使用openssl进行RSA2加解密以及签名算法（PHP）

在对接玖富债权项目中，用到了RSA加解密算法，特此记录下；

1. 公私钥成对出现，相互解密；
   公钥加密，私钥解密。
   私钥数字签名，公钥验证。

2. 生成RSA秘钥对，主要利用linux OPENSSL
   2.1 生成RSA私钥
   

   genrsa -out rsa_private_key.pem 1024
   

   2.2 把RSA私钥转换成PKCS8格式
   

   pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM –nocrypt
   

   2.3 生成RSA公钥
   

   rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem
   

打开rsa_public_key.pem可以看到—–BEGIN PUBLIC KEY—–开头，
—–END PUBLIC KEY—–结尾的没有换行的字符串，这个就是公钥

3. PHP中实现加解密类

class RSA {

    private $pubKey = null;
    private $priKey = null;

    /**
    * 构造函数
    * @param string 公钥文件（验签和加密时传入）
    * @param string 私钥文件（签名和解密时传入）
    */
    public function __construct($pubKeyFile = '', $priKeyFile = '')
    {
        if ($pubKeyFile) {
            $this->pubKey = $this->getFileContent($pubKeyFile);
        }
        if ($priKeyFile) {
            $this->priKey = $this->getFileContent($priKeyFile);
        }
    }

    /**
     * RSA签名
     * @param $data 待签名数据
     * @param $priKey 商户私钥文件路径 或 密钥内容本身
     * return $sign 签名结果
     */
    public function sign($data, $code = 'base64') 
    {
        $result = openssl_get_privatekey($this->priKey);
        if (openssl_sign($data, $sign, $result)) {
            openssl_free_key($result);
            $sign = $this->encode($sign, $code);
        }
        return $sign;
    }

    /**
    * 验证签名
    * @param $data 待签名数据
    * @param $sign 要校对的的签名结果
    * @param string 签名编码（base64/hex/bin）
    * @return bool
    */
    public function verify($data, $sign, $code = 'base64')
    {
        $ret = false;
        $result = openssl_get_publickey($this->pubKey);
        $sign = $this->decode($sign, $code);
        if ($sign !== false) {
            $ret = (bool) openssl_verify($data, $sign, $result); 
            openssl_free_key($result);
        }
        return $ret;
    }

    /**
     * RSA加密
     * @param $content 需要加密的内容
     * @param $this->pubKey 商户公钥文件路径 或 密钥内容本身
     * return 加密后内容，明文
     */
    public function encrypt($content, $code = 'base64')
    {
        $result = openssl_get_publickey($this->pubKey);
        $rslt = '';
        for ($i = 0; $i < ((strlen($content)-strlen($content)%117) / 117 + 1); $i++) {
            $data = mb_strcut($content, $i * 117, 117, 'utf-8');
            openssl_public_encrypt($data, $encrypted, $result);
            $rslt .= $encrypted;
        }
        openssl_free_key($result);
        $rslt = $this->encode($rslt, $code);
        return $rslt;
    }

    /**
     * RSA解密
     * @param $content 需要解密的内容，密文
     * @param $this->priKey 商户私钥文件路径 或 密钥内容本身
     * return 解密后内容，明文
     */
    public function decrypt($content, $code = 'base64')
    {
        $result = openssl_get_privatekey($this->priKey);
        $content = $this->decode($content, $code);
        $rslt = '';
        for ($i = 0; $i < strlen($content)/128; $i++) {
            $data = substr($content, $i * 128, 128);
            openssl_private_decrypt($data, $decrypt, $result);
            $rslt .= $decrypt;
        }
        openssl_free_key($result);
        return $rslt;
    }

    private function encode($data, $code)  
    {
        switch (strtolower($code)) {
            case 'base64':
                $data = base64_encode(''.$data);
            break;
        }
        return $data;
    }

    private function decode($data, $code)
    {
        switch (strtolower($code)) {
            case 'base64':
                $data = base64_decode($data);
            break;
        }
        return $data;
    }

    private function getFileContent($file)   
    {
        if (file_exists($file)) {
            return file_get_contents($file);
        }
        return $file;
    }
}

4.代码中具体调用：

/**
  * 同步债权信息
  * @param $orderNo 订单ID
  * @param $memberId 玖富理财用户ID
  * @return boolen
  */
 function syncRepayPlan($sDate, $eDate)
 {
     if (!$sDate || !$eDate) {
         return false;
     }
     $data = array('inputCharset' => jiufuStatus::JIUFU_INPUTCHARSET,
         'version' => jiufuStatus::JIUFU_VERSION,
         'channelId' => jiufuStatus::JIUFU_CHANNELID,
         'startTime' => $sDate,
         'endTime' => $eDate,
     );
     $requestNo = sprintf("%d:'%s':'%s'",
         jiufuStatus::REQTYPE_JIUFU_RSYNC_REPAY_PLAN, 'jiufuSyncRepayPlan', uniqid());
     $dataString = json_encode($data);
     $info = array(
         'requestno' => $requestNo,
         'type' => jiufuStatus::REQTYPE_JIUFU_RSYNC_REPAY_PLAN,
         'reqtime' => CMI_DATE_NOW,
         'data' => $dataString
     );
     $r = $this->xdReqst->createRequest($requestNo,
         jiufuStatus::REQTYPE_JIUFU_RSYNC_REPAY_PLAN, $info);
     if ($r) {
         $rslt = $this->excuteReq(__FUNCTION__, $data);
         return $this->handleRepayPlan($requestNo, $rslt);
     }
 }

 /**
  * 处理还款计划
  * @param $requestNo 请求ID
  * @param $rslt
  * @return boolen
  */
 function handleRepayPlan($requestNo, $rslt)
 {
     if ($rslt['returnCode'] != '0000' || empty($rslt['responseData'])) {
         printf('获取还款计划失败%s', $rslt['returnMessage']);
         return false;
     }
     $dataList = $rslt['responseData'];
     foreach ($dataList as $key => &$value) {
         $value['channelId'] = $rslt['channelId'];
     }
     $classFun = __FUNCTION__;
     $handleObj = new handleData();
     $handleObj->valList = $dataList;
     $r = $handleObj->$classFun();
     if ($r['Status'] == 'Fail') {
         $error = $r['Message'];
         $this->xdReqst->updateRequest($requestNo,
             REQSTATUS_FAILED, array('data' => $data, 'errorMsg' => $error));
         $this->errorMsg(__LINE__. $error);
         return false;
     }
     $this->xdReqst->updateRequest($requestNo, REQSTATUS_SUCCESS, $r);
     return true;
 }
 
 /**
 * 发送请求
 * @param $reqName 请求名称
 * @param $data 请求数据
 * @return array
 */
 public function excuteReq($reqName, $data = null)
 {
     $rsaObj = new rsa(PUBLIC_KEY_PATH, PRIVATE_KEY_PATH);

     //加密加签
     $secretData = $rsaObj->encrypt(json_encode($data));
     $secretSign = $rsaObj->sign(base64_decode($secretData));

     //请求接口
     $rslt = $this->proxy->$reqName(array('data' => $secretData, 'sign' => $secretSign));
     if (!$rsaObj->verify(base64_decode($rslt['data']), $rslt['sign'])) {
         $error = sprintf("验签失败");
         $this->errorMsg(__LINE__. $error);
     }

     //解密接口返回数据
     $rsltData = $rsaObj->decrypt($rslt['data']);
     return json_decode($rsltData, true);
 }