Binding digitally signed requests to sessions

• US 9,780,952 B1
• Filed: 12/12/2014
• Issued: 10/03/2017
• Est. Priority Date: 12/12/2014
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Behm, Bradley Jeffery, Roth, Gregory Branchek, Rubin, Gregory Alan
• Primary Examiner(s): Avery, Jeremiah
• Application Number:
  US14/569,596
• Time in Patent Office: 1,026 Days
• Field of Search: None
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 63/1466 Active attacks involving interception, injection, modification, spoofing of data unit addresses, e.g. hijacking, packet injection or TCP sequence number attacks
• CPC Class Codes: H04L 63/166 at the transport layer
• CPC Class Codes: H04L 9/0841 involving Diffie-Hellman or related key agreement protocols
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823

Abstract

A client establishes an cryptographically protected communications session and determines information usable to distinguish the session from other sessions. The client digitally signs the information using a cryptographic key that is independent of the session to enable a server to check whether the information matches the session that it established and whether the digital signature is correct. The server may perform mitigating operations if either or both of the information or the digital signature is/are invalid.

Claims

1. A computer-implemented method, comprising:

establishing a cryptographically protected communications session;

after the cryptographically protected communications session is established,

receiving, from a client over the cryptographically protected communications session, a request and a digital signature, the request including a parameter specific to a cryptographically protected communications session over which the request was submitted;

determining whether the cryptographically protected communications session is the same as the cryptographically protected communications session over which the request was submitted by at least;

determining information specific to the cryptographically protected communications session;

determining whether the information specific to the cryptographically protected communications session matches the parameter specific to the cryptographically protected communications session over which the request was submitted;

accessing a cryptographic key registered prior to establishment of the cryptographically protected communications session and in association with the client; and

determining, based at least in part on the request and the cryptographic key, whether the digital signature is valid; and

as a result of both the digital signature being valid and the information specific to the cryptographically protected communications session matching the parameter specific to the cryptographically protected communications session over which the request was submitted;

generating a response to the request;

using the cryptographic key to generate a digital signature of the response; and

transmitting the generated response and the generated digital signature to the client over the cryptographically protected communications session.

2. The computer-implemented method of claim 1, wherein the information specific to the cryptographically protected communications session is based at least in part on a secret negotiated as part of a handshake process to establish the cryptographically protected communications session.

3. The computer-implemented method of claim 2, wherein determining whether the information specific to the cryptographically protected communications session matches the parameter specific to the cryptographically protected communications session over which the request was submitted comprises deriving a reference parameter specific to the cryptographically protected communications session from the secret.

4. The computer-implemented method of claim 1, wherein the cryptographically protected communications session is a transport layer security session.

5. A system, comprising at least one computing device configured to implement one or more services, the one or more services configured to:

receive, over an established cryptographically protected communications session, a digital signature and a request associated with a client;

obtain, prior to establishment of the established cryptographically protected communications session, a cryptographic key associated with the client;

perform, based at least in part on the request, the cryptographic key, and the digital signature, a verification of whether the request was transmitted from the client to the system over the established cryptographically protected communications session; and

perform one or more mitigating actions if the verification results in the request being transmitted from the client to the system over the established cryptographically protected communications session being unverified.

6. The system of claim 5, wherein:

the one or more services are further configured to determine information specific to the established cryptographically protected communications session; and

the verification includes determining whether the determined information specific to the established cryptographically protected communications session matches a parameter in the request.

7. The system of claim 6, wherein the verification further comprises determining, based at least in part on the cryptographic key and the request, whether the digital signature is valid.

8. The system of claim 5, wherein the cryptographic key is shared as a secret between the client and the system prior to establishment of the established cryptographically protected communications session.

9. The system of claim 5, wherein the verification includes determining whether information resulting from a handshake process for establishing the established cryptographically protected communications session matches a parameter in the request.

10. The system of claim 5, wherein the one or more services are further configured such that successful verification that the request was transmitted from the client to the system over the established cryptographically protected communications session and successful verification of the digital signature are prerequisites for fulfilling the request.

11. The system of claim 5, wherein the one or more services are further configured to:

if determined that the digital signature is valid and that the request was transmitted from the client to the system over the established cryptographically protected communications session;

determine a response to the request; and

digitally sign the response to the request using a cryptographic key that is independent of the established cryptographically protected communications session.

12. The system of claim 11, wherein:

the cryptographic key that is associated with the client and the cryptographic key that is registered to the client independent of the established cryptographically protected communications session are a same symmetric cryptographic key.

13. The system of claim 5, wherein the one or more mitigating actions include digitally signing a denial of the request using a cryptographic key that is independent of the established cryptographically protected communications session.

14. A non-transitory computer-readable storage medium having stored thereon executable instructions that, when executed by one or more processors of a computer system, cause the computer system to at least:

establish a cryptographically protected communications session;

after establishment of the cryptographically protected communications session,

determine information usable to distinguish the established cryptographically protected communications session from other cryptographically protected communications session;

digitally sign a request that includes the determined information using a cryptographic key obtained prior to establishment of the cryptographically protected communications session, thereby generating a digital signature; and

transmit the request and the digital signature over the cryptographically protected communications session.

15. The non-transitory computer-readable storage medium of claim 14, wherein the instructions further comprise instructions that, when executed by the one or more processors, cause the computer system to:

receive a response to the request and a digital signature;

verify the digital signature using the cryptographic key; and

process the received response dependent on whether the digital signature is verified as valid.

16. The non-transitory computer-readable storage medium of claim 14, wherein the instructions further comprise instructions that, when executed by the one or more processors, cause the computer system to:

determine information specific to the request;

generate the request to include the determined information specific to the request; and

verify, based at least in part on the determined information specific to the request, whether a received response matches the request.

17. The non-transitory computer-readable storage medium of claim 14, wherein the information usable to distinguish the established cryptographically protected communications session is based at least in part on a secret negotiated as part of a handshake process for establishing the cryptographically protected communications session.

18. The non-transitory computer-readable storage medium of claim 14, wherein:

the cryptographically protected communications session is in accordance with a protocol that includes a record protocol and a handshake protocol;

the instructions that cause the computer system to establish the cryptographically protected communications session, when executed by the one or more processors, cause the computer system to perform a handshake process in accordance with the handshake protocol; and

the instructions that cause the computer system to transmit the request and the digital signature over the cryptographically protected communications session, when executed by the one or more processors, cause the computer system to transmit the request and the digital signature in accordance with the record protocol.

19. The non-transitory computer-readable storage medium of claim 14, wherein the information usable to distinguish the established cryptographically protected communications session is determined based at least in part on a digital certificate used to establish the cryptographically protected communications session.

20. The non-transitory computer-readable storage medium of claim 19, wherein the digital certificate is a server digital certificate presented to the computer system during establishment of the cryptographically protected communications session.

21. The non-transitory computer-readable storage medium of claim 19, wherein:

the instructions further comprise instructions that, when executed by the one or more processors, cause the computer system to;

receive a response to the request and a digital signature;

verify the digital signature using the cryptographic key;

verify whether a parameter of the response matches the information usable to distinguish the established cryptographically protected communications session from other cryptographically protected communications sessions; and

process the received response dependent on whether the digital signature is verified as valid and whether the parameter of the response matches the information usable to distinguish the established cryptographically protected communications session from other cryptographically protected communications sessions.