使用openssl实现rsa非对称加密算法示例

代码如下:
<?php
/**
 * 使用openssl实现非对称加密
 * @since 2010-07-08
 */
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);