BookStack/app/Access/ExternalBaseUserProvider.php

<?php

namespace BookStack\Access;

use Illuminate\Contracts\Auth\Authenticatable;
use Illuminate\Contracts\Auth\UserProvider;
use Illuminate\Database\Eloquent\Model;

class ExternalBaseUserProvider implements UserProvider
{
    /**
     * The user model.
     *
     * @var string
     */
    protected $model;

    /**
     * LdapUserProvider constructor.
     */
    public function __construct(string $model)
    {
        $this->model = $model;
    }

    /**
     * Create a new instance of the model.
     *
     * @return Model
     */
    public function createModel()
    {
        $class = '\\' . ltrim($this->model, '\\');

        return new $class();
    }

    /**
     * Retrieve a user by their unique identifier.
     *
     * @param mixed $identifier
     *
     * @return Authenticatable|null
     */
    public function retrieveById($identifier)
    {
        return $this->createModel()->newQuery()->find($identifier);
    }

    /**
     * Retrieve a user by their unique identifier and "remember me" token.
     *
     * @param mixed  $identifier
     * @param string $token
     *
     * @return Authenticatable|null
     */
    public function retrieveByToken($identifier, $token)
    {
        return null;
    }

    /**
     * Update the "remember me" token for the given user in storage.
     *
     * @param Authenticatable $user
     * @param string          $token
     *
     * @return void
     */
    public function updateRememberToken(Authenticatable $user, $token)
    {
        //
    }

    /**
     * Retrieve a user by the given credentials.
     *
     * @param array $credentials
     *
     * @return Authenticatable|null
     */
    public function retrieveByCredentials(array $credentials)
    {
        // Search current user base by looking up a uid
        $model = $this->createModel();

        return $model->newQuery()
            ->where('external_auth_id', $credentials['external_auth_id'])
            ->first();
    }

    /**
     * Validate a user against the given credentials.
     *
     * @param Authenticatable $user
     * @param array           $credentials
     *
     * @return bool
     */
    public function validateCredentials(Authenticatable $user, array $credentials)
    {
        // Should be done in the guard.
        return false;
    }
}