Hub-based token generation and endpoint selection for secure channel establishment

1. A system, comprising:

a first computing device including at least one hardware processor and memory and configured to:

generate an initiation message body for initiating a secure channel, the initiation message body comprising a public key of an initiator private-public key pair;

generate an initiation message authentication code based at least in part on the initiation message body;

select a cipher suite from a set of cryptographic protocols or algorithms for use during initiation, establishment, or use of the secure channel, the selected cipher suite comprising:

a particular scheme for generating the initiator private-public key pair and a responder private-public key pair, or

a particular scheme for generating the initiation message authentication code and a response message authentication code; and

send a secure channel initiation message to a second computing device, the secure channel initiation message including the initiation message body and the initiation message authentication code, and wherein the secure channel initiation message indicates the selected cipher suite for use during initiation, establishment, or use of the secure channel.

2. The system as recited in claim 1 , wherein the first computing device is further configured to:

responsive to receipt, from the second computing device, of a secure channel response message comprising a response message authentication code:

authenticate the secure channel response message using at least the response message authentication code according to the selected cipher suite; and

generate an initiator data communication key block to receive and send data over the secure channel with the second computing device, wherein the initiator data communication key block is generated using at least the private key of the initiator private-public key pair, the public key of the second private-public key pair, and a shared secret key according to the selected cipher suite.

3. The system as recited in claim 2 , wherein the selected cipher suite specifies a key derivation function for use in generating the initiator data communication key block and the initiator data communication key block.

4. The system as recited in claim 2 , further comprising:

a key management service configured to store the shared secret key.

5. The system as recited in claim 4 , wherein:

the first computing device comprises a stream client; and

the second computing device comprises a stream provider configured to provide data streams to requesting stream clients, the stream provider configured to:

receive an encrypted token from the stream client of the first computing device;

decrypt the encrypted token to obtain an identifier for the shared secret key; and

use the identifier to obtain the shared secret key from the key management service.

6. The system as recited in claim 5 ,

wherein the stream client of the first computing device and the stream provider are both configured to:

generate, based at least in part on the shared secret key, the respective private-public key pair for encrypting or decrypting the data stream; and

authenticate, based at least in part on the shared secret key, the control messages for establishing the secure channel.

7. The system as recited in claim 2 , wherein:

the second computing device comprises a stream provider configured to provide data streams to requesting stream clients; and

the first computing device comprises one of the requesting stream clients, configured to independently derive the shared secret key based at least in part on salt and the security credentials for the stream client; and

the security credentials for the stream client are not revealed to the stream provider.

8. The system as recited in claim 1 , wherein:

the second computing device comprises a stream provider configured to provide data streams to requesting stream clients;

the first computing device comprises one of the requesting stream clients; and

the system further comprises a hub service configured to:

receive a stream request and security credentials from the stream client of the first computing device;

authenticate the stream client based at least in part on the security credentials;

generate an encrypted token comprising information for establishing a secure channel between the stream client and the stream provider;

sign the encrypted token with a cryptographic signature; and

return, to the stream client, the encrypted token and an endpoint for the stream provider;

the stream provider is configured to verify that the encrypted token originated from the hub service based at least in part on the cryptographic signature; and

the encrypted token is not decryptable by the stream client.

9. A method, comprising;

performing, by a first computing device:

generating an initiation message body for initiating a secure channel, the initiation message body comprising a public key of an initiator private-public key pair;

generating an initiation message authentication code based at least in part on the initiation message body;

selecting a cipher suite from a set of cryptographic protocols or algorithms for use during initiation, establishment, or use of the secure channel, the selected cipher suite comprising:

a particular scheme for generating the initiator private-public key pair and a responder private-public key pair, or

a particular scheme for generating the initiation message authentication code and a response message authentication code; and

generating a secure channel initiation message that:

includes the initiation message body and the initiation message authentication code; and

indicates the selected cipher suite for use during initiation, establishment;

sending the secure channel initiation message to a second computing device.

10. The method as recited in claim 9 , further comprising:

responsive to receiving, by the first computing device from the second computing device, a secure channel response message comprising a response message authentication code:

authenticating, by the first computing device, the secure channel response message using at least the response message authentication code according to the selected cipher suite; and

generating, by the first computing device, an initiator data communication key block to receive and send data over the secure channel with the second computing device, wherein generating the initiator data communication key block comprises generating the key block using at least the private key of the initiator private-public key pair, the public key of the second private-public key pair, and a shared secret key according to the selected cipher suite.

11. The method as recited in claim 10 , wherein the selected cipher suite specifies a key derivation function for use in generating the initiator data communication key block and the initiator data communication key block.

12. The method as recited in claim 10 , further comprising:

obtaining, by the first computing device from a key management service, the shared secret key used in said generating the initiator data communication key block.

13. The method as recited in claim 12 , wherein:

the first computing device comprises a stream client;

the second computing device comprises a stream provider configured to provide data streams to requesting stream clients;

the method further comprises:

receiving, by the stream provider, an encrypted token from the stream client of the first computing device;

decrypting, by the stream provider, the encrypted token to obtain an identifier for the shared secret key; and

using, by the stream provider, the identifier to perform said obtaining the shared secret key from the key management service.

14. The method as recited in claim 13 ,

wherein the stream client of the first computing device and the stream provider are individually configured to perform:

generating, based at least in part on the shared secret key, the respective private-public key pair for encrypting or decrypting the data stream; and

authenticating, based at least in part on the shared secret key, the control messages for establishing the secure channel.

15. The method as recited in claim 10 , wherein:

the second computing device comprises a stream provider configured to provide data streams to requesting stream clients;

the first computing device comprises one of the requesting stream clients;

the method further comprises independently deriving, by the requesting stream client of the first computing device, the shared secret key based at least in part on salt and the security credentials for the stream client; and

the security credentials for the stream client are not revealed to the stream provider.

16. The method as recited in claim 9 , wherein:

the second computing device comprises a stream provider configured to provide data streams to requesting stream clients;

the first computing device comprises one of the requesting stream clients; and

the method further comprises:

receiving, by a hub service, a stream request and security credentials from the stream client of the first computing device;

authenticating, by the hub service, the stream client based at least in part on the security credentials;

generating, by the hub service, an encrypted token comprising information for establishing a secure channel between the stream client and the stream provider;

signing, by the hub service, the encrypted token with a cryptographic signature;

returning, by the hub service to the stream client, the encrypted token and an endpoint for the stream provider; and

verifying, by the stream provider, that the encrypted token originated from the hub service based at least in part on the cryptographic signature, wherein the encrypted token is not decryptable by the stream client.

17. One or more non-transitory computer-readable media storing program instructions executable on or across one or more processors to perform:

generating an initiation message body for initiating a secure channel, the initiation message body comprising a public key of an initiator private-public key pair;

generating an initiation message authentication code based at least in part on the initiation message body;

selecting a cipher suite from a set of cryptographic protocols or algorithms for use during initiation, establishment, or use of the secure channel, the selected cipher suite comprising:

a particular scheme for generating the initiator private-public key pair and a responder private-public key pair, or

a particular scheme for generating the initiation message authentication code and a response message authentication code; and

generating a secure channel initiation message that:

includes the initiation message body and the initiation message authentication code; and

indicates the selected cipher suite for use during initiation, establishment, or use of the secure channel;

sending the secure channel initiation message to a computing device.

18. The one or more non-transitory computer-readable media as recited in claim 17 , storing program instructions executable on or across the one or more processors to perform:

responsive to receiving, from the computing device, a secure channel response message comprising a response message authentication code:

authenticating the secure channel response message using at least the response message authentication code according to the selected cipher suite; and

generating an initiator data communication key block to receive and send data over the secure channel with the computing device, wherein generating the initiator data communication key block comprises generating the key block using at least the private key of the initiator private-public key pair, the public key of the second private-public key pair, and a shared secret key according to the selected cipher suite.

19. The one or more non-transitory computer-readable media as recited in claim 18 , wherein the selected cipher suite specifies a key derivation function and the program instructions are executable on or across the one or more processors to perform generating the initiator data communication key block and the initiator data communication key block using the key derivation function specified by the indicated cipher suite.

20. The one or more non-transitory computer-readable media as recited in claim 18 , storing program instructions executable on or across the one or more processors to perform:

obtaining, from a key management service, the shared secret key used in said generating the initiator data communication key block.