Ephem Import

char * cppImportSessionKeyEphem(const char * containerName, const char * containerPin, const char * sessionKey) {
    HCRYPTPROV hProv = 0;
    bool isPinOk = false;
    HCRYPTKEY hResKey = 0;
    size_t sessionDataSize = 0;
    unsigned char * sessionData = NULL;
    BYTE *pData = NULL;
    DWORD dwEphemKeyBlobLen= 0;
    BYTE *pbEphemKeyBlob = NULL;
    HCRYPTKEY hAgreeKey = 0;
    ProvKeyInfo pkInfo;
    DWORD keyBlobLen = 0;
    BYTE *keyBlob = NULL;
    char *keyId = NULL;
    //
    if (CryptAcquireContextA(&hProv, containerName, PROV_NAME, PROV_TYPE, CRYPT_SILENT)){
        isPinOk = true;
        if (strlen(containerPin) > 0) {
            if (!CryptSetProvParam(hProv, PP_KEYEXCHANGE_PIN, (BYTE *)containerPin, 0)){
                isPinOk = false;
            }
        }
    }
    //
    if (isPinOk) {
        if (CryptGetUserKey(hProv, AT_KEYEXCHANGE, &hResKey)) {
            sessionData = base64_decode(sessionKey, strlen(sessionKey), &sessionDataSize);
            pData = (BYTE *) sessionData;
        }
    }
    
    if (pData) {
        // получаем блоб эфемерного ключа
        memcpy(&dwEphemKeyBlobLen, pData, sizeof(DWORD));
        pData += sizeof(DWORD);
        pbEphemKeyBlob = pData;
        pData += dwEphemKeyBlobLen;
        // получаем ключ согласования
        if (CryptImportKey(hProv, pbEphemKeyBlob, dwEphemKeyBlobLen, hResKey, 0, &hAgreeKey)) {
            if (CryptAcquireContext(&pkInfo.provider, NULL, PROV_NAME, PROV_TYPE, CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) {
                // получаем блоб ключа
                memcpy(&keyBlobLen, pData, sizeof(DWORD));
                pData += sizeof(DWORD);
                keyBlob = pData;
                pData += keyBlobLen;
                
                if (CryptImportKey(pkInfo.provider, keyBlob, keyBlobLen, hAgreeKey, CRYPT_EXPORTABLE, &pkInfo.key)) {
                    memcpy(&pkInfo.IVLen, pData, sizeof(DWORD));
                    pData += sizeof(DWORD);
                    if (pkInfo.IVLen <= sizeof(pkInfo.IV)) {
                        memcpy(&pkInfo.IV, pData, pkInfo.IVLen);
//
                        if (CryptSetKeyParam(pkInfo.key, KP_IV, pkInfo.IV, 0)) {
                            keyId = ProvKeyInfoToB64(pkInfo);
                        }
                    }
                }
            }
        }
    }
    
    if (hResKey) {
        CryptDestroyKey(hResKey);
    }
    if (hAgreeKey) {
        CryptDestroyKey(hAgreeKey);
    }
    if (hProv) {
        CryptReleaseContext(hProv, 0);
    }
    if (sessionData) {
        free(sessionData);
    }
    return keyId;
}