generate_or_die
static struct sshkey *rsa = generate_or_die(KEY_RSA, 2048);
static struct sshkey *ecdsa256 = generate_or_die(KEY_ECDSA, 256);
static struct sshkey *ecdsa384 = generate_or_die(KEY_ECDSA, 384);
static struct sshkey *ecdsa521 = generate_or_die(KEY_ECDSA, 521);
static struct sshkey *ed25519 = generate_or_die(KEY_ED25519, 0);