Certificate status determining method

1. A method implemented by a receive end and comprising:

receiving, from a transmit end, a message comprising a transmit end certificate of the transmit end, wherein the transmit end certificate comprises first classification information, and wherein the first classification information comprises first level-1 classification information and first level-2 classification information;

determining, based on the first classification information, a set of revocation identifiers in a certificate revocation list, wherein the revocation identifiers comprise a first revocation identifier identifying a first revoked certificate in the certificate revocation list, wherein the first revocation identifier comprises second classification information of the first revoked certificate, wherein the second classification information is the same as the first classification information, and wherein determining the set of revocation identifiers comprises:

determining a first set of revocation identifiers in the certificate revocation list based on the first level-1 classification information, wherein second level-1 classification information in revocation identifiers in the first set is the same as the first level-1 classification information; and

determining, based on the first level-2 classification information, a second set of revocation identifiers in the first set, wherein second level-2 classification information in revocation identifiers in the second set is the same as the first level-2 classification information;

extracting first feature information of the transmit end certificate;

performing matching of the first feature information with second feature information of the first revoked certificate; and

determining, based on a result of the matching, a status of the transmit end certificate.

2. The method of claim 1 , wherein third feature information in the first revocation identifier is a random number of N bytes in a first defined field of the first revoked certificate, wherein N is a positive integer greater than 0, and wherein extracting the first feature information comprises intercepting the N bytes from the first defined field and using the N bytes as the first feature information.

3. The method of claim 1 , wherein third feature information in the first revocation identifier is a hash value of M bytes and is based on a hash operation on the first revoked certificate, wherein M is a positive integer greater than 0, and wherein extracting the first feature information comprises performing the hash operation on the transmit end certificate to obtain the hash value and using the hash value as the first feature information.

4. The method of claim 1 , wherein the first classification information is in a second defined field of the transmit end certificate.

5. The method of claim 4 , wherein the second defined field is a certificate identifier field of the transmit end certificate, a region field of the transmit end certificate, or a certificate revocation series field of the transmit end certificate.

6. The method of claim 1 , before determining the set of revocation identifiers, the method further comprises obtaining the certificate revocation list from a certificate revocation server.

7. The method of claim 6 , wherein obtaining the certificate revocation list comprises:

obtaining a full certificate revocation list from the certificate revocation server;

obtaining a differential certificate revocation list from the certificate revocation server, wherein the differential certificate revocation list comprises an added certificate revocation list and a deleted certificate revocation list, wherein the added certificate revocation list comprises an added revocation identifier in comparison with the full certificate revocation list, and wherein the deleted certificate revocation list comprises a deleted revocation identifier in comparison with the full certificate revocation list; and

refreshing the full certificate revocation list based on the differential certificate revocation list.

8. The method of claim 1 , wherein determining the status of the transmit end certificate comprises determining that the transmit end certificate is revoked when the first feature information is the same as the second feature information or that the transmit end certificate is not revoked when the first feature information is not the same as the second feature information.

9. The method of claim 1 , wherein the receive end or the transmit end is an on-board unit (OBU) or a roadside unit (RSU).

10. A method implemented by a receive end and comprising:

obtaining a certificate revocation fingerprint library from a certificate revocation server or a vehicle-to-everything communications unit by:

obtaining a full certificate revocation fingerprint library comprising fingerprint information of all revoked certificates;

obtaining a differential certificate revocation fingerprint location library that records bit information of changes to the full certificate revocation fingerprint library; and

performing, based on the differential certificate revocation fingerprint location library, a negation operation on a value corresponding to a bit that changes in the full certificate revocation fingerprint library;

receiving, from a transmit end, a message comprising a transmit end certificate of the transmit end;

calculating first fingerprint information of the transmit end certificate based on the transmit end certificate;

determining that second fingerprint information of a revoked certificate in the certificate revocation fingerprint library matches the first fingerprint information;

sending, to the certificate revocation server, the transmit end certificate to request verification of a status of the transmit end certificate;

receiving, from the certificate revocation server in response to the transmit end certificate, a verification result; and

determining the status based on the verification result.

11. The method of claim 10 , further comprising discarding the message when the transmit end certificate is revoked.

12. A vehicle-to-everything communications unit comprising:

an interface configured to receive, from a transmit end, a message comprising a transmit end certificate of the transmit end, wherein the transmit end certificate comprises first classification information, and wherein the first classification information comprises first level-1 classification information and first level-2 classification information; and

a processor coupled to the interface and configured to:

determine, based on the first classification information, a set of revocation identifiers in a certificate revocation list, wherein the revocation identifiers comprise a first revocation identifier identifying a first revoked certificate in the certificate revocation list, wherein the first revocation identifier comprises second classification information of the first revoked certificate, wherein the second classification information is the same as the first classification information, wherein the processor is configured to determine the set of revocation identifiers by:

determining a first set of revocation identifiers in the certificate revocation list based on the first level-1 classification information, wherein second level-1 classification information in revocation identifiers in the first set is the same as the first level-1 classification information; and

determining, based on the first level-2 classification information, a second set of revocation identifiers in the first set, wherein second level-2 classification information in revocation identifiers in the second set is the same as the first level-2 classification information;

extract first feature information of the transmit end certificate;

perform matching of the first feature information with second feature information of the first revoked certificate; and

determine, based on a result of the matching, a status of the transmit end certificate.

13. The vehicle-to-everything communications unit of claim 12 , wherein third feature information in the first revocation identifier is a random number of N bytes in a first defined field of the first revoked certificate, wherein N is a positive integer greater than 0, and wherein extracting the first feature information comprises intercepting the N bytes from the first defined field and using the N bytes as the first feature information.

14. The vehicle-to-everything communications unit of claim 12 , wherein third feature information in the first revocation identifier is a hash value of M bytes and is based on a hash operation on the first revoked certificate, wherein M is a positive integer greater than 0, and wherein extracting the first feature information comprises performing the hash operation on the transmit end certificate to obtain the hash value and using the hash value as the first feature information.

15. The vehicle-to-everything communications unit of claim 12 , wherein the first classification information is in a second defined field of the transmit end certificate.

16. The vehicle-to-everything communications unit of claim 15 , wherein the second defined field is a certificate identifier field of the transmit end certificate, a region field of the transmit end certificate, or a certificate revocation series field of the transmit end certificate.

17. The vehicle-to-everything communications unit of claim 12 , wherein before determining the first set and determining the second set, the processor is further configured to obtain the certificate revocation list from a certificate revocation server.

18. The vehicle-to-everything communications unit of claim 17 , wherein the processor is further configured to obtain the certificate revocation list by:

obtaining a full certificate revocation list from the certificate revocation server;

obtaining a differential certificate revocation list from the certificate revocation server, wherein the differential certificate revocation list comprises an added certificate revocation list and a deleted certificate revocation list, wherein the added certificate revocation list comprises an added revocation identifier in comparison with the full certificate revocation list, and wherein the deleted certificate revocation list comprises a deleted revocation identifier in comparison with the full certificate revocation list; and

refreshing the full certificate revocation list based on the differential certificate revocation list.

19. The vehicle-to-everything communications unit of claim 12 , wherein the processor is further configured to determine the status of the transmit end certificate by determining that the transmit end certificate is revoked when the first feature information is the same as the second feature information or that the transmit end certificate is not revoked when the first feature information is not the same as the second feature information.

20. The vehicle-to-everything communications unit of claim 12 , wherein the vehicle-to-everything communications unit or the transmit end is an on-board unit (OBU) or a roadside unit (RSU).