curl and OAuth tokens on macOS

[matthew_buckett]

When poking the Canvas API with curl I would often find myself copy and pasting lots of Authorization headers around to correctly authenticate against Canvas. This is error prone and also leaves your tokens accessible in your .bash_history file. To improve on this I wrote a small script for macOS that stores the tokens in Apple's keychain and then automatically adds the Authorization header to the curl request based on the URL in the command line. While this isn't perfect, it's much better and easier to use. The result is a script I call ccurl. 

Setup

Download a copy of ccurl, make it executable and set the CCURL_HOSTS environmental variable to a space separated list of hosts you wish to use ccurl against. 

$ curl -s -O https://gist.githubusercontent.com/buckett/ed3217fced4b9d129758157b4476aaa6/raw/1fa77f31bdb65b8bf6cb... chmod +x ccurl
$ echo 'export CCURL_HOSTS="canvas.instructure.com canvas.test.instructure.com canvas.beta.instructure.com"' >> ~/.bashrc‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

You may also wish to put ccurl somewhere on your PATH. Then to set a token for a host use (history -c flushes bash history so the token doesn't get save in plain sight):

$ security add-generic-password -a $USER -s canvas.instructure.com -w 7~1K9WJ3xobQp5RX8DUbbSdigxn2WD8yMOfUlCHbH9FIPlyL7E9E5QWSWN4CCVfqAEHC
$ history -c‍‍‍‍‍‍‍‍

Use

Then to use it just do a curl command but add the extra c, it passes all command line options through to curl so it should support all examples you see for the standard curl tool (jq is a tool to transform json, but here it just formats it to make it more readable):

$ ccurl -s  https://canvas.instructure.com/api/v1/users/self | jq .
{
  "id": 4539009,
  "name": "Matthew Buckett",
  "created_at": "2015-05-31T19:49:29+01:00",
  "sortable_name": "Buckett, Matthew",
  "short_name": "Matthew Buckett",
  "avatar_url": "https://canvas.instructure.com/images/messages/avatar-50.png",
  "locale": null,
  "effective_locale": "en-GB",
  "permissions": {
    "can_update_name": true,
    "can_update_avatar": true
  }
}
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Links

https://canvas.instructure.com/doc/api/file.oauth.html#manual-token-generation - How to create a token for your account.