OpenSSL::PKey::DH#initialize_copy

HAVE_EVP_PKEY_DUP
static VALUE
ossl_dh_initialize_copy(VALUE self, VALUE other)
{
    EVP_PKEY *pkey;
    DH *dh, *dh_other;
    const BIGNUM *pub, *priv;

    TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
    if (pkey)
        rb_raise(rb_eTypeError, "pkey already initialized");
    GetDH(other, dh_other);

    dh = DHparams_dup(dh_other);
    if (!dh)
        ossl_raise(eDHError, "DHparams_dup");

    DH_get0_key(dh_other, &pub, &priv);
    if (pub) {
        BIGNUM *pub2 = BN_dup(pub);
        BIGNUM *priv2 = BN_dup(priv);

        if (!pub2 || (priv && !priv2)) {
            BN_clear_free(pub2);
            BN_clear_free(priv2);
            ossl_raise(eDHError, "BN_dup");
        }
        DH_set0_key(dh, pub2, priv2);
    }

    pkey = EVP_PKEY_new();
    if (!pkey || EVP_PKEY_assign_DH(pkey, dh) != 1) {
        EVP_PKEY_free(pkey);
        DH_free(dh);
        ossl_raise(eDHError, "EVP_PKEY_assign_DH");
    }
    RTYPEDDATA_DATA(self) = pkey;
    return self;
}