Secure communication session resumption in a service function chain

• US 10,554,689 B2
• Filed: 04/28/2017
• Issued: 02/04/2020
• Est. Priority Date: 04/28/2017
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Reddy, K Tirumaleswar, Patil, Prashanth, Pignataro, Carlos M.
• Primary Examiner(s): Li, Meng
• Application Number:
  US15/582,026
• Publication Number:
  US 20180316724A1
• Time in Patent Office: 1,012 Days
• CPC Class Codes: H04L 2463/062 applying encryption of the keys
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/166 at the transport layer
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0827 involving distinctive intermediate devices or communication paths network architectures or network communication protocols using different networks H04L63/18

Abstract

A method for resuming a Transport Layer Security (TLS) session in a Service Function Chain comprising a plurality of Service Function nodes coupled to a Service Function Forwarder. A request is received at a first Service Function node to establish a TLS session, and a Pre-Shared Key (PSK) and a PSK identifier that uniquely correspond to the first Service Function node and the TLS session are generated. The PSK identifier is forwarded to one or more of the Service Function Forwarder and the plurality of Service Function nodes. A request to resume the TLS session is received from a client device that previously disconnected. It is determined that the connection request contains the PSK identifier, a second Service Function node is selected, and the TLS session is re-established between the client device and the second Service Function node using the same PSK as the prior TLS session.

Claims

1. A method comprising:

receiving, at a first Service Function (SF) node, a request to establish a Transport Layer Security (TLS) session, the first SF node being one of a plurality of SF nodes communicatively coupled to a Service Function Forwarder (SFF);

generating a Pre-Shared Key (PSK) and a PSK identifier, the PSK and the PSK identifier uniquely corresponding to the first SF node and the TLS session;

forwarding the PSK identifier to the SFF and/or one or more of the plurality of SF nodes, the forwarding including encapsulating the PSK identifier in Network Service Header (NSH) metadata;

receiving a connection request from a client device, the client device having previously disconnected from the TLS session;

determining the connection request contains the PSK identifier;

selecting a second SF node and using the PSK to re-establish the TLS session between the client device and the second SF node; and

using an NSH Metadata-Type 2 Type Length Value (NSH MD-Type 2 TLV) to indicate a Quick UDP Internet Connections (QUIC) connection has been closed with the SFF and/or the plurality of SF nodes.

2. The method of claim 1, wherein the second SF node is selected by determining the second SF node is uniquely associated with the PSK identifier from the connection request, such that the second SF node and the first SF node are the same node.

3. The method of claim 2, wherein the connection request is carried by a Transmission Control Protocol (TCP) SYN packet, such that the second SF node determines the TCP SYN packet contains the PSK identifier, and uses the PSK to decrypt and process an initial flight of data contained in the TCP SYN packet.

4. The method of claim 2, wherein the connection request is carried by a Quick UDP Internet Connections (QUIC) packet, such that the second SF node determines the QUIC packet contains the PSK identifier, and uses the PSK to decrypt and process an initial flight of data contained in the QUIC packet.

5. The method of claim 1, wherein the second SF node is selected by performing load balancing at the SFF, such that the second SF node can be any one of the plurality of SF nodes.

6. The method of claim 5, wherein the PSK is stored as an entry in a memory structure and the PSK identifier is a corresponding entry lookup key for the PSK, such that the second SF node extracts the PSK identifier from the connection request and obtains the PSK from the memory structure in order to re-establish the TLS session.

7. The method of claim 5, wherein the PSK identifier comprises a self-contained ticket containing an encrypted copy of the PSK, and wherein the second SF node receives required cryptographic keying material to decrypt the PSK from the SFF and/or one or more of the plurality of SF nodes, such that the second SF node extracts the PSK from the self-contained ticket in order to re-establish the TLS session.

8. The method of claim 1, wherein forwarding the PSK identifier to the SFF and/or one or more of the plurality of SF nodes comprises a publish-subscribe mechanism.

9. A computer-readable device having stored therein instructions which, when executed by at least one processor, cause the at least one processor to perform operations comprising:

receiving, at a first Service Function (SF) node, a request to establish a Transport Layer Security (TLS) session, the first SF node being one of a plurality of SF nodes communicatively coupled to a Service Function Forwarder (SFF);

generating a Pre-Shared Key (PSK) and a PSK identifier, the PSK and the PSK identifier uniquely corresponding to the first SF node and the TLS session;

forwarding the PSK identifier to the SFF and/or one or more of the plurality of SF nodes, the forwarding including encapsulating the PSK identifier in Network Service Header (NSH) metadata;

receiving a connection request from a client device, the client device having previously disconnected from the TLS session;

determining the connection request contains the PSK identifier;

selecting a second SF node and using the PSK to re-establish the TLS session between the client device and the second SF node; and

using an NSH Metadata-Type 2 Type Length Value (NSH MD-Type 2 TLV) to indicate a Quick UDP Internet Connections (QUIC) connection has been closed with the SFF and/or the plurality of SF nodes.

10. The computer-readable device of claim 9, wherein the instructions further cause the at least one processor to select the second SF node by determining the SF node is uniquely associated with the PSK identifier from the connection request, such that the second SF node and the first SF node are the same node.

11. The computer-readable device of claim 10, wherein the connection request is carried by a Transmission Control Protocol (TCP) SYN packet, such that the second SF node determines the TCP SYN packet contains the PSK identifier, and uses the PSK to decrypt and process an initial flight of data contained in the TCP SYN packet.

12. The computer-readable device of claim 10, wherein the connection request is carried by a Quick UDP Internet Connections (QUIC) packet, such that the second SF node determines the QUIC packet contains the PSK identifier, and uses the PSK to decrypt and process an initial flight of data contained in the QUIC packet.

13. The computer-readable device of claim 9, wherein the instructions further cause the at least one processor to select the second SF node by performing load balancing at the SFF, such that the second SF node can be any one of the plurality of SF nodes.

14. The computer-readable device of claim 13, wherein the PSK is stored as an entry in a memory structure and the PSK identifier is a corresponding entry lookup key for the PSK, such that the second SF node extracts the PSK identifier from the connection request and obtains the PSK from the memory structure in order to re-establish the TLS session.

15. The computer-readable device of claim 13, wherein the PSK identifier comprises a self-contained ticket containing an encrypted copy of the PSK, and wherein the second SF node receives required cryptographic keying material to decrypt the PSK from the SFF and/or one or more of the plurality of SF nodes, such that the second SF node extracts the PSK from the self-contained ticket in order to re-establish the TLS session.

16. The computer-readable device of claim 9, wherein the instructions further cause the at least one processor to forward the PSK identifier to the SFF and/or one or more of the plurality of SF nodes with a publish-subscribe mechanism or a modification of Network Service Header (NSH) metadata.