[转]php rsa加密解密实例

转自：http://blog.csdn.net/clh604/article/details/20224735

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

1、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）

下载开源RSA密钥生成工具openssl（通常Linux系统都自带该程序），解压缩至独立的文件夹，进入其中的bin目录，执行以下命令：

openssl genrsa -out rsa_private_key.pem 1024
openssl pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM -nocrypt -out private_key.pem
openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem

第一条命令生成原始 RSA私钥文件 rsa_private_key.pem，第二条命令将原始 RSA私钥转换为 pkcs8格式，第三条生成RSA公钥 rsa_public_key.pem
从上面看出通过私钥能生成对应的公钥，因此我们将私钥private_key.pem用在服务器端，公钥发放给android跟ios等前端

2、php中用生成的公钥、私钥进行加密解密，直接上代码

<?php
$private_key = '-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----';

$public_key = '-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC3//sR2tXw0wrC2DySx8vNGlqt
3Y7ldU9+LBLI6e1KS5lfc5jlTGF7KBTSkCHBM3ouEHWqp1ZJ85iJe59aF5gIB2kl
Bd6h4wrbbHA2XE1sq21ykja/Gqx7/IRia3zQfxGv/qEkyGOx+XALVoOlZqDwh76o
2n1vP1D+tD3amHsK7QIDAQAB
-----END PUBLIC KEY-----';

//echo $private_key;
$pi_key =  openssl_pkey_get_private($private_key);//这个函数可用来判断私钥是否是可用的，可用返回资源id Resource id
$pu_key = openssl_pkey_get_public($public_key);//这个函数可用来判断公钥是否是可用的
print_r($pi_key);echo "
";
print_r($pu_key);echo "
";


$data = "aassssasssddd";//原始数据
$encrypted = "";
$decrypted = "";

echo "source data:",$data,"
";

echo "private key encrypt:
";

openssl_private_encrypt($data,$encrypted,$pi_key);//私钥加密
$encrypted = base64_encode($encrypted);//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
echo $encrypted,"
";

echo "public key decrypt:
";

openssl_public_decrypt(base64_decode($encrypted),$decrypted,$pu_key);//私钥加密的内容通过公钥可用解密出来
echo $decrypted,"
";

echo "---------------------------------------
";
echo "public key encrypt:
";

openssl_public_encrypt($data,$encrypted,$pu_key);//公钥加密
$encrypted = base64_encode($encrypted);
echo $encrypted,"
";

echo "private key decrypt:
";
openssl_private_decrypt(base64_decode($encrypted),$decrypted,$pi_key);//私钥解密
echo $decrypted,"
";

<?php
/*
 * 使用openssl实现RSA非对称加密
 *
 * @version $Id: Rsa.php 2812 2014-08-14 08:20:19 $
 */

class Rsa
{
    /**
     * 私钥
     *
     * @var string
     */    
    private $_privateKey = '';

    /**
     * 公钥
     *
     * @var string
     */
    private $_publicKey = '';


    /**
     * 设置私钥路径
     *
     * @param  string $privateKeyPath 私钥路径
     * @param  string $passphrase       私钥密码
     * @return void
     */
    public function setPrivateKeyPath($privateKeyPath, $passphrase = '')
    {
        $privateKey = file_get_contents($privateKeyPath);

        $this->setPrivateKey($privateKey, $passphrase);
    }

    /**
     * 设置公钥路径
     *
     * @param  string $pubicKeyPath 公钥路径
     * @return void
     */
    public function setPublicKeyPath($pubicKeyPath)
    {
        $publicKey = file_get_contents($pubicKeyPath);

        $this->setPublicKey($publicKey);
    }

    /**
     * 设置私钥
     *
     * 注意：PHP使用的是RSA原始私钥而不是PKCS8格式的私钥
     *
     * @param  string $privateKey 私钥
     * @param  string $passphrase 私钥密码
     * @return void
     */
    public function setPrivateKey($privateKey, $passphrase = '')
    {
        if (strpos($privateKey, 'BEGIN RSA PRIVATE KEY') === FALSE)
        {
            $privateKey = chunk_split($privateKey, 64, "
");
            $privateKey = "-----BEGIN RSA PRIVATE KEY-----
" . $privateKey . "-----END RSA PRIVATE KEY-----
";
        }

