HTTPS with QT?

John9570

Hi,

I am trying to build an application for the Spark Core https://www.spark.io/

In order to do so, I need to acquire an access key and token as shown here:

http://docs.spark.io/api/#authentication-generate-a-new-access-token

I can figure out how to send an HTTP POST using QT, but I am not sure how to handle sending an HTTPS POST because I'm pretty sure it uses SSL, and when I searched online for examples on how to do this, I became very confused, the code seems long and is very hard to understand. I am not even sure which class(es) I need:

QHttp
QHttpPart
QUrl
QNetworkAccessManager
QNetworkReply
QSslSocket
QTcp . ...
etc.

I appreciate any help anyone could give me in how to set up this simple https post!
Thank you guys :)

JKSH

Hi @John9570,

HTTPS POST is done exactly the same way as HTTP POST, using QNetworkAccessManager::post(). QNetworkAccessmanager takes care of the SSL layer for you.

You simply need to include the access token in your POST data. (You might need QNetworkCookieJar for storing and retrieving cookies)

John9570

Thanks @JKSH !

I tried that just not but after a few hours of searching and tinkering I'm running into an unforgiving and very non specific issue.

Below is my code:

      manager = new QNetworkAccessManager(this);

     connect(manager, SIGNAL(finished(QNetworkReply*)),
            this, SLOT(replyFinished(QNetworkReply*)));

     connect(manager, SIGNAL(authenticationRequired(QNetworkReply*,QAuthenticator*)),
            SLOT(provideAuthenication(QNetworkReply*,QAuthenticator*)));

     QByteArray postData;


     postData.append("grant_type=password");
     postData.append("username=MYEMAIL");
     postData.append("password=MYPASS");

     manager->post(QNetworkRequest(QUrl("https://api.spark.io/oauth/token")), postData);

void clientGUI::provideAuthenication(QNetworkReply *reply, QAuthenticator *ator){
    qDebug() << "INSIDE AUTH";
    qDebug() << reply->readAll(); // this is just to see what we received
    ator->setUser(QString("spark"));
    ator->setPassword(QString("spark"));
}

void clientGUI::replyFinished(QNetworkReply *reply){
    if(reply->error())
    {
        qDebug() << "ERROR!";
        qDebug() << reply->errorString();
    }
    else {
     //i print out some stuff pertaining to the message
   }

    reply->deleteLater();
}

On the terminal when I run this with my credentials in the code (I am planning to remove them later and extract them from a GUI) this is what I see:

content-type missing in HTTP POST, defaulting to application/x-www-form-urlencoded. Use QNetworkRequest::setHeader() to fix this problem.
ERROR! 
"Error downloading https://api.spark.io/oauth/token - server replied: Bad Request"

So I never get to the Authentication part of the code.

Basically I am trying to convert this curl https post statement to one that is equivalent in QT code:

 curl https://api.spark.io/oauth/token -u spark:spark \
 -d grant_type=password -d username=joe@example.com -d password=SuperSecret

And I guess the part I'm missing is the -u spark:spark which is how curl sets a username and password for authentication.

Thanks again for the help! And sorry for the long post, I just wanted to make sure you could see everything to help me debug this.

EDIT: The output from the terminal saying "content-type missing ... defaulting to application/x-www-form-urlencoded. " is exactly the type I want. So why it defaults to is perfectly fine.

JKSH

Hi @John9570,

I don't have experience with the curl -u option so I don't know how it works. This might help: http://stackoverflow.com/questions/20737031/curlss-option-u

     postData.append("grant_type=password");
     postData.append("username=MYEMAIL");
     postData.append("password=MYPASS");

That's the same as postData.append("grant_type=passwordusername=MYEMAILpassword=MYPASS");. I believe you need an ampersand between each parameter

John9570

Thanks for all the help! :D

You were right about the ampersands, they are necessary.

I was able to figure out how to do the -u option with the link you provided. Incase anyone else is curious, my solution looks like this:

      QString concatenated = "spark:spark";
     QByteArray data = concatenated.toLocal8Bit().toBase64();
     QString headerData = "Basic " + data;


     QNetworkRequest request;
     request.setUrl(QUrl("https://api.spark.io/oauth/token"));

     request.setRawHeader("Authorization", headerData.toLocal8Bit());

If you look at the link, there is an " Authorization: " field, and then after that field the value is "Basic: blah blah blah", by using the code above you can set the username:password that would be set with the -u option in code, and the server will recognize it as thus. You dont need to use QAuthentication.

^.^

SGaist

Hi,

Since it's username/password your original clientGUI::provideAuthenication should have worked however I would not have read the content of the reply just called setUser and setPassword