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:
<"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 token echo("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); */ "htmlcode"><"color: #800000">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", $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。
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