<?php

namespace clue;

class RSAUtil
{
    public $privateKey;
    public $publicKey;

    /**
     * 构造方法
     * @access public
     */
    public function __construct($private_key,$public_key)
    {
        $this->privateKey = openssl_pkey_get_private($private_key);
        $this->publicKey = openssl_pkey_get_public($public_key);
    }

    public function __call($method, $args)
    {
        return json(['status' => '1', 'msg' => '方法不存在']);
    }

    public function privateEncrypt($data)
    {
        $crypto = '';
        foreach (str_split($data, 117) as $chunk) {
            openssl_private_encrypt($chunk, $encryptData, $this->privateKey);
            $crypto .= $encryptData;
        }
        //加密后的内容通常含有特殊字符，需要编码转换下，在网络间通过url传输时要注意base64编码是否是url安全的
        $encrypted = $this->urlsafeB64encode($crypto);
        return $encrypted;
    }

    //加密码时把特殊符号替换成URL可以带的内容
    function urlsafeB64encode($string)
    {
        $data = base64_encode($string);
        $data = str_replace(array('+', '/', '='), array('-', '_', ''), $data);
        return $data;
    }

    //解密码时把转换后的符号替换特殊符号
    function urlsafeB64decode($string)
    {
        $data = str_replace(array('-', '_'), array('+', '/'), $string);
        $mod4 = strlen($data) % 4;
        if ($mod4) {
            $data .= substr('====', $mod4);
        }
        return base64_decode($data);
    }

    //公钥加密
    public function publicEncrypt($data)
    {
        $crypto = '';
        foreach (str_split($data, 117) as $chunk) {
            openssl_public_encrypt($chunk, $encryptData, $this->publicKey);
            $crypto .= $encryptData;
        }
        $encrypted = $this->urlsafeB64encode($crypto);
        return $encrypted;
    }

    //私钥解密
    public function privateDecrypt($encrypted)
    {
        $crypto = '';
        foreach (str_split($this->urlsafeB64decode($encrypted), 128) as $chunk) {
            openssl_private_decrypt($chunk, $decryptData, $this->privateKey);
            $crypto .= $decryptData;
        }
        return $crypto;
    }
}