def main(): global options parser = argparse.ArgumentParser(description='certificate validation example') # === NSS Database Group === group = parser.add_argument_group('NSS Database', 'Specify & control the NSS Database') group.add_argument('-d', '--db-name', help='NSS database name (e.g. "sql:pki")') group.add_argument('-P', '--db-passwd', help='NSS database password') # === Certificate Group === group = parser.add_argument_group('Certificate', 'Specify how the certificate is loaded') group.add_argument('-f', '--file', dest='cert_filename', help='read cert from file') group.add_argument('-F', '--input-format', choices=['pem', 'der'], help='format of input cert') group.add_argument('-n', '--nickname', dest='cert_nickname', help='load cert from NSS database by looking it up under this nickname') # === Validation Group === group = parser.add_argument_group('Validation', 'Control the validation') group.add_argument('-u', '--usage', dest='cert_usage', action='append', choices=list(cert_usage_map.keys()), help='certificate usage flags, may be specified multiple times') group.add_argument('-c', '--check-sig', action='store_true', dest='check_sig', help='check signature') group.add_argument('-C', '--no-check-sig', action='store_false', dest='check_sig', help='do not check signature') group.add_argument('-l', '--log', action='store_true', dest='with_log', help='use verify log') group.add_argument('-L', '--no-log', action='store_false', dest='with_log', help='do not use verify log') group.add_argument('-a', '--check-ca', action='store_true', dest='check_ca', help='check if cert is CA') group.add_argument('-A', '--no-check-ca', action='store_false', dest='check_ca', help='do not check if cert is CA') # === Miscellaneous Group === group = parser.add_argument_group('Miscellaneous', 'Miscellaneous options') group.add_argument('-p', '--print-cert', action='store_true', dest='print_cert', help='print the certificate in a friendly fashion') parser.set_defaults(db_name = 'sql:pki', db_passwd = 'db_passwd', input_format = 'pem', check_sig = True, with_log = True, check_ca = True, print_cert = False, ) options = parser.parse_args() # Process the command line arguments # Get usage bitmask if options.cert_usage: intended_usage = 0 for usage in options.cert_usage: try: flag = cert_usage_map[usage] except KeyError: print("Unknown usage '%s', valid values: %s" % (usage, ', '.join(sorted(cert_usage_map.keys())))) return 1 else: intended_usage |= flag else: # We can't use nss.certificateUsageCheckAllUsages here because # it's a special value of zero instead of being the bitwise OR # of all the certificateUsage* flags (go figure!) intended_usage = 0 for usage in list(cert_usage_map.values()): intended_usage |= usage if options.cert_filename and options.cert_nickname: print("You may not specify both a cert filename and a nickname, only one or the other", file=sys.stderr) return 1 if not options.cert_filename and not options.cert_nickname: print("You must specify either a cert filename or a nickname to load", file=sys.stderr) return 1 # Initialize NSS. print(indented_output('NSS Database', options.db_name)) print() nss.nss_init(options.db_name) certdb = nss.get_default_certdb() nss.set_password_callback(password_callback) # Load the cert if options.cert_filename: # Read the certificate as DER encoded data then initialize a Certificate from the DER data filename = options.cert_filename si = nss.read_der_from_file(filename, options.input_format.lower() == 'pem') # Parse the DER encoded data returning a Certificate object cert = nss.Certificate(si) else: try: cert = nss.find_cert_from_nickname(options.cert_nickname) except Exception as e: print(e) print('Unable to load cert nickname "%s" from database "%s"' % \ (options.cert_nickname, options.db_name), file=sys.stderr) return 1 # Dump the cert if the user wants to see it if options.print_cert: print(cert) else: print(indented_output('cert subject', cert.subject)) print() # Dump the usages attached to the cert print(indented_output('cert has these usages', nss.cert_type_flags(cert.cert_type))) # Should we check if the cert is a CA cert? if options.check_ca: # CA Cert? is_ca, cert_type = cert.is_ca_cert(True) print() print(indented_output('is CA cert boolean', is_ca)) print(indented_output('is CA cert returned usages', nss.cert_type_flags(cert_type))) print() print(indented_output('verifying usages for', nss.cert_usage_flags(intended_usage))) print() # Use the log or non-log variant to verify the cert # # Note: Anytime a NSPR or NSS function returns an error in python-nss it # raises a NSPRError exception. When an exception is raised the normal # return values are discarded because the flow of control continues at # the first except block prepared to catch the exception. Normally this # is what is desired because the return values would be invalid due to # the error. However the certificate verification functions are an # exception (no pun intended). An error might be returned indicating the # cert failed verification but you may still need access to the returned # usage bitmask and the log (if using the log variant). To handle this a # special error exception `CertVerifyError` (derived from `NSPRError`) # is defined which in addition to the normal NSPRError fields will also # contain the returned usages and optionally the CertVerifyLog # object. If no exception is raised these are returned as normal return # values. approved_usage = 0 if options.with_log: try: approved_usage, log = cert.verify_with_log(certdb, options.check_sig, intended_usage, None) except nss_error.CertVerifyError as e: # approved_usage and log available in CertVerifyError exception on failure. print(e) print() print(indented_obj('log', e.log)) print() print(indented_output('approved usages from exception', nss.cert_usage_flags(e.usages))) approved_usage = e.usages # Get the returned usage bitmask from the exception except Exception as e: print(e) else: print(indented_output('approved usages', nss.cert_usage_flags(approved_usage))) if log.count: print() print(indented_obj('log', log)) else: try: approved_usage = cert.verify(certdb, options.check_sig, intended_usage, None) except nss_error.CertVerifyError as e: # approved_usage available in CertVerifyError exception on failure. print(e) print(indented_output('approved usages from exception', nss.cert_usage_flags(e.usages))) approved_usage = e.usages # Get the returned usage bitmask from the exception except Exception as e: print(e) else: print(indented_output('approved usages', nss.cert_usage_flags(approved_usage))) # The cert is valid if all the intended usages are in the approved usages valid = (intended_usage & approved_usage) == intended_usage print() if valid: print(indented_output('SUCCESS: cert is approved for', nss.cert_usage_flags(intended_usage))) return 0 else: print(indented_output('FAIL: cert not approved for', nss.cert_usage_flags(intended_usage ^ approved_usage))) return 1
def main(): global options parser = argparse.ArgumentParser( description='certificate validation example') # === NSS Database Group === group = parser.add_argument_group('NSS Database', 'Specify & control the NSS Database') group.add_argument('-d', '--db-name', help='NSS database name (e.g. "sql:pki")') group.add_argument('-P', '--db-passwd', help='NSS database password') # === Certificate Group === group = parser.add_argument_group('Certificate', 'Specify how the certificate is loaded') group.add_argument('-f', '--file', dest='cert_filename', help='read cert from file') group.add_argument('-F', '--input-format', choices=['pem', 'der'], help='format of input cert') group.add_argument( '-n', '--nickname', dest='cert_nickname', help='load cert from NSS database by looking it up under this nickname' ) # === Validation Group === group = parser.add_argument_group('Validation', 'Control the validation') group.add_argument( '-u', '--usage', dest='cert_usage', action='append', choices=list(cert_usage_map.keys()), help='certificate usage flags, may be specified multiple times') group.add_argument('-c', '--check-sig', action='store_true', dest='check_sig', help='check signature') group.add_argument('-C', '--no-check-sig', action='store_false', dest='check_sig', help='do not check signature') group.add_argument('-l', '--log', action='store_true', dest='with_log', help='use verify log') group.add_argument('-L', '--no-log', action='store_false', dest='with_log', help='do not use verify log') group.add_argument('-a', '--check-ca', action='store_true', dest='check_ca', help='check if cert is CA') group.add_argument('-A', '--no-check-ca', action='store_false', dest='check_ca', help='do not check if cert is CA') # === Miscellaneous Group === group = parser.add_argument_group('Miscellaneous', 'Miscellaneous options') group.add_argument('-p', '--print-cert', action='store_true', dest='print_cert', help='print the certificate in a friendly fashion') parser.set_defaults( db_name='sql:pki', db_passwd='db_passwd', input_format='pem', check_sig=True, with_log=True, check_ca=True, print_cert=False, ) options = parser.parse_args() # Process the command line arguments # Get usage bitmask if options.cert_usage: intended_usage = 0 for usage in options.cert_usage: try: flag = cert_usage_map[usage] except KeyError: print("Unknown usage '%s', valid values: %s" % (usage, ', '.join(sorted(cert_usage_map.keys())))) return 1 else: intended_usage |= flag else: # We can't use nss.certificateUsageCheckAllUsages here because # it's a special value of zero instead of being the bitwise OR # of all the certificateUsage* flags (go figure!) intended_usage = 0 for usage in list(cert_usage_map.values()): intended_usage |= usage if options.cert_filename and options.cert_nickname: print( "You may not specify both a cert filename and a nickname, only one or the other", file=sys.stderr) return 1 if not