OpenSSL::X509::Certificate#initialize_copy

static VALUE
ossl_x509_copy(VALUE self, VALUE other)
{
    X509 *a, *b, *x509;

    rb_check_frozen(self);
    if (self == other) return self;

    GetX509(self, a);
    GetX509(other, b);

    x509 = X509_dup(b);
    if (!x509) ossl_raise(eX509CertError, NULL);

    DATA_PTR(self) = x509;
    X509_free(a);

    return self;
}