Authentication method, device, and system

1. An authentication method, wherein the authentication method is applied to a next hop resolution protocol (NHRP) network, the NHRP network comprises a first network device and a second network device, and the method comprises:

determining, by the first network device, a first digest based on a fixed part field and a mandatory part field;

encrypting, by the first network device, the first digest by using a first private key, to obtain the first digital signature, wherein the first private key is symmetric to a first public key;

sending, by the first network device, a first NHRP registration request message to the second network device, wherein the first NHRP registration request message comprises the fixed part field and the mandatory part field and is used to request the second network device to perform digital certificate authentication on the first network device, and the first NHRP registration request message comprises first public key infrastructure (PKI) certificate information; and

receiving, by the first network device, a second NHRP registration request message sent by the second network device, wherein the second NHRP registration request message is used to request the first network device to perform digital certificate authentication on the second network device, and the second NHRP registration request message comprises second PKI certificate information, wherein the second PKI certificate information comprises a second digital certificate, a second digital signature, and a second public key;

determining, by the first network device, a second digest based on a fixed part field and a mandatory part field that are carried in the second NHRP registration request message;

decrypting, by the first network device, the second digital signature based on the second public key, to obtain a third digest; and

determining, by the first network device, that the second digest is the same as the third digest, and determining that the second digital certificate comprised in the second PKI certificate information and the first PKI certificate information stored in the first network device belong to a same certificate chain.

2. The method according to claim 1 , wherein the first PKI certificate information comprises a first digital certificate, the first digital signature, and the first public key, the first NHRP registration request message comprises a first authentication extension field and a first certificate extension field, the first authentication extension field comprises the first digital signature, the first certificate extension field comprises the first digital certificate and the first public key, and before the sending, by the first network device, of the first NHRP registration request message to the second network device, the method further comprises:

receiving, by the first network device, a first NHRP registration reply message sent by the second network device, wherein the first NHRP registration reply message indicates that the digital certificate authentication performed by the second network device on the first network device succeeds.

3. The method according to claim 2 , wherein the method further comprises:

sending, by the first network device, a second NHRP registration reply message to the second network device, wherein the second NHRP registration reply message indicates that the digital certificate authentication performed by the first network device on the second network device succeeds.

4. The method according to claim 1 , wherein the second NHRP registration request message comprises a second authentication extension field and a second certificate extension field, the second authentication extension field comprises the second digital signature, and the second certificate extension field comprises the second digital certificate and the second public key.

5. The method according to claim 3 , wherein the second NHRP registration request message and the first NHRP registration reply message are a same message.

6. A first network device, wherein the first network device is in a next hop resolution protocol (NHRP) network, the NHRP network further comprises a second network device, and the first network device comprises:

a processor, configured to

determine a first digest based on a fixed part field and a mandatory part field;

encrypt the first digest by using a first private key, to obtain a first digital signature, wherein the first private key is symmetric to a first public key;

generate a first NHRP registration request message, wherein the first NHRP registration request message comprises the fixed part field and the mandatory part field and is used to request the second network device to perform digital certificate authentication on the first network device, and the first NHRP registration request message comprises first public key infrastructure (PKI) certificate information;

a transmitter, configured to send the first NHRP registration request message to the second network device; and

a receiver, configured to receive a second NHRP registration request message sent by the second network device, wherein the second NHRP registration request message is used to request the first network device to perform digital certificate authentication on the second network device, and the second NHRP registration request message comprises second PKI certificate information wherein the second PKI certificate information comprises a second digital certificate, a second digital signature, and a second public key;

wherein the processor is further configured to:

determine a second digest based on a fixed part field and a mandatory part field that are carried in the second NHRP registration request message;

decrypt the second digital signature based on the second public key, to obtain a third digest; and

determine that the second digest is the same as the third digest, and determining that the second digital certificate comprised in the second PKI certificate information and the first PKI certificate information stored in the first network device belong to a same certificate chain.

7. The first network device according to claim 6 , wherein the first PKI certificate information comprises a first digital certificate, the first digital signature, and the first public key, the first NHRP registration request message comprises a first authentication extension field and a first certificate extension field, the first authentication extension field comprises the first digital signature, the first certificate extension field comprises the first digital certificate and the first public key, and the receiver is further configured to:

receive a first NHRP registration reply message sent by the second network device, wherein the first NHRP registration reply message indicates that the digital certificate authentication performed by the second network device on the first network device succeeds.

8. The first network device according to claim 7 , wherein

the transmitter is further configured to send a second NHRP registration reply message to the second network device, wherein the second NHRP registration reply message indicates that the digital certificate authentication performed by the first network device on the second network device succeeds.

9. The first network device according to claim 8 , wherein the second NHRP registration request message comprises a second authentication extension field and a second certificate extension field, the second authentication extension field comprises the second digital signature, and the second certificate extension field comprises the second digital certificate and the second public key.

10. The first network device according to claim 8 , wherein the second NHRP registration request message and the first NHRP registration reply message are a same message.

11. A second network device, wherein the second network device is in a next hop resolution protocol (NHRP) network, the NHRP network further comprises a first network device, and the second network device comprises:

a receiver, configured to receive a first NHRP registration request message sent by the first network device, wherein the first NHRP registration request message is used to request the second network device to perform digital certificate authentication on the first network device, and the first NHRP registration request message comprises first public key infrastructure (PKI) certificate information;

a processor, configured to determine, based on the first PKI certificate information, that the digital certificate authentication performed on the first network device succeeds; and

a transmitter, configured to send a first NHRP registration reply message to the first network device, wherein the first NHRP registration reply message indicates that the digital certificate authentication performed by the second network device on the first network device succeeds;

wherein the first PKI certificate information comprises a first digital certificate, a first digital signature, and a first public key, the first NHRP registration request message comprises a first authentication extension field and a first certificate extension field, the first authentication extension field comprises the first digital signature, the first certificate extension field comprises the first digital certificate and the first public key, and when the processor is configured to determine, based on the first PKI certificate information, that the digital certificate authentication performed on the first network device succeeds, the processor is specifically configured to:

determine a first digest based on a fixed part field and a mandatory part field that are carried in the first NHRP registration request message;

decrypt the first digital signature based on the first public key, to obtain a second digest; and

determine that the first digest is the same as the second digest, and determine that the first digital certificate comprised in the first PKI certificate information and a second digital certificate stored in the second network device belong to a same certificate chain.

12. The second network device according to claim 11 , wherein

the transmitter is further configured to send a second NHRP registration request message to the first network device, wherein the second NHRP registration request message is used to request the first network device to perform digital certificate authentication on the second network device, and the second NHRP registration request message comprises second PKI certificate information; and

the receiver is further configured to receive a second NHRP registration reply message sent by the first network device, wherein the second NHRP registration reply message indicates that the digital certificate authentication performed by the first network device on the second network device succeeds.

13. The second network device according to claim 12 , wherein the second NHRP registration request message and the first NHRP registration reply message are a same message.