转载：php和java之间rsa加密互通互转

担心原文内容不被删除而迷路，特意自我转载一份：

以下是php封装好的类，引入即可使用

<?php
/**
 * 作者：pjp
 * 邮箱：vippjp@163.com
 */
class RSA{
    private $privateKey='';//私钥（用于用户加密）
    private $publicKey='';//公钥（用于服务端数据解密）
 
    public function __construct(){
        $this->privateKey = openssl_pkey_get_private(file_get_contents('php_private.pem'));//私钥，用于加密
        $this->publicKey = openssl_pkey_get_public(file_get_contents('php_public.pem'));//公钥，用于解密
    }
    
    
    /**
     * 私钥加密
     * @param 原始数据 $data
     * @return 密文结果 string
     */
    public function encryptByPrivateKey($data) {
        openssl_private_encrypt($data,$encrypted,$this->privateKey,OPENSSL_PKCS1_PADDING);//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
        return $encrypted;
    }
    
    /**
     * 私钥解密
     * @param 密文数据 $data
     * @return 原文数据结果 string
     */
    public function decryptByPrivateKey($data){
        $data = base64_decode($data);
        openssl_private_decrypt($data,$encrypted,$this->privateKey,OPENSSL_PKCS1_PADDING);//私钥解密
        return $encrypted;
    }
    
    /**
     * 私钥签名
     * @param unknown $data
     */
    public function signByPrivateKey($data){
        openssl_sign($data, $signature, $this->privateKey);
        $encrypted = base64_encode($signature);//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
        return $encrypted;
    }
    
    
    /**
     * 公钥加密
     * @param 原文数据 $data
     * @return 加密结果 string
     */
    public function encryptByPublicKey($data) {
        openssl_public_encrypt($data,$decrypted,$this->publicKey,OPENSSL_PKCS1_PADDING);//公钥加密
        return base64_encode($decrypted);
    }
    
    /**
     * 公钥解密
     * @param 密文数据 $data
     * @return 原文结果 string
     */
    public function decryptByPublicKey($data) {
        $data = base64_decode($data);
        openssl_public_decrypt($data,$decrypted,$this->publicKey,OPENSSL_PKCS1_PADDING);//公钥解密
        return $decrypted;
    }
    
    /**
     * 公钥验签
     * @param unknown $data
     * @param unknown $sign
     */
    public function verifyByPublicKey($data,$sign){
        $sign = base64_decode($sign);
        return openssl_verify($data, $sign, $this->publicKey);
    }
    
    public function __destruct(){
        openssl_free_key($this->privateKey);
        openssl_free_key($this->publicKey);
    }
}

php公钥文件内容(php_public.pem)

公钥和私钥皆可自己重新生成

-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCm1YchJdHVy9iXsDfQfMEB2mdO
5wuaEiqUEerHO7HbKKkvhuIfc7haQV5bKTiKZ76FnkkXJMF+onMrQrrqk4TiWlYZ
oilesPM88jr01Z9MmhzKV7vWboVhYcd8cw2Mua0HwAMyl9TDt5OLWmT00C4/Lu72
lRL21avxRTvmDQoAqQIDAQAB
-----END PUBLIC KEY-----

php私钥文件内容(php_private.pem)

-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

以下是java封装好的方法

/**
 * 作者：pjp
 * 邮箱：vippjp@163.com
 */
 package crypt;
 
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.security.KeyFactory;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
 
import javax.crypto.Cipher;
 
public class Rsa {
    
    private String priKey;
    private String pubKey;
    
    public static void main(String[] args) {
        Rsa rsa = new Rsa();
        String str = "我要加密这段文字。";
        System.out.println("原文:"+"我要加密这段文字。");
        String crypt = rsa.encryptByPrivateKey(str);
        System.out.println("私钥加密密文:"+crypt);
        String result = rsa.decryptByPublicKey(crypt);
        System.out.println("原文:"+result);
        
        System.out.println("---");
        
        str = "我要加密这段文字。";
        System.out.println("原文:"+"我要加密这段文字。");
        crypt = rsa.encryptByPublicKey(str);
        System.out.println("公钥加密密文:"+crypt);
        result = rsa.decryptByPrivateKey(crypt);
        System.out.println("原文:"+result);
        
        System.out.println("---");
        
        str = "我要签名这段文字。";
        System.out.println("原文："+str);
        String str1 = rsa.signByPrivateKey(str);
        System.out.println("签名结果："+str1);
        if(rsa.verifyByPublicKey(str1, str)){
            System.out.println("成功");
        } else {
            System.out.println("失败");
        }
    }
 
    public Rsa(){
        priKey = readStringFromFile("java_private.pem");
        pubKey = readStringFromFile("java_public.pem");
    }
    
      /**
       * 使用私钥加密
       * @see decByPriKey
       */
      public String encryptByPrivateKey(String data) {
        // 加密
        String str = "";
        try {
            byte[] pribyte = base64decode(priKey.trim());
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(pribyte);
            KeyFactory fac = KeyFactory.getInstance("RSA");
            RSAPrivateKey privateKey = (RSAPrivateKey) fac.generatePrivate(keySpec);
            Cipher c1 = Cipher.getInstance("RSA/ECB/PKCS1Padding");
            c1.init(Cipher.ENCRYPT_MODE, privateKey);
            str = base64encode(c1.doFinal(data.getBytes()));
        } catch (Exception e) {
            e.printStackTrace();
            
