package com.bonus.sys;

import java.security.MessageDigest;
import java.util.Random;

import org.apache.shiro.codec.Base64;
import org.apache.shiro.codec.Hex;
import org.apache.shiro.crypto.AesCipherService;
import org.apache.shiro.crypto.SecureRandomNumberGenerator;
import org.apache.shiro.crypto.hash.Md5Hash;

/**
 * 
 */
public class CipherHelper {

	private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5",
			"6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

	/**
	 * cipher password 加密成MD5
	 * @param inputString
	 * @return
	 */
	public static String generatePassword(String inputString) {
		return encodeByMD5(inputString);
	}
	/**
	 * validate password
	 * @param password
	 * @param inputString
	 * @return
	 */
	public static boolean validatePassword(String password, String inputString) {
		if (password.equals(encodeByMD5(inputString))) {
			return true;
		} else {
			return false;
		}
	}
	/**
	 * encode
	 * @param originString
	 * @return
	 */
	private static String encodeByMD5(String originString) {
		if (originString != null) {
			try {
				MessageDigest md = MessageDigest.getInstance("MD5");
				byte[] results = md.digest(originString.getBytes());
				String resultString = byteArrayToHexString(results);
				return resultString.toUpperCase();
			} catch (Exception ex) {
				ex.printStackTrace();
			}
		}
		return null;
	}
	/**
	 * change the Byte[] to hex string
	 * @param b
	 * @return
	 */
	private static String byteArrayToHexString(byte[] b) {
		StringBuffer resultSb = new StringBuffer();
		for (int i = 0; i < b.length; i++) {
			resultSb.append(byteToHexString(b[i]));
		}
		return resultSb.toString();
	}

	/**
	 * change a byte to hex string
	 * 
	 * @param b
	 * @return
	 */
	private static String byteToHexString(byte b) {
		int n = b;
		if (n < 0)
			n = 256 + n;
		int d1 = n / 16;
		int d2 = n % 16;
		return hexDigits[d1] + hexDigits[d2];
	}
	 /** 
     * base64进制加密 
     * 
     * @param password 
     * @return 
     */ 
    public static String encrytBase64(String str) { 
        return Base64.encodeToString(str.getBytes()); 
    } 
    /** 
     * base64进制解密 
     * @param cipherText 
     * @return 
     */ 
    public static String decryptBase64(String str) { 
        return Base64.decodeToString(str); 
    } 
    /** 
     * 16进制加密 
     * 
     * @param str 
     * @return 
     */ 
    public static String encrytHex(String str) { 
        return Hex.encodeToString(str.getBytes()); 
    } 
    /** 
     * 16进制解密 
     * @param cipherText 
     * @return 
     */ 
    public static String decryptHex(String str) { 
        return new String(Hex.decode(str)); 
    } 
    public static String generateKey() { 
        AesCipherService aesCipherService=new AesCipherService(); 
        return Base64.encodeToString(aesCipherService.generateNewKey().getEncoded()); 
    } 
    
    /** 
     * 生成盐
     * @return 
     */ 
    public static String createSalt(){
    	return  (new SecureRandomNumberGenerator()).nextBytes().toHex(); 
    }
    /** 
     * 组合username,两次迭代，对密码进行加密 
     * @param username  用户名
     * @param password  密码
     * @param salt  盐
     * @return 
     */ 
    public static String createPwdEncrypt(String username,String password,String salt){
    	  return new Md5Hash(password,username+salt,2).toBase64(); 
    }
    /** 
     * 生成随机数字和字母
     * @param length 生成长度
     * @return 
     */ 
    public static String createRandomString(int length) {         
        String val = "";  
        Random random = new Random();     
        //参数length，表示生成几位随机数  
        for(int i = 0; i < length; i++) {    
            String charOrNum = random.nextInt(2) % 2 == 0 ? "char" : "num";  
            //输出字母还是数字  
            if( "char".equalsIgnoreCase(charOrNum) ) {  
                //输出是大写字母还是小写字母  
                int temp = random.nextInt(2) % 2 == 0 ? 65 : 97;  
                val += (char)(random.nextInt(26) + temp);  
            } else if( "num".equalsIgnoreCase(charOrNum) ) {  
                val += String.valueOf(random.nextInt(10));  
            }  
        }  
        return val;  
    }  
    
}