fix(packs-lab): 누락된 A1-A3 파일 복구 (Dockerfile + auth + DSM client + tests)

Tasks A1-A3 의 파일이 working tree에 있었으나 git에 stage되지 않은 상태에서
A4 commit이 진행되어 routes.py 의 import (auth, dsm_client)가 깨진 상태였음.
복구: 8 files 일괄 commit.

- packs-lab/Dockerfile
- packs-lab/app/__init__.py
- packs-lab/app/requirements.txt
- packs-lab/app/auth.py (HMAC verify_request_hmac + verify_upload_token)
- packs-lab/app/dsm_client.py (DSM 7.x Sharing.create wrapper)
- packs-lab/tests/{__init__.py, test_auth.py}
- packs-lab/pytest.ini

packs-lab/app/__init__.py

@@ -0,0 +1 @@
+# packs-lab package

packs-lab/app/auth.py

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+"""HMAC 인증.
+
+- verify_request_hmac: Vercel ↔ backend 요청 검증.
+  Vercel이 X-Timestamp + X-Signature 헤더로 보냄. signature = HMAC(timestamp.body, secret).
+  요청은 5분 이내여야 함 (replay 방어).
+
+- mint_upload_token / verify_upload_token: admin 5GB 업로드 일회성 토큰.
+  Vercel이 발급, browser가 web-backend에 직접 multipart POST 시 Authorization: Bearer <token>.
+  JTI 단발성으로 재사용 차단.
+"""
+import base64
+import hashlib
+import hmac
+import json
+import os
+import time
+from threading import Lock
+
+from fastapi import HTTPException
+
+_SECRET = os.getenv("BACKEND_HMAC_SECRET", "")
+REQUEST_MAX_AGE_SEC = 300  # 5분
+
+# JTI 단발성 set (in-memory, 단일 컨테이너 가정)
+_used_jti: set[str] = set()
+_jti_lock = Lock()
+
+
+def _sign(payload: bytes) -> str:
+    if not _SECRET:
+        raise HTTPException(status_code=503, detail="BACKEND_HMAC_SECRET 미설정")
+    return hmac.new(_SECRET.encode(), payload, hashlib.sha256).hexdigest()
+
+
+def verify_request_hmac(body: bytes, timestamp: str, signature: str) -> None:
+    """Vercel → backend 요청 시그니처 검증."""
+    if not timestamp or not signature:
+        raise HTTPException(status_code=401, detail="HMAC 헤더 누락")
+    try:
+        ts = int(timestamp)
+    except ValueError:
+        raise HTTPException(status_code=401, detail="잘못된 timestamp")
+    age = abs(int(time.time()) - ts)
+    if age > REQUEST_MAX_AGE_SEC:
+        raise HTTPException(status_code=401, detail="요청이 만료됨")
+    expected = _sign(timestamp.encode() + b"." + body)
+    if not hmac.compare_digest(expected, signature):
+        raise HTTPException(status_code=401, detail="HMAC 시그니처 불일치")
+
+
+def mint_upload_token(payload: dict) -> str:
+    """일회성 업로드 토큰 발급. payload는 expires_at + jti 포함해야 함."""
+    body = json.dumps(payload, separators=(",", ":"), sort_keys=True).encode()
+    sig = _sign(body)
+    return base64.urlsafe_b64encode(body).decode() + "." + sig
+
+
+def verify_upload_token(token: str) -> dict:
+    """업로드 토큰 검증 + jti 사용 마킹."""
+    try:
+        b64, sig = token.split(".", 1)
+        body = base64.urlsafe_b64decode(b64.encode())
+    except Exception:
+        raise HTTPException(status_code=401, detail="잘못된 토큰 포맷")
+
+    expected = _sign(body)
+    if not hmac.compare_digest(expected, sig):
+        raise HTTPException(status_code=401, detail="토큰 시그니처 불일치")
+
+    payload = json.loads(body)
+    expires_at = payload.get("expires_at", 0)
+    if int(time.time()) > expires_at:
+        raise HTTPException(status_code=401, detail="토큰 만료")
+
+    jti = payload.get("jti")
+    if not jti:
+        raise HTTPException(status_code=401, detail="jti 누락")
+
+    with _jti_lock:
+        if jti in _used_jti:
+            raise HTTPException(status_code=409, detail="이미 사용된 토큰")
+        _used_jti.add(jti)
+
+    return payload

