Cron Authentication Error I can not seem to find out what cron.php is doing exactly that it needs to have an ssl connection with Google. 
I keep getting the following error:


  ERROR: Authentication with Google failed. Reason: BadAuthentication


I've Googled it and basically come up with nothing that seems to be similar to my issue. 
Is there some cron.php configuration parameters I should be setting somewhere?

Thanks in advance,

SOLVED

The "Search" module is the culprit. Here's how I found it.
I hacked my cron.php file to add a couple functions it was calling so I could add logging information to help me track down the module. I copied both the module_invoke_all() and drupal_cron_run() functions into my cron.php, renaming them dev_module_invoke_all() and dev_drupal_cron_run(). The dev_module_invoke_all() is the logging is added and is shown below. The change I made in my dev_drupal_cron_run() was simply to change the module_invoke_all('cron') call to dev_module_invoke_all('cron'), so I am not pasting it. Then the cron.php call to drupal_cron_run() is changed to dev_drupal_cron_run() to use my functions.
I could then look in the "Recent log entries" under the Report menu to see the last module cron_hook() called. For me, it was the "Search" module. I disabled it, re-ran cron, and it successfully completed.

This is with a Drupal 6 installation.

function dev_module_invoke_all() {
  $args = func_get_args();
  $hook = $args[0];
  unset($args[0]);
  $return = array();
  foreach (module_implements($hook) as $module) {
    /*This logs a message out to the Recent Log Entries report.*/
    watchdog('cron', "Calling module: " . $module . " cron_hook: " . $module . '_' . $hook);
    $function = $module . '_' . $hook;
    $result = call_user_func_array($function, $args);
    if (isset($result) &amp;&amp; is_array($result)) {
      $return = array_merge_recursive($return, $result);
    }
    else if (isset($result)) {
      $return[] = $result;
    }
  }
  return $return;
}


Even more info. I added watchdog logging to the search.module's search_cron() to determine which module it was calling and tracked the issue to the node module. I then added watchdog logging to the node.module _update_index function to log out which node was being indexed. I then re-ran the cron and found the offending nodes. There turned out to be a couple of issues: A PHP page trying to do openssl authentication which was my original error. That page had been deprecated, but was still in the node list. I deleted the page. 

Dan
Check if you have a module that uses any of the Google's API (translate, maps, youtube, calendar,...). 

Seems that one of the modules implements hook_cron() where is trying to access to one of the Google services through its API.

If that is the case at Google Cloud Platform you can configure a key to solve the issue.

If that is not the problem, try to check the logs to see if you can get more info about this error.