RSA加密解密封装

来源：互联网发布：蜜蜂软件的注册码编辑：程序博客网时间：2024/05/14 05:38

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 {

/**
* 得到公钥
* @param key 密钥字符串（经过base64编码）
* @throws Exception
*/
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;
}
/**
* 得到私钥
* @param key 密钥字符串（经过base64编码）
* @throws Exception
*/
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;
}

/**
* 得到密钥字符串（经过base64编码）
* @return
*/
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);

}

}

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