options.cert_filename and not options.cert_nickname: print("You must specify either a cert filename or a nickname to load", file=sys.stderr) return 1 # Initialize NSS. print(indented_output('NSS Database', options.db_name)) print() nss.nss_init(options.db_name) certdb = nss.get_default_certdb() nss.set_password_callback(password_callback) # Load the cert if options.cert_filename: # Read the certificate as DER encoded data then initialize a Certificate from the DER data filename = options.cert_filename si = nss.read_der_from_file(filename, options.input_format.lower() == 'pem') # Parse the DER encoded data returning a Certificate object cert = nss.Certificate(si) else: try: cert = nss.find_cert_from_nickname(options.cert_nickname) except Exception as e: print(e) print('Unable to load cert nickname "%s" from database "%s"' % \ (options.cert_nickname, options.db_name), file=sys.stderr) return 1 # Dump the cert if the user wants to see it if options.print_cert: print(cert) else: print(indented_output('cert subject', cert.subject)) print() # Dump the usages attached to the cert print( indented_output('cert has these usages', nss.cert_type_flags(cert.cert_type))) # Should we check if the cert is a CA cert? if options.check_ca: # CA Cert? is_ca, cert_type = cert.is_ca_cert(True) print() print(indented_output('is CA cert boolean', is_ca)) print( indented_output('is CA cert returned usages', nss.cert_type_flags(cert_type))) print() print( indented_output('verifying usages for', nss.cert_usage_flags(intended_usage))) print() # Use the log or non-log variant to verify the cert # # Note: Anytime a NSPR or NSS function returns an error in python-nss it # raises a NSPRError exception. When an exception is raised the normal # return values are discarded because the flow of control continues at # the first except block prepared to catch the exception. Normally this # is what is desired because the return values would be invalid due to # the error. However the certificate verification functions are an # exception (no pun intended). An error might be returned indicating the # cert failed verification but you may still need access to the returned # usage bitmask and the log (if using the log variant). To handle this a # special error exception `CertVerifyError` (derived from `NSPRError`) # is defined which in addition to the normal NSPRError fields will also # contain the returned usages and optionally the CertVerifyLog # object. If no exception is raised these are returned as normal return # values. approved_usage = 0 if options.with_log: try: approved_usage, log = cert.verify_with_log(certdb, options.check_sig, intended_usage, None) except nss_error.CertVerifyError as e: # approved_usage and log available in CertVerifyError exception on failure. print(e) print() print(indented_obj('log', e.log)) print() print( indented_output('approved usages from exception', nss.cert_usage_flags(e.usages))) approved_usage = e.usages # Get the returned usage bitmask from the exception except Exception as e: print(e) else: print( indented_output('approved usages', nss.cert_usage_flags(approved_usage))) if log.count: print() print(indented_obj('log', log)) else: try: approved_usage = cert.verify(certdb, options.check_sig, intended_usage, None) except nss_error.CertVerifyError as e: # approved_usage available in CertVerifyError exception on failure. print(e) print( indented_output('approved usages from exception', nss.cert_usage_flags(e.usages))) approved_usage = e.usages # Get the returned usage bitmask from the exception except Exception as e: print(e) else: print( indented_output('approved usages', nss.cert_usage_flags(approved_usage))) # The cert is valid if all the intended usages are in the approved usages valid = (intended_usage & approved_usage) == intended_usage print() if valid: print( indented_output('SUCCESS: cert is approved for', nss.cert_usage_flags(intended_usage))) return 0 else: print( indented_output( 'FAIL: cert not approved for', nss.cert_usage_flags(intended_usage ^ approved_usage))) return 1
cert = nss.find_cert_from_nickname(options.cert_nickname) except Exception, e: print e print >>sys.stderr, 'Unable to load cert nickname "%s" from database "%s"' % \ (options.cert_nickname, options.dbdir) return 1 # Dump the cert if the user wants to see it if options.print_cert: print cert else: print indented_output('cert subject', cert.subject) print # Dump the usages attached to the cert print indented_output('cert has these usages', nss.cert_type_flags(cert.cert_type)) # Should we check if the cert is a CA cert? if options.check_ca: # CA Cert? is_ca, cert_type = cert.is_ca_cert(True) print print indented_output('is CA cert boolean', is_ca) print indented_output('is CA cert returned usages', nss.cert_type_flags(cert_type)) print print indented_output('verifying usages for', nss.cert_usage_flags(intended_usage)) print # Use the log or non-log variant to verify the cert #