在 FastAPI 版本 `0.122.0` 之前，當內建的安全工具在身分驗證失敗後回傳錯誤給用戶端時，會使用 HTTP 狀態碼 `403 Forbidden`。

從 FastAPI 版本 `0.122.0` 起，改為使用更合適的 HTTP 狀態碼 `401 Unauthorized`，並在回應中依據 HTTP 規範加上合理的 `WWW-Authenticate` 標頭，參考 [RFC 7235](https://datatracker.ietf.org/doc/html/rfc7235#section-3.1)、[RFC 9110](https://datatracker.ietf.org/doc/html/rfc9110#name-401-unauthorized)。

 * [okhttp3.OkHttpClient.Builder.authenticator] or [okhttp3.OkHttpClient.Builder.proxyAuthenticator].
 */
class JavaNetAuthenticator(
  private val defaultDns: Dns = Dns.SYSTEM,
) : okhttp3.Authenticator {
  @Throws(IOException::class)
  override fun authenticate(
    route: Route?,
    response: Response,
  ): Request? {
    val challenges = response.challenges()
    val request = response.request
    val url = request.url

                ntlm = (NtlmPasswordAuthentication) ssn.getAttribute("npa-" + server);
            }
            if (ntlm == null) {
                resp.setHeader("WWW-Authenticate", "NTLM");
                if (offerBasic) {
                    resp.addHeader("WWW-Authenticate", "Basic realm=\"" + realm + "\"");
                }
                resp.setHeader("Connection", "close");

        self.auto_error = auto_error

    def make_not_authenticated_error(self) -> HTTPException:
        return HTTPException(
            status_code=HTTP_401_UNAUTHORIZED,
            detail="Not authenticated",
            headers={"WWW-Authenticate": "Bearer"},
        )

    async def __call__(self, request: Request) -> str | None:
        authorization = request.headers.get("Authorization")
        if not authorization:

        // Full NTLM handshake testing would require more complex mocking

        // Arrange - Mock a server that supports NTLM
        mockResponse(HTTP_UNAUTHORIZED, "Unauthorized", Collections.singletonMap("WWW-Authenticate", Collections.singletonList("NTLM")),
                new ByteArrayInputStream(new byte[0]));

        // Act - Trigger handshake
        int responseCode = ntlmConnection.getResponseCode();

/// tip

The *path operation* for `swagger_ui_redirect` is a helper for when you use OAuth2.

If you integrate your API with an OAuth2 provider, you will be able to authenticate and come back to the API docs with the acquired credentials. And interact with it using the real OAuth2 authentication.

Swagger UI will handle it behind the scenes for you, but it needs this "redirect" helper.

///

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

    'sts',
    region_name='us-east-1',
    use_ssl=False,
    endpoint_url='http://localhost:9000',
)

app = Flask(__name__)


@app.route('/')
def homepage():
    text = '<a href="%s">Authenticate with keycloak</a>'
    return text % make_authorization_url()


def make_authorization_url():
    # Generate a random string for the state parameter
    # Save it for use later to prevent xsrf attacks

     */
    AuthType getAuthType();

    /**
     * Authenticates using the provided context
     *
     * @param context the CIFS context
     * @param challenge the server challenge (may be null for some auth types)
     * @return authentication response data
     * @throws CIFSException if authentication fails
     */
    byte[] authenticate(CIFSContext context, byte[] challenge) throws CIFSException;

    /**

import jcifs.internal.smb2.Smb2Constants;
import jcifs.internal.util.SMBUtil;

/**
 * SMB2 Session Setup request message. This command is used to establish a security session
 * and authenticate a user to the server.
 *
 * @author mbechler
 *
 */
public class Smb2SessionSetupRequest extends ServerMessageBlock2Request<Smb2SessionSetupResponse> {

    private final byte[] token;