int libssh2_session_handshake(LIBSSH2_SESSION *session, libssh2_socket_t socket);
DESCRIPTIONsession - Session instance as returned by libssh2_session_init_ex(3)
socket - Connected socket descriptor. Typically a TCP connection though the protocol allows for any reliable transport and the library will attempt to use any berkeley socket.
Begin transport layer protocol negotiation with the connected host.
RETURN VALUEReturns 0 on success, negative on failure.
ERRORSLIBSSH2_ERROR_SOCKET_NONE - The socket is invalid.
LIBSSH2_ERROR_BANNER_SEND - Unable to send banner to remote host.
LIBSSH2_ERROR_KEX_FAILURE - >Encryption key exchange with the remote host failed.
LIBSSH2_ERROR_SOCKET_SEND - Unable to send data on socket.
LIBSSH2_ERROR_SOCKET_DISCONNECT - The socket was disconnected.
LIBSSH2_ERROR_PROTO - An invalid SSH protocol response was received on the socket.
LIBSSH2_ERROR_EAGAIN - Marked for non-blocking I/O but the call would block.