C#如何對任何文件加密解密

Question

http://support.microsoft.com/kb/307010/zh-cn
http://blog.csdn.net/loundar/article/details/3138058

Answer 1

我有找到這些,也有寫了測試發現對.dll,.lab的文件加密后,再解密出來的文件就無法使用了...
對.txt是沒問題...

Answer 2

解密的算法有问题吧
找个小一点的文件,1K左右的
加密之前,分析一下byte数组
解密之后,再看byte数组,看到底一致不一致

Answer 3

這樣寫的... 
   public class EncryptKit
    {
        /// <summary>   
        /// Call this function to remove the key from memory after use for security   
        /// </summary>   
        /// <param name="Destination"></param>   
        /// <param name="Length"></param>   
        /// <returns></returns>   
        [System.Runtime.InteropServices.DllImport("KERNEL32.DLL", EntryPoint = "RtlZeroMemory")]
        public static extern bool ZeroMemory(IntPtr Destination, int Length);
        /// <summary>   
        /// Function to Generate a 64 bits Key.   
        /// </summary>   
        /// <returns>返回生成的密钥</returns>   
        public static string GenerateKey()
        {
            // Create an instance of Symetric Algorithm. Key and IV is generated automatically.   
            //DESCryptoServiceProvider desCrypto = (DESCryptoServiceProvider)DESCryptoServiceProvider.Create();
            // Use the Automatically generated key for Encryption.   
            //return ASCIIEncoding.ASCII.GetString(desCrypto.Key);            byte[] key = new byte[] { 10, 20, 3, 94, 22, 90, 44, 31 };
            return ASCIIEncoding.UTF8.GetString(key);
        }
        /// <summary>   
        /// 加密文件   
        /// </summary>   
        /// <param name="sInputFilename">要加密的文件</param>   
        /// <param name="sOutputFilename">加密后保存的文件</param>   
        /// <param name="sKey">密钥</param>   
        public static void EncryptFile(string sInputFilename, string sOutputFilename, string sKey)
        {
            using (FileStream fsInput = new FileStream(sInputFilename, FileMode.Open, FileAccess.Read))
            {
                byte[] bytearrayinput = new byte[fsInput.Length];
                fsInput.Read(bytearrayinput, 0, bytearrayinput.Length);
                fsInput.Close();
                FileStream fsEncrypted = new FileStream(sOutputFilename,
                   FileMode.OpenOrCreate,
                   FileAccess.Write);
                DESCryptoServiceProvider DES = new DESCryptoServiceProvider();                DES.Key = ASCIIEncoding.UTF8.GetBytes(sKey);
                DES.IV = ASCIIEncoding.UTF8.GetBytes(sKey);                ICryptoTransform desencrypt = DES.CreateEncryptor();
                CryptoStream cryptostream = new CryptoStream(fsEncrypted, desencrypt, CryptoStreamMode.Write);
                cryptostream.Write(bytearrayinput, 0, bytearrayinput.Length);
                cryptostream.Close();
                fsEncrypted.Close();
            }
        }
        /// <summary>   
        ///    
        /// </summary>   
        /// <param name="sInputFilename">要解密的文件</param>   
        /// <param name="sOutputFilename">解决后保存的文件</param>   
        /// <param name="sKey">密钥</param>   
        public static void DecryptFile(string sInputFilename, string sOutputFilename, string sKey)
        {
            DESCryptoServiceProvider DES = new DESCryptoServiceProvider();
            //A 64 bit key and IV is required for this provider.   
            //Set secret key For DES algorithm.   
            DES.Key = ASCIIEncoding.UTF8.GetBytes(sKey);
            //Set initialization vector.   
            DES.IV = ASCIIEncoding.UTF8.GetBytes(sKey);            //Create a file stream to read the encrypted file back.   
            using (FileStream fsread = new FileStream(sInputFilename, FileMode.Open, FileAccess.Read))
            {
                //Create a DES decryptor from the DES instance.   
                ICryptoTransform desdecrypt = DES.CreateDecryptor();
                //Create crypto stream set to read and do a   
                //DES decryption transform on incoming bytes.   
                CryptoStream cryptostreamDecr = new CryptoStream(fsread, desdecrypt, CryptoStreamMode.Read);                
                //Print the contents of the decrypted file.   
                StreamWriter fsDecrypted = new StreamWriter(sOutputFilename);
                fsDecrypted.Write(new StreamReader(cryptostreamDecr).ReadToEnd());
                fsDecrypted.Flush();
                fsDecrypted.Close();
            }
        }
    }

Answer 4

我买了一套文档，其中一个word加密打不开，求高手解密！

Answer 5

利用对称算法加密和解密文件示例
//加密文件示例
 protected void Button1_Click(object sender, EventArgs e)
    {
        string myFile = TextBox1.Text;
        string myPassword = TextBox2.Text;
        string myEnFile = TextBox3.Text;
        try
        {
            byte[] myIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
            byte[] myKey = System.Text.Encoding.UTF8.GetBytes(myPassword);
            FileStream myInStream = new FileStream(myFile, FileMode.Open, FileAccess.Read);
            FileStream myOutStream = new FileStream(myEnFile, FileMode.OpenOrCreate, FileAccess.Write);
            myOutStream.SetLength(0);
            byte[] myBytes = new byte[100];
            long myInLength = 0;
            long myLength = myInStream.Length;
            DES myProvider = new DESCryptoServiceProvider();//指定DES
            CryptoStream myCryptoStream = new CryptoStream(myOutStream, myProvider.CreateEncryptor(myKey, myIV), CryptoStreamMode.Write);
            while (myInLength < myLength)
            {
                int mylen = myInStream.Read(myBytes, 0, 100);
                myCryptoStream.Write(myBytes, 0, mylen);
                myInLength += mylen;
            }//codego.net/tags/15/1/
            myCryptoStream.Close();
            myInStream.Close();
            myOutStream.Close();
            Response.Write("<script>alert('加密文件成功！');</script>");
        }
        catch (Exception ex)
        {
            Response.Write("<script>alert('" + ex.Message + "');</script>");
        }
    }
//解密示例
protected void Button1_Click(object sender, EventArgs e)
{
    string str1 = TextBox1.Text;
    string strPwd = TextBox2.Text;
    string str2 = TextBox3.Text;
    try
    {
        byte[] myIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
        byte[] myKey = System.Text.Encoding.UTF8.GetBytes(strPwd);
        FileStream myFileIn = new FileStream(str1, FileMode.Open, FileAccess.Read);
        FileStream myFileOut = new FileStream(str2, FileMode.OpenOrCreate, FileAccess.Write);
        myFileOut.SetLength(0);
        byte[] myBytes = new byte[100];
        long myLength = myFileIn.Length;
        long myInLength = 0;
        DES myProvider = new DESCryptoServiceProvider();
        CryptoStream myDeStream = new CryptoStream(myFileOut, myProvider.CreateDecryptor(myKey, myIV), CryptoStreamMode.Write);
        while (myInLength < myLength)
        {
            int mylen = myFileIn.Read(myBytes, 0, 100);
            myDeStream.Write(myBytes, 0, mylen);
            myInLength += mylen;
        }
        myDeStream.Close();
        myFileOut.Close();
        myFileIn.Close();
        Response.Write("<script>alert('解密文件成功！');</script>");
    }
    catch (Exception ex)
    {
        Response.Write("<script>alert('" + ex.Message + "');</script>");
    }