net.unmz.java.util.security.RSAUtils Maven / Gradle / Ivy
package net.unmz.java.util.security;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import java.io.ByteArrayOutputStream;
import java.security.*;
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;
/**
* Project Name:
* 功能描述：
*
* @author [email protected]
* @version 1.0
* @date 2018/3/23 11:03
* @since JDK 1.8
*/
public class RSAUtils {
/** *//**
* 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)
*
*
* @return
* @throws Exception
*/
public static Map 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 keyMap = new HashMap(2);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/** *//**
*
* 用私钥对信息生成数字签名
*
*
* @param data 已加密数据
* @param privateKey 私钥(BASE64编码)
*
* @return
* @throws Exception
*/
public static String sign(byte[] data, String privateKey) throws Exception {
String keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes.getBytes());
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(privateK);
signature.update(data);
return String.valueOf(Base64Utils.encode(signature.sign()));
}
/** *//**
*
* 校验数字签名
*
*
* @param data 已加密数据
* @param publicKey 公钥(BASE64编码)
* @param sign 数字签名
*
* @return
* @throws Exception
*
*/
public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {
String keyBytes = Base64Utils.encode(publicKey);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes.getBytes());
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(Base64Utils.decode(sign).getBytes());
}
/** *//**
*
* 私钥解密
*
*
* @param encryptedData 已加密数据
* @param privateKey 私钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey) throws Exception {
String keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes.getBytes());
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;
int i = 0;
// 对数据分段解密
setData(encryptedData, cipher, inputLen, out, offSet, i);
byte[] decryptedData = out.toByteArray();
out.close();
return decryptedData;
}
/** *//**
*
* 公钥解密
*
*
* @param encryptedData 已加密数据
* @param publicKey 公钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey) throws Exception {
String keyBytes = Base64Utils.decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes.getBytes());
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicK);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
int i = 0;
setData(encryptedData, cipher, inputLen, out, offSet, i);
byte[] decryptedData = out.toByteArray();
out.close();
return decryptedData;
}
private static void setData(byte[] encryptedData, Cipher cipher, int inputLen, ByteArrayOutputStream out, int offSet, int i) throws IllegalBlockSizeException, BadPaddingException {
byte[] cache;// 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;
}
}
/** *//**
*
* 公钥加密
*
*
* @param data 源数据
* @param publicKey 公钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception {
String keyBytes = Base64Utils.decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes.getBytes());
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
setData(data, cipher, inputLen, out, offSet, i);
byte[] encryptedData = out.toByteArray();
out.close();
return encryptedData;
}
/** *//**
*
* 私钥加密
*
*
* @param data 源数据
* @param privateKey 私钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] encryptByPrivateKey(byte[] data, String privateKey) throws Exception {
String keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes.getBytes());
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
setData(data, cipher, inputLen, out, offSet, i);
byte[] encryptedData = out.toByteArray();
out.close();
return encryptedData;
}
/** *//**
*
* 获取私钥
*
*
* @param keyMap 密钥对
* @return
* @throws Exception
*/
public static String getPrivateKey(Map keyMap) throws Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return String.valueOf(Base64Utils.encode(key.getEncoded()));
}
/** *//**
*
* 获取公钥
*
*
* @param keyMap 密钥对
* @return
* @throws Exception
*/
public static String getPublicKey(Map keyMap) throws Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
return String.valueOf(Base64Utils.encode(key.getEncoded()));
}
}