C # folder Encryption

You can encrypt the contents of the file or encrypt the folder itself, and this article encrypts the folder.

One, specify or generate a key

1) The specified key

/// <summary> ///  //</summary>publicstaticstring"? \a?? (? ";

2) You can also generate a key

/// <summary>///generate a 64-bit key/// </summary>/// <returns>string</returns> Public Static stringGenerateKey () {//creates an instance of a symmetric algorithm. Auto-generated keys and IV. DESCryptoServiceProvider Descrypto =(DESCryptoServiceProvider) descryptoserviceprovider.create (); //encrypted using an auto-generated key.     returnASCIIEncoding.ASCII.GetString (Descrypto.key);}

Second, call the ZeroMemory function to remove the key from memory

<summary> //// Call this function to remove the key from memory using //</summary>[DllImport ("  KERNEL32. DLL""rtlzeromemory")]publicstatic extern BOOL int Length);

Third, encrypt files

/// <summary>        ///Encrypting Files/// </summary>        /// <param name= "sInputFilename" >the full path of the file to be encrypted</param>        /// <param name= "sOutputFileName" >The full path of the encrypted file</param>         Public Static voidEncryptFile (stringsInputFilename,stringsOutputFileName) {FileStream fsinput=NewFileStream (sInputFilename, FileMode.Open, FileAccess.Read); FileStream fsencrypted=NewFileStream (sOutputFileName, FileMode.Create, FileAccess.Write); DESCryptoServiceProvider DES=NewDESCryptoServiceProvider (); Des. Key=ASCIIEncoding.ASCII.GetBytes (sSecretKey); Des.iv=ASCIIEncoding.ASCII.GetBytes (sSecretKey); ICryptoTransform desencrypt=DES.            CreateEncryptor (); CryptoStream CryptoStream=NewCryptoStream (fsencrypted, desencrypt, CryptoStreamMode.Write); byte[] bytearrayinput =New byte[fsInput.Length]; fsInput.Read (Bytearrayinput,0, bytearrayinput.            Length); CryptoStream. Write (Bytearrayinput,0, bytearrayinput.            Length); CryptoStream.            Flush ();            Fsinput.flush ();            Fsencrypted.flush (); CryptoStream.            Close ();            Fsinput.close ();        Fsencrypted.close (); }

Iv. Decryption of files

/// <summary>        ///Decrypt Files/// </summary>        /// <param name= "sInputFilename" >The full path of the file to be decrypted</param>        /// <param name= "sOutputFileName" >The full path of the decrypted file</param>         Public Static voidDecryptFile (stringsInputFilename,stringsOutputFileName) {DESCryptoServiceProvider DES=NewDESCryptoServiceProvider (); Des. Key=ASCIIEncoding.ASCII.GetBytes (sSecretKey); Des.iv=ASCIIEncoding.ASCII.GetBytes (sSecretKey); FileStream Fsread=NewFileStream (sInputFilename, FileMode.Open, FileAccess.Read); ICryptoTransform Desdecrypt=DES.            CreateDecryptor (); CryptoStream CRYPTOSTREAMDECR=NewCryptoStream (fsread, Desdecrypt, CryptoStreamMode.Read); StreamWriter fsdecrypted=NewStreamWriter (sOutputFileName); Fsdecrypted.write (NewStreamReader (CRYPTOSTREAMDECR).            ReadToEnd ());            Fsdecrypted.flush ();        Fsdecrypted.close (); }

Five, complete code

/// <summary>    ///file Encryption/// </summary>     Public classFilesecrethelper {/// <summary>        ///Key , this password can be arbitrarily specified/// </summary>         Public Static stringsSecretKey ="? \a?? (?"; /// <summary>        ///Call this function to remove the key from memory using/// </summary>[DllImport ("KERNEL32. DLL", EntryPoint ="RtlZeroMemory")]         Public Static extern BOOLZeroMemory (IntPtr Destination,intLength); /// <summary>        ///generate a 64-bit key/// </summary>        /// <returns>string</returns>         Public Static stringGenerateKey () {//creates an instance of a symmetric algorithm. Auto-generated keys and IV. DESCryptoServiceProvider Descrypto =(DESCryptoServiceProvider) descryptoserviceprovider.create (); //encrypted using an auto-generated key.             returnASCIIEncoding.ASCII.GetString (Descrypto.key); }        /// <summary>        ///Encrypting Files/// </summary>        /// <param name= "sInputFilename" >the full path of the file to be encrypted</param>        /// <param name= "sOutputFileName" >The full path of the encrypted file</param>         Public Static voidEncryptFile (stringsInputFilename,stringsOutputFileName) {FileStream fsinput=NewFileStream (sInputFilename, FileMode.Open, FileAccess.Read); FileStream fsencrypted=NewFileStream (sOutputFileName, FileMode.Create, FileAccess.Write); DESCryptoServiceProvider DES=NewDESCryptoServiceProvider (); Des. Key=ASCIIEncoding.ASCII.GetBytes (sSecretKey); Des.iv=ASCIIEncoding.ASCII.GetBytes (sSecretKey); ICryptoTransform desencrypt=DES.            CreateEncryptor (); CryptoStream CryptoStream=NewCryptoStream (fsencrypted, desencrypt, CryptoStreamMode.Write); byte[] bytearrayinput =New byte[fsInput.Length]; fsInput.Read (Bytearrayinput,0, bytearrayinput.            Length); CryptoStream. Write (Bytearrayinput,0, bytearrayinput.            Length); CryptoStream.            Flush ();            Fsinput.flush ();            Fsencrypted.flush (); CryptoStream.            Close ();            Fsinput.close ();        Fsencrypted.close (); }        /// <summary>        ///Decrypt Files/// </summary>        /// <param name= "sInputFilename" >The full path of the file to be decrypted</param>        /// <param name= "sOutputFileName" >The full path of the decrypted file</param>         Public Static voidDecryptFile (stringsInputFilename,stringsOutputFileName) {DESCryptoServiceProvider DES=NewDESCryptoServiceProvider (); Des. Key=ASCIIEncoding.ASCII.GetBytes (sSecretKey); Des.iv=ASCIIEncoding.ASCII.GetBytes (sSecretKey); FileStream Fsread=NewFileStream (sInputFilename, FileMode.Open, FileAccess.Read); ICryptoTransform Desdecrypt=DES.            CreateDecryptor (); CryptoStream CRYPTOSTREAMDECR=NewCryptoStream (fsread, Desdecrypt, CryptoStreamMode.Read); StreamWriter fsdecrypted=NewStreamWriter (sOutputFileName); Fsdecrypted.write (NewStreamReader (CRYPTOSTREAMDECR).            ReadToEnd ());            Fsdecrypted.flush ();        Fsdecrypted.close (); }    }

C # folder Encryption