In my webrtc web app in Chrome, I used to specify my own encryption key by overriding the crypto information in the SDP. I am now migrating my webrtc web app to use DTLS-SRTP for encryption. With DTLS enabled, is there a way to tell Chrome which encryption key to send to the other client?
No you cannot specify your own keys since the actual keys are sent over a secure media connection and are not part of the SDP.
来源：https://stackoverflow.com/questions/21921946/can-i-specify-my-own-encryption-key-in-dtls-srtp-encryption