ok = (password == stored_password)
+
+    if email == "admin" and password_ok:
         user_info = {
             "accessToken": "local_admin_session", # dummy value
             "userEmail": "admin",
@@ -1028,19 +1064,7 @@ async def api_invites_create(request: Request) -> JSONResponse:
     import uuid
     token = uuid.uuid4().hex
     # Prepare password hash, if provided
-    def hash_password(pw: str) -> str:
-        try:
-            if not pw:
-                return ""
-            import os as _os
-            import binascii as _binascii
-            salt = _os.urandom(16)
-            iterations = 200_000
-            dk = hashlib.pbkdf2_hmac('sha256', pw.encode('utf-8'), salt, iterations)
-            return f"pbkdf2_sha256${iterations}${_binascii.hexlify(salt).decode()}${_binascii.hexlify(dk).decode()}"
-        except Exception:
-            return ""
-    pw_hash = hash_password(invite_password or "") if (invite_password and str(invite_password).strip()) else None
+    pw_hash = _hash_password(invite_password or "") if (invite_password and str(invite_password).strip()) else None
     # Owner info from session
     owner_user_id = str(request.session.get("userId") or "")
     owner_email = str(request.session.get("userEmail") or "")
@@ -1235,16 +1259,8 @@ async def api_invite_update(token: str, request: Request) -> JSONResponse:
     if "password" in (body or {}):
         pw = str((body or {}).get("password") or "").strip()
         if pw:
-            # Reuse hasher from above
-            def _hash_pw(pw: str) -> str:
-                import os as _os
-                import binascii as _binascii
-                salt = _os.urandom(16)
-                iterations = 200_000
-                dk = hashlib.pbkdf2_hmac('sha256', pw.encode('utf-8'), salt, iterations)
-                return f"pbkdf2_sha256${iterations}${_binascii.hexlify(salt).decode()}${_binascii.hexlify(dk).decode()}"
             fields.append("password_hash = ?")
-            params.append(_hash_pw(pw))
+            params.append(_hash_password(pw))
         else:
             fields.append("password_hash = NULL")
     # Reset usage
@@ -1488,21 +1504,7 @@ async def api_invite_auth(token: str, request: Request) -> JSONResponse:
         request.session["inviteAuth"] = ia
         return JSONResponse({"ok": True, "authorized": True})
     # verify
-    def verify_password(stored: str, pw: Optional[str]) -> bool:
-        if not pw:
-            return False
-        try:
-            algo, iter_s, salt_hex, hash_hex = stored.split("$")
-            if algo != 'pbkdf2_sha256':
-                return False
-            iterations = int(iter_s)
-            import binascii as _binascii
-            salt = _binascii.unhexlify(salt_hex)
-            dk = hashlib.pbkdf2_hmac('sha256', pw.encode('utf-8'), salt, iterations)
-            return _binascii.hexlify(dk).decode() == hash_hex
-        except Exception:
-            return False
-    if not verify_password(password_hash, provided):
+    if not _verify_password(password_hash, provided):
         return JSONResponse({"error": "invalid_password"}, status_code=403)
     ia = request.session.get("inviteAuth") or {}
     ia[token] = True