import org.apache.commons.codec.binary.Base64; import javax.crypto.Cipher;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map; /**
* RSA加密和解密工具
*
* @Author: syj
* @CreateDate: 2018/7/20 16:52
*/
public class RSAUtil { /**
* 数字签名，密钥算法
*/
private static final String RSA_KEY_ALGORITHM = "RSA"; /**
* 数字签名签名/验证算法
*/
private static final String SIGNATURE_ALGORITHM = "MD5withRSA"; /**
* RSA密钥长度，RSA算法的默认密钥长度是1024密钥长度必须是64的倍数，在512到65536位之间
*/
private static final int KEY_SIZE = 1024; /**
* 生成密钥对
*/
private static Map<String, String> initKey() throws Exception {
KeyPairGenerator keygen = KeyPairGenerator.getInstance(RSA_KEY_ALGORITHM);
SecureRandom secrand = new SecureRandom();
/**
* 初始化随机产生器
*/
secrand.setSeed("initSeed".getBytes());
/**
* 初始化密钥生成器
*/
keygen.initialize(KEY_SIZE, secrand);
KeyPair keys = keygen.genKeyPair(); byte[] pub_key = keys.getPublic().getEncoded();
String publicKeyString = Base64.encodeBase64String(pub_key); byte[] pri_key = keys.getPrivate().getEncoded();
String privateKeyString = Base64.encodeBase64String(pri_key); Map<String, String> keyPairMap = new HashMap<>();
keyPairMap.put("publicKeyString", publicKeyString);
keyPairMap.put("privateKeyString", privateKeyString); return keyPairMap;
} /**
* 密钥转成字符串
*
* @param key
* @return
*/
public static String encodeBase64String(byte[] key) {
return Base64.encodeBase64String(key);
} /**
* 密钥转成byte[]
*
* @param key
* @return
*/
public static byte[] decodeBase64(String key) {
return Base64.decodeBase64(key);
} /**
* 公钥加密
*
* @param data 加密前的字符串
* @param publicKey 公钥
* @return 加密后的字符串
* @throws Exception
*/
public static String encryptByPubKey(String data, String publicKey) throws Exception {
byte[] pubKey = RSAUtil.decodeBase64(publicKey);
byte[] enSign = encryptByPubKey(data.getBytes(), pubKey);
return Base64.encodeBase64String(enSign);
} /**
* 公钥加密
*
* @param data 待加密数据
* @param pubKey 公钥
* @return
* @throws Exception
*/
public static byte[] encryptByPubKey(byte[] data, byte[] pubKey) throws Exception {
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKey);
KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
return cipher.doFinal(data);
} /**
* 私钥加密
*
* @param data 加密前的字符串
* @param privateKey 私钥
* @return 加密后的字符串
* @throws Exception
*/
public static String encryptByPriKey(String data, String privateKey) throws Exception {
byte[] priKey = RSAUtil.decodeBase64(privateKey);
byte[] enSign = encryptByPriKey(data.getBytes(), priKey);
return Base64.encodeBase64String(enSign);
} /**
* 私钥加密
*
* @param data 待加密的数据
* @param priKey 私钥
* @return 加密后的数据
* @throws Exception
*/
public static byte[] encryptByPriKey(byte[] data, byte[] priKey) throws Exception {
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKey);
KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
return cipher.doFinal(data);
} /**
* 公钥解密
*
* @param data 待解密的数据
* @param pubKey 公钥
* @return 解密后的数据
* @throws Exception
*/
public static byte[] decryptByPubKey(byte[] data, byte[] pubKey) throws Exception {
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKey);
KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicKey);
return cipher.doFinal(data);
} /**
* 公钥解密
*
* @param data 解密前的字符串
* @param publicKey 公钥
* @return 解密后的字符串
* @throws Exception
*/
public static String decryptByPubKey(String data, String publicKey) throws Exception {
byte[] pubKey = RSAUtil.decodeBase64(publicKey);
byte[] design = decryptByPubKey(Base64.decodeBase64(data), pubKey);
return new String(design);
} /**
* 私钥解密
*
* @param data 待解密的数据
* @param priKey 私钥
* @return
* @throws Exception
*/
public static byte[] decryptByPriKey(byte[] data, byte[] priKey) throws Exception {
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKey);
KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
return cipher.doFinal(data);
} /**
* 私钥解密
*
* @param data 解密前的字符串
* @param privateKey 私钥
* @return 解密后的字符串
* @throws Exception
*/
public static String decryptByPriKey(String data, String privateKey) throws Exception {
byte[] priKey = RSAUtil.decodeBase64(privateKey);
byte[] design = decryptByPriKey(Base64.decodeBase64(data), priKey);
return new String(design);
} /**
* RSA签名
*
* @param data 待签名数据
* @param priKey 私钥
* @return 签名
* @throws Exception
*/
public static String sign(byte[] data, byte[] priKey) throws Exception {
// 取得私钥
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKey);
KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
// 生成私钥
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 实例化Signature
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
// 初始化Signature
signature.initSign(privateKey);
// 更新
signature.update(data);
return Base64.encodeBase64String(signature.sign());
} /**
* RSA校验数字签名
*
* @param data 待校验数据
* @param sign 数字签名
* @param pubKey 公钥
* @return boolean 校验成功返回true，失败返回false
*/
public boolean verify(byte[] data, byte[] sign, byte[] pubKey) throws Exception {
// 实例化密钥工厂
KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
// 初始化公钥
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKey);
// 产生公钥
PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
// 实例化Signature
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
// 初始化Signature
signature.initVerify(publicKey);
// 更新
signature.update(data);
// 验证
return signature.verify(sign);
} public static void main(String[] args) {
try {
Map<String, String> keyMap = initKey();
String publicKeyString = keyMap.get("publicKeyString");
String privateKeyString = keyMap.get("privateKeyString");
System.out.println("公钥:" + publicKeyString);
System.out.println("私钥:" + privateKeyString); // 待加密数据
String data = "admin123";
// 公钥加密
String encrypt = RSAUtil.encryptByPubKey(data, publicKeyString);
// 私钥解密
String decrypt = RSAUtil.decryptByPriKey(encrypt, privateKeyString); System.out.println("加密前:" + data);
System.out.println("加密后:" + encrypt);
System.out.println("解密后:" + decrypt);
} catch (Exception e) {
e.printStackTrace();
}
} }