verify_host_key
if (kex->verify_host_key == NULL) {
if (kex->verify_host_key(server_host_key, ssh) == -1)
int (*verify_host_key)(struct sshkey *, struct ssh *);
ssh->kex->verify_host_key =&_ssh_verify_host_key;
ssh->kex->verify_host_key = cb;
int verify_host_key(char *, struct sockaddr *, struct sshkey *,
if (verify_host_key(xxx_host, xxx_hostaddr, hostkey,
ssh->kex->verify_host_key=&verify_host_key_callback;