QNetworkAccessManager post to url: Error downloading https://api.instagram.com/oauth/access_token - server replied: BAD REQUEST

[gridorian]

Hello guys, I'm trying to write an Instagram tool, but I've encountered a problem with QNetworkAccessManager. Even though, the same details ran with curl in CLI it throws some information, while using Qt I always get the error in the title. Am I doing smth wrong in the post script? I followed a dozen examples which were all saying the same thing.

@curl -F 'client_id=d01483900e3949c194ff6a73910886ba' -F 'client_secret=6d43805a777645ca9d7e96416d4fb83d' -F 'grant_type=authorization_code' -F 'redirect_uri=http://instagram.com' -F 'code=9e1aa67677c64b23abe1bb02fc81df96' https://api.instagram.com/oauth/access_token@

@void MainWindow::_loadWebAuthToken()
{
this->_debug("_loadWebAuthToken: TOKEN OBTAIN");

QNetworkAccessManager *manager = new QNetworkAccessManager(this);
connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(_loadWebAuthTokenReplyFinish(QNetworkReply*)));

QUrl url;
url.setUrl("https://api.instagram.com/oauth/access_token");
QNetworkRequest request(url);
request.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");

QByteArray postData;
postData.append("client_id=d01483900e3949c194ff6a73910886ba")
        .append("&client_secret=6d43805a777645ca9d7e96416d4fb83d")
        .append("&grant_type=authorization_code")
        .append("&redirect_uri=http://instagram.com")
        .append("&code=9e1aa67677c64b23abe1bb02fc81df96");

QNetworkReply *reply = manager->post(request, postData);

}

void MainWindow::_loadWebAuthTokenReplyFinish(QNetworkReply *reply)
{
reply->deleteLater();

if(reply->error() == QNetworkReply::NoError) {
    // Get the http status code
    int v = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
    if (v >= 200 && v < 300) { // Success
        // Here we got the final reply
        this->_debug("::reply");
        QString replyText(reply->readAll());
        this->_debug("{" + replyText + "}");
    } else if (v >= 300 && v < 400) {  // Redirection
        // Get the redirection url
        this->_debug("::redirect");
        QUrl newUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();
        // Because the redirection url can be relative,
        // we have to use the previous one to resolve it
        newUrl = reply->url().resolved(newUrl);

        QNetworkAccessManager *manager = reply->manager();
        QNetworkRequest redirection(newUrl);
        QNetworkReply *newReply = manager->get(redirection);
        connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(_loadWebAuthTokenReplyFinish(QNetworkReply*)));

        return; // to keep the manager for the next request
    }
} else {
    // Error
    this->_debug("::error");
    QString error(reply->errorString());
    this->_debug(error);
}

reply->manager()->deleteLater();

}@

[ChrisW67]

curl "-F" options will cause the request to be sent Content-Type "multipart/form-data":http://tools.ietf.org/html/rfc2388 and your Qt code is using application/x-www-form-urlencoded. If Instagram is expecting the multipart format then you should look at QHttpMultiPart

[ihaveajob]

It looks like a problem with the URL-encoded code that you're exchanging for a login token. I wrote about authenticating a Qt app with Google SSO, and there I describe how to intercept the login parameters and URL-decode them before Qt continues with the flow.

[Pl45m4]

@ihaveajob

You think after 7 1/2 years OP is still looking for help in this case? ;-)

[eyllanesc]

@ihaveajob I see that you have published in several old posts a similar message that seems spam to me, some moderator can analyze this behavior