<?PHP
/**
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* PHP Google two-factor authentication module.
*
* See http://www.idontplaydarts.com/2011/07/google-totp-two-factor-authentication-for-php/
* for more details
*
* @author Phil
**/
class Google2FA {
const keyRegeneration = 30; // Interval between key regeneration
const otpLength = 6; // Length of the Token generated
private static $lut = array( // Lookup needed for Base32 encoding
"A" => 0, "B" => 1,
"C" => 2, "D" => 3,
"E" => 4, "F" => 5,
"G" => 6, "H" => 7,
"I" => 8, "J" => 9,
"K" => 10, "L" => 11,
"M" => 12, "N" => 13,
"O" => 14, "P" => 15,
"Q" => 16, "R" => 17,
"S" => 18, "T" => 19,
"U" => 20, "V" => 21,
"W" => 22, "X" => 23,
"Y" => 24, "Z" => 25,
"2" => 26, "3" => 27,
"4" => 28, "5" => 29,
"6" => 30, "7" => 31
);
/**
* Generates a 16 digit secret key in base32 format
* @return string
**/
public static function generate_secret_key($length = 16) {
$b32 = "234567QWERTYUIOPASDFGHJKLZXCVBNM";
$s = "";
for ($i = 0; $i < $length; $i++)
$s .= $b32[rand(0,31)];
return $s;
}
/**
* Returns the current Unix Timestamp devided by the keyRegeneration
* period.
* @return integer
**/
public static function get_timestamp() {
return floor(microtime(true)/self::keyRegeneration);
}
/**
* Decodes a base32 string into a binary string.
**/
public static function base32_decode($b32) {
$b32 = strtoupper($b32);
if (!preg_match('/^[ABCDEFGHIJKLMNOPQRSTUVWXYZ234567]+$/', $b32, $match))
throw new Exception('Invalid characters in the base32 string.');
$l = strlen($b32);
$n = 0;
$j = 0;
$binary = "";
for ($i = 0; $i < $l; $i++) {
$n = $n << 5; // Move buffer left by 5 to make room
$n = $n + self::$lut[$b32[$i]]; // Add value into buffer
$j = $j + 5; // Keep track of number of bits in buffer
if ($j >= 8) {
$j = $j - 8;
$binary .= chr(($n & (0xFF << $j)) >> $j);
}
}
return $binary;
}
/*by tang*/
public static function base32_encode($data, $length){
$basestr = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
$count = 0;
if ($length > 0) {
$buffer = $data[0];
$next = 1;
$bitsLeft = 8;
while (($bitsLeft > 0 || $next < $length)) {
if ($bitsLeft < 5) {
if ($next < $length) {
$buffer <<= 8;
$buffer |= $data[$next++] & 0xFF;
$bitsLeft += 8;
} else {
$pad = 5 - $bitsLeft;
$buffer <<= $pad;
$bitsLeft += $pad;
}
}
$index = 0x1F & ($buffer >> ($bitsLeft - 5));
$bitsLeft -= 5;
$result .= $basestr[$index];
$count++;
}
}
return $result;
}
/**
* Takes the secret key and the timestamp and returns the one time
* password.
*
* @param binary $key - Secret key in binary form.
* @param integer $counter - Timestamp as returned by get_timestamp.
* @return string
**/
public static function oath_hotp($key, $counter)
{
if (strlen($key) < 8)
throw new Exception('Secret key is too short. Must be at least 16 base 32 characters');
$bin_counter = pack('N*', 0) . pack('N*', $counter); // Counter must be 64-bit int
$hash = hash_hmac ('sha1', $bin_counter, $key, true);
return str_pad(self::oath_truncate($hash), self::otpLength, '0', STR_PAD_LEFT);
}
/**
* Verifys a user inputted key against the current timestamp. Checks $window
* keys either side of the timestamp.
*
* @param string $b32seed
* @param string $key - User specified key
* @param integer $window
* @param boolean $useTimeStamp
* @return boolean
**/
public static function verify_key($b32seed, $key, $window = 5, $useTimeStamp = true) {
$timeStamp = self::get_timestamp();
if ($useTimeStamp !== true) $timeStamp = (int)$useTimeStamp;
$binarySeed = self::base32_decode($b32seed);
for ($ts = $timeStamp - $window; $ts <= $timeStamp + $张二维码显示在页面，用于用户开通动态口令。为了兼容google authtication，其二维码格式与谷歌一样。生成二维码的方法见我的另一篇《Thinkphp3.2.3整合phpqrcode生成带logo的二维码》 。
生成密钥二维码代码如下：
public function qrcode()
{
Vendor('oath.base32');
$base32 = new \Base32();
$rand = random(16);//生成随机种子
$rand = $base32->encode($rand);
$rand=str_replace('=','',$rand);//去除填充的‘='
$errorCorrectionLevel =intval(3) ;//容错级别
$matrixPointSize = intval(8);//生成图片大小
//生成二维码图片
Vendor('phpqrcode.phpqrcode');
$object = new \QRcode();
$text = sprintf("otpauth://totp/%s?secret=%s", $user, $rand);
$object->png($text, false, $errorCorrectionLevel, $matrixPointSize, 2);
生成的种子$rand保存到数据库的temp_seed字段
}
random是生成随机字符串函数。$rand=str_replace('=','',$rand)这句代码是因为谷歌手机令牌中base32解码算法并没有填充的‘='号。
验证用户动态口令的代码如下：
从数据库读取temp_seed
Vendor('oath.oath');
$object = new \Google2FA();
if($object->verify_key($temp_seed, $otp)){
验证成功，将数据库更新seed为temp_seed，auth_type为1，last_otp为otp
}
2）、动态口令登录
用户动态口令登录验证的代码：
从数据库读取auth_type,seed,last_otp字段。
if($auth_type==1){//动态口令
//防止重复认证
if($lat_otp == $otp) {
动态口令重复使用返回
}
Vendor('oath.oath');
$object = new \Google2FA();
if(!$object->verify_key($seed, $otp))
{
动态口令不正确
}
else
{
登录成功，将数据库更新last_otp为$otp,last_logintime为time()
}
}
4、测试验证
下载google authtication，使用静态密码登录系统，进入修改密码页面。
打开google authtication，扫描二维码，会显示动态口令。
保存内容，开通动态口令成功！
然后你就可以用高大上的动态口令登录系统了!
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持社区。
转播
