c++/qt调阿里云视觉智能开发平台

官方参考文档：

        阿里云人脸活体检测api文档：调用DetectLivingFace进行人脸活体检测_视觉智能开放平台(VIAPI)-阿里云帮助中心

        阿里云视觉智能平台公共请求参数文档：人体人脸分析API接口的公共请求参数_视觉智能开放平台(VIAPI)-阿里云帮助中心

        这个公共请求参数文档里面，官方给了完整的java代码，用于请求人脸活体检测接口，但是阿里云官方对c++的支持很弱，没有c++相关的示例，这篇文章就是根据这个官方java示例，给出qt/c++的代码

先给出完整qt代码
头文件：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QImage>
#include <QNetworkAccessManager>
#include <QNetworkReply>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_imgBtn_clicked();

private:
    Ui::MainWindow *ui;

    QNetworkAccessManager *_manager = nullptr;
    QUrl url;

    void doAliDetectLivingFace();
    QString specialUrlEncode(const QString &value);
    QString sign(const QString &accessSecret, const QString &stringToSign);
    QString sign2(const QString &accessSecret, const QString &stringToSign);

private slots:
    void finishedReplay();
    void downloadProgress(qint64 bytesSent, qint64 bytesTotal);
    void slotError(QNetworkReply::NetworkError net_error);
};

#endif // MAINWINDOW_H

cpp 文件：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QBuffer>
#include <QFileInfo>
#include <QCryptographicHash>
#include <QDebug>
#include <QFileDialog>
#include <QUrlQuery>
#include <QUuid>
#include <QMessageAuthenticationCode>
#include <QTimeZone>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    _manager =new QNetworkAccessManager(this);
    doAliDetectLivingFace();
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::finishedReplay()
{
    QNetworkReply *reply = dynamic_cast<QNetworkReply*>(sender());
    QByteArray bytes = reply->readAll();

    qDebug()<<"finished:\n";
    QString  html_text = bytes;
    qDebug()<<"get ready,read size:"<<html_text.size();
    qDebug()<< "ret_html_text:\n"<<html_text<<"\n";
    reply->deleteLater();
}

void MainWindow::downloadProgress(qint64 bytesSent, qint64 bytesTotal)
{
    qDebug()<< "\ndownloadProgress done:\n";
    qDebug() << "bytesSent: " << bytesSent<< "  " << "bytesTocal: " << bytesTotal;
}

void MainWindow::slotError(QNetworkReply::NetworkError net_error)
{
    qDebug()<< "slotError:"<<net_error;
}

void MainWindow::doAliDetectLivingFace()
{
    /*
    最终url:
    http://facebody.cn-shanghai.aliyuncs.com/?Signature=olXJ3UlVH4bSG1OHrg3kQWE0lrE%3D
        &AccessKeyId=LTAI5tFopUsaPTXZCvSdrkpQ
        &Action=DetectLivingFace
        &Format=JSON
        &RegionId=cn-shanghai
        &SignatureMethod=HMAC-SHA1
        &SignatureNonce=2a90f9ef-9d6d-438e-b20f-5106653654d2
        &SignatureVersion=1.0
        &Tasks.1.ImageURL=http%3A%2F%2Fviapi-test.oss-cn-shanghai.aliyuncs.com%2Fviapi-3.0domepic%2Ffacebody%2FDetectLivingFace%2FDetectLivingFace11.jpg
        &Tasks.2.ImageURL=http%3A%2F%2Fviapi-test.oss-cn-shanghai.aliyuncs.com%2Fviapi-3.0domepic%2Ffacebody%2FDetectLivingFace%2FDetectLivingFace13.jpg
        &Timestamp=2024-10-31T09%3A03%3A08Z
        &Version=2019-12-30
    */

    QDateTime currentTime = QDateTime::currentDateTime();
    QDateTime eightHoursAgo = currentTime.addSecs(-8 * 3600);
    QTimeZone gmtTimeZone("GMT");
    eightHoursAgo.setTimeZone(gmtTimeZone);
    QString currentTimeStr = eightHoursAgo.toString("yyyy-MM-dd'T'HH:mm:ss'Z'");
    
