function login_history_get_device_id_from_cookie in Login History 7

Gets a device id from a login history cookie while validating authenticity.

Parameters

array $cookie: The cookie array i.e. $_COOKIE.

string $salt: The salt, e.g. from drupal_get_hash_salt().

Return value

string The device id, if it exists and is authenticated by the hmac.

Throws

Exception If there's any problem parsing the cookie.

6 calls to login_history_get_device_id_from_cookie()

LoginHistoryCookieTest::testCookieDataContents in tests/LoginHistoryTest.php

Invalid hmac.

LoginHistoryCookieTest::testCookieDataStructure in tests/LoginHistoryTest.php

All 3 elements are present, but fail basic sanity check for length.

LoginHistoryCookieTest::testInvalidCookie in tests/LoginHistoryTest.php

Cookie present, but invalid structure.

LoginHistoryCookieTest::testMissingCookieException in tests/LoginHistoryTest.php

No login history cookie present.

LoginHistoryCookieTest::testParsingGoodCookies in tests/LoginHistoryTest.php

Test parsing some good cookies. Yum.

... See full list

File

./login_history.inc, line 25

Helper functions for login_history that have no dependencies.

Code

function login_history_get_device_id_from_cookie($cookie, $salt) {

  // Is the cookie value even set?
  if (array_key_exists('Drupal_visitor_login_history', $cookie)) {

    // Are the elements set? Does it have some data right elements?
    $potential_device_message = explode('-', $cookie['Drupal_visitor_login_history']);
    if (3 == count($potential_device_message)) {
      list($message_hmac, $device_id, $login_id) = $potential_device_message;

      // Test all the required data is present and minimally valid.
      if (strlen($message_hmac) == 64 && strlen($device_id) == 64 && !empty($login_id)) {

        // If the hmac is valid, return the device id.
        if (hash_equals(login_history_assemble_cookie($device_id, $login_id, $salt), $cookie['Drupal_visitor_login_history'])) {
          return $device_id;
        }
        throw new Exception('Invalid login history hmac');
      }
      throw new Exception('Login history cookie data not structured properly.');
    }
    throw new Exception('Invalid login history cookie data.');
  }
  throw new Exception('Login history device id not present.');
}