PHP封装的非对称加密RSA算法示例

//====================demo=======================
//以下是一个简单的测试demo，如果不需要请删除
$rsa = new rsa('sslkey'); //sslkey为存放密钥的路径，将已有的密钥文件复制到该路径下，公钥名称为pub.key，私钥名称为priv.key
$rsa->createkey(); //创建一对密钥，如果密钥对已经存在，不需调用
//私钥加密，公钥解密
echo 'source：<br />';
$pre = $rsa->privencrypt('');
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======================

<?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);
        $this->_privkey = openssl_pkey_get_private($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);
    }
}