php集成动态口令认证

php  /  管理员 发布于 7年前   190

大多数系统目前均使用的静态密码进行身份认证登录，但由于静态密码容易被窃取，其安全性无法满足安全要求。

动态口令采用一次一密、用过密码作废的方式防止了密码被窃取带来的安全问题。
动态口令分为HOTP（基于事件计数的动态口令，RFC4226）、TOTP（基于时间计数的动态口令,RFC6238）、OCRA（挑战应答式动态口令,RFC6287）等方式。

本文介绍了集成TOTP方式的动态口令认证的方案，PHP框架采用Thinkphp3.2.3，动态口令生成器使用的是google authtication。

1、为Thinkphp框架添加oath算法类

oath算法封装类oath.php代码如下：

. * * 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 + $window; $ts++)   if (self::oath_hotp($binarySeed, $ts) == $key)    return true;  return false; } /**  * Extracts the OTP from the SHA1 hash.  * @param binary $hash  * @return integer  **/ public static function oath_truncate($hash) {  $offset = ord($hash[19]) & 0xf;  return (   ((ord($hash[$offset+0]) & 0x7f) << 24 ) |   ((ord($hash[$offset+1]) & 0xff) << 16 ) |   ((ord($hash[$offset+2]) & 0xff) << 8 ) |   (ord($hash[$offset+3]) & 0xff)  ) % pow(10, self::otpLength); }}/*$InitalizationKey = "LFLFMU2SGVCUIUCZKBMEKRKLIQ";     // Set the inital key$TimeStamp  = Google2FA::get_timestamp();$secretkey  = Google2FA::base32_decode($InitalizationKey); // Decode it into binary$otp    = Google2FA::oath_hotp($secretkey, $TimeStamp); // Get current tokenecho("Init key: $InitalizationKey\n");echo("Timestamp: $TimeStamp\n");echo("One time password: $otp\n");// Use this to verify a key as it allows for some time drift.$result = Google2FA::verify_key($InitalizationKey, "123456");var_dump($result);*/?>

由于google的动态口令算法中种子密钥使用了base32编码，因此需要base32算法，base32.php内容如下：

 * @link http://christianriesen.com * @license MIT License see LICENSE file */class Base32{ /**  * Alphabet for encoding and decoding base32  *  * @var array  */ private static $alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567='; /**  * Creates an array from a binary string into a given chunk size  *  * @param string $binaryString String to chunk  * @param integer $bits Number of bits per chunk  * @return array  */ private static function chunk($binaryString, $bits) {  $binaryString = chunk_split($binaryString, $bits, ' ');  if (substr($binaryString, (strlen($binaryString)) - 1) == ' ') {   $binaryString = substr($binaryString, 0, strlen($binaryString)-1);  }  return explode(' ', $binaryString); } /**  * Encodes into base32  *  * @param string $string Clear text string  * @return string Base32 encoded string  */ public static function encode($string) {  if (strlen($string) == 0) {   // Gives an empty string   return '';  }  // Convert string to binary  $binaryString = '';  foreach (str_split($string) as $s) {   // Return each character as an 8-bit binary string   $binaryString .= sprintf('%08b', ord($s));  }  // Break into 5-bit chunks, then break that into an array  $binaryArray = self::chunk($binaryString, 5);  // Pad array to be divisible by 8  while (count($binaryArray) % 8 !== 0) {   $binaryArray[] = null;  }  $base32String = '';  // Encode in base32  foreach ($binaryArray as $bin) {   $char = 32;   if (!is_null($bin)) {    // Pad the binary strings    $bin = str_pad($bin, 5, 0, STR_PAD_RIGHT);    $char = bindec($bin);   }   // Base32 character   $base32String .= self::$alphabet[$char];  }  return $base32String; } /**  * Decodes base32  *  * @param string $base32String Base32 encoded string  * @return string Clear text string  */ public static function decode($base32String) {  // Only work in upper cases  $base32String = strtoupper($base32String);  // Remove anything that is not base32 alphabet  $pattern = '/[^A-Z2-7]/';  $base32String = preg_replace($pattern, '', $base32String);  if (strlen($base32String) == 0) {   // Gives an empty string   return '';  }  $base32Array = str_split($base32String);  $string = '';  foreach ($base32Array as $str) {   $char = strpos(self::$alphabet, $str);   // Ignore the padding character   if ($char !== 32) {    $string .= sprintf('%05b', $char);   }  }  while (strlen($string) %8 !== 0) {   $string = substr($string, 0, strlen($string)-1);  }  $binaryArray = self::chunk($string, 8);  $realString = '';  foreach ($binaryArray as $bin) {   // Pad each value to 8 bits   $bin = str_pad($bin, 8, 0, STR_PAD_RIGHT);   // Convert binary strings to ASCII   $realString .= chr(bindec($bin));  }  return $realString; }}?>

将这两个文件放到Thinkphp框架的ThinkPHP\Library\Vendor\oath目录下，oath目录是自己创建的。

2、添加数据库字段

用户表添加如下字段:
auth_type（0-静态密码，1-动态口令）
seed（种子密钥）
temp_seed（临时种子密钥）
last_logintime（上次登录成功时间）
last_otp（上次使用密码）
其中auth_type是为了标明用户使用的哪种认证方式，seed为用户的种子密钥，temp_seed为用户未开通前临时保存的一个种子密钥，如果用户开通动态口令认证成功，该字段内容会填到seed字段。last_logintime和last_otp为上次认证成功的时间和动态口令，用于避免用户同一个口令重复使用。

3、代码集成

1）、开通动态口令

在原有系统的修改密码页面，加上认证方式的选择，例如：

如果用户选择动态口令方式，则会生成一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_seedVendor('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。

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