check vin validity (#25199)

selfdrive/car/car_helpers.py

@@ -7,7 +7,7 @@ from common.basedir import BASEDIR
 from system.version import is_comma_remote, is_tested_branch
 from selfdrive.car.interfaces import get_interface_attr
 from selfdrive.car.fingerprints import eliminate_incompatible_cars, all_legacy_fingerprint_cars
-from selfdrive.car.vin import get_vin, VIN_UNKNOWN
+from selfdrive.car.vin import get_vin, is_valid_vin, VIN_UNKNOWN
 from selfdrive.car.fw_versions import get_fw_versions_ordered, match_fw_to_car, get_present_ecus
 from system.swaglog import cloudlog
 import cereal.messaging as messaging
@@ -106,7 +106,7 @@ def fingerprint(logcan, sendcan):
     vin, vin_rx_addr = VIN_UNKNOWN, 0
     exact_fw_match, fw_candidates, car_fw = True, set(), []
 
-  if len(vin) != 17:
+  if not is_valid_vin(vin):
     cloudlog.event("Malformed VIN", vin=vin, error=True)
     vin = VIN_UNKNOWN
   cloudlog.warning("VIN %s", vin)

selfdrive/car/vin.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+import re
 import struct
 import traceback
 
@@ -15,6 +16,11 @@ UDS_VIN_REQUEST = bytes([uds.SERVICE_TYPE.READ_DATA_BY_IDENTIFIER]) + struct.pac
 UDS_VIN_RESPONSE = bytes([uds.SERVICE_TYPE.READ_DATA_BY_IDENTIFIER + 0x40]) + struct.pack("!H", uds.DATA_IDENTIFIER_TYPE.VIN)
 
 VIN_UNKNOWN = "0" * 17
+VIN_RE = "[A-HJ-NPR-Z0-9]{17}"
+
+
+def is_valid_vin(vin: str):
+  return re.fullmatch(VIN_RE, vin) is not None
 
 
 def get_vin(logcan, sendcan, bus, timeout=0.1, retry=5, debug=False):