Google Assignments LTI OAuth signature failure

Google Assignments LTI OAuth signature failure

Jon Witts - દ્વારા
Number of replies: 2
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Hi there,

We have been using Google Assignments in Moodle for some time but all of a sudden things have stopped working...

When adding content through the external tool all goes well until you save in Google Assignments and it passes back to Moodle (3.9); at which contentitem_return.php throws this error:

Exception - OAuth signature failed: Invalid signature ours= i+K2pu+DyaCzuvsQ4lP3ZTceT8c= yours=TUm+1Ejj+c/HmnixFatKMVhy5uc= 
Debug: \nError code: generalexceptionmessage\n* line 1329 of /mod/lti/locallib.php:
moodle\\mod\\lti\\OAuthException thrown\n* line 71 of /mod/lti/contentitem_return.php:
call to lti_verify_oauth_signature()\n, referer: https://assignments.google.com/

The only change to our Moodle configuration of late was that we moved it behind a reverse proxy... I am wondering if the reverse proxy could be causing the error with the OAuth signature but don't really know how to begin troubleshooting that!

I have run a network trace in Chrome for the process too, and we are seeing a 404 error for contentitem_return.php at the same point as the OAuth error occurs...

Any help or pointers greatly received!

Jon


In reply to Jon Witts

Re: Google Assignments LTI OAuth signature failure

Jake Dallimore - દ્વારા
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Hi Jon,

Sorry to hear you're having trouble with this now. Full disclosure, I've not set up Google Assignments with Moodle before, so am really just troubleshooting the general LTI flow. Could you perhaps attach the network trace as a HAR file, so I can run through it on my end?

Which version of 3.9 are you running? Are you up to date?

Cheers,
Jake
In reply to Jake Dallimore

Re: Google Assignments LTI OAuth signature failure

Jon Witts - દ્વારા
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Hi Jake,

Sorry for the delay in getting back to you... It's been a busy term!

We are running Moodle 3.9.11+ (Build: 20211207) so only a point release behind the latest...

I will try and get the HAR file tomorrow for you...

Thanks for looking;
Jon