php服务端与客户端交互、提供开放api时,通常需要对敏感的部分api数据传输进行数据加密,这时候rsa非对称加密就能派上用处了,下面通过一个例子来说明如何用php来实现数据的加密解密
加密解密的第一步是生成公钥、私钥对,私钥加密的内容能通过公钥解密(反过来亦可以)
通过私钥能生成对应的公钥,因此我们将私钥用在服务器端,公钥发放给android、ios等前端。
以下是加密类文件(Rsa.class.php)代码:
<?php
/**
* RSA算法类
* 签名及密文编码:base64字符串/十六进制字符串/二进制字符串流
* 填充方式: PKCS1Padding(加解密)/NOPadding(解密)
*
* Notice:Only accepts a single block. Block size is equal to the RSA key size!
* 如密钥长度为1024 bit,则加密时数据需小于128字节,加上PKCS1Padding本身的11字节信息,所以明文需小于117字节
*/
class RSA
{
private $pubKey = null;
private $priKey = null;
/**
* 构造函数
*/
public function __construct()
{
// 需要开启openssl扩展
if (!extension_loaded("openssl")) {
$this->_error("Please open the openssl extension first.");
}
}
/**
* 读取公钥和私钥
* @param string $public_key_file 公钥文件(验签和加密时传入)
* @param string $private_key_file 私钥文件(签名和解密时传入)
*/
public function init($public_key_file = '', $private_key_file = '')
{
if ($public_key_file) {
$this->_getPublicKey($public_key_file);
}
if ($private_key_file) {
$this->_getPrivateKey($private_key_file);
}
}
/**
* 自定义错误处理
*/
private function _error($msg)
{
die('RSA Error:' . $msg); //TODO
}
/**
* 检测填充类型
* 加密只支持PKCS1_PADDING
* 解密支持PKCS1_PADDING和NO_PADDING
*
* @param int 填充模式
* @param string 加密en/解密de
* @return bool
*/
private function _checkPadding($padding, $type)
{
if ($type == 'en') {
switch ($padding) {
case OPENSSL_PKCS1_PADDING:
$ret = true;
break;
default:
$ret = false;
}
} else {
switch ($padding) {
case OPENSSL_PKCS1_PADDING:
case OPENSSL_NO_PADDING:
$ret = true;
break;
default:
$ret = false;
}
}
return $ret;
}
private function _encode($data, $code)
{
switch (strtolower($code)) {
case 'base64':
$data = base64_encode('' . $data);
break;
case 'hex':
$data = bin2hex($data);
break;
case 'bin':
default:
}
return $data;
}
private function _decode($data, $code)
{
switch (strtolower($code)) {
case 'base64':
$data = base64_decode($data);
break;
case 'hex':
$data = $this->_hex2bin($data);
break;
case 'bin':
default:
}
return $data;
}
private function _getPublicKey($file)
{
$key_content = $this->_readFile($file);
if ($key_content) {
$this->pubKey = openssl_get_publickey($key_content);
}
}
private function _getPrivateKey($file)
{
$key_content = $this->_readFile($file);
if ($key_content) {
$this->priKey = openssl_get_privatekey($key_content);
}
}
private function _readFile($file)
{
$ret = false;
if (!file_exists($file)) {
$this->_error("The file {$file} is not exists");
} else {
$ret = file_get_contents($file);
}
return $ret;
}
private function _hex2bin($hex = false)
{
$ret = $hex !== false && preg_match('/^[0-9a-fA-F]+$/i', $hex) ? pack("H*", $hex) : false;
return $ret;
}
/**
* 生成Rsa公钥和私钥
* @param int $private_key_bits 建议:[512, 1024, 2048, 4096]
* @return array
*/
public function generate($private_key_bits = 2048)
{
$rsa = [
"private_key" => "",
"public_key" => ""
];
$config = [
"digest_alg" => "sha512",
"private_key_bits" => $private_key_bits, #此处必须为int类型
"private_key_type" => OPENSSL_KEYTYPE_RSA,
"config" => "D:\phpStudy\PHPTutorial\Apache\conf\openssl.cnf" //如果没有配置这项,openssl_pkey_new会返回false
];
//创建公钥和私钥
$res = openssl_pkey_new($config);
