int PKCS7_add_certificate(PKCS7 *p7, X509 *x509)
{
    int i;
    STACK_OF(X509) **sk;

    i = OBJ_obj2nid(p7->type);
    switch (i) {
    case NID_pkcs7_signed:
        sk = &(p7->d.sign->cert);
        break;
    case NID_pkcs7_signedAndEnveloped:
        sk = &(p7->d.signed_and_enveloped->cert);
        break;
    default:
        PKCS7err(PKCS7_F_PKCS7_ADD_CERTIFICATE, PKCS7_R_WRONG_CONTENT_TYPE);
        return (0);
    }

    if (*sk == NULL)
        *sk = sk_X509_new_null();
    if (*sk == NULL) {
        PKCS7err(PKCS7_F_PKCS7_ADD_CERTIFICATE, ERR_R_MALLOC_FAILURE);
        return 0;
    }
    CRYPTO_add(&x509->references, 1, CRYPTO_LOCK_X509);
    if (!sk_X509_push(*sk, x509)) {
        X509_free(x509);
        return 0;
    }
    return (1);
}
int PKCS7_add_certificate(PKCS7 *p7, X509 *x509)
{
    int i;
    STACK_OF(X509) **sk;

    i = OBJ_obj2nid(p7->type);
    switch (i) {
    case NID_pkcs7_signed:
        sk = &(p7->d.sign->cert);
        break;
    case NID_pkcs7_signedAndEnveloped:
        sk = &(p7->d.signed_and_enveloped->cert);
        break;
    default:
        PKCS7err(PKCS7_F_PKCS7_ADD_CERTIFICATE, PKCS7_R_WRONG_CONTENT_TYPE);
        return (0);
    }

    if (*sk == NULL)
        *sk = sk_X509_new_null();
    if (*sk == NULL) {
        PKCS7err(PKCS7_F_PKCS7_ADD_CERTIFICATE, ERR_R_MALLOC_FAILURE);
        return 0;
    }
    CRYPTO_add(&x509->references, 1, CRYPTO_LOCK_X509);
    if (!sk_X509_push(*sk, x509)) {
        X509_free(x509);
        return 0;
    }
    return (1);
}