feat: Phase 3 보안 강화 - API 키 AES-256 암호화

- server/encryption.py: AES-256 암호화/복호화 함수 추가
- test_admin.py: API 키 암호화 저장 및 조회 로직 구현
- static/admin.js: 암호화 상태 표시 UI 추가
- static/admin.css: 암호화 배지 스타일 추가

API 키가 이제 AES-256으로 암호화되어 저장됩니다.

test_admin.py

@@ -20,6 +20,18 @@ from fastapi.templating import Jinja2Templates
 from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
 import uvicorn
 
+# Import encryption module
+try:
+    from server.encryption import encrypt_api_key, decrypt_api_key, is_encrypted
+    ENCRYPTION_AVAILABLE = True
+except ImportError:
+    print("⚠️  Encryption module not available, using plain text storage")
+    ENCRYPTION_AVAILABLE = False
+    
+    def encrypt_api_key(key): return key
+    def decrypt_api_key(key): return key
+    def is_encrypted(key): return False
+
 # FastAPI 앱 초기화
 app = FastAPI(title="AI Server Admin Dashboard (Test Mode)")
 
@@ -51,21 +63,44 @@ TEST_USERS = {
     }
 }
 
-# 임시 데이터 저장소
-api_keys_store = {
-    "test-key-1": {
-        "name": "Test Key 1",
-        "key": "test-api-key-abcd1234",
-        "created_at": datetime.now().isoformat(),
-        "usage_count": 42,
-    },
-    "test-key-2": {
-        "name": "Development Key",
-        "key": "dev-api-key-efgh5678",
-        "created_at": datetime.now().isoformat(),
-        "usage_count": 128,
+# 임시 데이터 저장소 (암호화된 API 키)
+def initialize_api_keys():
+    """Initialize API keys with encryption"""
+    keys = {
+        "test-key-1": {
+            "name": "Test Key 1",
+            "key": "test-api-key-abcd1234",
+            "created_at": datetime.now().isoformat(),
+            "usage_count": 42,
+        },
+        "test-key-2": {
+            "name": "Development Key", 
+            "key": "dev-api-key-efgh5678",
+            "created_at": datetime.now().isoformat(),
+            "usage_count": 128,
+        }
     }
-}
+    
+    # Encrypt API keys if encryption is available
+    if ENCRYPTION_AVAILABLE:
+        for key_id, key_data in keys.items():
+            if not is_encrypted(key_data["key"]):
+                try:
+                    key_data["key"] = encrypt_api_key(key_data["key"])
+                    key_data["encrypted"] = True
+                    print(f"🔒 Encrypted API key: {key_data['name']}")
+                except Exception as e:
+                    print(f"❌ Failed to encrypt key {key_data['name']}: {e}")
+                    key_data["encrypted"] = False
+            else:
+                key_data["encrypted"] = True
+    else:
+        for key_data in keys.values():
+            key_data["encrypted"] = False
+    
+    return keys
+
+api_keys_store = initialize_api_keys()
 
 # 테스트용 모델 데이터
 test_models = [
@@ -307,15 +342,25 @@ async def admin_test_model(request: dict, api_key: str = Depends(require_api_key
 
 @app.get("/admin/api-keys")
 async def admin_get_api_keys(api_key: str = Depends(require_api_key)):
-    """API 키 목록 조회"""
+    """API 키 목록 조회 (복호화된 키 반환)"""
     keys = []
     for key_id, key_data in api_keys_store.items():
+        # Decrypt key for display
+        display_key = key_data.get("key", "")
+        if ENCRYPTION_AVAILABLE and key_data.get("encrypted", False):
+            try:
+                display_key = decrypt_api_key(display_key)
+            except Exception as e:
+                print(f"❌ Failed to decrypt key {key_data.get('name')}: {e}")
+                display_key = "DECRYPTION_FAILED"
+        
         keys.append({
             "id": key_id,
             "name": key_data.get("name", "Unnamed"),
-            "key": key_data.get("key", ""),
+            "key": display_key,
             "created_at": key_data.get("created_at", datetime.now().isoformat()),
             "usage_count": key_data.get("usage_count", 0),
+            "encrypted": key_data.get("encrypted", False),
         })
     
     return {"api_keys": keys}
@@ -323,19 +368,37 @@ async def admin_get_api_keys(api_key: str = Depends(require_api_key)):
 
 @app.post("/admin/api-keys")
 async def admin_create_api_key(request: dict, api_key: str = Depends(require_api_key)):
-    """새 API 키 생성"""
+    """새 API 키 생성 (암호화 저장)"""
     name = request.get("name", "Unnamed Key")
     new_key = secrets.token_urlsafe(32)
     key_id = str(uuid.uuid4())
     
+    # Encrypt the key before storing
+    stored_key = new_key
+    encrypted = False
+    
+    if ENCRYPTION_AVAILABLE:
+        try:
+            stored_key = encrypt_api_key(new_key)
+            encrypted = True
+            print(f"🔒 Created encrypted API key: {name}")
+        except Exception as e:
+            print(f"❌ Failed to encrypt new key {name}: {e}")
+            encrypted = False
+    
     api_keys_store[key_id] = {
         "name": name,
-        "key": new_key,
+        "key": stored_key,
         "created_at": datetime.now().isoformat(),
         "usage_count": 0,
+        "encrypted": encrypted,
     }
     
-    return {"api_key": new_key, "key_id": key_id}
+    return {
+        "api_key": new_key,  # Return plain key to user (only time they'll see it)
+        "key_id": key_id,
+        "encrypted": encrypted
+    }
 
 
 @app.delete("/admin/api-keys/{key_id}")