RSA非对称加密算法实现过程

RSA非对称加密算法实现过程

非对称加密算法有很多，RSA算法就是其中比较出名的算法之一，下面是具体实现过程

 <?php
 /**
  * 使用openssl实现非对称加密  */
 class Rsa
 {
     /**
      * private key
      */
         private $_privKey;

         /**
          * public key
          */
         private $_pubKey;

         /**
          * the keys saving path
          */
         private $_keyPath;

         /**
          * the construtor,the param $path is the keys saving path
          */
         public function __construct($path)
         {
                 if(empty($path) || !is_dir($path)){
                         throw new Exception('Must set the keys save path');
                 }

                 $this->_keyPath = $path;
         }

         /**
          * create the key pair,save the key to $this->_keyPath
          */
         public function createKey()
         {
                 $r = openssl_pkey_new();
                 openssl_pkey_export($r, $privKey);
                 file_put_contents($this->_keyPath . DIRECTORY_SEPARATOR . 'priv.key', $privKey);
                 $this->_privKey = openssl_pkey_get_public($privKey);

                 $rp = openssl_pkey_get_details($r);
                 $pubKey = $rp['key'];
                 file_put_contents($this->_keyPath . DIRECTORY_SEPARATOR .  'pub.key', $pubKey);
                 $this->_pubKey = openssl_pkey_get_public($pubKey);
         }

         /**
          * setup the private key
          */
         public function setupPrivKey()
         {
                 if(is_resource($this->_privKey)){
                         return true;
                 }
                 $file = $this->_keyPath . DIRECTORY_SEPARATOR . 'priv.key';
                 $prk = file_get_contents($file);
                 $this->_privKey = openssl_pkey_get_private($prk);
                 return true;
         }

         /**
          * setup the public key
          */
         public function setupPubKey()
         {
                 if(is_resource($this->_pubKey)){
                         return true;
                 }
                 $file = $this->_keyPath . DIRECTORY_SEPARATOR .  'pub.key';
                 $puk = file_get_contents($file);
                 $this->_pubKey = openssl_pkey_get_public($puk);
                 return true;
         }

         /**
          * encrypt with the private key
          */
         public function privEncrypt($data)
         {
                 if(!is_string($data)){
                         return null;
                 }

                 $this->setupPrivKey();

                 $r = openssl_private_encrypt($data, $encrypted, $this->_privKey);
                 if($r){
                         return base64_encode($encrypted);
                 }
                 return null;
         }

         /**
          * decrypt with the private key
          */
         public function privDecrypt($encrypted)
         {
                 if(!is_string($encrypted)){
                         return null;
                 }

                 $this->setupPrivKey();

                 $encrypted = base64_decode($encrypted);

                 $r = openssl_private_decrypt($encrypted, $decrypted, $this->_privKey);
                 if($r){
                         return $decrypted;
                 }
                 return null;
         }

         /**
          * encrypt with public key
          */
         public function pubEncrypt($data)
         {
                 if(!is_string($data)){
                         return null;
                 }

                 $this->setupPubKey();

                 $r = openssl_public_encrypt($data, $encrypted, $this->_pubKey);
                 if($r){
                         return base64_encode($encrypted);
                 }
                 return null;
         }

         /**
          * decrypt with the public key
          */
         public function pubDecrypt($crypted)
         {
                 if(!is_string($crypted)){
                         return null;
                 }

                 $this->setupPubKey();

                 $crypted = base64_decode($crypted);

                 $r = openssl_public_decrypt($crypted, $decrypted, $this->_pubKey);
                 if($r){
                         return $decrypted;
                 }
                 return null;
         }

         public function __destruct()
         {
                 @ fclose($this->_privKey);
                 @ fclose($this->_pubKey);
         }

 }

 //====================demo=======================
 //以下是一个简单的测试demo，如果不需要请删除
 $rsa = new Rsa('ssl-key');

 //私钥加密，公钥解密
 echo 'source：我是老鳖<br />';
 $pre = $rsa->privEncrypt('我是老鳖');
 echo 'private encrypted:<br />' . $pre . '<br />';

 $pud = $rsa->pubDecrypt($pre);
 echo 'public decrypted:' . $pud . '<br />';

 //公钥加密，私钥解密
 echo 'source:干IT的<br />';
 $pue = $rsa->pubEncrypt('干IT的');
 echo 'public encrypt:<br />' . $pue . '<br />';

 $prd = $rsa->privDecrypt($pue);
 echo 'private decrypt:' . $prd;
 //========================demo======================
 ?>

参考链接：RSA非对称加密