from Charlene Wendling; OK bcallah@
Comment:
generate shared secret using ECDH function
Description:
Crypt::Curve25519 is a state-of-the-art Diffie-Hellman function
suitable for a wide variety of applications.
Given a user's 32-byte secret key, Crypt::Curve25519 computes the
user's 32-byte public key. Given the user's 32-byte secret key and
another user's 32-byte public key, Crypt::Curve25519 computes a
32-byte secret shared by the two users. This secret can then be
used to authenticate and encrypt messages between the two users.
