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package com.quanran.utils;
import java.io.ByteArrayOutputStream;
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.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Cipher;
import org.apache.commons.codec.binary.Base64;
/**
* <p>Description: [RSA util工具]</p>
* Created on 2018年7月17日 下午8:36:55
* @author <a href="mailto: [email protected]">全冉</a>
* @version 1.0
* Copyright (c) 2018 全冉技术部
*/
public class RSA {
/**
* 加密算法RSA
*/
public static final String KEY_ALGORITHM = "RSA";
/**
* 签名算法
*/
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
/**
* 获取公钥的key
*/
private static final String PUBLIC_KEY = "RSAPublicKey";
/**
* 获取私钥的key
*/
private static final String PRIVATE_KEY = "RSAPrivateKey";
/**
* RSA最大加密明文大小
*/
private static final int MAX_ENCRYPT_BLOCK = 117;
/**
* RSA最大解密密文大小
*/
private static final int MAX_DECRYPT_BLOCK = 128;
/**
* 生成密钥对(公钥和私钥)
*/
public static Map<String, Object> genKeyPair() throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(1024);
KeyPair keyPair = keyPairGen.generateKeyPair();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
Map<String, Object> keyMap = new HashMap<String, Object>(2);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/**
* 拿到生成的密钥对里的私钥
*/
public static String getPrivateKey(Map<String, Object> keyMap) throws Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return Base64.encodeBase64String(key.getEncoded());
}
/**
* 拿到生成的密钥对里的公钥
*/
public static String getPublicKey(Map<String, Object> keyMap) throws Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
return Base64.encodeBase64String(key.getEncoded());
}
/**
* 公钥加密
*/
public static String encryptByPublicKey(String content, String publicKey, String charset) throws Exception {
byte[] data = content.getBytes(charset);
byte[] keyBytes = Base64.decodeBase64(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return Base64.encodeBase64String(encryptedData);
}
/**
* 私钥解密
*/
public static String decryptByPrivateKey(String content, String privateKey, String charset) throws Exception {
byte[] encryptedData = Base64.decodeBase64(content);
byte[] keyBytes = Base64.decodeBase64(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateK);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return new String(decryptedData, charset);
}
/**
* 签名
*/
public static String sign(String content, String privateKey, String charset) throws Exception {
byte[] data = content.getBytes(charset);
byte[] keyBytes = Base64.decodeBase64(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(privateK);
signature.update(data);
return Base64.encodeBase64String(signature.sign());
}
/**
* 验签
*/
public static boolean verify(String content, String publicKey, String sign, String charset) throws Exception {
byte[] data = content.getBytes(charset);
byte[] keyBytes = Base64.decodeBase64(publicKey);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PublicKey publicK = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(publicK);
signature.update(data);
return signature.verify(Base64.decodeBase64(sign));
}
/**
* 加解密 加签验签
* @param args
*/
public static void main(String[] args) {
try {
/**
* 生成 RSA publicKey privateKey
*/
Map<String, Object> keyPair = genKeyPair();
String publicKey = getPublicKey(keyPair);
String privateKey = getPrivateKey(keyPair);
System.out.println(String.format("rsa privateKey:%s\nrsa publicKey:%s", privateKey, publicKey));
/**
* rsa加解密:公钥加密,私钥解密
*/
// 明文
String data = "123";
//publicKey加密
String encryptData = encryptByPublicKey(data, publicKey, "UTF-8");
//privateKey解密
String decryptData = decryptByPrivateKey(encryptData, privateKey, "UTF-8");
System.out.println(String.format("data:%s, encryptData:%s, decryptData:%s", data, encryptData, decryptData));
/**
* RSA签名与验签
*/
//privateKey签名
String sign = sign(data, privateKey, "UTF-8");
//publicKey验签
boolean verify = verify(data, publicKey, sign, "UTF-8");
System.out.println(String.format("data:%s, sign:%s, verify:%s", data, sign, verify));
} catch (Exception e) {
e.printStackTrace();
}
}
}