OpenSSL::PKey::DH#export

static VALUE
ossl_dh_export(VALUE self)
{
    DH *dh;
    BIO *out;
    VALUE str;

    GetDH(self, dh);
    if (!(out = BIO_new(BIO_s_mem()))) {
        ossl_raise(eDHError, NULL);
    }
    if (!PEM_write_bio_DHparams(out, dh)) {
        BIO_free(out);
        ossl_raise(eDHError, NULL);
    }
    str = ossl_membio2str(out);

    return str;
}