Info: | See github for the latest source. |
---|---|
Author: | Bernie Hackett <[email protected]> |
A native Kerberos client implementation for Python on Windows. This module mimics the API of pykerberos to implement Kerberos authentication with Microsoft's Security Support Provider Interface (SSPI). It supports Python 3.8+.
WinKerberos is in the Python Package Index (pypi). Use pip to install it:
python -m pip install winkerberos
WinKerberos requires Windows 7 / Windows Server 2008 R2 or newer.
You must have the correct version of VC++ installed for your version of Python:
- Python 3.8+ - Visual Studio 2015+ (Any version)
Once you have the required compiler installed, run the following command from the root directory of the WinKerberos source:
pip install .
First install Sphinx:
python -m pip install Sphinx
Then run the following command from the root directory of the WinKerberos source:
pip install -e . python -m sphinx -b html doc doc/_build
This is a simplified example of a complete authentication session following RFC-4752, section 3.1:
import winkerberos as kerberos
def send_response_and_receive_challenge(response):
# Your server communication code here...
pass
def authenticate_kerberos(service, user, channel_bindings=None):
# Initialize the context object with a service principal.
status, ctx = kerberos.authGSSClientInit(service)
# GSSAPI is a "client goes first" SASL mechanism. Send the
# first "response" to the server and receive its first
# challenge.
if channel_bindings is not None:
status = kerberos.authGSSClientStep(ctx, "", channel_bindings=channel_bindings)
else:
status = kerberos.authGSSClientStep(ctx, "")
response = kerberos.authGSSClientResponse(ctx)
challenge = send_response_and_receive_challenge(response)
# Keep processing challenges and sending responses until
# authGSSClientStep reports AUTH_GSS_COMPLETE.
while status == kerberos.AUTH_GSS_CONTINUE:
if channel_bindings is not None:
status = kerberos.authGSSClientStep(
ctx, challenge, channel_bindings=channel_bindings
)
else:
status = kerberos.authGSSClientStep(ctx, challenge)
response = kerberos.authGSSClientResponse(ctx) or ""
challenge = send_response_and_receive_challenge(response)
# Decrypt the server's last challenge
kerberos.authGSSClientUnwrap(ctx, challenge)
data = kerberos.authGSSClientResponse(ctx)
# Encrypt a response including the user principal to authorize.
kerberos.authGSSClientWrap(ctx, data, user)
response = kerberos.authGSSClientResponse(ctx)
# Complete authentication.
send_response_and_receive_challenge(response)
Channel bindings can be generated with help from the cryptography module. See https://tools.ietf.org/html/rfc5929#section-4.1 for the rules regarding hash algorithm choice:
from cryptography import x509
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes
def channel_bindings(ssl_socket):
server_certificate = ssl_socket.getpeercert(True)
cert = x509.load_der_x509_certificate(server_certificate, default_backend())
hash_algorithm = cert.signature_hash_algorithm
if hash_algorithm.name in ("md5", "sha1"):
digest = hashes.Hash(hashes.SHA256(), default_backend())
else:
digest = hashes.Hash(hash_algorithm, default_backend())
digest.update(server_certificate)
application_data = b"tls-server-end-point:" + digest.finalize()
return kerberos.channelBindings(application_data=application_data)
Use the help function in the python interactive shell:
>>> import winkerberos
>>> help(winkerberos)