class Net::SSH::Transport::Kex::EcdhSHA2NistP256

key-exchange algorithm. (defined in RFC 5656)
A key-exchange service implementing the “ecdh-sha2-nistp256”

def compute_shared_secret(server_ecdh_pubkey)

compute shared secret from server's public key and client's private key 
def compute_shared_secret(server_ecdh_pubkey)
  pk = OpenSSL::PKey::EC::Point.new(OpenSSL::PKey::EC.new(curve_name).group,
                                    OpenSSL::BN.new(server_ecdh_pubkey, 2))
  OpenSSL::BN.new(ecdh.dh_compute_key(pk), 2)
end

def curve_name 

def curve_name
  OpenSSL::PKey::EC::CurveNameAlias['nistp256']
end

def digester 

def digester
  OpenSSL::Digest::SHA256
end

def ecdh_public_key_bytes

# string Q_C, client's ephemeral public key octet string 
def ecdh_public_key_bytes
  ecdh.public_key.to_bn.to_s(2)
end

def generate_key # :nodoc:

:nodoc: 
def generate_key # :nodoc:
  OpenSSL::PKey::EC.generate(curve_name)
end