RSA_generate_key_ex
!RSA_generate_key_ex(rsa, num, bn, cb))
if (RSA_generate_key_ex(rsa, bits, e, &cb)) {
ret = RSA_generate_key_ex(rsa, rctx->nbits, rctx->pub_exp, pcb);
int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb);
!RSA_generate_key_ex(private, bits, f4, NULL)) {