md5.cs

MD5加密的C#实现.可加密16位和32位MD5值.

using System.Security.Cryptography;
using System.IO;
using System.Text; 


/*
 * 本类功能：
 * Md5加密
 * 返回md5hash字符串
 * 返回兼容asp 的 md5的值
 * 16位为兼容asp加密类
 * 32位为.net正常加密类
 */
public partial class MD5
{
    #region MD5
    /// <summary>
    /// 16位MD5加密方法,以前的DVBBS所使用
    /// </summary>
    /// <param name="strSource">待加密字串</param>
    /// <returns>加密后的字串</returns>
    public static string MD5Encrypt(string strSource)
    {
        return MD5Encrypt(strSource, 16);
    }
    /// <summary>
    /// MD5加密,和动网上的16/32位MD5加密结果相同
    /// </summary>
    /// <param name="strSource">待加密字串</param>
    /// <param name="length">16或32值之一,其它则采用.net默认MD5加密算法</param>
    /// <returns>加密后的字串</returns>
    public static string MD5Encrypt(string strSource, int length)
    {
        byte[] bytes = Encoding.ASCII.GetBytes(strSource);
        byte[] hashValue = ((System.Security.Cryptography.HashAlgorithm)System.Security.Cryptography.CryptoConfig.CreateFromName("MD5")).ComputeHash(bytes);
        StringBuilder sb = new StringBuilder();
        switch (length)
        {
            case 16:
                for (int i = 4; i < 12; i++)
                    sb.Append(hashValue[i].ToString("x2"));
                break;
            case 32:
                for (int i = 0; i < 16; i++)
                {
                    sb.Append(hashValue[i].ToString("x2"));
                }
                break;
            default:
                for (int i = 0; i < hashValue.Length; i++)
                {
                    sb.Append(hashValue[i].ToString("x2"));
                }
                break;
        }
        return sb.ToString();
    }
    #endregion
}