requests Kerberos/GSSAPI authentication library =============================================== Requests is an HTTP library, written in Python, for human beings. This library adds optional Kerberos/GSSAPI authentication support and supports mutual authentication. Basic GET usage: .. code-block:: python >>> import requests >>> from requests_kerberos import HTTPKerberosAuth >>> r = requests.get("http://example.org", auth=HTTPKerberosAuth()) ... The entire ``requests.api`` should be supported. Authentication Failures ----------------------- Client authentication failures will be communicated to the caller by returning the 401 response. Mutual Authentication --------------------- REQUIRED ^^^^^^^^ By default, ``HTTPKerberosAuth`` will require mutual authentication from the server, and if a server emits a non-error response which cannot be authenticated, a ``requests_kerberos.errors.MutualAuthenticationError`` will be raised. If a server emits an error which cannot be authenticated, it will be returned to the user but with its contents and headers stripped. If the response content is more important than the need for mutual auth on errors, (eg, for certain WinRM calls) the stripping behavior can be suppressed by setting ``sanitize_mutual_error_response=False``: .. code-block:: python >>> import requests >>> from requests_kerberos import HTTPKerberosAuth, REQUIRED >>> kerberos_auth = HTTPKerberosAuth(mutual_authentication=REQUIRED, sanitize_mutual_error_response=False) >>> r = requests.get("https://windows.example.org/wsman", auth=kerberos_auth) ... OPTIONAL ^^^^^^^^ If you'd prefer to not require mutual authentication, you can set your preference when constructing your ``HTTPKerberosAuth`` object: .. code-block:: python >>> import requests >>> from requests_kerberos import HTTPKerberosAuth, OPTIONAL >>> kerberos_auth = HTTPKerberosAuth(mutual_authentication=OPTIONAL) >>> r = requests.get("http://example.org", auth=kerberos_auth) ... This will cause ``requests_kerberos`` to attempt mutual authentication if the server advertises that it supports it, and cause a failure if authentication fails, but not if the server does not support it at all. DISABLED ^^^^^^^^ While we don't recommend it, if you'd prefer to never attempt mutual authentication, you can do that as well: .. code-block:: python >>> import requests >>> from requests_kerberos import HTTPKerberosAuth, DISABLED >>> kerberos_auth = HTTPKerberosAuth(mutual_authentication=DISABLED) >>> r = requests.get("http://example.org", auth=kerberos_auth) ... Preemptive Authentication ------------------------- ``HTTPKerberosAuth`` can be forced to preemptively initiate the Kerberos GSS exchange and present a Kerberos ticket on the initial request (and all subsequent). By default, authentication only occurs after a ``401 Unauthorized`` response containing a Kerberos or Negotiate challenge is received from the origin server. This can cause mutual authentication failures for hosts that use a persistent connection (eg, Windows/WinRM), as no Kerberos challenges are sent after the initial auth handshake. This behavior can be altered by setting ``force_preemptive=True``: .. code-block:: python >>> import requests >>> from requests_kerberos import HTTPKerberosAuth, REQUIRED >>> kerberos_auth = HTTPKerberosAuth(mutual_authentication=REQUIRED, force_preemptive=True) >>> r = requests.get("https://windows.example.org/wsman", auth=kerberos_auth) ... Hostname Override ----------------- If communicating with a host whose DNS name doesn't match its kerberos hostname (eg, behind a content switch or load balancer), the hostname used for the Kerberos GSS exchange can be overridden by setting the ``hostname_override`` arg: .. code-block:: python >>> import requests >>> from requests_kerberos import HTTPKerberosAuth, REQUIRED >>> kerberos_auth = HTTPKerberosAuth(hostname_override="internalhost.local") >>> r = requests.get("https://externalhost.example.org/", auth=kerberos_auth) ... Explicit Principal ------------------ ``HTTPKerberosAuth`` normally uses the default principal (ie, the user for whom you last ran ``kinit`` or ``kswitch``, or an SSO credential if applicable). However, an explicit principal can be specified, which will cause Kerberos to look for a matching credential cache for the named user. This feature depends on OS support for collection-type credential caches, as well as working principal support in pykerberos (it is broken in many builds). An explicit principal can be specified with the ``principal`` arg: .. code-block:: python >>> import requests >>> from requests_kerberos import HTTPKerberosAuth, REQUIRED >>> kerberos_auth = HTTPKerberosAuth(principal="user@REALM") >>> r = requests.get("http://example.org", auth=kerberos_auth) ... **Windows users:** Explicit Principal is currently not supported when using ``kerberos-sspi``. Providing a value for ``principal`` in this scenario will raise ``NotImplementedError``. Logging ------- This library makes extensive use of Python's logging facilities. Log messages are logged to the ``requests_kerberos`` and ``requests_kerberos.kerberos_`` named loggers. If you are having difficulty we suggest you configure logging. Issues with the underlying kerberos libraries will be made apparent. Additionally, copious debug information is made available which may assist in troubleshooting if you increase your log level all the way up to debug.