User authentication

1. A non-transitory computer-readable medium storing instructions executable by a processing resource to cause a computer to:

enroll a user to use a Virtual Private Network (VPN) server by:

requesting a token seed from a home subscriber server (HSS) through a token gateway, wherein the token seed comprises a shared key; and

receiving the token seed;

generate a token code comprising a one-to-one mapping of the user to the token seed associated with the token code;

fetch a token code, via the token gateway, from the HSS for the user; and

permit the user to login to the VPN server using the token code.

2. The medium of claim 1 , wherein the instructions are executable by the processing resource to cause the computer to authenticate the user at the VPN server by using verification information.

3. The medium of claim 2 , wherein the verification information includes at least one of:

a user name;

a mobile phone number;

a PIN code; and

a password.

4. The medium of claim 1 , comprising instructions executable by the processing resource to cause the computer to, prior to fetching the token code, enroll the user to use the VPN server by requesting the token seed and receiving the token seed.

5. The medium of claim 4 , comprising instructions executable by the processing resource to cause the computer to store an association between the received token seed and the user.

6. The medium of claim 5 , comprising instructions executable by the processing resource to cause the computer to compare information received from the user and the stored association.

7. The medium of claim 6 , wherein the information received from the user includes user information and a token code from the user.

8. A system for user authentication, comprising:

a token gateway, wherein the token gateway is operable to:

receive a request from a user device for a token code to authenticate access to a Virtual Private Network (VPN) server;

request the token code from a home subscriber server (HSS); and

send the token code to the VPN server for VPN authentication; and

an HSS, wherein the HSS is operable to:

generate the token code comprising a one-to-one mapping of the user to a token seed associated with the token code, wherein the token seed comprises a shared key; and

send the token code to the token gateway.

9. The system of claim 8 , wherein the token gateway comprises one of a short messaging service (SMS) gateway and a transport layer security (TLS) server.

10. The system of claim 8 , wherein the token gateway is operable to, at a first request from the user device:

enroll a new user of the user device; and

send a token seed associated with the new user to the VPN server.

11. The system of claim 8 , wherein the token code is generated based on a one-to-one mapping of the user of the user device to the token seed.

12. A method for user authentication, comprising:

receiving a request from a new user for enrollment of the new user into a Virtual Private Network (VPN) server;

generating a token seed for the new user, wherein the token seed is mapped to the new user, wherein the token seed comprises a shared key;

sending the token seed to the VPN server to be stored;

receiving a request for a token code from the new user; and

generating the token code comprising a one-to-one mapping of the new user to a token seed associated with the token code;

sending, via a token gateway, the token code based on the token seed to the new user.

13. The method of claim 12 , comprising sending user login information and the token code to the VPN server.

14. The method of claim 12 , comprising:

calculating an expected token code from the user; and

comparing the expected token code to the token code received from the new user.

15. The method of claim 14 , comprising authenticating the new user when the expected token code and the received token code match.

16. The medium of claim 1 , wherein the token code is generated based on a time stamp or a time period that the token code is in effect.

17. The medium of claim 1 , further comprising instructions to store the token seed in the VPN server.

18. The medium of claim 17 , further comprising instructions to store the token seed in the HSS.

19. The system of claim 8 , wherein the shared key further comprises a shared key between the HSS and an entity.

20. The system of claim 19 , wherein the entity further comprises the VPN server.