Python SPNEGO Authentication Library

import spnego
import os

# Example for a client initiating a Negotiate (SPNEGO) context
# Replace with actual credentials or environment variables
username = os.environ.get('SPNEGO_USERNAME', 'testuser')
password = os.environ.get('SPNEGO_PASSWORD', 'testpassword')
service_principal_name = os.environ.get('SPNEGO_SPN', 'HTTP@myservice.example.com')

try:
    # Create a client context. 'negotiate' is the default protocol.
    # For NTLM: protocol='ntlm'
    # For Kerberos: protocol='kerberos' (requires system GSSAPI/Kerberos libs on Linux)
    client_context = spnego.client.Context(
        username=username,
        password=password,
        hostname=service_principal_name.split('@')[1] if '@' in service_principal_name else None,
        service=service_principal_name.split('@')[0] if '@' in service_principal_name else None,
        protocol='negotiate'
    )

    # The client typically sends an initial token
    initial_token = client_context.step()

    print(f"Initial SPNEGO token (base64 encoded): {initial_token.decode('utf-8')}")

    # In a real scenario, this token would be sent to the server,
    # which would then return a response token. The client would then
    # call client_context.step(server_response_token) until complete.

except spnego.exceptions.NegotiateError as e:
    print(f"Authentication error: {e}")
except Exception as e:
    print(f"An unexpected error occurred: {e}")