ssh_add_hostkey
if ((r = ssh_add_hostkey(server, privkey)) != 0 ||
(r = ssh_add_hostkey(client, pubkey)) != 0) {
ASSERT_INT_EQ(ssh_add_hostkey(server, private), 0);
ASSERT_INT_EQ(ssh_add_hostkey(client, public), 0);
ASSERT_INT_EQ(ssh_add_hostkey(server2, private), 0);
int ssh_add_hostkey(struct ssh *ssh, struct sshkey *key);