Add ability to temporarily override logged in user

CRM/ACL/API.php

@@ -113,18 +113,18 @@ public static function whereClause(
       }
     }
 
-    if (!$contactID) {
-      $contactID = CRM_Core_Session::getLoggedInContactID();
-    }
-    $contactID = (int) $contactID;
-
     // first see if the contact has edit / view all permission
     if (CRM_Core_Permission::check('edit all contacts', $contactID) ||
       ($type == self::VIEW && CRM_Core_Permission::check('view all contacts', $contactID))
     ) {
       return $deleteClause;
     }
 
+    if (is_null($contactID)) {
+      $contactID = CRM_Core_Session::getLoggedInContactID();
+    }
+    $contactID = (int) $contactID;
+
     $whereClause = CRM_ACL_BAO_ACL::whereClause($type,
       $tables,
       $whereTables,

CRM/Core/Permission.php

@@ -111,13 +111,20 @@ public static function getPermission() {
    *
    * @param int $contactId
    *   Contact id to check permissions for. Defaults to current logged-in user.
+   *   Pass 0 for no user (anonymous)
    *
    * @return bool
    *   true if contact has permission(s), else false
    */
   public static function check($permissions, $contactId = NULL) {
     $permissions = (array) $permissions;
+    // If the logged in contact id is being overridden, use the substitute contactId
+    $contactId = $contactId ?? CRM_Core_Session::getOverriddenUser();
     $userId = CRM_Core_BAO_UFMatch::getUFId($contactId);
+    // If contact has no associated user, set to 0 for anonymous (logged-out)
+    if ($contactId === 0 || ($contactId && !$userId)) {
+      $userId = 0;
+    }
 
     /** @var CRM_Core_Permission_Temp $tempPerm */
     $tempPerm = CRM_Core_Config::singleton()->userPermissionTemp;

CRM/Core/Permission/Backdrop.php

@@ -67,11 +67,10 @@ class CRM_Core_Permission_Backdrop extends CRM_Core_Permission_DrupalBase {
    *
    * @param string $str
    *   The permission to check.
-   *
    * @param int $userId
+   *   NULL = current user; 0 = anonymous (logged-out)
    *
    * @return bool
-   *   true if yes, else false
    */
   public function check($str, $userId = NULL) {
     $str = $this->translatePermission($str, 'Drupal', [
@@ -85,10 +84,7 @@ public function check($str, $userId = NULL) {
       return TRUE;
     }
     if (function_exists('user_access')) {
-      $account = NULL;
-      if ($userId) {
-        $account = user_load($userId);
-      }
+      $account = is_numeric($userId) ? user_load($userId) : NULL;
       return user_access($str, $account);
     }
     return TRUE;

CRM/Core/Permission/Drupal.php

@@ -66,11 +66,10 @@ class CRM_Core_Permission_Drupal extends CRM_Core_Permission_DrupalBase {
    *
    * @param string $str
    *   The permission to check.
-   *
    * @param int $userId
+   *   NULL = current user; 0 = anonymous (logged-out)
    *
    * @return bool
-   *   true if yes, else false
    */
   public function check($str, $userId = NULL) {
     $str = $this->translatePermission($str, 'Drupal', [
@@ -84,10 +83,7 @@ public function check($str, $userId = NULL) {
       return TRUE;
     }
     if (function_exists('user_access')) {
-      $account = NULL;
-      if ($userId) {
-        $account = user_load($userId);
-      }
+      $account = is_numeric($userId) ? user_load($userId) : NULL;
       return user_access($str, $account);
     }
     return TRUE;

CRM/Core/Permission/Drupal6.php

@@ -66,11 +66,10 @@ class CRM_Core_Permission_Drupal6 extends CRM_Core_Permission_DrupalBase {
    *
    * @param string $str
    *   The permission to check.
-   *
    * @param int $userId
+   *   NULL = current user; 0 = anonymous (logged-out)
    *
    * @return bool
-   *   true if yes, else false
    */
   public function check($str, $userId = NULL) {
     $str = $this->translatePermission($str, 'Drupal6', [
@@ -84,10 +83,7 @@ public function check($str, $userId = NULL) {
       return TRUE;
     }
     if (function_exists('user_access')) {
-      $account = NULL;
-      if ($userId) {
-        $account = user_load($userId);
-      }
+      $account = is_numeric($userId) ? user_load($userId) : NULL;
       return user_access($str, $account);
     }
     return TRUE;

