OFFLOADING CRYPTOGRAPHIC PROTECTION PROCESSING

• US 20100228962A1
• Filed: 03/09/2009
• Published: 09/09/2010
• Est. Priority Date: 03/09/2009
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Simon, Daniel R., Swander, Brian D., Menezes, Pascal
• Application Number:
  US12/400,281
• Publication Number:
  US 20100228962A1
• Time in Patent Office: Days
• US Class Current: 713/150
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0471 applying encryption by an intermediary, e.g. receiving clear information at the intermediary and encrypting the received information at the intermediary before forwarding
• CPC Class Codes: H04L 63/0485 Networking architectures for enhanced packet encryption processing, e.g. offloading of IPsec packet processing or efficient security association look-up
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys

Abstract

Some embodiments are directed to processing packet data sent according to a security protocol between a first computer and a second computer via a forwarding device. The forwarding device performs a portion of the processing, and forwards the packet data to a third computer, connected to the forwarding device, for other processing. The third computer may support non-standard extensions to the security protocol, such as extensions used in authorizing and establishing a connection over the secure protocol. The packet data may be subject to policies, such as firewall policies or security policies, that may be detected by the third computer. The third computer sends the results of its processing, such as a cryptographic key, or a detected access control policy, to the forwarding device.

Claims

1. A method of processing encryption data in a computer system comprising a first computer that communicates with at least one second computer via a packet forwarding device coupled to a third computer, the method comprising:

receiving, at the packet forwarding device, a first packet sent from the first computer to the at least one second computer, wherein the first computer does not designate the third computer as a recipient of the first packet;

determining whether the first packet comprises a control packet for configuring an encrypted connection between the first computer and the at least one second computer;

when it is determined that the first packet comprises a control packet;

sending the control packet to the third computer; and

in response to sending the control packet to the third computer, receiving from the third computer at least one cryptographic key; and

when it is determined that the first packet comprises at least one cryptographically protected data packet;

cryptographically unprotecting the at least one cryptographically protected data packet using the at least one cryptographic key.

2. The method of claim 1, wherein the first packet is sent according to either the TLS protocol or the SSL protocol.

3. The method of claim 1, wherein the first packet is sent according to the IPsec protocol.

4. The method of claim 3, wherein the control packet comprises a packet sent according to a negotiation protocol, and wherein the negotiation protocol comprises at least one of the Internet Key Exchange (IKE) protocol or the AuthIP protocol.

5. The method of claim 4, wherein the method further comprises an act of establishing on the third computer a Security Association (SA) operating in transport mode negotiated according to the negotiation protocol between the first computer and the third computer.

6. The method of claim 5, wherein the act of receiving from the third computer at least one cryptographic key further comprises an act of receiving from the third computer at least one cryptographic key and at least one Security Parameter Index (SPI), wherein the at least one cryptographic key and the at least one SPI are associated with the SA negotiated between the first computer and the third computer, and wherein the method further comprises storing in computer memory on the forwarding device the at least one cryptographic key and the at least one SPI.

7. The method of claim 6, wherein the at least one cryptographic key and the at least one SPI are received over a NIC offload interface on the third computer.

8. The method of claim 7, wherein that act of determining that the first packet comprises at least one cryptographically protected data packet comprises determining that the first packet comprises at least one cryptographically protected data packet associated with the at least one cryptographic key and the at least one SPI.

9. At least one computer-readable medium encoded with instructions that, when executed on a computer system, perform a method of processing encryption data, wherein the computer system comprises a first computer that communicates with at least one second computer via a packet forwarding device, the computer system further comprising a third computer connected to the packet forwarding device, the method comprising:

receiving, at the third computer, an encapsulated packet from the packet forwarding device;

decapsulating the encapsulated packet to generate a decapsulated packet;

injecting the decapsulated packet onto a networking stack on the third computer;

detecting at least one access control policy applied to the decapsulated packet by the third computer; and

sending information describing the at least one access control policy to the packet forwarding device.

10. The at least one computer-readable medium of claim 9, wherein the decapsulated packet comprises a packet that was sent from the first computer to the at least one second computer.

11. The at least one computer-readable medium of claim 10, wherein the at least one access control policy comprises at least one firewall policy indicating whether the decapsulated packet should be forwarded to the at least one second computer.

12. The at least one computer-readable medium of claim 10, wherein the at least one access control policy comprises at least one cryptographic protection policy indicating whether the decapsulated packet should be cryptographically protected before being forwarded to the at least one second computer.

13. The at least one computer-readable medium of claim 10, wherein the at least one access control policy is specified by a group policy object.

14. The at least one computer-readable medium of claim 10, wherein detecting at least one access control policy applied to the decapsulated packet by the third computer is performed using a detection filter operating via a filtering platform.

15. The at least one computer-readable medium of claim 10, wherein the act of injecting the decapsulated packet onto a networking stack on third computer is performed by an injection filter operating via a filtering platform.

16. A packet forwarding device for use in a computer system comprising the packet forwarding device, a first computer that communicates with at least one second computer via the packet forwarding device, and a third computer coupled to the packet forwarding device, the packet forwarding device comprising:

a communication interface; and

at least one controller that;

receives, via the communication interface, a first packet sent from the first computer to the at least one second computer;

determines by consulting information stored in a memory of the packet forwarding device whether the first packet is associated with a connection between the first computer and the at least one second computer that is permitted according to at least one access control policy;

when it is determined that the first packet is associated with a connection between the first computer and the at least one second computer that is permitted according to at least one access control policy;

sends the first packet to the at least one second computer; and

when it is determined that the first packet is not associated with a connection between the first computer and the at least one second computer that is permitted according to at least one access control policy;

sends the first packet to the third computer;

in response to sending the first packet to the third computer, receives information describing at least one access control policy indicating whether the first packet may be sent to the at least one second computer; and

updates the information stored in the memory of the packet forwarding device with the information describing the at least one access control policy for a connection between the first computer and the at least one second computer.

17. The packet forwarding device of claim 16, wherein:

the information describing the at least one access control policy comprises at least one cryptographic key; and

prior to sending the first packet to the at least one second computer, the at least one controller;

determines by consulting the information stored in the memory whether the first packet is to be encrypted and/or cryptographically integrity-protected;

and

when it is determined that the first packet is to be encrypted and/or integrity-protected, encrypts and/or integrity-protects the first packet to generate a protected packet using the at least one cryptographic key.

18. The packet forwarding device of claim 16, wherein the at least one controller sends the first packet to a NIC offload interface on the third computer.

19. The packet forwarding device of claim 16, wherein the at least one controller encapsulates the first packet to generate an encapsulated packet, and sends the encapsulated packet to the third computer.

20. The packet forwarding device of claim 16, wherein the first packet is formatted according to the IPsec protocol.