首先,先簡單介紹一下MD5
MD5的全稱是message-digest algorithm 5(信息-摘要算法，在90年代初由mit laboratory for computer science和rsa data security inc的ronald l. rivest開發出來， 經md2、md3和md4發展而來。
MD5具有很好的安全性(因爲它具有不可逆的特徵,加過密的密文經過解密後和加密前的東東相同的可能性極小)
引用
using System.Security.Cryptography;
using System.Text;
具體代碼如下(寫在按鈕的Click事件裏):
byte[] result = Encoding.Default.GetBytes(this.tbPass.Text.Trim()); //tbPass爲輸入密碼的文本框
MD5 md5 = new MD5CryptoServiceProvider();
byte[] output = md5.ComputeHash(result);
this.tbMd5pass.Text = BitConverter.ToString(output).Replace("-",""); //tbMd5pass爲輸出加密文本的文本框
方法二
C# md5加密（上）
string a; //加密前數據
string b; //加密後數據
b=System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(a,"MD5")
using System;
using System.Security.Cryptography;
方法2
public static string GetMD5(string myString)
{
MD5 md5 = new MD5CryptoServiceProvider();
byte[] fromData = System.Text.Encoding.Unicode.GetBytes(myString);
byte[] targetData = md5.ComputeHash(fromData);
string byte2String = null;
for (int i=0; i<targetData.Length; i++)
{
byte2String += targetData[i].ToString("x");
}
return byte2String;
}
using System.Security.Cryptography;
/// <summary>
/// 給一個字符串進行MD5加密
/// </summary>
/// <param name="strText">待加密字符串</param>
/// <returns>加密後的字符串</returns>
public static string MD5Encrypt(string strText)
{
MD5 md5 = new MD5CryptoServiceProvider();
byte[] result = md5.ComputeHash(System.Text.Encoding.Default.GetBytes(strText));
return System.Text.Encoding.Default.GetString(result);
}
C# MD5加密
using System.Security.Cryptography;
private void btnOK_Click(object sender, System.EventArgs e)
{
string strConn = "server=192.168.0.51;database=chengheng;User id=sa; password=123";
if(texName.Text.Trim()=="")
{
this.RegisterStartupScript("sf","<script language='javascript'>alert('用戶名不能爲空');document.all('texName').focus()</script>");
return;
}
else if(texPassword.Text.Trim()=="")
{
this.RegisterStartupScript("sfs","<script language='javascript'>alert('密碼不能爲空');document.all('texPassword').focus()</script>");
return;
}
else
{
//將獲取的密碼加密與數據庫中加了密的密碼相比較
byte[] by = md5.ComputeHash(utf.GetBytes(texPassword.Text.Trim()));
string resultPass = System.Text.UTF8Encoding.Unicode.GetString(by);
conn.ConnectionString=strConn;
SqlCommand comm = new SqlCommand();
string name = texName.Text.Trim().ToString();
comm.CommandText="select Ruser_pwd,Ruser_nm from Ruser where Accountno = @name";
comm.Parameters.Add("@name",SqlDbType.NVarChar,40);
comm.Parameters["@name"].Value=name;
try
{
conn.Open();
comm.Connection=conn;
SqlDataReader dr=comm.ExecuteReader();
if(dr.Read())
{
//用戶存在，對密碼進行檢查
if(dr.GetValue(0).Equals(resultPass))
{
string user_name=dr.GetValue(1).ToString();
string user_Accountno=texName.Text.Trim();
Session["logon_name"]=user_name;
Session["logon_Accountno"]=user_Accountno;
//登錄成功，進行頁面導向
}
else
{
this.RegisterStartupScript("wp","<script language='javascript'>alert('密碼錯誤，請檢查。')</script>");
}
}
else
{
this.RegisterStartupScript("nu","<script language=javascript>alert('用戶名不存在，請檢查。')</script>");
}
}
catch(Exception exec)
{
this.RegisterStartupScript("wc","<script language=javascript>alert('網絡連接有異，請稍後重試。')</script>");
}
finally
{
conn.Close();
}
}
}
方法三
C# MD5加密
C#開發筆記 一、C# MD5-16位加密實例,32位加密實例(兩種方法)
環境：vs.net2005/sql server2000/xp測試通過
1.MD5 16位加密實例
using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;
namespace md5
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine(UserMd5("8"));
Console.WriteLine(GetMd5Str("8"));
}
/**//// <summary>
/// MD5 16位加密 加密後密碼爲大寫
/// </summary>
/// <param name="ConvertString"></param>
/// <returns></returns>
public static string GetMd5Str(string ConvertString)
{
MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);
t2 = t2.Replace("-", "");
return t2;
}
/**//// <summary>
/// MD5 16位加密 加密後密碼爲小寫
/// </summary>
/// <param name="ConvertString"></param>
/// <returns></returns>
public static string GetMd5Str(string ConvertString)
{
MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);
t2 = t2.Replace("-", "");
t2 = t2.ToLower();
return t2;
}
/**//// <summary>
/// MD5 32位加密
/// </summary>
/// <param name="str"></param>
/// <returns></returns>
static string UserMd5(string str)
{
string cl = str;
string pwd = "";
MD5 md5 = MD5.Create();//實例化一個md5對像
// 加密後是一個字節類型的數組，這裏要注意編碼UTF8/Unicode等的選擇
byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));
// 通過使用循環，將字節類型的數組轉換爲字符串，此字符串是常規字符格式化所得
for (int i = 0; i < s.Length; i++)
{
// 將得到的字符串使用十六進制類型格式。格式後的字符是小寫的字母，如果使用大寫（X）則格式後的字符是大寫字符
pwd = pwd + s[i].ToString("X");
}
return pwd;
}
}
}
using System.Security.Cryptography;
using System.Text;
public static string StringToMD5Hash(string inputString)
{
MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
byte[] encryptedBytes = md5.ComputeHash(Encoding.ASCII.GetBytes(inputString));
StringBuilder sb = new StringBuilder();
for (int i = 0; i < encryptedBytes.Length; i++)
{
sb.AppendFormat("{0:x2}", encryptedBytes[i]);
}
return sb.ToString();
}