Server host key blob (K_S).
Client SSH_MSG_KEXINIT payload.
Server SSH_MSG_KEXINIT payload.
Client ephemeral public key (Q_C).
Server ephemeral public key (Q_S).
Shared secret K as an unsigned big-endian magnitude.
Client identification string (no CRLF).
Server identification string (no CRLF).
The ordered inputs to the ECDH exchange hash.