将Google API接入Qt应用时遭遇OAuth2认证异常问题

我参考Qt官方博客实现了Qt应用中的Google登录功能，编写了GoogleGateway类处理OAuth2认证流程。目前点击GUI按钮可以正常跳转至浏览器完成登录操作，但调试时出现以下错误，应用始终无法收到认证信息：

qt.networkauth.oauth2: Unexpected call
qt.networkauth.replyhandler: Error transferring https://oauth2.googleapis.com/token - server replied:

相关代码 #

#include "googleapi.h"
#include <QObject>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QString>
#include <QFile>
#include <QDir>
#include <QUrl>
#include <QOAuthHttpServerReplyHandler>
#include <QDesktopServices>

GoogleGateway::GoogleGateway(QObject* parent) : QObject(parent)
{
    this->google = new QOAuth2AuthorizationCodeFlow(this);
    this->google->setScope("email");

    connect(this->google, &QOAuth2AuthorizationCodeFlow::authorizeWithBrowser, &QDesktopServices::openUrl);

    QByteArray val;
    QFile file;
    file.setFileName(QDir::toNativeSeparators("/path/credential_file.json"));
    if (file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        val = file.readAll();
        file.close();
    }

    QJsonDocument document = QJsonDocument::fromJson(val);
    QJsonObject object = document.object();
    const auto settingsObject = object["installed"].toObject();
    //qDebug() << settingsObject["auth_uri"].toString() << settingsObject["client_id"].toString() << settingsObject["token_uri"].toString() << settingsObject["client_secret"].toString();

    const QUrl authUri(settingsObject["auth_uri"].toString());
    const auto clientId = settingsObject["client_id"].toString();
    const QUrl tokenUri(settingsObject["token_uri"].toString());
    const auto clientSecret(settingsObject["client_secret"].toString());

    const auto redirectUris = settingsObject["redirect_uris"].toArray();
    const QUrl redirectUri(redirectUris[0].toString());
    const auto port = static_cast<quint16>(redirectUri.port());

    this->google->setAuthorizationUrl(authUri);
    this->google->setClientIdentifier(clientId);
    this->google->setAccessTokenUrl(tokenUri);
    this->google->setClientIdentifierSharedKey(clientSecret);

    auto replyHandler = new QOAuthHttpServerReplyHandler(8080, this);
    this->google->setReplyHandler(replyHandler);
    this->google->grant();

    connect(this->google, &QOAuth2AuthorizationCodeFlow::granted, [=]() {
        qDebug() << __FUNCTION__ << __LINE__ << "Access Granted!";
        auto reply = this->google->get(QUrl("https://www.googleapis.com/plus/v1/people/me"));
        connect(reply, &QNetworkReply::finished, [reply]() {
            qDebug() << "REQUEST FINISHED. Error? " << (reply->error() != QNetworkReply::NoError);
            qDebug() << reply->readAll();
        });
    });
}

已排查内容 #

• 确认网络连接正常
• 检查重定向URI与Google Cloud控制台配置一致
• 验证客户端ID、密钥等凭证信息正确
• 尝试连接QOAuth2AuthorizationCodeFlow::error信号，但未获取到有效错误信息

请求技术帮助解决该认证失败问题。

内容的提问来源于stack exchange，提问作者Karim Kamel