        }
        return str;
      }
      
      /**
       * 使用私钥解密
       * @see decByPriKey
       */
      public String decryptByPrivateKey(String data) {
        // 加密
        String str = "";
        try {
            byte[] pribyte = base64decode(priKey.trim());
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(pribyte);
            KeyFactory fac = KeyFactory.getInstance("RSA");
            RSAPrivateKey privateKey = (RSAPrivateKey) fac.generatePrivate(keySpec);
            Cipher c1 = Cipher.getInstance("RSA/ECB/PKCS1Padding");
            c1.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] temp = c1.doFinal(base64decode(data));
            str = new String(temp);
        } catch (Exception e) {
            e.printStackTrace();
            
        }
        return str;
      }
 
      
      /**
       * 使用公钥加密
       * @see decByPriKey
       */
      public String encryptByPublicKey(String data) {
        // 加密
        String str = "";
        try {
            byte[] pubbyte = base64decode(pubKey.trim());
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(pubbyte);
            KeyFactory fac = KeyFactory.getInstance("RSA");
            RSAPublicKey rsaPubKey = (RSAPublicKey) fac.generatePublic(keySpec);
            Cipher c1 = Cipher.getInstance("RSA/ECB/PKCS1Padding");
            c1.init(Cipher.ENCRYPT_MODE, rsaPubKey);
            str = base64encode(c1.doFinal(data.getBytes()));
        } catch (Exception e) {
            e.printStackTrace();
            
        }
        return str;
      }
      
      /**
       * 使用公钥解密
       * @see decByPriKey
       */
      public String decryptByPublicKey(String data) {
        // 加密
        String str = "";
        try {
            byte[] pubbyte = base64decode(pubKey.trim());
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(pubbyte);
            KeyFactory fac = KeyFactory.getInstance("RSA");
            RSAPublicKey rsaPubKey = (RSAPublicKey) fac.generatePublic(keySpec);
            Cipher c1 = Cipher.getInstance("RSA/ECB/PKCS1Padding");
            c1.init(Cipher.DECRYPT_MODE, rsaPubKey);
            byte[] temp = c1.doFinal(base64decode(data));
            str = new String(temp);
        } catch (Exception e) {
            e.printStackTrace();
            
        }
        return str;
      }
    /**
     * 本方法使用SHA1withRSA签名算法产生签名
     * @param String src 签名的原字符串
     * @return String 签名的返回结果(16进制编码)。当产生签名出错的时候，返回null。
     */
    public String signByPrivateKey(String src) {
        try {
            Signature sigEng = Signature.getInstance("SHA1withRSA");
            byte[] pribyte = base64decode(priKey.trim());
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(pribyte);
            KeyFactory fac = KeyFactory.getInstance("RSA");
            RSAPrivateKey privateKey = (RSAPrivateKey) fac.generatePrivate(keySpec);
            sigEng.initSign(privateKey);
            sigEng.update(src.getBytes());
            byte[] signature = sigEng.sign();
            return base64encode(signature);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
 
    /**
     * 使用共钥验证签名
     * @param sign
     * @param src
     * @return
     */
    public boolean verifyByPublicKey(String sign, String src) {
        try {
            Signature sigEng = Signature.getInstance("SHA1withRSA");
            byte[] pubbyte = base64decode(pubKey.trim());
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(pubbyte);
            KeyFactory fac = KeyFactory.getInstance("RSA");
            RSAPublicKey rsaPubKey = (RSAPublicKey) fac.generatePublic(keySpec);
            sigEng.initVerify(rsaPubKey);
            sigEng.update(src.getBytes());
            byte[] sign1 = base64decode(sign);
            return sigEng.verify(sign1);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
 
    /**
     *  base64加密
     * @param bstr
     * @return
     */
    @SuppressWarnings("restriction")
    private String base64encode(byte[] bstr) {
        String str =  new sun.misc.BASE64Encoder().encode(bstr);
        str = str.replaceAll("\r\n", "").replaceAll("\r", "").replaceAll("\n", "");
        return str;
    }
 
    /**
     * base64解密
     * @param str
     * @return byte[]
     */
    @SuppressWarnings("restriction")
    private byte[] base64decode(String str) {
        byte[] bt = null;
        try {
            sun.misc.BASE64Decoder decoder = new sun.misc.BASE64Decoder();
            bt = decoder.decodeBuffer(str);
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        return bt;
    }
 
    /**
     * 从文件中读取所有字符串
     * @param fileName
     * @return    String
     */
    private String readStringFromFile(String fileName){
        StringBuffer str = new StringBuffer();
        try {
            File file = new File(fileName);
            FileReader fr = new FileReader(file);
            char[] temp = new char[1024];
            while (fr.read(temp) != -1) {
                str.append(temp);
            }
            fr.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
 
        }
        return str.toString();
    }
}

java公钥文件内容(java_public.pem)

MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCm1YchJdHVy9iXsDfQfMEB2mdO
5wuaEiqUEerHO7HbKKkvhuIfc7haQV5bKTiKZ76FnkkXJMF+onMrQrrqk4TiWlYZ
oilesPM88jr01Z9MmhzKV7vWboVhYcd8cw2Mua0HwAMyl9TDt5OLWmT00C4/Lu72
lRL21avxRTvmDQoAqQIDAQAB

java私钥文件内容(java_private.pem)
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说明：

java和php的RSA加解密版本已全部通过测试。并且可以相互加解密。
私钥是服务器保留，公钥可以发放给对应的客户端，甚至可以是公共的。
采用私钥加密-》公钥解密 和 公钥加密-》私钥解密 的加密方式。
但是如果客户端是需要更高安全性的支付系统，那么应该采用两对密钥。
每一方分别是自己的私钥和对方的公钥，采用私钥加密并签名-》公钥解密并验签的方式。

注意：给出的是两个版本的两对密钥，实际上只是一对密钥。区别是java的密钥去掉了头尾注释。而PHP的密钥保留了头尾注释。

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版权声明：本文为CSDN博主「蝶开三月」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/panjiapengfly/article/details/75318930