dac revocation: Fallback method to parse VID/PID from crl signer

credentials/generate-revocation-set.py

@@ -64,6 +64,26 @@ def extract_single_integer_attribute(subject, oid):
  return None
 
 
+def parse_vid_pid_from_distinguished_name(distinguished_name):
+ # VID/PID encoded using Matter specific RDNs
+ vid = extract_single_integer_attribute(distinguished_name, OID_VENDOR_ID)
+ pid = extract_single_integer_attribute(distinguished_name, OID_PRODUCT_ID)
+
+ # Fallback method to get the VID/PID, encoded in CN as "Mvid:FFFF Mpid:1234"
+ if vid is None and pid is None:
+ cn = distinguished_name.get_attributes_for_oid(x509.ObjectIdentifier("2.5.4.3"))[0].value
+
+ vid_start = cn.find('Mvid:')
+ if vid_start != -1:
+ vid = int(cn[vid_start + 5:vid_start + 9], 16)
+
+ pid_start = cn.find('Mpid:')
+ if pid_start != -1:
+ pid = int(cn[pid_start + 5:pid_start + 9], 16)
+
+ return vid, pid
+
+
 class DCLDClient:
  '''
  A client for interacting with DCLD using either the REST API or command line interface (CLI).
@@ -248,14 +268,11 @@ def main(use_main_net_dcld: str, use_test_net_dcld: str, use_main_net_http: bool
  is_paa = revocation_point["isPAA"]
 
  # 3. && 4. Validate VID/PID
- # TODO: Need to support alternate representation of VID/PID (see spec "6.2.2.2. Encoding of Vendor ID and Product ID in subject and issuer fields")
- crl_vid = extract_single_integer_attribute(crl_signer_certificate.subject, OID_VENDOR_ID)
- crl_pid = extract_single_integer_attribute(crl_signer_certificate.subject, OID_PRODUCT_ID)
+ crl_vid, crl_pid = parse_vid_pid_from_distinguished_name(crl_signer_certificate.subject)
 
  if is_paa:
  if crl_vid is not None:
  if vid != crl_vid:
- # TODO: Need to log all situations where a continue is called
  logging.warning("VID is not CRL VID, continue...")
  continue
  else: