VPN enrollment protocol gateway

• US 7,171,556 B2
• Filed: 05/20/2005
• Issued: 01/30/2007
• Est. Priority Date: 04/12/2000
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Balaz, Rudolph, Su, Xiaohong, Vogel, Keith R., Heller, Victor W.
• Primary Examiner(s): REVAK, CHRISTOPHER A
• Application Number:
  US11/134,713
• Publication Number:
  US 20050210237A1
• Time in Patent Office: 620 Days
• Field of Search: None
• US Class Current: 713/156
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 63/0272 Virtual private networks
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 9/3265 using certificate chains, trees or paths; Hierarchical trust model
• CPC Class Codes: H04L 9/3268 using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]

Abstract

A virtual private network (VPN) enrollment protocol gateway is described herein. The protocol gateway is implemented as a registration authority that operates as an intermediary between routers and a certificate authority, allowing routers operating in accordance with one protocol to obtain and maintain certificates for a VPN from a certificate authority operating in accordance with another protocol. In accordance with one aspect, the gateway protocol supports various requests from the router, including router enrollment requests, get certificate revocation list request, get certificate requests, get certificate authority certificate requests, and password requests.

Claims

1. A registration authority comprising:

means for receiving messages from a router targeting a certificate authority, and to receive messages from the certificate authority targeting the router;

means for maintaining a mapping of certificate authority request IDs to hash values of the router requests;

wherein the means for receiving is further for converting the messages received from the router in accordance with a first protocol and converting the messages received from the router to a second protocol and subsequently communicating the converted messages to the certificate authority; and

wherein the means for receiving is further for converting the messages received from the certificate authority in accordance with the second protocol and converting the messages received from the certificate authority to the first protocol and subsequently communicating the converted messages to the router.

2. A registration authority as recited in claim 1, wherein the registration authority is independent of the certificate authority.

3. A registration authority as recited in claim 1, wherein the messages received from the router comprise one or more of:

a router enrollment message, a get certificate revocation list (CRL) message, a get certificate message, and a get certificate authority (CA) certificate message.

4. A registration authority as recited in claim 1, wherein each message received from the certificate authority comprises a response to a message received by the registration authority from the router.

5. A registration authority as recited in claim 1, wherein the router is unaware that it is communicating with a registration authority rather than directly with the certificate authority.

6. A registration authority as recited in claim 1, further comprising means for maintaining a mapping of router transaction IDs received from the router to certificate authority request IDs received from the certificate authority.

7. A registration authority as recited in claim 1, further comprising means for maintaining a valid password issued to the router.

8. A registration authority as recited in claim 1, further comprising means for receiving a request for a certificate of the certificate authority and, in response to the request, returning a certificate of the registration authority.

9. A registration authority as recited in claim 8, wherein the registration authority is a dynamically linked library.

10. A method implemented by a registration authority, the method comprising:

receiving, from a device, a first message in accordance with a first protocol, wherein the first message comprises an enrollment message;

generating, based on the first message, a second message in accordance with a second protocol;

sending the second message to a certificate authority;

receiving, from the certificate authority, a third message in response to the second message and in accordance with the second protocol, wherein the third message comprises a certificate authority pending response;

generating, based on the third message, a fourth message in accordance with the first protocol;

sending the fourth message to the device as a response to the first message; and

generating, in response to the certificate authority pending response;

a hash value based on the enrollment message;

a hash table entry mapping a pending response ID, corresponding to the certificate authority pending response, to the hash value; and

a transaction ID table entry mapping the transaction ID, corresponding to the enrollment message, to a pending response ID corresponding to the certificate authority pending response.

11. A method as recited in claim 10, wherein generating the second message comprises:

verifying that the first message has been digitally signed by the device;

decrypting the first message;

extracting a certificate enrollment request from the first message;

generating a certificate authority request including the certificate enrollment request and a subject alternative names extension; and

creating the second message by digitally signing the certificate authority request.

12. A method as recited in claim 10, wherein generating the fourth message comprises:

generating a pending response;

encrypting the pending response; and

creating the fourth message by digitally signing the encrypted pending response.

13. A method as recited in claim 10, further comprising:

receiving an additional enrollment message from the device;

accessing the transaction ID table to obtain the pending response ID corresponding to the additional enrollment message; and

transmitting, to the certificate authority, a certificate request including the pending response ID.

14. A method as recited in claim 10, further comprising:

receiving an additional enrollment message from the device;

generating a new hash value based on the additional enrollment message;

checking whether an entry in the hash table matches the new hash value; and

if an entry in the hash table matches the new hash value, then,

obtaining a pending response ID, from the hash table, corresponding to the new hash value, and

transmitting, to the certificate authority, a certificate request including the pending response ID.

15. A method as recited in claim 10, further comprising:

maintaining the transaction ID table entry in the transaction ID table for a selected amount of time.

16. A registration authority comprising:

a processor;

a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the processor to;

receive, from a device, a first message in accordance with a first protocol, wherein the first message comprises an enrollment message;

generate, based on the first message, a second message in accordance with a second protocol;

send the second message to a certificate authority;

receive, from the certificate authority, a third message in response to the second message and in accordance with the second protocol, wherein the third message comprises a certificate authority pending response;

generate, based on the third message, a fourth message in accordance with the first protocol;

send the fourth message to the device as a response to the first message; and

generate, in response to the certificate authority pending response;

a hash value based on the enrollment message;

a hash table entry mapping a pending response ID, corresponding to the certificate authority pending response, to the hash value; and

a transaction ID table entry mapping the transaction ID, corresponding to the enrollment message, to a pending response ID corresponding to the certificate authority pending response.

17. A registration authority as recited in claim 16, wherein to generate the second message is to:

verify that the first message has been digitally signed by the device;

decrypt the first message;

extract a certificate enrollment request from the first message;

generate a certificate authority request including the certificate enrollment request and a subject alternative names extension; and

create the second message by digitally signing the certificate authority request.

18. A registration authority as recited in claim 16, wherein to generate the fourth message is to:

generate a pending response;

encrypt the pending response; and

create the fourth message by digitally signing the encrypted pending response.

19. A registration authority as recited in claim 16, wherein the instructions further cause the processor to:

receive an additional enrollment message from the device;

access the transaction ID table to obtain the pending response ID corresponding to the additional enrollment message; and

transmit, to the certificate authority, a certificate request including the pending response ID.

20. A registration authority as recited in claim 16, wherein the instructions further cause the processor to:

receive an additional enrollment message from the device;

generate a new hash value based on the additional enrollment message;

check whether an entry in the hash table matches the new hash value; and

if an entry in the hash table matches the new hash value, then

obtain a pending response ID, from the hash table, corresponding to the new hash value, and

transmit, to the certificate authority, a certificate request including the pending response ID.