rfc3161-client

import os import hashlib from rfc3161_client import TimestampRequest, VerifierBuilder, HashAlgorithm from rfc3161_client.exceptions import TSAResponseError, TimestampVerificationError # Use a public TSA URL. For production, ensure this is a trusted service. # Example: http://timestamp.digicert.com or a URL from your trusted provider. TSA_URL = os.environ.get('RFC3161_TSA_URL', 'http://timestamp.digicert.com') # 1. Prepare data to be timestamped message = b"This is the data to be timestamped." message_hash = hashlib.sha256(message).digest() print(f"Attempting to timestamp data using TSA: {TSA_URL}") # 2. Request a timestamp from the TSA try: request = TimestampRequest( tsa_url=TSA_URL, hashed_message=message_hash, hash_algorithm=HashAlgorithm.SHA256, ) timestamp_response = request.get_timestamp_response() print("Timestamp received successfully.") # 3. Verify the timestamp response # For robust verification, provide 'trusted_root_certs' of the TSA. # If not provided, the verifier attempts to build a chain from certs # embedded in the response or system CAs where possible (less secure). verifier = VerifierBuilder().build() is_valid = verifier.verify( timestamp_response=timestamp_response, hashed_message=message_hash, hash_algorithm=HashAlgorithm.SHA256, # trusted_root_certs=[b"-----BEGIN CERTIFICATE-----\n...\n-----END CERTIFICATE-----"], ) if is_valid: print("Timestamp verification successful.") else: print("Timestamp verification FAILED.") except TSAResponseError as e: print(f"Error from TSA: {e}") except TimestampVerificationError as e: print(f"Timestamp verification error: {e}") except Exception as e: print(f"An unexpected error occurred: {e}")