package com.luo.util;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class DecriptUtil {
    /** 
     *  AES加密
     * @parameter： str：待加密字符串，secretKeyBase：用于生成密鑰的基礎(chǔ)字符串
     * @return：  加密字節(jié)數(shù)組
    **/
    public static byte[] encryptAES(String str, String secretKeyBase) {
        try {
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, new SecureRandom(secretKeyBase.getBytes()));
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 創(chuàng)建密碼器
            byte[] byteContent = str.getBytes("UTF-8");
            cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
            byte[] result = cipher.doFinal(byteContent);
            return result; // 加密
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
        return null;
    }

  /** 
     * AES解密
     * @parameter： strByteArray：待解密字節(jié)數(shù)組，
     * @parameter： secretKeyBase：用于生成密鑰的基礎(chǔ)字符串， 需要注意的是EAS是對稱加密，所以secretKeyBase在加密解密時要一樣的
     * @return：  解密后字符串
    **/
    public static String decryptAES(byte[] strByteArray, String secretKeyBase) {
        try {
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, new SecureRandom(secretKeyBase.getBytes()));
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 創(chuàng)建密碼器
            cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
            String result = new String(cipher.doFinal(strByteArray),"UTF-8");
            return result; // 加密
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return null;
    }

    /** 
     *  SHA、SHA1加密
     * @parameter：   str：待加密字符串
     * @return：  加密串
    **/
    public static String SHA1(String str) {
        try {
            MessageDigest digest = java.security.MessageDigest
                    .getInstance("SHA-1"); //如果是SHA加密只需要將"SHA-1"改成"SHA"即可
            digest.update(str.getBytes());
            byte messageDigest[] = digest.digest();
            // Create Hex String
            StringBuffer hexStr = new StringBuffer();
            // 字節(jié)數(shù)組轉(zhuǎn)換為 十六進制 數(shù)
            for (int i = 0; i < messageDigest.length; i++) {
                String shaHex = Integer.toHexString(messageDigest[i] & 0xFF);
                if (shaHex.length() < 2) {
                    hexStr.append(0);
                }
                hexStr.append(shaHex);
            }
            return hexStr.toString();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }

    /** 
     *  MD5加密
     * @parameter：   str：待加密字符串
     * @return：  加密串
    **/
    public static String MD5(String str) {
        try {
            // 獲得MD5摘要算法的 MessageDigest 對象
            MessageDigest mdInst = MessageDigest.getInstance("MD5");
            // 使用指定的字節(jié)更新摘要
            mdInst.update(str.getBytes());
            // 獲得密文
            byte[] md = mdInst.digest();
            // 把密文轉(zhuǎn)換成十六進制的字符串形式
            StringBuffer hexString = new StringBuffer();
            // 字節(jié)數(shù)組轉(zhuǎn)換為 十六進制 數(shù)
            for (int i = 0; i < md.length; i++) {
                String shaHex = Integer.toHexString(md[i] & 0xFF);
                if (shaHex.length() < 2) {
                    hexString.append(0);
                }
                hexString.append(shaHex);
            }
            return hexString.toString();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }
}