        $this->_privateKey = openssl_pkey_get_private($privateKey, $passphrase);
    }
    
    /**
     * 设置公钥
     *
     * @param  string $publicKey 公钥
     * @return void
     */
    public function setPublicKey($publicKey)
    {
        if (strpos($publicKey, 'BEGIN PUBLIC KEY') === FALSE)
        {
            $publicKey = chunk_split($publicKey, 64, "
");
            $publicKey = "-----BEGIN PUBLIC KEY-----
" . $publicKey . "-----END PUBLIC KEY-----
";
        }

        $this->_publicKey = openssl_pkey_get_public($publicKey);
    }
    
    /**
     * 私钥加密字符串
     *
     * @param  string  $string  待加密的字符串
     * @param  integer $padding 填充方式
     * @return string
     */
    public function privateEncrypt($string, $padding = OPENSSL_PKCS1_PADDING)
    {
        $crypted = '';
        $result  = openssl_private_encrypt($string, $crypted, $this->_privateKey, $padding);
        if ($result)
        {
            $crypted = base64_encode($crypted);
        }

        return $crypted;
    }
    
    /**
     * 公钥解密私钥加密的字符串
     *
     * @param  string  $crypted 待解密的字符串
     * @param  integer $padding 填充方式
     * @return string
     */
    public function publicDecrypt($crypted, $padding = OPENSSL_PKCS1_PADDING)
    {
        $decrypted = '';
        $crypted   = base64_decode($crypted);
        $result    = openssl_public_decrypt($crypted, $decrypted, $this->_publicKey, $padding);

        return $decrypted;
    }
    
    /**
     * 公钥加密字符串
     * 
     * @param  string  $string 待加密的字符串
     * @param  integer $padding 填充方式
     * @return string
     */
    public function publicEncrypt($string, $padding = OPENSSL_PKCS1_PADDING)
    {
        $crypted = '';
        $result  = openssl_public_encrypt($string, $crypted, $this->_publicKey, $padding);
        if ($result)
        {
            $crypted = base64_encode($crypted);
        }

        return $crypted;
    }

    /**
     * 私钥解密公钥加密的字符串
     *
     * @param  string  $crypted 待解密的字符串
     * @param  integer $padding 填充方式
     * @return string
     */
    public function privateDecrypt($crypted, $padding = OPENSSL_PKCS1_PADDING)
    {
        $decrypted = '';
        $crypted   = base64_decode($crypted);
        $result    = openssl_private_decrypt($crypted, $decrypted, $this->_privateKey, $padding);

        return $decrypted;
    }
    
    /**
     * 私钥签名
     * 
     * @param  string  $string 待签名的字符串
     * @param  integer $algo   签名算法
     * @return string
     */
    public function sign($string, $algo = OPENSSL_ALGO_SHA1)
    {
        $signature = '';

        $result = openssl_sign($string, $signature, $this->_privateKey, $algo);
        if ($result)
        {
            $signature = base64_encode($signature);
        }

        return $signature;
    }
    
    /**
     * 公钥验证签名
     * 
     * @param  string  $string       待验证的字符串
     * @param  string  $signature 字符串的签名
     * @param  integer $algo         签名算法
     * @return boolean
     */
    public function verify($string, $signature, $algo = OPENSSL_ALGO_SHA1)
    {
        $signature = base64_decode($signature);
        $result    = openssl_verify($string, $signature, $this->_publicKey, $algo);

        // 1=正确 0=不正确 -1=错误
        if ($result == 1)
        {
            return TRUE;
        }

        return FALSE;
    }
    
    /**
     * 在析构函数中释放资源
     */
    public function __destruct()
    {
        if (is_resource($this->_privateKey))
        {
            openssl_free_key($this->_privateKey);
        }

        if (is_resource($this->_publicKey))
        {
            openssl_free_key($this->_publicKey);
        }
    }
}