<?php

    /**
     * RSA签名类
     * 注意：公钥和私钥必须是一行字符串，并且去掉生成时的头部和尾部
     * 带“----”的两行，并且注意去掉最后一行的换行
     */
    class Rsa
    {

        public $publicKey = '';
        public $privateKey = '';
        private $_privKey;
        private  $encryptBlockSize = 117;//加密切割长度
        private  $decryptBlockSize = 128;//解密切割长度
        /**
         * * private key
         */
        private $_pubKey;

        /**
         * * public key
         */
        private $_keyPath;

        /**
         * * the keys saving path
         */

        /**
         * * the construtor,the param $path is the keys saving path
         */
        function __construct($publicKey = null, $privateKey = null)
        {
            $this->setKey($publicKey, $privateKey);
        }

        /**
         * 设置公钥和私钥
         * @param string $publicKey 公钥
         * @param string $privateKey 私钥
         */
        public function setKey($publicKey = null, $privateKey = null)
        {
            if (!is_null($publicKey))
                $this->publicKey = $publicKey;
            if (!is_null($privateKey))
                $this->privateKey = $privateKey;
        }

        /**
         * * setup the private key
         */
        private function setupPrivKey()
        {
            if (is_resource($this->_privKey))
            {
                return true;
            }
            $pem = chunk_split($this->privateKey, 64, "\n");
            $pem = "-----BEGIN PRIVATE KEY-----\n" . $pem . "-----END PRIVATE KEY-----\n";
            $this->_privKey = openssl_pkey_get_private($pem);
            return true;
        }

        /**
         * * setup the public key
         */
        private function setupPubKey()
        {
            if (is_resource($this->_pubKey))
            {
                return true;
            }
            $pem = chunk_split($this->publicKey, 64, "\n");
            $pem = "-----BEGIN PUBLIC KEY-----\n" . $pem . "-----END PUBLIC KEY-----\n";
            $this->_pubKey = openssl_pkey_get_public($pem);
            return true;
        }

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

            //私钥分段加密
            $result='';
            $data = str_split($data, $this->encryptBlockSize);
            foreach ($data as $block) {
                openssl_private_encrypt($block, $encrypted, $this->_privKey);
                $result .= $encrypted;
            }
            return $result ? base64_encode($result) : null;

            /*$r = openssl_private_encrypt($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);

            //分段解密
            $result = '';
            $data = str_split($encrypted, $this->decryptBlockSize);
            foreach ($data as $block) {
                openssl_private_decrypt($block, $decrypted, $this->_privKey);
                $result .= $decrypted;
            }
            return $result ? $result : null;

           /* $r = openssl_private_decrypt($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();

            //分段加密
            $result='';
            $data = str_split($data, $this->encryptBlockSize);
            foreach ($data as $block) {
                openssl_public_encrypt($block, $encrypted, $this->_pubKey);
                $result .= $encrypted;
            }
            return  $result ? base64_encode($result) : null;

            /*$r = openssl_public_encrypt($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);

            $result = '';
            $data = str_split($crypted, $this->decryptBlockSize);
            foreach ($data as $block) {
                openssl_public_decrypt($block, $decrypted, $this->_pubKey);
                $result .= $decrypted;
            }
            return $result ? $result : null;

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

        /**
         * 构造签名
         * @param string $dataString 被签名数据
         * @return string
         */
        public function sign($dataString)
        {
            $this->setupPrivKey();
            $signature = false;
            openssl_sign($dataString, $signature, $this->_privKey);
            return base64_encode($signature);
        }

        /**
         * 验证签名
         * @param string $dataString 被签名数据
         * @param string $signString 已经签名的字符串
         * @return number 1签名正确 0签名错误
         */
        public function verify($dataString, $signString)
        {
            $this->setupPubKey();
            $signature = base64_decode($signString);
            $flg = openssl_verify($dataString, $signature, $this->_pubKey);
            return $flg;
        }

        public function __destruct()
        {
            is_resource($this->_privKey) && @openssl_free_key($this->_privKey);
            is_resource($this->_pubKey) && @openssl_free_key($this->_pubKey);
        }

    }

    $rsa =new Rsa($public_key,$private_key);
    //私钥解密
    $arginfo = "公钥加密字符串";
    $y = $rsa->privDecrypt($arginfo);
    $params = json_decode($y,true);
    print_r($params);

    //私钥加密
    $rsa =new Rsa($public_key,$private_key);
    $string = $rsa->privEncrypt("待加密字符串");
    echo $string;