The cryptography system parsed a CRL file that contains a revoked certificate with a serial number of 0.

[onepeople158]

Version:
cryptography-44.0.2

Hello Developer,

I have a CRL file that contains a revoked certificate with a serial number of 0. Cryptography successfully parsed this serial number without any errors. However, according to RFC 5280, the certificate serial number must be a non-negative integer. At the same time, tests show that cryptography will reject the parsing of revoked certificates with negative serial numbers.

Code:

from cryptography.x509 import load_pem_x509_crl, load_der_x509_crl
from cryptography.x509 import ExtensionNotFound
import sys

def load_crl(file_path):
    with open(file_path, "rb") as f:
        crl_data = f.read()
    try:
        crl = load_pem_x509_crl(crl_data)
    except ValueError:
        crl = load_der_x509_crl(crl_data)
    return crl

def print_crl_issuer(file_path):
    crl=load_crl(file_path)
    try:
        for entry in crl:
               print(entry)
    except Exception as e:
        print(f"Error occurred: {e}")

file_path = 'crl_revoked_serial_0.der'
print_crl_issuer(file_path)

Test Case:

crl_revoked_serial_0.zip

Another Test Case:

crl_revoked_serial_-24.zip