Migrating old FuelPHP Amazon SES package to Signature Version 4

Question

I am supporting a client that has an old FuelPHP web app. Emails are bing send with this FuelPHP package, that does not exist on Github anyomore.

• Amazon Email Delivery library for FuelPHP
• @link http://github.com/unforeseen/fuel-amazon-ses

The package was working until Amazon migrate to Signature Version 4. Can anyone help me what do I need to upgrade in the package so I make it comply with this new signature version. Here is the package code.

<?php

/**
 * Amazon Email Delivery library for FuelPHP
 *
 * @package     Amazon
 * @version     1.1
 * @author      Rob McCann ([email protected])
 * @link        http://github.com/unforeseen/fuel-amazon-ses
 * 
 */

class Email_Driver_SES extends \Email_Driver {

    public $region = null;
    protected $debug = true;
    
    public function __construct($config) 
    {
        parent::__construct($config);
        \Config::load('ses', true);
        
        $this->region = \Config::get('ses.region','us-east-1');
    }

    /**
     * Sends the email using the Amazon SES email delivery system
     * 
     * @return boolean  True if successful, false if not.
     */ 
    protected function _send()
    {
        $params = array(
            'Action' => 'SendEmail',
            'Source' => static::format_addresses(array($this->config['from'])),
            'Message.Subject.Data' => $this->subject,
            'Message.Body.Text.Data' => $this->alt_body,
            'Message.Body.Html.Data' => $this->body
        );
        
        $i = 0;
        foreach($this->to as $value)
        {
            $params['Destination.ToAddresses.member.'.($i+1)] = static::format_addresses(array($value));
            ++$i;
        }
        
        $i = 0;
        foreach($this->cc as $value)
        {
            $params['Destination.CcAddresses.member.'.($i+1)] = static::format_addresses(array($value));
            ++$i;
        }
        
        $i = 0;
        foreach($this->bcc as $value)
        {
            $params['Destination.BccAddresses.member.'.($i+1)] = static::format_addresses(array($value));
            ++$i;
        }
        
        $i = 0;
        foreach($this->reply_to as $value)
        {
            $params['ReplyToAddresses.member.'.($i+1)] = static::format_addresses(array($value));
            ++$i;
        }   

        $date = date(DATE_RSS);
        $signature = $this->_sign_signature($date);
        
        $curl = \Request::forge('https://email.' . $this->region . '.amazonaws.com/', array(
            'driver' => 'curl',
            'method' => 'post'
        ))->set_header('Content-Type','application/x-www-form-urlencoded')
            ->set_header('X-Amzn-Authorization','AWS3-HTTPS AWSAccessKeyId='.\Config::get('ses.access_key').', Algorithm=HmacSHA256, Signature=' . $signature)
            ->set_header('Date', $date);
        
        $response = $curl->execute($params);        
        
        if (intval($response->response()->status / 100) != 2) 
        {
            return false;
        }
        
        return true;
    }
    
    /**
     * Calculate signature
     * @param   string  date used in the header
     * @return  string  RFC 2104-compliant HMAC hash
     */
    private function _sign_signature($date)
    {
        $hash = hash_hmac('sha256', $date, \Config::get('ses.secret_key'), TRUE);
        return base64_encode($hash);
    }

}

I imagine I need to update these headers, but beats me at the moment how:

$curl = \Request::forge('https://email.' . $this->region . '.amazonaws.com/', array(
        'driver' => 'curl',
        'method' => 'post'
    ))->set_header('Content-Type','application/x-www-form-urlencoded')
        ->set_header('X-Amzn-Authorization','AWS3-HTTPS AWSAccessKeyId='.\Config::get('ses.access_key').', Algorithm=HmacSHA256, Signature=' . $signature)
        ->set_header('Date', $date);