然后我们可以使用 `secrets.compare_digest()` 来确保 `credentials.username` 是 `"stanleyjobson"`，且 `credentials.password` 是`"swordfish"`。

{* ../../docs_src/security/tutorial007_an_py39.py hl[1,12:24] *}

这类似于：

```Python
if not (credentials.username == "stanleyjobson") or not (credentials.password == "swordfish"):
    # Return some error
    ...
```

但使用 `secrets.compare_digest()`，可以防御**时差攻击**，更加安全。

### 时差攻击

    mod = importlib.import_module(f"docs_src.security.{request.param}")
    return TestClient(mod.app)


def test_security_http_basic(client: TestClient):
    response = client.get("/users/me", auth=("stanleyjobson", "swordfish"))
    assert response.status_code == 200, response.text
    assert response.json() == {"username": "stanleyjobson"}


def test_security_http_basic_no_credentials(client: TestClient):

{* ../../docs_src/security/tutorial007_an_py39.py hl[1,12:24] *}

Esto sería similar a:

```Python
if not (credentials.username == "stanleyjobson") or not (credentials.password == "swordfish"):
    # Devuelve algún error
    ...
```

{* ../../docs_src/security/tutorial007_an_py39.py hl[1,12:24] *}

Dies wäre das gleiche wie:

```Python
if not (credentials.username == "stanleyjobson") or not (credentials.password == "swordfish"):
    # Einen Error zurückgeben
    ...
```

{* ../../docs_src/security/tutorial007_an_py39.py hl[1,12:24] *}

Это было бы похоже на:

```Python
if not (credentials.username == "stanleyjobson") or not (credentials.password == "swordfish"):
    # Вернуть ошибку
    ...
```

{* ../../docs_src/security/tutorial007_an_py39.py hl[1,12:24] *}

This would be similar to:

```Python
if not (credentials.username == "stanleyjobson") or not (credentials.password == "swordfish"):
    # Return some error
    ...
```

    is_correct_username = secrets.compare_digest(
        current_username_bytes, correct_username_bytes
    )
    current_password_bytes = credentials.password.encode("utf8")
    correct_password_bytes = b"swordfish"
    is_correct_password = secrets.compare_digest(
        current_password_bytes, correct_password_bytes
    )
    if not (is_correct_username and is_correct_password):
        raise HTTPException(