PHP版谷歌驗證(Google Authenticator)

• 什么是谷歌驗證？

  谷歌驗證是一種用戶登錄時需要進行的額外的二次驗證以保證更加安全的一種安全手段，它是由手機端生成的一次性驗證碼。實現Google Authenticator功能需要服務器端和客戶端的支持。服務器端負責密鑰的生成、驗證一次性密碼是否正確。客戶端記錄密鑰后生成一次性密碼。

• 怎么接在網站上？

  以下是做法參考：
  第一種，做登陸驗證碼時，第一次生成密鑰不變，然后生成一個二維碼用GoogleAuthenticatorAPP掃一下就添加進去了服務器判斷secret為第一次生成的密鑰，code就是動態驗證碼，這樣比較一下如果相同就通過。
  第二種，對每個會員邦定動態驗證或密碼。注冊會員時首次生成一個密鑰保存到會員表里，下次登陸就把那個對應的密鑰輸出來代碼如下：

$checkResult = $ga->verifyCode('會員注冊時生成的密鑰secret', '在登陸時或其它操作時需要動態驗證code', 1);

因為每個人的秘鑰都是唯一的，這樣相對更加的安全。

• 核心代碼如下：

點擊查看代碼

<?php
namespace app\admin\common;
/**
 * 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 GoogleAuthenticator
{
    protected $_codeLength = 6;

    /**
     * Create new secret.
     * 16 characters, randomly chosen from the allowed base32 characters.
     * 生成谷歌驗證碼秘鑰
     * @param int $secretLength
     *
     * @return string
     */
    public function createSecret($secretLength = 16)
    {
        $validChars = $this->_getBase32LookupTable();

        // Valid secret lengths are 80 to 640 bits
        if ($secretLength < 16 || $secretLength > 128) {
            throw new Exception('Bad secret length');
        }
        $secret = '';
        $rnd = false;
        if (function_exists('random_bytes')) {
            $rnd = random_bytes($secretLength);
        } elseif (function_exists('mcrypt_create_iv')) {
            $rnd = mcrypt_create_iv($secretLength, MCRYPT_DEV_URANDOM);
        } elseif (function_exists('openssl_random_pseudo_bytes')) {
            $rnd = openssl_random_pseudo_bytes($secretLength, $cryptoStrong);
            if (!$cryptoStrong) {
                $rnd = false;
            }
        }
        if ($rnd !== false) {
            for ($i = 0; $i < $secretLength; ++$i) {
                $secret .= $validChars[ord($rnd[$i]) & 31];
            }
        } else {
            throw new Exception('No source of secure random');
        }

        return $secret;
    }

    /**
     * Calculate the code, with given secret and point in time.
     * 獲取谷歌驗證碼
     * @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
     * @param array  $params
     * 獲取谷歌驗證二維碼秘鑰
     * @return string
     */
    public function getQRCodeGoogleUrl($name, $secret, $title = null, $params = array())
    {
        $width = !empty($params['width']) && (int) $params['width'] > 0 ? (int) $params['width'] : 200;
        $height = !empty($params['height']) && (int) $params['height'] > 0 ? (int) $params['height'] : 200;
        $level = !empty($params['level']) && array_search($params['level'], array('L', 'M', 'Q', 'H')) !== false ? $params['level'] : 'M';

        $urlencoded = urlencode('otpauth://totp/'.$name.'?secret='.$secret.'');
        if (isset($title)) {
            $urlencoded .= urlencode('&issuer='.urlencode($title));
        }

        return "https://api.qrserver.com/v1/create-qr-code/?data=$urlencoded&size=${width}x${height}&ecc=$level";
    }

    /**
     * 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 $currentTimeSlice time slice if we want use other that time()
     * 驗證用戶輸入的谷歌驗證碼是否正確
     * @return bool
     */
    public function verifyCode($secret, $code, $discrepancy = 1, $currentTimeSlice = null)
    {
        if ($currentTimeSlice === null) {
            $currentTimeSlice = floor(time() / 30);
        }
        if (strlen($code) != 6) {
            return false;
        }
        for ($i = -$discrepancy; $i <= $discrepancy; ++$i) {
            $calculatedCode = $this->getCode($secret, $currentTimeSlice + $i);
            if ($this->timingSafeEquals($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;
    }

    /**
     * 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
        );
    }

    /**
     * A timing safe equals comparison
     * more info here: http://blog.ircmaxell.com/2014/11/its-all-about-time.html.
     *
     * @param string $safeString The internal (safe) value to be checked
     * @param string $userString The user submitted (unsafe) value
     * 對比用戶輸入的驗證碼與服務端生成的是否一致
     * @return bool True if the two strings are identical
     */
    private function timingSafeEquals($safeString, $userString)
    {
        if (function_exists('hash_equals')) {
            return hash_equals($safeString, $userString);
        }
        $safeLen = strlen($safeString);
        $userLen = strlen($userString);

        if ($userLen != $safeLen) {
            return false;
        }

        $result = 0;

        for ($i = 0; $i < $userLen; ++$i) {
            $result |= (ord($safeString[$i]) ^ ord($userString[$i]));
        }

        // They are only identical strings if $result is exactly 0...
        return $result === 0;
    }
}

• 客戶端調用：

點擊查看代碼

<?php
require_once 'GoogleAuthenticator.php';
 
$ga = new GoogleAuthenticator();
 
//創建一個新的"安全密匙SecretKey"
//把本次的"安全密匙SecretKey" 入庫,和賬戶關系綁定,客戶端也是綁定這同一個"安全密匙SecretKey"
$secret = $ga->createSecret();
echo "安全密匙SecretKey: ".$secret."\n\n";
 
$qrCodeUrl = $ga->getQRCodeGoogleUrl('www.2asp.cn', $secret); //第一個參數是"標識",第二個參數為"安全密匙SecretKey" 生成二維碼信息
echo "Google Charts URL for the QR-Code: ".$qrCodeUrl."\n\n"; //Google Charts接口 生成的二維碼圖片,方便手機端掃描綁定安全密匙SecretKey
 
$oneCode = $ga->getCode($secret); //服務端計算"一次性驗證碼"
echo "服務端計算的驗證碼是:".$oneCode."\n\n";
 
//把提交的驗證碼和服務端上生成的驗證碼做對比
// $secret 服務端的 "安全密匙SecretKey"
// $oneCode 手機上看到的 "一次性驗證碼"
// 最后一個參數 為容差時間,這里是2 那么就是 2* 30 sec 一分鍾.
// 這里改成自己的業務邏輯
 
$checkResult = $ga->verifyCode($secret, $code, 1);
if ($checkResult) {
    echo '匹配! OK';
} else {
    echo '不匹配! FAILED';
}

原文地址：https://blog.csdn.net/luxiaoqi1188/article/details/78891167