java實現RSA加解密工具類

RSAUtil

package com.zhuyun.rsa;
 
import java.io.IOException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
 
import javax.crypto.Cipher;
 
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
 
public class RSAUtil {
	//生成祕鑰對
	public static KeyPair getKeyPair() throws Exception {
		KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
		keyPairGenerator.initialize(2048);
		KeyPair keyPair = keyPairGenerator.generateKeyPair();
		return keyPair;
	}
	
	//獲取公鑰(Base64編碼)
	public static String getPublicKey(KeyPair keyPair){
		PublicKey publicKey = keyPair.getPublic();
		byte[] bytes = publicKey.getEncoded();
		return byte2Base64(bytes);
	}
	
	//獲取私鑰(Base64編碼)
	public static String getPrivateKey(KeyPair keyPair){
		PrivateKey privateKey = keyPair.getPrivate();
		byte[] bytes = privateKey.getEncoded();
		return byte2Base64(bytes);
	}
	
	//將Base64編碼後的公鑰轉換成PublicKey對象
	public static PublicKey string2PublicKey(String pubStr) throws Exception{
		byte[] keyBytes = base642Byte(pubStr);
		X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance("RSA");
		PublicKey publicKey = keyFactory.generatePublic(keySpec);
		return publicKey;
	}
	
	//將Base64編碼後的私鑰轉換成PrivateKey對象
	public static PrivateKey string2PrivateKey(String priStr) throws Exception{
		byte[] keyBytes = base642Byte(priStr);
		PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance("RSA");
		PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
		return privateKey;
	}
	
	//公鑰加密
	public static byte[] publicEncrypt(byte[] content, PublicKey publicKey) throws Exception{
		Cipher cipher = Cipher.getInstance("RSA");
		cipher.init(Cipher.ENCRYPT_MODE, publicKey);
		byte[] bytes = cipher.doFinal(content);
		return bytes;
	}
	
	//私鑰解密
	public static byte[] privateDecrypt(byte[] content, PrivateKey privateKey) throws Exception{
		Cipher cipher = Cipher.getInstance("RSA");
		cipher.init(Cipher.DECRYPT_MODE, privateKey);
		byte[] bytes = cipher.doFinal(content);
		return bytes;
	}
	
	//字節數組轉Base64編碼
	public static String byte2Base64(byte[] bytes){
		BASE64Encoder encoder = new BASE64Encoder();
		return encoder.encode(bytes);
	}
	
	//Base64編碼轉字節數組
	public static byte[] base642Byte(String base64Key) throws IOException{
		BASE64Decoder decoder = new BASE64Decoder();
		return decoder.decodeBuffer(base64Key);
	}
}

TestRSA

package com.zhuyun.test;
 
import java.security.KeyPair;
import java.security.PrivateKey;
import java.security.PublicKey;
 
import org.junit.Test;
 
import com.zhuyun.rsa.RSAUtil;
 
public class TestRSA {
 
	@Test
	public void testRSA(){
		try {
			//===============生成公鑰和私鑰，公鑰傳給客戶端，私鑰服務端保留==================
			//生成RSA公鑰和私鑰，並Base64編碼
			KeyPair keyPair = RSAUtil.getKeyPair();
			String publicKeyStr = RSAUtil.getPublicKey(keyPair);
			String privateKeyStr = RSAUtil.getPrivateKey(keyPair);
			System.out.println("RSA公鑰Base64編碼:" + publicKeyStr);
			System.out.println("RSA私鑰Base64編碼:" + privateKeyStr);
			
			//=================客戶端=================
			//hello, i am infi, good night!加密
			String message = "hello, i am infi, good night!";
			//將Base64編碼後的公鑰轉換成PublicKey對象
			PublicKey publicKey = RSAUtil.string2PublicKey(publicKeyStr);
			//用公鑰加密
			byte[] publicEncrypt = RSAUtil.publicEncrypt(message.getBytes(), publicKey);
			//加密後的內容Base64編碼
			String byte2Base64 = RSAUtil.byte2Base64(publicEncrypt);
			System.out.println("公鑰加密並Base64編碼的結果：" + byte2Base64);
			
			
			//##############	網絡上傳輸的內容有Base64編碼後的公鑰 和 Base64編碼後的公鑰加密的內容     #################
			
			
			
			//===================服務端================
			//將Base64編碼後的私鑰轉換成PrivateKey對象
			PrivateKey privateKey = RSAUtil.string2PrivateKey(privateKeyStr);
			//加密後的內容Base64解碼
			byte[] base642Byte = RSAUtil.base642Byte(byte2Base64);
			//用私鑰解密
			byte[] privateDecrypt = RSAUtil.privateDecrypt(base642Byte, privateKey);
			//解密後的明文
			System.out.println("解密後的明文: " + new String(privateDecrypt));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
 
}

測試結果如下：

RSA公鑰Base64編碼:MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA20p3Q88SmVUPpA+r/0hWY/LbMCsllwXK
UrXY13pG26BKsgtMm6IAGr6psS8cQ+AU75RpH3lTtt81wIfCHm9+vo4kVt66y8G0kfYSJ9Qlw2oH
5lwab8knPPb+NQNwE7WvceRczKh4XIEfNcgXZyKrcDUIpIsP6rNbZ70JYRhYiagqyLsb39ib4eO6
Zf6nmnrl3NPGeW4qFoivNudAld5E04gt2vCEEpuVt3x1/W3lVzD2gzz9rfkzjFvWwfGYjHMcZZNH
Z1h1G60ssSHh7WKV8f6EglPRQssimUKXX4De6g5SVABPs6MEOj0RYYyunJ8unA448u7/TCcMjV/b
vnndDwIDAQAB
RSA私鑰Base64編碼:MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQDbSndDzxKZVQ+kD6v/SFZj8tsw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公鑰加密並Base64編碼的結果：rbHqJI9jlPLj/n4VP7d4jJRG1WDsDoWYib4BGjXEep6ym9FLiuCKCEwTDPuvvRzlH2BVFjkA0nN+
cjDo/u4PPofxK0a8Ipz0xYvnnQc9q+k8r0QD1uTx8PmnZLEv4rjwfIra/ho8VpYkPA7F1KkwDTyI
RIL06hngkhCi1aDym5oIP4vv+kxvi1uArVU04afXo6K4MTtzAesbG8f/qLHV7ywcBVNvb0QnuLNX
7jAWtfHfEGQibuA1EKbh35RcTjKlSW6vHTmg/f3fdHAfwKM/eh9LdMUjpsmfUoFfm8Ep7avjXbn+
12aXhtVZy8EYLIf1ZckefM95F808XN4HIsth6A==
解密後的明文: hello, i am infi, good night!

轉自：https://blog.csdn.net/qq_32523587/article/details/79092364