// Adapted semantic slice of apps/req.c at OpenSSL revision
// 437b14b533fe7f7408e3ebca6d5569f1d3347b1a.
struct Key {
    int value;
};

struct Certificate {
    Key* key;
};

int copyPublicKey(Certificate certificate) {
    Key* pktmp = certificate.key;
    // Models the downstream use by X509_REQ_set_pubkey without its dependencies.
    return pktmp->value;
}

int main() {
    Certificate certificate{nullptr};
    return copyPublicKey(certificate);
}