/Upload/inc/3rdparty/2fa/GoogleAuthenticator.php

<?php



/**

 * PHP Class for handling Google Authenticator 2-factor authentication

 *

 * @author Michael Kliewe

 * @copyright 2012 Michael Kliewe

 * @license http://www.opensource.org/licenses/bsd-license.php BSD License

 * @link http://www.phpgangsta.de/

 */



class PHPGangsta_GoogleAuthenticator

{

    protected $_codeLength = 6;



    /**

     * Create new secret.

     * 16 characters, randomly chosen from the allowed base32 characters.

     *

     * @param int $secretLength

     * @return string

     */

    public function createSecret($secretLength = 16)

    {

        $validChars = $this->_getBase32LookupTable();

        unset($validChars[32]);



        $secret = '';

        for ($i = 0; $i < $secretLength; $i++) {

            $secret .= $validChars[array_rand($validChars)];

        }

        return $secret;

    }



    /**

     * Calculate the code, with given secret and point in time

     *

     * @param string $secret

     * @param int|null $timeSlice

     * @return string

     */

    public function getCode($secret, $timeSlice = null)

    {

        if ($timeSlice === null) {

            $timeSlice = floor(time() / 30);

        }



        $secretkey = $this->_base32Decode($secret);



        // Pack time into binary string

        $time = chr(0).chr(0).chr(0).chr(0).pack('N*', $timeSlice);

        // Hash it with users secret key

        $hm = hash_hmac('SHA1', $time, $secretkey, true);

        // Use last nipple of result as index/offset

        $offset = ord(substr($hm, -1)) & 0x0F;

        // grab 4 bytes of the result

        $hashpart = substr($hm, $offset, 4);



        // Unpak binary value

        $value = unpack('N', $hashpart);

        $value = $value[1];

        // Only 32 bits

        $value = $value & 0x7FFFFFFF;



        $modulo = pow(10, $this->_codeLength);

        return str_pad($value % $modulo, $this->_codeLength, '0', STR_PAD_LEFT);

    }



    /**

     * Get QR-Code URL for image, from google charts

     *

     * @param string $name

     * @param string $secret

     * @param string $title

     * @return string

     */

    public function getQRCodeGoogleUrl($name, $secret, $title = null) {

        $urlencoded = urlencode('otpauth://totp/'.$name.'?secret='.$secret.'');

	if(isset($title)) {

                $urlencoded .= urlencode('&issuer='.urlencode($title));

        }

        return 'https://chart.googleapis.com/chart?chs=200x200&chld=M|0&cht=qr&chl='.$urlencoded.'';

    }



    /**

     * Check if the code is correct. This will accept codes starting from $discrepancy*30sec ago to $discrepancy*30sec from now

     *

     * @param string $secret

     * @param string $code

     * @param int $discrepancy This is the allowed time drift in 30 second units (8 means 4 minutes before or after)

     * @param int|null $currentTimeSlice time slice if we want use other that time()

     * @return bool

     */

    public function verifyCode($secret, $code, $discrepancy = 1, $currentTimeSlice = null)

    {

        if ($currentTimeSlice === null) {

            $currentTimeSlice = floor(time() / 30);

        }



        for ($i = -$discrepancy; $i <= $discrepancy; $i++) {

            $calculatedCode = $this->getCode($secret, $currentTimeSlice + $i);

            if ($calculatedCode == $code ) {

                return true;

            }

        }



        return false;

    }



    /**

     * Set the code length, should be >=6

     *

     * @param int $length

     * @return PHPGangsta_GoogleAuthenticator

     */

    public function setCodeLength($length)

    {

        $this->_codeLength = $length;

        return $this;

    }



    /**

     * Helper class to decode base32

     *

     * @param $secret

     * @return bool|string

     */

    protected function _base32Decode($secret)

    {

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



        $base32chars = $this->_getBase32LookupTable();

        $base32charsFlipped = array_flip($base32chars);



        $paddingCharCount = substr_count($secret, $base32chars[32]);

        $allowedValues = array(6, 4, 3, 1, 0);

        if (!in_array($paddingCharCount, $allowedValues)) return false;

        for ($i = 0; $i < 4; $i++){

            if ($paddingCharCount == $allowedValues[$i] &&

                substr($secret, -($allowedValues[$i])) != str_repeat($base32chars[32], $allowedValues[$i])) return false;

        }

        $secret = str_replace('=','', $secret);

        $secret = str_split($secret);

        $binaryString = "";

        for ($i = 0; $i < count($secret); $i = $i+8) {

            $x = "";

            if (!in_array($secret[$i], $base32chars)) return false;

            for ($j = 0; $j < 8; $j++) {

                $x .= str_pad(base_convert(@$base32charsFlipped[@$secret[$i + $j]], 10, 2), 5, '0', STR_PAD_LEFT);

            }

            $eightBits = str_split($x, 8);

            for ($z = 0; $z < count($eightBits); $z++) {

                $binaryString .= ( ($y = chr(base_convert($eightBits[$z], 2, 10))) || ord($y) == 48 ) ? $y:"";

            }

        }

        return $binaryString;

    }



    /**

     * Helper class to encode base32

     *

     * @param string $secret

     * @param bool $padding

     * @return string

     */

    protected function _base32Encode($secret, $padding = true)

    {

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



        $base32chars = $this->_getBase32LookupTable();



        $secret = str_split($secret);

        $binaryString = "";

        for ($i = 0; $i < count($secret); $i++) {

            $binaryString .= str_pad(base_convert(ord($secret[$i]), 10, 2), 8, '0', STR_PAD_LEFT);

        }

        $fiveBitBinaryArray = str_split($binaryString, 5);

        $base32 = "";

        $i = 0;

        while ($i < count($fiveBitBinaryArray)) {

            $base32 .= $base32chars[base_convert(str_pad($fiveBitBinaryArray[$i], 5, '0'), 2, 10)];

            $i++;

        }

        if ($padding && ($x = strlen($binaryString) % 40) != 0) {

            if ($x == 8) $base32 .= str_repeat($base32chars[32], 6);

            elseif ($x == 16) $base32 .= str_repeat($base32chars[32], 4);

            elseif ($x == 24) $base32 .= str_repeat($base32chars[32], 3);

            elseif ($x == 32) $base32 .= $base32chars[32];

        }

        return $base32;

    }



    /**

     * Get array with all 32 characters for decoding from/encoding to base32

     *

     * @return array

     */

    protected function _getBase32LookupTable()

    {

        return array(

            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', //  7

            'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', // 15

            'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', // 23

            'Y', 'Z', '2', '3', '4', '5', '6', '7', // 31

            '='  // padding char

        );

    }

}