content: /**
   * Copyright (c) 2005-2012 springside.org.cn
   */
  package com.jeespring.common.security;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.security.GeneralSecurityException;
  import java.security.MessageDigest;
  import java.security.SecureRandom;
  
  import org.apache.commons.lang3.Validate;
  
  import com.jeespring.common.utils.Exceptions;
  
  /**
   * 支持SHA-1/MD5消息摘要的工具类.
   * 
   * 返回ByteSource，可进一步被编码为Hex, Base64或UrlSafeBase64
   * 
   * @author JeeSpring
   */
  public class Digests {
  
  	private static final String SHA1 = "SHA-1";
  	private static final String MD5 = "MD5";
  
  	private static SecureRandom random = new SecureRandom();
  
  	/**
  	 * 对输入字符串进行md5散列.
  	 */
  	public static byte[] md5(byte[] input) {
  		return digest(input, MD5, null, 1);
  	}
  	public static byte[] md5(byte[] input, int iterations) {
  		return digest(input, MD5, null, iterations);
  	}
  	
  	/**
  	 * 对输入字符串进行sha1散列.
  	 */
  	public static byte[] sha1(byte[] input) {
  		return digest(input, SHA1, null, 1);
  	}
  
  	public static byte[] sha1(byte[] input, byte[] salt) {
  		return digest(input, SHA1, salt, 1);
  	}
  
  	public static byte[] sha1(byte[] input, byte[] salt, int iterations) {
  		return digest(input, SHA1, salt, iterations);
  	}
  
  	/**
  	 * 对字符串进行散列, 支持md5与sha1算法.
  	 */
  	private static byte[] digest(byte[] input, String algorithm, byte[] salt, int iterations) {
  		try {
  			MessageDigest digest = MessageDigest.getInstance(algorithm);
  
  			if (salt != null) {
  				digest.update(salt);
  			}
  
  			byte[] result = digest.digest(input);
  
  			for (int i = 1; i < iterations; i++) {
  				digest.reset();
  				result = digest.digest(result);
  			}
  			return result;
  		} catch (GeneralSecurityException e) {
  			throw Exceptions.unchecked(e);
  		}
  	}
  
  	/**
  	 * 生成随机的Byte[]作为salt.
  	 * 
  	 * @param numBytes byte数组的大小
  	 */
  	public static byte[] generateSalt(int numBytes) {
  		Validate.isTrue(numBytes > 0, "numBytes argument must be a positive integer (1 or larger)", numBytes);
  
  		byte[] bytes = new byte[numBytes];
  		random.nextBytes(bytes);
  		return bytes;
  	}
  
  	/**
  	 * 对文件进行md5散列.
  	 */
  	public static byte[] md5(InputStream input) throws IOException {
  		return digest(input, MD5);
  	}
  
  	/**
  	 * 对文件进行sha1散列.
  	 */
  	public static byte[] sha1(InputStream input) throws IOException {
  		return digest(input, SHA1);
  	}
  
  	private static byte[] digest(InputStream input, String algorithm) throws IOException {
  		try {
  			MessageDigest messageDigest = MessageDigest.getInstance(algorithm);
  			int bufferLength = 8 * 1024;
  			byte[] buffer = new byte[bufferLength];
  			int read = input.read(buffer, 0, bufferLength);
  
  			while (read > -1) {
  				messageDigest.update(buffer, 0, read);
  				read = input.read(buffer, 0, bufferLength);
  			}
  
  			return messageDigest.digest();
  		} catch (GeneralSecurityException e) {
  			throw Exceptions.unchecked(e);
  		}
  	}
  
  	public static String string2MD5(String inStr){
  		MessageDigest md5 = null;
  		try{
  			md5 = MessageDigest.getInstance("MD5");
  		}catch (Exception e){
  			System.out.println(e.toString());
  			e.printStackTrace();
  			return "";
  		}
  		char[] charArray = inStr.toCharArray();
  		byte[] byteArray = new byte[charArray.length];
  
  		for (int i = 0; i < charArray.length; i++)
  			byteArray[i] = (byte) charArray[i];
  		byte[] md5Bytes = md5.digest(byteArray);
  		StringBuffer hexValue = new StringBuffer();
  		for (int i = 0; i < md5Bytes.length; i++){
  			int val = ((int) md5Bytes[i]) & 0xff;
  			if (val < 16)
  				hexValue.append("0");
  			hexValue.append(Integer.toHexString(val));
  		}
  		return hexValue.toString();
  
  	}
  }
  