package com.edu.hpu;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class No14 {
public static void main(String[] args) throws Exception {
String content = "***";
System.out.println("加密前：" + content);
String key = "123";
System.out.println("加密密鑰和解密密鑰：" + (int)'1' + " " + (int)'2' + " " + (int)'3' );
String encrypt = aesEncrypt(content, key);
System.out.println("密文：" + encrypt);
String decrypt = aesDecrypt(encrypt, key);
System.out.println("解密後：" + decrypt);
}
/**
* 將byte[]轉為各種進制的字符串
* @param bytes byte[]
* @param radix 可以轉換進制的范圍，從Character.MIN_RADIX到Character.MAX_RADIX，超出范圍後變為10進制
* @return 轉換後的字符串
*/
public static String binary(byte[] bytes, int radix){
return new BigInteger(1, bytes).toString(radix);// 這裡的1代表正數
}
/**
* base 64 encode
* @param bytes 待編碼的byte[]
* @return 編碼後的base 64 code
*/
public static String base64Encode(byte[] bytes){
return new BASE64Encoder().encode(bytes);
}
/**
* base 64 decode
* @param base64Code 待解碼的base 64 code
* @return 解碼後的byte[]
* @throws Exception
*/
public static byte[] base64Decode(String base64Code) throws Exception{
return QStringUtil.isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
}
/**
* 獲取byte[]的md5值
* @param bytes byte[]
* @return md5
* @throws Exception
*/
public static byte[] md5(byte[] bytes) throws Exception {
MessageDigest md = MessageDigest.getInstance("MD5");
md.update(bytes);
return md.digest();
}
/**
* 獲取字符串md5值
* @param msg
* @return md5
* @throws Exception
*/
public static byte[] md5(String msg) throws Exception {
return QStringUtil.isEmpty(msg) ? null : md5(msg.getBytes());
}
/**
* 結合base64實現md5加密
* @param msg 待加密字符串
* @return 獲取md5後轉為base64
* @throws Exception
*/
public static String md5Encrypt(String msg) throws Exception{
return QStringUtil.isEmpty(msg) ? null : base64Encode(md5(msg));
}
/**
* AES加密
* @param content 待加密的內容
* @param encryptKey 加密密鑰
* @return 加密後的byte[]
* @throws Exception
*/
public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {
//加密解密時都加上,否則不同機器加密結果不一致
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom random=SecureRandom.getInstance("SHA1PRNG");
random.setSeed(encryptKey.getBytes());
kgen.init(128, random);
//一般寫法
//KeyGenerator kgen = KeyGenerator.getInstance("AES");
//kgen.init(128, new SecureRandom(encryptKey.getBytes()));
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
return cipher.doFinal(content.getBytes("utf-8"));
}
/**
* AES加密為base 64 code
* @param content 待加密的內容
* @param encryptKey 加密密鑰
* @return 加密後的base 64 code
* @throws Exception
*/
public static String aesEncrypt(String content, String encryptKey) throws Exception {
return base64Encode(aesEncryptToBytes(content, encryptKey));
}
/**
* AES解密
* @param encryptBytes 待解密的byte[]
* @param decryptKey 解密密鑰
* @return 解密後的String
* @throws Exception
*/
public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
//加密解密時都加上,否則不同機器加密結果不一致
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom random=SecureRandom.getInstance("SHA1PRNG");
random.setSeed(decryptKey.getBytes());
kgen.init(128, random);
//一般寫法
//KeyGenerator kgen = KeyGenerator.getInstance("AES");
//kgen.init(128, new SecureRandom(decryptKey.getBytes()));
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
byte[] decryptBytes = cipher.doFinal(encryptBytes);
return new String(decryptBytes);
}
/**
* 將base 64 code AES解密
* @param encryptStr 待解密的base 64 code
* @param decryptKey 解密密鑰
* @return 解密後的string
* @throws Exception
*/
public static String aesDecrypt(String encryptStr, String decryptKey) throws Exception {
return QStringUtil.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
}
}
class QStringUtil {
public static boolean isEmpty(String str){
if(str==null){
return true;
}else{
return false;
}
}
}