CRM/Core/Permission/Drupal8.php

@@ -43,8 +43,8 @@ class CRM_Core_Permission_Drupal8 extends CRM_Core_Permission_DrupalBase {
    *
    * @param string $str
    *   The permission to check.
-   *
    * @param int $userId
+   *   NULL = current user; 0 = anonymous (logged-out)
    *
    * @return bool
    */
@@ -59,7 +59,7 @@ public function check($str, $userId = NULL) {
     if ($str == CRM_Core_Permission::ALWAYS_ALLOW_PERMISSION) {
       return TRUE;
     }
-    $acct = $userId ? \Drupal\user\Entity\User::load($userId) : \Drupal::currentUser();
+    $acct = is_numeric($userId) ? \Drupal\user\Entity\User::load((int) $userId) : \Drupal::currentUser();
     return $acct->hasPermission($str);
   }
 

CRM/Core/Permission/Joomla.php

@@ -44,16 +44,14 @@ class CRM_Core_Permission_Joomla extends CRM_Core_Permission_Base {
    * @param string $str
    *   The permission to check.
    * @param int $userId
+   *   NULL = current user; 0 = anonymous (logged-out)
    *
    * @return bool
-   *   true if yes, else false
    */
   public function check($str, $userId = NULL) {
     $config = CRM_Core_Config::singleton();
-    // JFactory::getUser does strict type checking, so convert falesy values to NULL
-    if (!$userId) {
-      $userId = NULL;
-    }
+    // JFactory::getUser does strict type checking, so convert non-numeric values to NULL
+    $userId = is_numeric($userId) ? (int) $userId : NULL;
 
     $translated = $this->translateJoomlaPermission($str);
     if ($translated === CRM_Core_Permission::ALWAYS_DENY_PERMISSION) {

CRM/Core/Permission/WordPress.php

@@ -44,9 +44,9 @@ class CRM_Core_Permission_WordPress extends CRM_Core_Permission_Base {
    * @param string $str
    *   The permission to check.
    * @param int $userId
+   *   NULL = current user; 0 = anonymous (logged-out)
    *
    * @return bool
-   *   true if yes, else false
    */
   public function check($str, $userId = NULL) {
     // Generic cms 'administer users' role tranlates to users with the 'edit_users' capability' in WordPress
@@ -72,20 +72,19 @@ public function check($str, $userId = NULL) {
     require_once ABSPATH . WPINC . '/pluggable.php';
 
     // for administrators give them all permissions
-    if (!function_exists('current_user_can')) {
+    if (!function_exists('current_user_can') && !is_numeric($userId)) {
       return TRUE;
     }
 
-    $user = $userId ? get_userdata($userId) : wp_get_current_user();
-
-    if ($user->has_cap('super admin') || $user->has_cap('administrator')) {
-      return TRUE;
-    }
+    $user = is_numeric($userId) ? get_userdata((int) $userId) : wp_get_current_user();
 
     // Make string lowercase and convert spaces into underscore
     $str = CRM_Utils_String::munge(strtolower($str));
 
-    if ($user->exists()) {
+    if ($user && $user->exists()) {
+      if ($user->has_cap('super admin') || $user->has_cap('administrator')) {
+        return TRUE;
+      }
       // Check whether the logged in user has the capabilitity
       if ($user->has_cap($str)) {
         return TRUE;

CRM/Core/Session.php

@@ -65,6 +65,13 @@ class CRM_Core_Session {
    */
   static private $_singleton = NULL;
 
+  /**
+   * Stack of contact ids when overriding current user
+   *
+   * @var array
+   */
+  static private $userOverride = [];
+
   /**
    * Constructor.
    *
@@ -250,6 +257,11 @@ public function get($name, $prefix = NULL) {
     // create session scope
     $this->createScope($prefix, TRUE);
 
