sshbuf_get_ec
if ((r = sshbuf_get_ec(buf, dh_pub, group)) != 0) {
return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
if ((r = sshbuf_get_ec(b, q, g)) != 0) {
int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g);