simple_encryptor.php

<?php

namespace PMVC\PlugIn\simple_encryptor;
use UnexpectedValueException;

${_INIT_CONFIG}[_CLASS] = __NAMESPACE__ . '\SimpleEncryptor';

class SimpleEncryptor extends \PMVC\PlugIn
{
    private $_methods;

    public function init()
    {
        if (!isset($this['method'])) {
            $this['method'] = 'aes-256-cfb';
        }
    }

    private function _getPassphrase()
    {
        if (!isset($this['key'])) {
            $passphraseKey = isset($this['passphraseKey'])
                ? $this['passphraseKey']
                : 'passphraseKey';
            $this['key'] = \PMVC\plug('get')->get($passphraseKey);
        }
        if (is_null($this['key'])) {
            throw new UnexpectedValueException(
                '[SimpleEncryptor] Passphrase is not setted.'
            );
        }
        return $this['key'];
    }

    private function _isCipher($method)
    {
        if (empty($this->_methods)) {
            $this->_methods = array_flip(openssl_get_cipher_methods());
        }
        $method = strtolower($method);
        if (isset($this->_methods[$method])) {
            return true;
        } else {
            return false;
        }
    }

    private function _genIv($method)
    {
        $iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($method));
        return $iv;
    }

    /**
     * @see http://micmap.org/php-by-example/en/function/openssl_encrypt
     */
    public function encode($string)
    {
        $passphrase = $this->_getPassphrase();
        if ($this->_isCipher($this['method'])) {
            if (empty($this['iv'])) {
                $this['iv'] = $this->_genIv($this['method']);
            }
            return openssl_encrypt(
                $string,
                $this['method'],
                $passphrase,
                0,
                $this['iv']
            ) .
                '|' .
                base64_encode($this['iv']);
        } else {
            return openssl_encrypt($string, $this['method'], $passphrase);
        }
    }

    /**
     * @see http://micmap.org/php-by-example/en/function/openssl_decrypt
     */
    public function decode($string)
    {
        $passphrase = $this->_getPassphrase();
        $data = explode('|', $string);
        if (isset($data[1])) {
            return openssl_decrypt(
                $data[0],
                $this['method'],
                $passphrase,
                0,
                base64_decode($data[1])
            );
        } else {
            return openssl_decrypt($data[0], $this['method'], $passphrase);
        }
    }
}