三步搞定AIoT对接：百宝箱平台与xiaozhi协议的完美融合

Http* Ota::SetupHttp() {
    ......
    auto http = board.CreateHttp();
    http->SetHeader("Device-Id", SystemInfo::GetMacAddress().c_str()); // 在你的智能体里做了导入的设备的 mac 地址
    http->SetHeader("Device-Key", device_key.c_str()); // 从 https://www.tbox.cn/open/iot 页面右上角复制过来

#define HMAC_OUTPUT_LEN 32  // HMAC-SHA256 输出长度
#define MAC_ADDRESS_LEN 18  // MAC 地址长度
std::vector<unsigned char> hexStringToByteArray(const std::string& hex_str) {
    // 每个字节由两个字符表示，因此需要的字节数是字符串长度的一半
    std::vector<unsigned char> byteArray;
    if (hex_str.length() % 2 != 0) {
        throw std::invalid_argument("Hex string must have an even length");
    }
    for (size_t i = 0; i < hex_str.length(); i += 2) {
        // 取出每两个字符
        std::string byteString = hex_str.substr(i, 2);
        // 将字符转换为十进制整数
        unsigned char byte = static_cast<unsigned char>(strtol(byteString.c_str(), nullptr, 16));
        byteArray.push_back(byte);
    }
    return byteArray;
}
void generate_signature(const char *mac, const char *token, const unsigned char *device_key, unsigned char *signature) {
    char message[MAC_ADDRESS_LEN + 256]; // 存储 MAC + token
    snprintf(message, sizeof(message), "%s%s", mac, token); // 合并 MAC 和 token
    // 使用 HMAC-SHA256 生成签名
    mbedtls_md_context_t ctx;
    const mbedtls_md_info_t *info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
    
    mbedtls_md_init(&ctx);
    mbedtls_md_setup(&ctx, info, 1);  // 1表示使用HMAC
    mbedtls_md_hmac_starts(&ctx, device_key, HMAC_OUTPUT_LEN);
    mbedtls_md_hmac_update(&ctx, (const unsigned char *)message, strlen(message));
    mbedtls_md_hmac_finish(&ctx, signature);
    mbedtls_md_free(&ctx);
}
bool WebsocketProtocol::OpenAudioChannel() {
    if (websocket_ != nullptr) {
        delete websocket_;
    }
    // 获取设备唯一标识符
    std::string mac_address = SystemInfo::GetMacAddress();
    ESP_LOGW(TAG, "Device mac addr: %s\n", mac_address.c_str());
    // 生成签名
    Settings settings("websocket", false);
    std::string url = settings.GetString("url");
    std::string token = settings.GetString("token");
    auto device_key_array = hexStringToByteArray(device_key);
    unsigned char signature[HMAC_OUTPUT_LEN] = { 0 }; // 存储签名
    generate_signature(mac_address.c_str(), token.c_str(), device_key_array.data(), signature);
    std::string signature_string =  bytesToHexString(signature, HMAC_OUTPUT_LEN);
    int version = settings.GetInt("version");
    if (version != 0) {
        version_ = version;
    }
    error_occurred_ = false;
    websocket_ = Board::GetInstance().CreateWebSocket();
    
    if (!signature_string.empty()) {
        // If token not has a space, add "Bearer " prefix
        if (signature_string.find(" ") == std::string::npos) {
            signature_string = "Bearer " + signature_string;
        }
        // ESP_LOGI(TAG, "signature_string %s", signature_string.c_str());
        websocket_->SetHeader("Authorization", signature_string.c_str());
    }