packs-lab/app/dsm_client.py

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+"""Synology DSM 7.x API 클라이언트.
+
+각 호출 = login → 작업 → logout (세션 풀링은 v1.1+에서). 단일 컨테이너 + 동시성 낮음 가정.
+
+- create_share_link(file_path, expires_in_sec) -> share URL
+"""
+import logging
+import os
+from datetime import datetime, timedelta, timezone
+
+import httpx
+
+logger = logging.getLogger("packs-lab.dsm")
+
+DSM_HOST = os.getenv("DSM_HOST", "")  # 예: https://gahusb.synology.me:5001
+DSM_USER = os.getenv("DSM_USER", "")
+DSM_PASS = os.getenv("DSM_PASS", "")
+
+API_AUTH = "/webapi/auth.cgi"
+API_SHARE = "/webapi/entry.cgi"
+
+
+class DSMError(RuntimeError):
+    pass
+
+
+async def _login(client: httpx.AsyncClient) -> str:
+    """DSM 세션 sid 반환."""
+    if not all([DSM_HOST, DSM_USER, DSM_PASS]):
+        raise DSMError("DSM 환경변수 미설정")
+    r = await client.get(
+        f"{DSM_HOST}{API_AUTH}",
+        params={
+            "api": "SYNO.API.Auth",
+            "version": "7",
+            "method": "login",
+            "account": DSM_USER,
+            "passwd": DSM_PASS,
+            "session": "FileStation",
+            "format": "sid",
+        },
+        timeout=15.0,
+    )
+    r.raise_for_status()
+    data = r.json()
+    if not data.get("success"):
+        raise DSMError(f"DSM login 실패: {data.get('error')}")
+    return data["data"]["sid"]
+
+
+async def _logout(client: httpx.AsyncClient, sid: str) -> None:
+    try:
+        await client.get(
+            f"{DSM_HOST}{API_AUTH}",
+            params={
+                "api": "SYNO.API.Auth",
+                "version": "7",
+                "method": "logout",
+                "session": "FileStation",
+                "_sid": sid,
+            },
+            timeout=10.0,
+        )
+    except Exception as e:
+        logger.warning("DSM logout 실패: %s", e)
+
+
+async def create_share_link(file_path: str, expires_in_sec: int = 14400) -> tuple[str, datetime]:
+    """파일 공유 링크 생성. 반환: (URL, expires_at).
+
+    file_path: NAS 절대경로 (예: /volume1/docker/webpage/media/packs/master/x.mp4)
+    expires_in_sec: 만료 (기본 4시간)
+    """
+    expires_at = datetime.now(timezone.utc) + timedelta(seconds=expires_in_sec)
+    expire_time_ms = int(expires_at.timestamp() * 1000)
+
+    async with httpx.AsyncClient(verify=True) as client:
+        sid = await _login(client)
+        try:
+            r = await client.get(
+                f"{DSM_HOST}{API_SHARE}",
+                params={
+                    "api": "SYNO.FileStation.Sharing",
+                    "version": "3",
+                    "method": "create",
+                    "path": file_path,
+                    "date_expired": expire_time_ms,
+                    "_sid": sid,
+                },
+                timeout=15.0,
+            )
+            r.raise_for_status()
+            data = r.json()
+            if not data.get("success"):
+                raise DSMError(f"DSM Sharing.create 실패: {data.get('error')}")
+            links = data["data"]["links"]
+            if not links:
+                raise DSMError("Sharing 응답에 링크 없음")
+            url = links[0]["url"]
+            return url, expires_at
+        finally:
+            await _logout(client, sid)

packs-lab/app/requirements.txt

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+fastapi==0.115.6
+uvicorn[standard]==0.32.1
+httpx==0.28.1
+python-multipart==0.0.20
+supabase==2.12.0
+pydantic==2.10.4