do_kex_with_key
do_kex_with_key(kex, "aes128-ctr", "hmac-sha2-256", key,
do_kex_with_key(kex, NULL, NULL, NULL, KEY_RSA, 2048);
do_kex_with_key(kex, NULL, NULL, NULL, KEY_ECDSA, 256);
do_kex_with_key(kex, NULL, NULL, NULL, KEY_ED25519, 256);