DWORD buffer_len = 0;
if (CryptDecryptMessage(&_message_para->message_para,
        message, message_len, NULL, &buffer_len, NULL)) {
    BYTE *buffer = emalloc(buffer_len);
    if (!buffer) {
        return;
    }
    PCCERT_CONTEXT cert_context = NULL;
    if (CryptDecryptMessage(&_message_para->message_para,
            message, message_len, buffer, &buffer_len, &cert_context)) {
        printf("%p\n", cert_context); // cert_context == NULL
        // но сообщение расшифровывается
        // message_para.certStores   = (CertOpenSystemStore(null, "MY");)
        // message_para.encodingType = X509_ASN_ENCODING | PKCS_7_ASN_ENCODING
    }
}