Is it possible to login to Drupal with a custom user field, instead of username/pass?

Question

I have two websites - One of them is Drupal 7, and the other is a different site (Site #2). In Site #2, within the user tables, is a field called "customid". Each user on Site #2 has a unique, randomly generated 30 character alphanumeric string within their respective "customid" field.

I can pull the value of the "customid" field for the user on Site #2, and use it as an input value in a form post to the Drupal 7 site.

In the Drupal 7 site, I created a custom user field "customid" as well.

Is it possible to make a form post from Site #2 to Drupal 7 - with the "customid" value as an input, and if it matches the "customid" field in the Drupal user table, log them in, else - redirect to the registration page?

We're essentially bypassing the username/password to log them in - I'm trying to log them in via custom user field.

I searched everywhere, and just couldn't find anything where something like this had been discussed. Thanks anyone for your time and help!

UPDATE:

I've tried implementing W.M.'s solution below, however upon attempting to enable the module, I get the white screen of death. Nothing shows up in the logs for the error.

For my custom module, I have two files:
ra_login.module
ra_login.info

Info file:

name = RA Login
description = Check ID and Login if there is a match, else go to Registration Page.
core = 7.x

; Information added by Drupal.org packaging script on 2013-12-16
version = "7.x-1.0"
core = "7.x"
project = "ra_login"
datestamp = "1387203506"

Module File:

<?php

function ra_login_menu()
{
    $items['authenticate-by'] = array( // or any other custom path you choose
        'title' => 'Login by SSO',
        'access callback' => true, // no point in authenticating at this point in code execution
        'page callback' => 'ra_login_function',
        'type' => MENU_CALLBACK,
        );
    return $items;
}

function ra_login_function($CONTACTID)
{
    // post the data to /authenticate-by as json with a parameter / property named CONTACTID holding the CONTACTID
    $postData = file_get_contents('php://input');

    $Data = json_decode($postData);

    $query = new EntityFieldQuery();
    $query->entityCondition('entity_type', 'user')
        ->propertyCondition('uid', 1, '<>')
        // User number 1 should not be able to log in using this method
        ->fieldCondition('field_contactid', 'value', $Data->CONTACTID, '=')
        ->range(0,1);

    $result = $query->execute();

    if (isset($result['user'])) {
        $uid = array_keys($result['user'])[0];
        $account = user_load($uid);
        global $user;
        $user->uid = $uid;
        $user->name = $account->name;
        $user->timezone = $account->timezone;
        user_login_finalize(); // Log user in
        drupal_goto('/user'); // or any other path to redirect logged in users to
    } else {
        drupal_goto('/user/register');
    }

}

Again, for some reason when I try to enable the module, I get a white screen. Thanks for anyone who can help!

UPDATE:

I turned on errors in php.ini - now instead of the white screen, it shows me the following error:

Parse error: syntax error, unexpected '[' in C:\inetpub\wwwroot\sites\all\modules\ra_login\ra_login.module on line 31 

Line 31 is:

$uid = array_keys($result['user'])[0];

Any help is greatly appreciated!

Answer 1

function YOUR_MODULE_page_build(&$page) {
  if(isset($_POST['customid'])){
    $customid=$_POST['customid']; //get your id
    $uid=get_uid_based_on_customid($customid);//you function to identify if someone has customid that customid
    if(empty($uid)){
        //if uid not found send user to login
        drupal_goto('/user');
    }else{
        //if uid found load user, authenticat it and redirect to page
        global $user; //global because is same var as the one drupal uses
        $user = user_load($uid);//set used data for you and drupal
        $login_array = array('name' => $user->name);
        user_login_finalize($login_array);//key function, will record user sessions
        drupal_set_message(t('User loged in!'));
        drupal_goto('/');
    }
  }
}

function get_uid_based_on_customid($customid){

  $query = new EntityFieldQuery();
  $query->entityCondition('entity_type', 'user')
  //->propertyCondition('uid', 1, '<>')
  // User number 1 should not be able to log in using this method because he is always admin, pay attention and uncomment when you go to prod
  ->fieldCondition('field_customid', 'value', $customid, '=')
  ->range(0,1);

  $result = $query->execute();

  if(!empty($result)){
    $data=$result['user'];
    reset($data);
    $first_element=current($data);
    $uid = $first_element->uid;

    return $uid;
  }else{
    return '';
  }

}

Answer 2

This is the code you need. In the Drupal site create the following module:

Update:

function my_special_login_menu()
{
    $items['authinticate-by-customerid'] = array( // or any other custom path you choose
        'title' => 'Login by customerid',
        'access callback' => true, // no point in authenticating at this point in code execution
        'page callback' => 'my_special_login_function',
        'type' => MENU_CALLBACK,
        );
    return $items;
}

function my_special_login_function($customerid)
{
    // post the data to /authinticate-by-customerid as json with a parameter / property named customerid holding the customerid
    $postData = file_get_contents('php://input');

    $Data = json_decode($postData);

    $query = new EntityFieldQuery();
    $query->entityCondition('entity_type', 'user')
        ->propertyCondition('uid', 1, '<>')
        // User number 1 should not be able to log in using this method
        ->fieldCondition('field_customerid', 'value', $Data->customerid, '=')
        ->range(0,1);

    $result = $query->execute();

    if (isset($result['user'])) {
        $uid = array_keys($result['user'])[0];
        $account = user_load($uid);
        global $user;
        $user->uid = $uid;
        $user->name = $account->name;
        $user->timezone = $account->timezone;
        user_login_finalize(); // Log user in
        drupal_goto('/user'); // or any other path to redirect logged in users to
    } else {
        drupal_goto('/user/register');
    }

}

For this code to work you need Entity API module and you should serve the site over SSL in order to encrypt the data transferred between the two sites.

Answer 3

I have no exact solution for your problem, but get idea how to deal with this,

By implementing following algorithm you can achieve.

• Requirement

  -In Drupal Site you are saving "customid" this id is refer to "Site #2".
  -When you store this "customid" in drupal database you need to update password field also and store this "customid" in password field by drupal encryption format.

---

• Now how to login by "customid"
  -From site#2 you are sending "customid" to drupal site, write custom module to catch this customid in to drupal site.
  -Now check this "customid" into drupal db and fetch user_name of this related "customid".
  -Now you have user_name and password(customid), pass this to the drupal login form post function.
  -Drupal will check user_name and password if match user will log in.

Answer 4

Please review this contrib module: https://www.drupal.org/project/login_custom_field