Files
fusionpbx/resources/classes/google_authenticator.php

123 lines
3.8 KiB
PHP

<?php
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// @package GoogleAuthenticator
// @link https://github.com/chregu/GoogleAuthenticator.php
// @author Christian Stocker
// @license http://www.apache.org/licenses/LICENSE-2.0 Apache 2.0
class google_authenticator {
static $PASS_CODE_LENGTH = 6;
static $PIN_MODULO;
static $SECRET_LENGTH = 10;
public function __construct() {
self::$PIN_MODULO = pow(10, self::$PASS_CODE_LENGTH);
}
/**
* Checks if the provided code is valid based on the secret and time.
*
* @param string $secret The secret to verify against.
* @param string $code The code to check for validity.
*
* @return bool True if the code is valid, false otherwise.
*/
public function checkCode($secret, $code) {
$time = floor(time() / 30);
for ($i = -1; $i <= 1; $i++) {
if ($this->getCode($secret, $time + $i) == $code) {
return true;
}
}
return false;
}
/**
* Generates a PIN code based on the provided secret and time.
*
* @param string $secret The secret to use for generating the code.
* @param int|null $time The current time in seconds since the Unix epoch. Defaults to the current time divided
* by 30.
*
* @return string A six-digit PIN code.
*/
public function getCode($secret, $time = null) {
if (!$time) {
$time = floor(time() / 30);
}
$base32 = new base2n(5, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567', true, true);
$secret = $base32->decode($secret);
$time = pack("N", $time);
$time = str_pad($time, 8, chr(0), STR_PAD_LEFT);
$hash = hash_hmac('sha1', $time, $secret, true);
$offset = ord(substr($hash, -1));
$offset = $offset & 0xF;
$truncatedHash = self::hashToInt($hash, $offset) & 0x7FFFFFFF;
$pinValue = str_pad($truncatedHash % self::$PIN_MODULO, 6, "0", STR_PAD_LEFT);
return $pinValue;
}
/**
* Converts a byte array to an integer value.
*
* @param string $bytes The byte array to convert.
* @param int $start The starting position in the byte array.
*
* @return int The converted integer value.
*/
protected function hashToInt($bytes, $start) {
$input = substr($bytes, $start, strlen($bytes) - $start);
$val2 = unpack("N", substr($input, 0, 4));
return $val2[1];
}
/**
* Generates a URL for the Google QR code.
*
* @param string $user The user's username.
* @param string $hostname The hostname of the service.
* @param string $secret The secret to encode in the QR code.
*
* @return string A URL that can be used to generate a QR code with the provided secret.
*/
public function getUrl($user, $hostname, $secret) {
$url = sprintf("otpauth://totp/%s@%s?secret=%s", $user, $hostname, $secret);
$encoder = "https://www.google.com/chart?chs=200x200&chld=M|0&cht=qr&chl=";
$encoderURL = sprintf("%sotpauth://totp/%s@%s&secret=%s", $encoder, $user, $hostname, $secret);
return $encoderURL;
}
/**
* Generates a secret based on random characters and converts it to Base32.
*
* @return string The generated secret in Base32 format.
*/
public function generateSecret() {
$secret = "";
for ($i = 1; $i <= self::$SECRET_LENGTH; $i++) {
$c = rand(0, 255);
$secret .= pack("c", $c);
}
$base32 = new base2n(5, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567', true, true);
return $base32->encode($secret);
}
}