OK, so that's not an issue in Rakudo then. Closed.
On 2019-03-05 11:16:41, sortiz wrote: > The problem is the PEM_write_bio_RSAPrivateKey signature used in the > NativeCall declaration, it missed five arguments. > > From the manual: > > int PEM_write_bio_RSAPrivateKey(BIO *bp, RSA *x, const EVP_CIPHER > *enc, > unsigned char *kstr, int > klen, > pem_password_cb *cb, void > *u); > > So when called it received random values. > > My modernized example attached that succeds.