密码加密解密工具类(其中的keyValue/key为公钥)

import java.security.Key;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.spec.SecretKeySpec;

import net.sf.json.JSONArray;

import net.sf.json.JSONObject;

/**

* 计算单位转换工具类

* @author Administrator

*

*/

public class AppUtil {

public static final String KEY_ALGORITHM="AES";

public static final String CIPHER_ALGORITHM="AES";

public static byte[] initkey() throws Exception{

//实例化密钥生成器

KeyGenerator kg=KeyGenerator.getInstance(KEY_ALGORITHM);

kg.init(256);

kg.init(128);

SecretKey secretKey=kg.generateKey();

return secretKey.getEncoded();

}

public static byte[] initRootKey() throws Exception{

return new byte[] { 0x08, 0x08, 0x04, 0x0b, 0x02, 0x0f, 0x0b, 0x0c,

0x01, 0x03, 0x09, 0x07, 0x0c, 0x03, 0x07, 0x0a, 0x04, 0x0f,

0x06, 0x0f, 0x0e, 0x09, 0x05, 0x01, 0x0a, 0x0a, 0x01, 0x09,

0x06, 0x07, 0x09, 0x0d };

}

public static Key toKey(byte[] key) throws Exception{

SecretKey secretKey=new SecretKeySpec(key,KEY_ALGORITHM);

return secretKey;

}

public static byte[] encrypt(byte[] data,String keyValue) throws Exception{

byte[] key=AppUtil.MD5(keyValue).getBytes();

Key k=toKey(key);

Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM);

cipher.init(Cipher.ENCRYPT_MODE, k);

return cipher.doFinal(data);

}

public static byte[] decrypt(byte[] data,byte[] key) throws Exception{

Key k =toKey(key);

Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM);

cipher.init(Cipher.DECRYPT_MODE, k);

return cipher.doFinal(data);

}

public static String MD5(String sourceStr) {

String result = "";

try {

MessageDigest md = MessageDigest.getInstance("MD5");

md.update(sourceStr.getBytes());

byte b[] = md.digest();

int i;

StringBuffer buf = new StringBuffer("");

for (int offset = 0; offset < b.length; offset++) {

i = b[offset];

if (i < 0)

i += 256;

if (i < 16)

buf.append("0");

buf.append(Integer.toHexString(i));

}

result = buf.toString();

} catch (NoSuchAlgorithmException e) {

System.out.println(e);

}

System.out.println("md5:"+result);

return result;

}

private static byte[] MD52(String sourceStr) {

try {

MessageDigest md = MessageDigest.getInstance("MD5");

md.update(sourceStr.getBytes());

byte b[] = md.digest();

return b;

} catch (NoSuchAlgorithmException e) {

System.out.println(e);

}

return null;

}

public static String bytesToHexString(byte[] src){

StringBuilder stringBuilder = new StringBuilder("");

if (src == null || src.length <= 0) {

return null;

}

for (int i = 0; i < src.length; i++) {

int v = src[i] & 0xFF;

String hv = Integer.toHexString(v);

if (hv.length() < 2) {

stringBuilder.append(0);

}

stringBuilder.append(hv);

}

return stringBuilder.toString();

}

public static byte[] hexStringToBytes(String hexString) {

if (hexString == null || hexString.equals("")) {

return null;

}

hexString = hexString.toUpperCase();

int length = hexString.length() / 2;

char[] hexChars = hexString.toCharArray();

byte[] d = new byte[length];

for (int i = 0; i < length; i++) {

int pos = i * 2;

d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));

}

return d;

}

private static byte charToByte(char c) {

return (byte) "0123456789ABCDEF".indexOf(c);

}

// 解密成一个对象

public static <T> T decryptObject(String str,Class className,String keyValue) throws Exception{

byte[] key=AppUtil.MD5(keyValue).getBytes();

byte[] data= hexStringToBytes(str);

Key k =toKey(key);

Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM);

cipher.init(Cipher.DECRYPT_MODE, k);

String decryptString = new String(cipher.doFinal(data),"utf-8");

// byte[] temp=decryptString.getBytes("gbk");//这里写原编码方式

// byte[] newtemp=new String(temp, "gbk").getBytes("utf-8");//这里写转换后的编码方式

// String newStr=new String(newtemp,"utf-8");//这里写转换后的编码方式

JSONObject obj=JSONObject.fromObject(decryptString);

return (T) JSONObject.toBean(obj, className);

}

// 解密成一个String

public static String decryptStr(String str,String keyValue) throws Exception{

byte[] key=AppUtil.MD5(keyValue).getBytes();

byte[] data= hexStringToBytes(str);

Key k =toKey(key);

Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM);

cipher.init(Cipher.DECRYPT_MODE, k);

String decryptString = new String(cipher.doFinal(data));

return decryptString;

}

public static String addSecureToStr(String str,String keyValue){

byte[] data=null;

try {

data = AppUtil.encrypt(str.getBytes("utf-8"),keyValue);

} catch (Exception e1) {

e1.printStackTrace();

}

return AppUtil.bytesToHexString(data);

}

}