feat(auth): JWT iat + users.password_changed_at invalidation (PR-Docsrv-JWT-Invalidation-1)

PR-Infra-Sec-1H Phase 0 audit 에서 DS jwt invalidation 정책 부재 확정.
password rotation 으로 구 365d JWT (voice-memo-bot 등) invalidate 안 되는
hard gate STOP 진입 → 선행 PR 분리.

- migration 269: users.password_changed_at timestamptz NULL (legacy 호환)
- create_access_token / create_refresh_token: payload 에 iat (int 초) 추가
- verify_password_changed_at helper: int(password_changed_at.timestamp()) > int(iat) 시 401
- get_current_user + refresh_token route: verify helper 호출
- change_password / setup signup / seed_admin INSERT+UPDATE: password_changed_at 갱신

NULL = 검증 skip (migration 직후 운영 영향 0). 첫 password 변경 후만 iat
검증 활성. Sec-1H 의 G-token-old hard gate 통과 path 확보.

app/api/auth.py

@@ -19,6 +19,7 @@ from core.auth import (
     create_voice_memo_bot_token,
     decode_token,
     get_current_user,
+    verify_password_changed_at,
     hash_password,
     verify_password,
     verify_totp,
@@ -161,6 +162,7 @@ async def refresh_token(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail="유저를 찾을 수 없음",
         )
+    verify_password_changed_at(payload, user)
 
     # 새 refresh token → cookie
     _set_refresh_cookie(response, create_refresh_token(user.username))
@@ -203,5 +205,6 @@ async def change_password(
         )
 
     user.password_hash = hash_password(body.new_password)
+    user.password_changed_at = datetime.now(timezone.utc)
     await session.commit()
     return {"message": "비밀번호가 변경되었습니다"}

app/api/setup.py

@@ -8,6 +8,7 @@ from pathlib import Path
 from typing import Annotated
 
 import pyotp
+from datetime import datetime, timezone
 from fastapi import APIRouter, Depends, HTTPException, Request, status
 from fastapi.responses import HTMLResponse
 from fastapi.templating import Jinja2Templates
@@ -137,6 +138,7 @@ async def create_admin(
         username=body.username,
         password_hash=hash_password(body.password),
         is_active=True,
+        password_changed_at=datetime.now(timezone.utc),
     )
     session.add(user)
     await session.commit()

app/core/auth.py

@@ -33,8 +33,9 @@ def hash_password(password: str) -> str:
 
 def create_access_token(subject: str, expires_minutes: int | None = None) -> str:
     minutes = expires_minutes if expires_minutes is not None else ACCESS_TOKEN_EXPIRE_MINUTES
-    expire = datetime.now(timezone.utc) + timedelta(minutes=minutes)
+    now = datetime.now(timezone.utc)
-    payload = {"sub": subject, "exp": expire, "type": "access"}
+    expire = now + timedelta(minutes=minutes)
+    payload = {"sub": subject, "exp": expire, "iat": int(now.timestamp()), "type": "access"}
     return jwt.encode(payload, settings.jwt_secret, algorithm=ALGORITHM)
 
 
@@ -51,8 +52,9 @@ def create_voice_memo_bot_token(username: str) -> str | None:
 
 
 def create_refresh_token(subject: str) -> str:
-    expire = datetime.now(timezone.utc) + timedelta(days=REFRESH_TOKEN_EXPIRE_DAYS)
+    now = datetime.now(timezone.utc)
-    payload = {"sub": subject, "exp": expire, "type": "refresh"}
+    expire = now + timedelta(days=REFRESH_TOKEN_EXPIRE_DAYS)
+    payload = {"sub": subject, "exp": expire, "iat": int(now.timestamp()), "type": "refresh"}
     return jwt.encode(payload, settings.jwt_secret, algorithm=ALGORITHM)
 
 
@@ -63,6 +65,21 @@ def decode_token(token: str) -> dict | None:
         return None
 
 
+
+
+def verify_password_changed_at(payload: dict, user) -> None:
+    # legacy 호환: password_changed_at NULL 이면 검증 skip (migration 전 발급 token 유지)
+    # password 변경 후 발급 token 만 검증 — iat (int 초) >= int(password_changed_at.timestamp())
+    if user.password_changed_at is None:
+        return
+    iat = payload.get("iat")
+    pwd_changed_int = int(user.password_changed_at.timestamp())
+    if iat is None or pwd_changed_int > int(iat):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="비밀번호 변경 후 재로그인 필요",
+        )
+
 def verify_totp(code: str, secret: str | None = None) -> bool:
     """TOTP 코드 검증 (유저별 secret 또는 글로벌 설정)"""
     totp_secret = secret or settings.totp_secret
@@ -96,6 +113,7 @@ async def get_current_user(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail="유저를 찾을 수 없음",
         )
+    verify_password_changed_at(payload, user)
     return user
 
 

app/models/user.py

@@ -21,3 +21,4 @@ class User(Base):
         DateTime(timezone=True), default=datetime.now
     )
     last_login_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    password_changed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))

migrations/269_users_password_changed_at.sql

@@ -0,0 +1,4 @@
+-- 2026-05-17 PR-Docsrv-JWT-Invalidation-1: users.password_changed_at 컬럼 추가.
+-- JWT iat (issued_at) claim 과 비교해 password 변경 시 구 access/refresh token 자동 invalidation.
+-- NULL = 검증 skip (legacy 호환). change-password / seed_admin / setup signup 시 now() 갱신.
+ALTER TABLE users ADD COLUMN IF NOT EXISTS password_changed_at timestamptz;

scripts/seed_admin.py

@@ -55,14 +55,14 @@ async def seed_admin():
         if result.scalar_one_or_none():
             print(f"'{username}' 계정이 이미 존재합니다. 비밀번호를 업데이트합니다.")
             await session.execute(
-                text("UPDATE users SET password_hash = :hash WHERE username = :username"),
+                text("UPDATE users SET password_hash = :hash, password_changed_at = NOW() WHERE username = :username"),
                 {"hash": password_hash, "username": username},
             )
         else:
             await session.execute(
                 text(
-                    "INSERT INTO users (username, password_hash, is_active) "
+                    "INSERT INTO users (username, password_hash, is_active, password_changed_at) "
-                    "VALUES (:username, :hash, TRUE)"
+                    "VALUES (:username, :hash, TRUE, NOW())"
                 ),
                 {"username": username, "hash": password_hash},
             )