//提取私钥 由于上一步传入了$config参数,所以这一步也需要传入这个参数,
openssl_pkey_export($res, $rsa['private_key'],null,$config);//
//生成公钥
$rsa['public_key'] = openssl_pkey_get_details($res)["key"];
// print_r($rsa);die;
return $rsa;
}
/**
* 生成签名
*
* @param string 签名材料
* @param string 签名编码(base64/hex/bin)
* @return bool|string 签名值
*/
public function sign($data, $code = 'base64')
{
$ret = false;
if (openssl_sign($data, $ret, $this->priKey)) {
$ret = $this->_encode($ret, $code);
}
return $ret;
}
/**
* 验证签名
*
* @param string 签名材料
* @param string 签名值
* @param string 签名编码(base64/hex/bin)
* @return bool
*/
public function verify($data, $sign, $code = 'base64')
{
$ret = false;
$sign = $this->_decode($sign, $code);
if ($sign !== false) {
switch (openssl_verify($data, $sign, $this->pubKey)) {
case 1:
$ret = true;
break;
case 0:
case -1:
default:
$ret = false;
}
}
return $ret;
}
/**
* 加密
*
* @param string 明文
* @param string 密文编码(base64/hex/bin)
* @param int 填充方式(貌似php有bug,所以目前仅支持OPENSSL_PKCS1_PADDING)
* @return string 密文
*/
public function encrypt($data, $code = 'base64', $padding = OPENSSL_PKCS1_PADDING)
{
$ret = false;
if (!$this->_checkPadding($padding, 'en')) $this->_error('padding error');
if (openssl_public_encrypt($data, $result, $this->pubKey, $padding)) {
$ret = $this->_encode($result, $code);
}
return $ret;
}
/**
* 解密
*
* @param string 密文
* @param string 密文编码(base64/hex/bin)
* @param int 填充方式(OPENSSL_PKCS1_PADDING / OPENSSL_NO_PADDING)
* @param bool 是否翻转明文(When passing Microsoft CryptoAPI-generated RSA cyphertext, revert the bytes in the block)
* @return string 明文
*/
public function decrypt($data, $code = 'base64', $padding = OPENSSL_PKCS1_PADDING, $rev = false)
{
$ret = false;
$data = $this->_decode($data, $code);
if (!$this->_checkPadding($padding, 'de')) $this->_error('padding error');
if ($data !== false) {
if (openssl_private_decrypt($data, $result, $this->priKey, $padding)) {
$ret = $rev ? rtrim(strrev($result), "\0") : '' . $result;
}
}
return $ret;
}
}
下面是测试文件(user.php)代码:
<?php
if (!class_exists("RSA")) {
require_once "Rsa.class.php";
}
$private_key_file = __DIR__ . "/private_key.pem";
$public_key_file = __DIR__ . "/public_key.pem";
$rsa = new RSA();
// 没有就生成一对
if (!file_exists($private_key_file) || !file_exists($public_key_file)) {
$key = $rsa->generate();
file_put_contents($private_key_file, $key['private_key'], LOCK_EX);
file_put_contents($public_key_file, $key['public_key'], LOCK_EX);
} else {
$key = [
"private_key" => file_get_contents($private_key_file),
"public_key" => file_get_contents($public_key_file)
];
}
//显示数据
echo "private_key:\n" . $key['private_key'] . "<hr/>";
echo "public_key:\n" . $key['public_key'] . "<hr/>";
//要加密的数据
$data = "123456";
echo '加密的数据:' . $data, "<hr/>";
$rsa->init($public_key_file, $private_key_file);
//加密
$encrypt = $rsa->encrypt($data);
echo "公钥加密后的数据: " . $encrypt . "<hr/>";
//解密
$decrypt = $rsa->decrypt($encrypt);
echo "私钥解密后的数据: " . $decrypt, "<hr/>";
//签名
$sign = $rsa->sign($data);
echo "签名的数据(私钥加密): " . $sign . "<hr/>";
//验证
$verify = $rsa->verify($data, $sign);
echo "验证的数据: " . $verify . "<hr/>";
运行结果如下图: