一.使用16位、32位、64位MD5方法对用户名加密
1)16位的MD5加密
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/// <summary> /// 16位MD5加密 /// </summary> /// <param name="password"></param> /// <returns></returns> public static string MD5Encrypt16( string password)
{ var md5 = new MD5CryptoServiceProvider();
string t2 = BitConverter.ToString(md5.ComputeHash(Encoding.Default.GetBytes(password)), 4, 8);
t2 = t2.Replace( "-" , "" );
return t2;
} |
2)32位的MD5加密
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/// <summary> /// 32位MD5加密 /// </summary> /// <param name="password"></param> /// <returns></returns> public static string MD5Encrypt32( string password)
{ string cl = password;
string pwd = "" ;
MD5 md5 = MD5.Create(); //实例化一个md5对像
// 加密后是一个字节类型的数组,这里要注意编码UTF8/Unicode等的选择
byte [] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));
// 通过使用循环,将字节类型的数组转换为字符串,此字符串是常规字符格式化所得
for ( int i = 0; i < s.Length; i++)
{
// 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母,如果使用大写(X)则格式后的字符是大写字符
pwd = pwd + s[i].ToString( "X" );
}
return pwd;
} |
3)64位的MD5加密
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public static string MD5Encrypt64( string password)
{ string cl = password;
//string pwd = "";
MD5 md5 = MD5.Create(); //实例化一个md5对像
// 加密后是一个字节类型的数组,这里要注意编码UTF8/Unicode等的选择
byte [] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));
return Convert.ToBase64String(s);
} |
4)使用MD5为用户密码加密
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/// <summary> /// 加密用户密码 /// </summary> /// <param name="password">密码</param> /// <param name="codeLength">加密位数</param> /// <returns>加密密码</returns> public static string md5( string password, int codeLength)
{ if (! string .IsNullOrEmpty(password))
{
// 16位MD5加密(取32位加密的9~25字符)
if (codeLength == 16)
{
return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(password, "MD5" ).ToLower().Substring(8, 16);
}
// 32位加密
if (codeLength == 32)
{
return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(password, "MD5" ).ToLower();
}
}
return string .Empty;
} |
由于MD5是不可逆的,所以加密之后就无法解密,取用户名和密码时候,需要再加密一边用户输入的数据与数据库中已加密的数据进行比对。如果比对结果一致,则可以判定登陆成功!代码如下所示:
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/// <summary> /// 登陆 /// </summary> public Model.UserInfo UserLogOn( string USERID, string pwd, out string statusCode)
{ //假设已经通过用户ID获取到UserInfo的Model对象
Model.UserInfo model = GetModel(USERID);
if (model != null )
{
if (model.PASSWORD == MD5Encrypt64(pwd))
{
statusCode = "登陆成功" ;
}
else {
statusCode = “密码错误”;
}
}
else
{
statusCode = "用户不存在!" ;
model = null ;
}
return model;
} |
5)通过DESCryptoServiceProvider对象对字符串进行加密解密
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/// <summary> /// DES数据加密 /// </summary> /// <param name="targetValue">目标值</param> /// <param name="key">密钥</param> /// <returns>加密值</returns> public static string Encrypt( string targetValue, string key)
{ if ( string .IsNullOrEmpty(targetValue))
{
return string .Empty;
}
var returnValue = new StringBuilder();
var des = new DESCryptoServiceProvider();
byte [] inputByteArray = Encoding.Default.GetBytes(targetValue);
// 通过两次哈希密码设置对称算法的初始化向量
des.Key = Encoding.ASCII.GetBytes(FormsAuthentication.HashPasswordForStoringInConfigFile
(FormsAuthentication.HashPasswordForStoringInConfigFile(key, "md5" ).
Substring(0, 8), "sha1" ).Substring(0, 8));
// 通过两次哈希密码设置算法的机密密钥
des.IV = Encoding.ASCII.GetBytes(FormsAuthentication.HashPasswordForStoringInConfigFile
(FormsAuthentication.HashPasswordForStoringInConfigFile(key, "md5" )
.Substring(0, 8), "md5" ).Substring(0, 8));
var ms = new MemoryStream();
var cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
foreach ( byte b in ms.ToArray())
{
returnValue.AppendFormat( "{0:X2}" , b);
}
return returnValue.ToString();
} |
此种算法可以通过加密密钥进行解密,解密方法如下:
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/// <summary> /// DES数据解密 /// </summary> /// <param name="targetValue"></param> /// <param name="key"></param> /// <returns></returns> public static string Decrypt( string targetValue, string key)
{ if ( string .IsNullOrEmpty(targetValue))
{
return string .Empty;
}
// 定义DES加密对象
var des = new DESCryptoServiceProvider();
int len = targetValue.Length / 2;
var inputByteArray = new byte [len];
int x, i;
for (x = 0; x < len; x++)
{
i = Convert.ToInt32(targetValue.Substring(x * 2, 2), 16);
inputByteArray[x] = ( byte )i;
}
// 通过两次哈希密码设置对称算法的初始化向量
des.Key = Encoding.ASCII.GetBytes(FormsAuthentication.HashPasswordForStoringInConfigFile
(FormsAuthentication.HashPasswordForStoringInConfigFile(key, "md5" ).
Substring(0, 8), "sha1" ).Substring(0, 8));
// 通过两次哈希密码设置算法的机密密钥
des.IV = Encoding.ASCII.GetBytes(FormsAuthentication.HashPasswordForStoringInConfigFile
(FormsAuthentication.HashPasswordForStoringInConfigFile(key, "md5" )
.Substring(0, 8), "md5" ).Substring(0, 8));
// 定义内存流
var ms = new MemoryStream();
// 定义加密流
var cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
return Encoding.Default.GetString(ms.ToArray());
} |
以上内容是基于C#对用户密码使用MD5加密与解密的全部叙述,希望大家喜欢。