Reddit Example failing

SGaist

Hi and welcome to devnet,

Which version of Qt are you using ?
On which platform ?

Based on you error, I would guess Windows, and if so you are likely missing OpenSSL. You can get it through the online installer.

HappyCerberus

I tried this in Windows (5.15.1) and WSL2 (Ubuntu 20 - 5.12.8).
I'm getting a slightly different error on WSL2.

What do I need to do to enable the OpenSSL in the example?

SGaist

As I suggested above: install it using the online installer.

HappyCerberus

Yes, obviously. I did that.
I'm asking what do I need to change in the project, so it links and enables OpenSSL?

SGaist

There's no linking to be done. OpenSSL is dynamically loaded at run time. One thing you can to is to copy the dlls in the same folders as your application.

The other is to modify the PATH environment variable in the Run part of the Project panel and add the folder that contains the dlls to it.

By the way, which compiler are you using ?

HappyCerberus

I'm still seeing this error in the output:

qt.networkauth.oauth2: Unexpected call

But it did succeed authenticating. I'm using Mingw.
OK, so this at least works on Windows. Now to make it work on WSL2/Linux.

SGaist

What error are you getting on Linux ?

HappyCerberus

On Linux I'm struggling with the entire process. I can't figure out where the redirect_uri is comming from.

Because it's not generated from QOAuthHttpServerReplyHandler. If I manually change the URL to point to the correct IP i get qt.networkauth.oauth2: Error: invalid_grant, but I think that is expected.

SGaist

The URL is set in your Reddit application configuration on the website.

HappyCerberus

Well, then something is broken in Qt. Because the redirect_uri definitely does not match what I set in my Reddit app.

artwaw

@HappyCerberus Please note that openSSL redistributed with Qt is for MSVC only. For use with MinGW you'd need to find precompiled binaries build with MinGW, version 1.1.1.4 (or 1.1.1.d), respectively x86 or x64. Or build them yourself.

HappyCerberus

@artwaw So, what you are saying is that the single case that I actually managed to get working is one that should not work :-D This is getting better and better :-)

artwaw

@HappyCerberus It is a bit of a mystery for me too :) But I learned the hard way the first time they included OpenSSL in Qt and since then I don't rely this particular source.

artwaw

@HappyCerberus I've de-dusted my old problems I had with SSL supplied via onlineinstaller - here goes the summary:

I compile with MinGW on Windows. Always have been.
once OpenSSL became available I was very happy, since it should simplify things. I began to use it but users reported to me that on some machines it doesn't work.
I've spent quite some time debugging until I took a look into libraries provided. They're compiled with MSVC so they need MSVC libraries to run. If you have them installed, everything will work just fine. So if it worked, it worked but some of my users have not had those libs installed.
Since then I stopped using bundled OpenSSL, as it is just potential additional overhead and more dependencies.

So if it worked for you, you simply had those Microsoft runtime libraries installed. But I'd check with dependency free MinGW compiled SSL libs too, just to be sure.

HappyCerberus

@artwaw Yeah, my problem now is that it doesn't work on Linux, and I suspect that it will not work because of the redirect_uri.

artwaw

@HappyCerberus That's beyond my area of experience, I am afraid. Hopefully more experienced colleagues here can be of help.

SGaist

Do you get the same issue with a "classic" Linux rather than WSL2 ?

HappyCerberus

Yeah, unfortunately the redirect_uri is again wrong and when I manually change it I get:

qt.networkauth.oauth2: Unexpected call
qt.networkauth.oauth2: Error: invalid_grant

unseemlysloth

I was having the same problem.

I had to manually set the redirect_uri for the RequestingAuthorization stage to just get that first part to work.

After that I get the same invalid_grant error.

The reddit api says that you get this error if you use an expired code, or reuse a code. Apparently though, you also get it if the redirect_uris in both the RequestingAuthorization stage and the RequestingAccessToken stage don't match.

    oauth2.setModifyParametersFunction([&](QAbstractOAuth::Stage stage, QVariantMap *parameters) {
        if(stage == QAbstractOAuth::Stage::RequestingAuthorization) {
            parameters->insert("duration", "permanent");
            parameters->insert("redirect_uri", QByteArray("http://127.0.0.1:1337"));
        } else if(stage == QAbstractOAuth::Stage::RequestingAccessToken) {
            parameters->insert("redirect_uri", QByteArray("http://127.0.0.1:1337"));
        }
    });

That seems to have worked.