复制代码 代码如下:

import java.security.Key;

import java.security.KeyFactory;

import java.security.KeyPair;

import java.security.KeyPairGenerator;

import java.security.PrivateKey;

import java.security.PublicKey;

import java.security.interfaces.RSAPrivateKey;

import java.security.interfaces.RSAPublicKey;

import java.security.spec.PKCS8EncodedKeySpec;

import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

import sun.misc.BASE64Decoder;

import sun.misc.BASE64Encoder;

public class RSAHelper {

public static PublicKey getPublicKey(String key) throws Exception {

byte[] keyBytes;

keyBytes = (new BASE64Decoder()).decodeBuffer(key);

X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance("RSA");

PublicKey publicKey = keyFactory.generatePublic(keySpec);

return publicKey;

}

public static PrivateKey getPrivateKey(String key) throws Exception {

byte[] keyBytes;

keyBytes = (new BASE64Decoder()).decodeBuffer(key);

PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance("RSA");

PrivateKey privateKey = keyFactory.generatePrivate(keySpec);

return privateKey;

}

public static String getKeyString(Key key) throws Exception {

byte[] keyBytes = key.getEncoded();

String s = (new BASE64Encoder()).encode(keyBytes);

return s;

}

public static void main(String[] args) throws Exception {

KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");

//密钥位数

keyPairGen.initialize(1024);

//密钥对

KeyPair keyPair = keyPairGen.generateKeyPair();

// 公钥

PublicKey publicKey = (RSAPublicKey) keyPair.getPublic();

// 私钥

PrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

String publicKeyString = getKeyString(publicKey);

System.out.println("public:n" + publicKeyString);

String privateKeyString = getKeyString(privateKey);

System.out.println("private:n" + privateKeyString);

//加解密类

Cipher cipher = Cipher.getInstance("RSA");//Cipher.getInstance("RSA/ECB/PKCS1Padding");

//明文

byte[] plainText = "我们都很好！邮件：@sina.com".getBytes();

//加密

cipher.init(Cipher.ENCRYPT_MODE, publicKey);

byte[] enBytes = cipher.doFinal(plainText);

//通过密钥字符串得到密钥

publicKey = getPublicKey(publicKeyString);

privateKey = getPrivateKey(privateKeyString);

//解密

cipher.init(Cipher.DECRYPT_MODE, privateKey);

byte[]deBytes = cipher.doFinal(enBytes);

publicKeyString = getKeyString(publicKey);

System.out.println("public:n" +publicKeyString);

privateKeyString = getKeyString(privateKey);

System.out.println("private:n" + privateKeyString);

String s = new String(deBytes);

System.out.println(s);

}

}