You may want to refer my tutorial to run YOURLS with Docker

1. Meet the prerequisite
2. Get the generated grabled password in browser
3. Register user in array $yourls_user_passwords in config file /user/config.php

This plugins is written because my lab is using GitLab as a SSO provider.
However, there's no plugin for (generic) OAuth sign in (except one for Google Auth only) which make me start to write one by myself.
Of course, such a plugin should support not only GitLab but various SSO providers. That's why I choose thephpleague/oauth2-client as the vendor of this plugin, which is continually updated and easy to use (important).

Actually, this plugin use omines/oauth2-gitlab as the vendor, which is based on the former one.

• YOURLS 1.7.4 (or 1.7.x?)
  • Using official docker images: yourls:1.7.4-fpm-alpine, mysql:8.0.18, and nginx:1.17.5-alpine
• omines/oauth2-gitlab 3.1.2 (or 3.x?)
  • Using composer (in Alpine) to require
  • It's based on league/oauth2-client:^2.2
• GitLab 11+ (or 8.17+?)
  • Because GitLab move from API v3 to v4
  • Use league/oauth2-client:^2 as mentioned if still using older v3 api

Before start cloning or using this plugin, you have to make sure omines/oauth2-gitlab is installed using following command:

$ composer require omines/oauth2-gitlab:^3.1.2    # run in container

In case you're using official docker image 1.7.4-fpm-alpine, you'd like to run $ apk add composer in the container first.

1. Clone files (at least plugin.php and config_provider.php) to YOURLS_ROOT/user/plugins/yourls-oauth_sign_in

$ # apk add git                                   # install as needed
$ cd /var/www/html/user/plugins/                  # path in docker
$ git clone https://github.com/LouisSung/yourls-oauth_sign_in

2. You should able to sign in using existing user & password (in user/config.php)...
3. Visit https://YOURLS_SITE/admin/plugins.php to active plugin named Sign in with OAuth
4. Sign out and get your new username & password in browser developer tools (DevTools, Web Inspector, etc.)
5. Register the account(s) by editing array $yourls_user_passwords in /user/config.php
6. ฅ• ω •ฅ, you should able to sign in with GitLab by clicking button on https://YOURLS_SITE/admin/index.php

1. Make sure you're using HTTPS to prevent potential eavesdroppers!
2. The principle of this plugin is NOT to bypass the original log in mechanism, but to get auto generated password instead!
   1. First, the OAuth part is done by thephpleague and omines (thanks again), so this plugin don't claim it
   2. Once the response is got, we're able to get user info including id, username, email, etc. (the others may not have corresponding wrapper in their implementations)
   3. User should define their own account mapping garbled password generating function using id, username, and email (which are rarely changed)
   4. Once the account is got (by mapping one of the user info) and password is calculated (by predefined function), we're ready to sign in
   5. Now, it's time for JavaScript to take place
      1. The password generation is done by PHP on the server side (which should be safe)
      2. The generated password is passed to browser via HTTP response (which should also be safe if using HTTPS...)
      3. jQuery is used to help on fill in the account & password form and submit the form automatically for you (where user can modify front-end code and do dangerous things :p)
      4. Once the account & password is submit, it use the original authentication method, which don't claim by us either
      5. You can treat this plugin as a wrapper that bridges the OAuth response and original Auth process!
3. To make things happened, you should check the grabled password and register before user can really sign in!
4. Once the registration procedure is done, user can easily sign in by clicking button and SSO :D

1. When your start runing this plugin, your https://YOURLS_SITE/admin/index.php should look like screenshot above
2. Toggle $WARNING_PRINT_PASSWORD_IN_BROWSER as true in plugin.php at line #L30
   1. ▼
      
   2. It then stop and wait after fill in account & password rather than auto submit for user
   3. Now, password shows in plaintext in JavaScript code, where you can copy from and do the following registration
   4. ▼
      
3. !! REMEMBER to toggle value back to false, or just remove whole if statement (delete line #L65-L78 & #L94)

• Refer #L56-L63, I use username as account and 64 digits garbled as password

  $account = $user->getUsername();
  [$PRIME_16DIGITS, $INITIALIZATION_VECTOR] = ['2355457523880889', '7897466719774591'];
  $tmp_pass = str_repeat(substr(strrev($account), -8).substr($account, -8).
                         substr(number_format($user->getID()*floatval($PRIME_16DIGITS), 1, '%', '&'), -16), 4);
  $password = substr(openssl_encrypt($tmp_pass, 'AES-256-CTR', $account, 0, $INITIALIZATION_VECTOR), 7, 64);

  • For example, when username == 'yourls' and id == 17 get:

    $account  = 'yourls'
    $tmp_pass = 'slruoyyourls77&905&975&112%0slruoyyourls77&905&975&112%0slruoyyourls77&905&975&112%0slruoyyourls77&905&975&112%0'
    $password = 'JS/3dllhgxuZMYDdDwPdUyuhP6s5N6XzqTNjwAZH+qa78IuIMOaWb1bAZNp9l0zf'

• Random seeds:
  1. Tow of them are major ones: $PRIME_16DIGITS and $INITIALIZATION_VECTOR #L60
  2. Others like part of account, 16 digits int, %, $, substr, etc. are seeds that can change

This project is licensed under the following 3 licenses, YOURLS, MIT, and EPL

1. YOURLS: aka Do whatever the hell you want with it
2. MIT: aka MadeInTaiwan Licence :3
3. EPL: aka EPL Public License, where EPL stands for EmbeddedPlatformLab (like GNU or YAML, quite cool, huh?)

Feel free to modify it to your own version as needed
Contact me if having any comments :D