.NET提供了安全支持,不用自己写MD5算法.
byte[] data = new byte[DATA_SIZE];// This is one implementation of the abstract class MD5.
MD5 md5 = new MD5CryptoServiceProvider();byte[] result = md5.ComputeHash(data);这样就可以了.
byte[] data = new byte[DATA_SIZE];// This is one implementation of the abstract class MD5.
MD5 md5 = new MD5CryptoServiceProvider();byte[] result = md5.ComputeHash(data);这样就可以了.
{
MD5 md5 = new MD5CryptoServiceProvider();
byte[] result = md5.ComputeHash(System.Text.Encoding.Default.GetBytes(strText));
return System.Text.Encoding.Default.GetString(result);
}
public string DesEncrypt(string strText, string strEncrKey)
//解密字符串,注意strEncrKey的长度为8位(如果要增加或者减少key长度,调整IV的长度就是了) public string DesDecrypt(string strText,string sDecrKey) //加密数据文件,注意strEncrKey的长度为8位(如果要增加或者减少key长度,调整IV的长度就是了) public void DesEncrypt(string m_InFilePath,string m_OutFilePath,string strEncrKey) //解密数据文件,注意strEncrKey的长度为8位(如果要增加或者减少key长度,调整IV的长度就是了) public void DesDecrypt(string m_InFilePath,string m_OutFilePath,string sDecrKey) //MD5加密 public string MD5Encrypt(string strText) */
/******************************************************************************************
* Cryptography class is for Cryptography
author:Jim
e_mail:[email protected]
* thanks:
* URI:
*
*
*****************************************************************************************/
using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;
using System.Windows.Forms ; namespace Netbee.Classes.Security
{
/// <summary>
///Cryptography
/// </summary>
public class Cryptography
{
public Cryptography()
{ }
/// <summary>
/// Encrypt the string
/// Attention:key must be 8 bits
/// </summary>
/// <param name="strText">string</param>
/// <param name="strEncrKey">key</param>
/// <returns></returns>
public string DesEncrypt(string strText, string strEncrKey)
{
byte[] byKey=null;
byte[] IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
try
{
byKey = System.Text.Encoding.UTF8.GetBytes(strEncrKey.Substring(0,8));
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
byte[] inputByteArray = Encoding.UTF8.GetBytes(strText);
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write) ;
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
return Convert.ToBase64String(ms.ToArray());
}
catch(System.Exception error)
{
MessageBox.Show(error.Message);
return "error:" +error.Message+"\r";
}
}
/// <summary>
/// Decrypt string
/// Attention:key must be 8 bits
/// </summary>
/// <param name="strText">Decrypt string</param>
/// <param name="sDecrKey">key</param>
/// <returns>output string</returns>
public string DesDecrypt(string strText,string sDecrKey)
{
byte[] byKey = null;
byte[] IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
byte[] inputByteArray = new Byte[strText.Length];
try
{
byKey = System.Text.Encoding.UTF8.GetBytes(sDecrKey.Substring(0,8));
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
inputByteArray = Convert.FromBase64String(strText);
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
System.Text.Encoding encoding = new System.Text.UTF8Encoding();
return encoding.GetString(ms.ToArray());
}
catch(System.Exception error)
{
MessageBox.Show(error.Message);
return "error:"+error.Message+"\r";
}
}
/// <summary>
/// Encrypt files
/// Attention:key must be 8 bits
/// </summary>
/// <param name="m_InFilePath">Encrypt file path</param>
/// <param name="m_OutFilePath">output file</param>
/// <param name="strEncrKey">key</param>
public void DesEncrypt(string m_InFilePath,string m_OutFilePath,string strEncrKey)
{
byte[] byKey=null;
byte[] IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
try
{
byKey = System.Text.Encoding.UTF8.GetBytes(strEncrKey.Substring(0,8));
FileStream fin = new FileStream(m_InFilePath, FileMode.Open, FileAccess.Read);
FileStream fout = new FileStream(m_OutFilePath, FileMode.OpenOrCreate, FileAccess.Write);
fout.SetLength(0);
//Create variables to help with read and write.
byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
long rdlen = 0; //This is the total number of bytes written.
long totlen = fin.Length; //This is the total length of the input file.
int len; //This is the number of bytes to be written at a time. DES des = new DESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write);
//Read from the input file, then encrypt and write to the output file.
while(rdlen < totlen)
{
len = fin.Read(bin, 0, 100);
encStream.Write(bin, 0, len);
rdlen = rdlen + len;
} encStream.Close();
fout.Close();
fin.Close();
}
catch(System.Exception error)
{
MessageBox.Show(error.Message.ToString()); }
}
/// <summary>
/// Decrypt files
/// Attention:key must be 8 bits
/// </summary>
/// <param name="m_InFilePath">Decrypt filepath</param>
/// <param name="m_OutFilePath">output filepath</param>
/// <param name="sDecrKey">key</param>
public void DesDecrypt(string m_InFilePath,string m_OutFilePath,string sDecrKey)
{
byte[] byKey = null;
byte[] IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
try
{
byKey = System.Text.Encoding.UTF8.GetBytes(sDecrKey.Substring(0,8));
FileStream fin = new FileStream(m_InFilePath, FileMode.Open, FileAccess.Read);
FileStream fout = new FileStream(m_OutFilePath, FileMode.OpenOrCreate, FileAccess.Write);
fout.SetLength(0);
//Create variables to help with read and write.
byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
long rdlen = 0; //This is the total number of bytes written.
long totlen = fin.Length; //This is the total length of the input file.
int len; //This is the number of bytes to be written at a time. DES des = new DESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write);
//Read from the input file, then encrypt and write to the output file.
while(rdlen < totlen)
{
len = fin.Read(bin, 0, 100);
encStream.Write(bin, 0, len);
rdlen = rdlen + len;
} encStream.Close();
fout.Close();
fin.Close(); }
catch(System.Exception error)
{
MessageBox.Show( "error:"+error.Message);
}
}
/// <summary>
/// MD5 Encrypt
/// </summary>
/// <param name="strText">text</param>
/// <returns>md5 Encrypt string</returns>
public 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);
}
}
}
主要是把字符串變成一串的數字,后又解譯回來前面幾位都已提供了例子了
樓主可以在google找一下就知
打个简单比方.
我上传了一个50m的文件.
上传后我把它的内容用MD5算出来.
如果生成的长字符串和没上传前生成的一样.
表明这个文件上传过程中内容一个字节也没出现错误.
我这里有一个用C++做的的验证程序.
但是我想知道用C#怎么实现.
用STREAM取得这个文件流.把内容用MD5算一次.
生成的长字符串就是了.
MD5只能加密不能解密。不可能会再解译回来的。
要是能解译回来那就不是MD5了。
MD5应该是哈希的,是单向的,不能够恢复的吧?
----------------MD5 是单向的,楼主用它不是用来加密,是想生成一个 文件 的内容摘要,一旦文件发生任何更改 再计算出来的MD5 就和以前的不一样了,就能发现文件被人窜改过。我也想用这个给些视频文件(几G大小一个 :( )算MD5 , 可是不知如何实现。在网上倒是发现勒一个老外用C# 写的一个叫winmd5 的小程序,很好用算个6xxM的 iso 就十来秒,可惜不知到是如何实现的。 期待高手ing..............................
http://expert.csdn.net/Expert/TopicView1.asp?id=2645415讨论的是RSA,不过用MD5的话方法也应该是比较类似的。具体的例子嘛,你可以参见IDE里面按Alt-H、I,然后将下面一行的文字粘贴到那个输入框里面:
MD5CryptoServiceProvider 类, 示例如果有什么问题再来问。
注意命名空间.System.IO.FileStream filestream=new FileStream("e:\\temp\\temp.iso",FileMode.Open,FileAccess.Read);
MD5 md5 = new MD5CryptoServiceProvider();
byte[] result = md5.ComputeHash(filestream);
string bs1="";
for(int a=0;a<result.Length;a++)
{
bs1+=result[a].ToString("X2");
}
this.Text=bs1;