学步园

用C#实现的MD5加密算法，可以广泛用在用户密码，身份验证上面。

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
namespace yunfly
{
    /// <summary>
    /// MD5 的摘要说明
    /// </summary>
    public class MD5
    {
        public MD5()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }

        public static string GetMD5(string input,int n)
        {
            System.Security.Cryptography.MD5CryptoServiceProvider m = new System.Security.Cryptography.MD5CryptoServiceProvider();

            byte[] data = m.ComputeHash(System.Text.Encoding.Default.GetBytes(input));

            System.Text.StringBuilder sb = new System.Text.StringBuilder();          

            switch (n)
            {
                case 16:
                    {
                        for (int i = 4; i <= 11; i++)
                            sb.Append(data[i].ToString("x2"));
                        break;
                    }
                case 32:
                    {
                        for (int i = 0; i <= 15; i++)
                            sb.Append(data[i].ToString("x2"));
                        break;
                    }
                default:
                    {
                        for (int i = 4; i <= 11; i++)
                            sb.Append(data[i].ToString("x2"));
                        break;
                    }
            }

            return sb.ToString();
        }
    }

}