Converting cURL command and openSSL signing to Qt

PrateekKhatri

I currently use an HTTP PUT request using cURL and openSSL to upload files on S3 Bucket.
Being new to Qt and not being familiar with Windows environment too much, I am pretty much stuck trying to figure out the best way to go about this.
I have contemplated on installing cURL, openSSL, date, base64 etc. on Windows environment and using Qt to invoke command line, but that involves a lot of dependencies with my application. It would be really great to use Qt framework to be able to request this successfully.

Here is the shell script I had been using on the Linux Environment:

#!/bin/bash

fileName=$1
AccessKey="EXAMPLEACCESSKEY"
SecretKey="mysecretkey"
RFCDate=`date -R`
S3Bucket="my-bucket"
S3Path="/${S3Bucket}/${fileName}"
ContentType="application/octet-stream"
StringToSign="PUT\\n\\n${ContentType}\\n${RFCDate}\\n${S3Path}"
SignString=`echo -en ${StringToSign} | openssl sha1 -hmac ${SecretKey} -binary
| base64`
curl -X PUT -T "${fileName}" \
-H "Host: ${S3Bucket}.s3.amazonaws.com" \
-H "Date: ${RFCDate}" \
-H "Content-Type: ${ContentType}" \
-H "Authorization: AWS ${AccessKey}:${SignString}" \
http://${S3Bucket}.s3.amazonaws.com/${fileName}

Please advise on how to go about converting this to Qt framework.

Thanks!

Pablo J. Rogina

@PrateekKhatri you may want to take a look at QNetworkAccessManager::put() method.

SGaist

Hi,

You'll need at least OpenSSL for the encryption part. The rest you can do with QNetworkAccessManager as @Pablo-J-Rogina suggests. Base64 is already supported by QByteArray.

PrateekKhatri

@SGaist

void LogMgr::startLogUpload()
{
    QNetworkAccessManager networkAccessManager;

    QByteArray RFCDate = QDateTime::currentDateTime().toString(Qt::RFC2822Date).toUtf8();
    QByteArray S3Path = "/" + m_S3Bucket + "/" + m_logFileName.toUtf8();
    QByteArray StringToSign = "PUT\n\n" + m_ContentType + "\n" + RFCDate + "\n" + S3Path;
    QByteArray SignString = QMessageAuthenticationCode::hash(StringToSign,
                                                             m_SecretKey, QCryptographicHash::Sha1).toBase64();

    QNetworkRequest request(QUrl(m_S3Bucket + ".s3.amazonaws.com/" + m_logFileName));
    request.setRawHeader("Host", m_S3Bucket + ".s3.amazonaws.com");
    request.setRawHeader("Date", RFCDate);
    request.setHeader(QNetworkRequest::ContentTypeHeader, m_ContentType);
    request.setRawHeader("Authorization", "AWS " + m_AccessKey + ":" + SignString);

    QFile file(m_logFileName);

    qDebug() << "Sending Request";
    m_networkReply = networkAccessManager.put(request, &file);
    connect(m_networkReply, &QNetworkReply::finished, this, &LogMgr::fileUploadResponseCheck);

    qDebug() << m_networkReply->errorString();
    qDebug() << m_networkReply->error();
}

void LogMgr::fileUploadResponseCheck()
{
    disconnect(m_networkReply, &QNetworkReply::finished, this, &LogMgr::fileUploadResponseCheck);
    qDebug() << "Are we ever here??";
    QList<QByteArray> headerList = m_networkReply->rawHeaderList();

    for (quint8 i = 0; i < headerList.length(); ++i)
    {
        qDebug() << m_networkReply->rawHeader(headerList[i]);
    }

}

This is what I could currently have. However, I am seeing Unknown Error as output for errorString() and QNetworkReply::NetworkError(NoError) as output for error().
Also, the slot for finished() signal is never being called.

How do I exactly get OpenSSL to work with Qt, and how would I use it in this case?

PrateekKhatri

Update:

After a lot of reading and trial and error, I've reached to a point where I do get a response from the S3 server and the finished signal emits.

Here is the Code I have now:

void LogMgr::startLogUpload()
{
    QNetworkAccessManager * networkAccessManager;
    networkAccessManager = new QNetworkAccessManager(this);
    connect(networkAccessManager, SIGNAL(finished(QNetworkReply*)), this, SLOT(fileUploadResponseCheck(QNetworkReply*)));

    QByteArray RFCDate = QDateTime::currentDateTime().toString(Qt::RFC2822Date).toUtf8();
    qDebug() << RFCDate;
    QByteArray S3Path = "/" + m_S3Bucket + "/" + m_logFileName.toUtf8();
    QByteArray StringToSign = "PUT\n\n" + m_ContentType + "\n" + RFCDate + "\n" + S3Path;
    QByteArray SignString = QMessageAuthenticationCode::hash(StringToSign,
                                                             m_SecretKey, QCryptographicHash::Sha1).toBase64();

    QNetworkRequest request(QUrl("http://" + m_S3Bucket + ".s3.amazonaws.com/" + m_logFileName));
    request.setRawHeader("Host", m_S3Bucket + ".s3.amazonaws.com");
    request.setRawHeader("Date", RFCDate);
    request.setHeader(QNetworkRequest::ContentTypeHeader, m_ContentType);
    request.setRawHeader("Authorization", "AWS " + m_AccessKey + ":" + SignString);

    QIODevice * fileData = new QFile(m_logFileName, this);
    if (fileData->open(QIODevice::ReadOnly))
    {
        qDebug() << "Sending Request";
        networkAccessManager->put(request, fileData);
    }
}

void LogMgr::fileUploadResponseCheck(QNetworkReply * reply)
{
    qDebug() << "File Upload Response Check";
    if (reply == nullptr)
    {
        qDebug() << "Network reply ptr empty";
        return;
    }
    qDebug() << "Response " << reply->readAll();
}

I have never used AWS S3 before so I am unaware of this response error:

"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<Error><Code>AccessDenied</Code><Message>AWS authentication requires a valid Date or x-amz-date header</Message><RequestId>C9EDED0BEC1D699F</RequestId><HostId>ivgJ79t3rydmrW9Eeh8j1osjPlNKXgVHRIQeZ40iivrq4yZTb/u0c2yETZ0YGhGsDTW/0w2HZv0=</HostId></Error>"

AWS Authentication requires a valid Date or x-amz-date header
Surely this has something to do with the RFCDate header!

Any advise on this would be really helpful.

Edit:
I found that the shell script returns date: Mon, 30 Apr 2018 18:35:18 -0700
Qt RFC2822Date is returned as: "30 Apr 2018 18:28:23 -0700

Going to try fixing this and will try again.

Thanks,
Prateek