<?php

defined('fileaway') or die('Water, water everywhere, but not a drop to drink.');

if(!class_exists('fileaway_encrypted'))

{

	class fileaway_encrypted

	{

		public function url($file = false)

		{

			if(!$file) return false;	

			$file = fileaway_utility::urlesc($file);

			$nonce = wp_create_nonce('fileaway-download');

			$ops = get_option('fileaway_options');

			return $ops['baseurl'].'?fileaway_download=1&fileaway='.$this->encrypt($file).'&nonce='.$nonce;	

		}

		public function encrypt($file)

		{ 

			if(empty($file)) return '';

			$op = get_option('fileaway_options');

			if(!isset($op['encryption_key']) || strlen($op['encryption_key']) < 16) $key = $this->key($op);

			else $key = $op['encryption_key'];	

			$encrypted = '';

			$keys = array_values(array_unique(str_split($key)));

			$keyr = array_reverse($keys);

			foreach(str_split(strrev(base64_encode($file))) as $s) $encrypted .= in_array($s, $keys) ? $keyr[array_search($s, $keys)] : $s;

			return fileaway_utility::urlesc($encrypted);

		}

		private function key($options)

		{

			if(function_exists('openssl_random_pseudo_bytes'))

				$options['encryption_key'] = bin2hex(openssl_random_pseudo_bytes(16));

			else

			{

				$key = '';

				$keys = array_merge(range(0, 9), range('a', 'z'));

				for($i = 0; $i < 32; $i++) $key .= $keys[array_rand($keys)];

				$options['encryption_key'] = $key;

			}

			update_option('fileaway_options', $options);

			return $options['encryption_key'];

		}

	}

}