I just set up an LTI-handshake between Canvas (https://mitt.uib.no; my University's LMS) and Moodle (https://nukit.ihelse.net) using Moodle 3.3.
The reason: I wanted to use Moodle's anonymous Feedback activity in a canvas course (see our recent publication doi: 10.1177/2058460117720858
To set up LTI, The documentation http://docs.moodle.org/33/en/Publish_as_LTI_tool worked pretty much as expected.
However: You MUST enable the "Publish as LTI tool" plugin under
Site/Plugins/Enrolmens/Publish as LTI tool BEFORE you create the LTI configuration for your moodle course.
There were some minor glitches getting things to work in Canvas. Go to Settings/Apps and press "+ App". Choose the configuration type "Paste XML
In Moodle, go to Course administration/Published at LTI tools.
Navigate to the page under "Cartridge URL" and paste the XML
code into the dialog box in Canvas. Make sure it is pure XML without formatting codes inserted by Internet Explorer etc.
The "user key" in Canvas is the name of your LTI object in Moodle, the "shared secret" is the secret in Moodle.
Once the app is saved in Canvas, you can embed it in any Canvas module like any static page etc.
However, the external Moodle page did not come up at once. I had to edit the module and the properties of the app and check "open in a separate tab". From that point onward, things worked like a charm.