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