    // 这里换成自己阿里云账户的accessKeyId和accessKeySecret
    QString accessKeyId = "***************";
    QString  accessKeySecret = "***************";

    QMap<QString, QString> urlQueryMap;

    urlQueryMap.insert("Tasks.1.ImageURL", "http://viapi-test.oss-cn-shanghai.aliyuncs.com/viapi-3.0domepic/facebody/DetectLivingFace/DetectLivingFace11.jpg");
    urlQueryMap.insert("Tasks.2.ImageURL", "http://viapi-test.oss-cn-shanghai.aliyuncs.com/viapi-3.0domepic/facebody/DetectLivingFace/DetectLivingFace13.jpg");
    urlQueryMap.insert("SignatureMethod", "HMAC-SHA1");

    QUuid uuid = QUuid::createUuid();
    QString uuidString = uuid.toString();
    uuidString = uuidString.mid(1, uuidString.size() -2);
    // urlQueryMap.insert("SignatureNonce", "4449ddb6-d72a-4e56-899c-c33365a8caf2");
    urlQueryMap.insert("SignatureNonce", uuidString);
    urlQueryMap.insert("AccessKeyId", accessKeyId);
    urlQueryMap.insert("SignatureVersion", "1.0");
    // urlQueryMap.insert("Timestamp", "2024-10-28T02:02:26Z");
    urlQueryMap.insert("Timestamp", currentTimeStr);
    urlQueryMap.insert("Format", "JSON");
    urlQueryMap.insert("RegionId", "cn-shanghai");
    urlQueryMap.insert("Version", "2019-12-30");
    urlQueryMap.insert("Action", "DetectLivingFace");
    // urlQueryMap.insert("ImageURL", "https://ainemo-testdev.oss-cn-beijing.aliyuncs.com/wenkeTest/1.png");
    if (urlQueryMap.contains("Signature")) {
        urlQueryMap.remove("Signature");
    }

    QString sortQueryStringTmp;
    for(auto it = urlQueryMap.begin(); it != urlQueryMap.end(); ++it)
    {
        sortQueryStringTmp.append("&").append(specialUrlEncode(it.key())).append("=").append(specialUrlEncode(it.value()));
    }

    QString sortedQueryString = sortQueryStringTmp.mid(1);

    QString stringToSign;
    stringToSign.append("POST").append("&");
    stringToSign.append(specialUrlEncode("/")).append("&");
    stringToSign.append(specialUrlEncode(sortedQueryString));

    // QString signStr = QString::fromStdString(SignUtil::sign(QString(accessKeySecret + "&").toStdString(), stringToSign.toStdString()));
    // signStr = signStr.left(signStr.size() - 1);
    QString signStr = sign(accessKeySecret + "&", stringToSign);
    QString signature = specialUrlEncode(signStr);

    QString urlStr = QString("http://facebody.cn-shanghai.aliyuncs.com/?Signature=%1&%2").arg(signature, sortedQueryString);

    // qDebug() << "timeStamp is " << "2024-10-28T02:02:26Z";
    qDebug() <<"sortedQueryString is " << sortedQueryString;
    qDebug() <<"stringToSign is " << stringToSign;
    qDebug() <<"signStr is " << signStr;
    qDebug() <<"signature is " << signature;
    qDebug() << "url str is " << urlStr;

    QNetworkRequest request;
    QString accept = "application/json";
    QString content_type = "application/json";
    request.setRawHeader(QByteArray("accept"), accept.toLocal8Bit());
    request.setHeader(QNetworkRequest::ContentTypeHeader,content_type);
    request.setUrl(QUrl(urlStr));

    QNetworkReply *reply = _manager->post(request, "");
    connect(reply, SIGNAL(finished()), this, SLOT(finishedReplay()));
    connect(reply, SIGNAL(error(QNetworkReply::NetworkError)),
            this, SLOT(slotError(QNetworkReply::NetworkError)));
    connect(reply,SIGNAL(downloadProgress(qint64,qint64)),
            this,SLOT(downloadProgress(qint64,qint64)));
}

