OpenSSL::X509::Certificate#public_key=

static VALUE
ossl_x509_set_public_key(VALUE self, VALUE key)
{
    X509 *x509;
    EVP_PKEY *pkey;

    GetX509(self, x509);
    pkey = GetPKeyPtr(key);
    ossl_pkey_check_public_key(pkey);
    if (!X509_set_pubkey(x509, pkey))
        ossl_raise(eX509CertError, "X509_set_pubkey");
    return key;
}