extern bool rsa_write_pem_public_key(rsa_t *rsa, FILE *fp) ATTR_WARN_UNUSED;
extern bool rsa_write_pem_private_key(rsa_t *rsa, FILE *fp) ATTR_WARN_UNUSED;
extern bool rsa_write_pem_public_key(rsa_t *rsa, FILE *fp) ATTR_WARN_UNUSED;
extern bool rsa_write_pem_private_key(rsa_t *rsa, FILE *fp) ATTR_WARN_UNUSED;