QString MainWindow::specialUrlEncode(const QString &value)
{
    QString encodedValue = QUrl::toPercentEncoding(value, "", "");
    encodedValue.replace("+", "%20");
    encodedValue.replace("*", "%2A");
    encodedValue.replace("%7E", "~");
    return encodedValue;
}

QString MainWindow::sign(const QString &accessSecret, const QString &stringToSign)
{
    QByteArray key = accessSecret.toUtf8();
    QByteArray data = stringToSign.toUtf8();

    int blockSize = 64; // HMAC-SHA1 block size
    if (key.length() > blockSize) {
        key = QCryptographicHash::hash(key, QCryptographicHash::Sha1);
    } else if (key.length() < blockSize) {
        key = key.leftJustified(blockSize, '\0');
    }

    QByteArray ipad(blockSize, 0x36);
    QByteArray opad(blockSize, 0x5c);

    // XOR key with inner and outer padding
    for (int i = 0; i < blockSize; i++) {
        ipad[i] = ipad[i] ^ key.at(i);
        opad[i] = opad[i] ^ key.at(i);
    }

    QByteArray innerHash = QCryptographicHash::hash(ipad + data, QCryptographicHash::Sha1);
    QByteArray finalData = opad + innerHash;

    QByteArray signData = QCryptographicHash::hash(finalData, QCryptographicHash::Sha1);

    // Encode the result in Base64
    QByteArray base64SignData = signData.toBase64();

    return QString(base64SignData);
}

QString MainWindow::sign2(const QString &accessSecret, const QString &stringToSign)
{
    QByteArray key = accessSecret.toUtf8();
    QByteArray data = stringToSign.toUtf8();

    // Calculate HMAC-SHA1
    QByteArray signData = QMessageAuthenticationCode::hash(data, key, QCryptographicHash::Sha1);

    // Encode the result in Base64
    QByteArray base64SignData = QByteArray(signData).toBase64();

    return QString(base64SignData);
}


void MainWindow::on_imgBtn_clicked()
{
    QString imgPath = QFileDialog::getOpenFileName(this, "select image", "", tr("Images (*.png *.xpm *.jpg)"));
    doAliDetectLivingFace();
    ui->imgLineEdit->setText(imgPath);
}

        关键就是doAliDetectLivingFace函数，里面有几个细节：
1、时间的获取需要比当前时间早8个小时

2、注意stringToSign获取细节，url的query需要按字母顺序排序好，同时需要经specialUrlEncode，这一块自己仔细看代码

3、获取认证字符串的函数sign、sign2都可以使用，是一样的结果，其中sign函数呈现了更多细节

        另外，考虑到有些开发者只熟悉原生c++，不熟悉qt，而上面sign函数是关键，其它地方都好写出替代代码，所以这里给出用openssl实现的sign函数，qt的开发者可以不管这个
 

std::string SignUtil::sign(const std::string &accessSecret, const std::string &stringToSign)
{
    unsigned char hash[EVP_MAX_MD_SIZE];
    unsigned int hashLen = 0;

    // 初始化HMAC上下文
    HMAC_CTX* hmacCtx = HMAC_CTX_new();
    HMAC_Init_ex(hmacCtx, accessSecret.c_str(), accessSecret.length(), EVP_sha1(), NULL);

    // 更新HMAC上下文
    HMAC_Update(hmacCtx, (const unsigned char *)stringToSign.c_str(), stringToSign.length());

    // 完成HMAC计算
    HMAC_Final(hmacCtx, hash, &hashLen);

    // 释放HMAC上下文
    HMAC_CTX_free(hmacCtx);

    // 创建一个Base64编码器
    BIO* bio = BIO_new(BIO_s_mem());
    BIO* b64 = BIO_new(BIO_f_base64());
    bio = BIO_push(b64, bio);

    // 将哈希值写入BIO
    BIO_write(bio, hash, hashLen);
    BIO_flush(bio);

    // 从BIO读取Base64编码后的字符串
    BUF_MEM* buffer;
    BIO_get_mem_ptr(bio, &buffer);
    std::string base64Encoded(buffer->data, buffer->length);

    // 清理BIO
    BIO_free_all(bio);

    return base64Encoded;
}