+    if (!$prefix && $name == 'userID' && self::$userOverride) {
+      end(self::$userOverride);
+      return current(self::$userOverride);
+    }
+
     if (empty($this->_session) || empty($this->_session[$this->_key])) {
       return NULL;
     }
@@ -573,4 +585,60 @@ public function isEmpty() {
     return empty($_SESSION);
   }
 
+  /**
+   * Temporarily masquerade as a different user.
+   *
+   * Note: the override is stored in a static variable so does not persist past this page request.
+   *
+   * Returns a handle to identify this override so you can revert it later.
+   *
+   * @param int $contactId
+   *   Contact id to spoof as current user.
+   * @param string|int $handle
+   *   Specify your own handle if you wish.
+   * @return bool|string|int
+   *   Handle if anything was done, FALSE otherwise
+   */
+  public function overrideCurrentUser($contactId, $handle = NULL) {
+    if ($contactId == $this->get('userID')) {
+      // Current user is already $contactId; nothing to do
+      return FALSE;
+    }
+    $handle = $handle ?? uniqid();
+    self::$userOverride[$handle] = $contactId;
+    return $handle;
+  }
+
+  /**
+   * Reverts $this->overrideCurrentUser
+   *
+   * @param string|int $handle
+   *   Optionally specify the override to revert, else it will just
+   *   pop the latest override off the stack.
+   *
+   * @return bool
+   *   Whether or not anything was done.
+   */
+  public function restoreCurrentUser($handle = NULL) {
+    if (self::$userOverride) {
+      $handle = $handle ?? array_reverse(array_keys(self::$userOverride))[0];
+      if (array_key_exists($handle, self::$userOverride)) {
+        unset(self::$userOverride[$handle]);
+        return TRUE;
+      }
+    }
+    return FALSE;
+  }
+
+  /**
+   * If the contact id of the logged-in user has been overridden, return it.
+   *
+   * Otherwise return null to indicate the current user is not being overridden.
+   *
+   * @return int|null
+   */
+  public static function getOverriddenUser() {
+    return self::$userOverride ? self::getLoggedInContactID() : NULL;
+  }
+
 }

tests/phpunit/E2E/Core/UserOverrideTest.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace E2E\Core;
+
+/**
+ * Class UserOverrideTest
+ *
+ * Check that overriding session user behaves as expected.
+ *
+ * @package E2E\Core
+ * @group e2e
+ */
+class UserOverrideTest extends \CiviEndToEndTestCase {
+
+  protected function setUp() {
+    parent::setUp();
+  }
+
+  protected function tearDown() {
+    while (\CRM_Core_Session::singleton()->restoreCurrentUser()) {
+      // Loop until all overrides are cleared
+    }
+  }
+
+  public function testOverride() {
+    $session = \CRM_Core_Session::singleton();
+    $originalUser = $session::getLoggedInContactID();
+    // Set user CID to 2
+    $o1 = $session->overrideCurrentUser(2);
+    $this->assertEquals(2, $session::getLoggedInContactID());
+    // Set user CID to 3
+    $o2 = $session->overrideCurrentUser(3);
+    $this->assertEquals(3, $session::getLoggedInContactID());
+    // Set user CID to 4
+    $o3 = $session->overrideCurrentUser(4);
+    // Clear the second override
+    $this->assertTrue($session->restoreCurrentUser($o2));
+    // Latest override should still stand
+    $this->assertEquals(4, $session::getLoggedInContactID());
+    // Clear the last override, should revert to the one remaining override
+    $this->assertTrue($session->restoreCurrentUser());
+    $this->assertEquals(2, $session::getLoggedInContactID());
+    $this->assertEquals(2, $session->getOverriddenUser());
+    // Clear the final override
+    $this->assertTrue($session->restoreCurrentUser());
+    $this->assertEquals($originalUser, $session::getLoggedInContactID());
+    // Assert there are no overrides left to clear
+    $this->assertNull($session->getOverriddenUser());
+    $this->assertFalse($session->restoreCurrentUser());
+  }
+
+}