Exploration through RFCs concludes that random numbers used in the creation of Master Key and Key Block(Key material for Encryption Key and Mac Secret) are from ServerHello.random and ...
Note that this question is somewhat similar to Can I use my random IV (for AES) as a salt for PBKDF2? My current encryption format computes two random PBKDF2 salts (encryption and HMAC, 8 bytes each) ...
This is not my design, but used in the onepw protocol used for the new sync scheme in firefox by mozilla. https://github.com/mozilla/fxa-auth-server/wiki/onepw-protocol In this scheme a key is ...