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DESCryptoServiceProvider.CreateEncryptor Method (Byte[], Byte[])

Creates a symmetric Data Encryption Standard (DES) encryptor object with the specified key (Key) and initialization vector (IV).

Namespace: System.Security.Cryptography
Assembly: mscorlib (in mscorlib.dll)

public override ICryptoTransform CreateEncryptor (
	byte[] rgbKey,
	byte[] rgbIV
)
public ICryptoTransform CreateEncryptor (
	byte[] rgbKey, 
	byte[] rgbIV
)
public override function CreateEncryptor (
	rgbKey : byte[], 
	rgbIV : byte[]
) : ICryptoTransform
Not applicable.

Parameters

rgbKey

The secret key to use for the symmetric algorithm.

rgbIV

The initialization vector to use for the symmetric algorithm.

Return Value

A symmetric DES encryptor object.

Exception typeCondition

CryptographicException

The value of the Mode property is OFB.

-or-

The value of the Mode property is CFB and the value of the FeedbackSize property is not 8.

-or-

An invalid key size was used.

-or-

The algorithm key size was not available.

Use the CreateDecryptor overload with the same parameters to decrypt the result of this method.

The following code example shows how to create and use a DESCryptoServiceProvider object to encrypt and decrypt data in a file.

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class DESCSPSample
{

    static void Main()
    {
        try
        {
            // Create a new DESCryptoServiceProvider object
            // to generate a key and initialization vector (IV).
            DESCryptoServiceProvider DESalg = new DESCryptoServiceProvider();

            // Create a string to encrypt.
            string sData = "Here is some data to encrypt.";
            string FileName = "CText.txt";

            // Encrypt text to a file using the file name, key, and IV.
            EncryptTextToFile(sData, FileName, DESalg.Key, DESalg.IV);

            // Decrypt the text from a file using the file name, key, and IV.
            string Final = DecryptTextFromFile(FileName, DESalg.Key, DESalg.IV);
            
            // Display the decrypted string to the console.
            Console.WriteLine(Final);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
       
    }

    public static void EncryptTextToFile(String Data, String FileName, byte[] Key, byte[] IV)
    {
        try
        {
            // Create or open the specified file.
            FileStream fStream = File.Open(FileName,FileMode.OpenOrCreate);

            // Create a CryptoStream using the FileStream 
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(fStream, 
                new DESCryptoServiceProvider().CreateEncryptor(Key,IV), 
                CryptoStreamMode.Write); 

            // Create a StreamWriter using the CryptoStream.
            StreamWriter sWriter = new StreamWriter(cStream);

            // Write the data to the stream 
            // to encrypt it.
            sWriter.WriteLine(Data);
  
            // Close the streams and
            // close the file.
            sWriter.Close();
            cStream.Close();
            fStream.Close();
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
        }
        catch(UnauthorizedAccessException  e)
        {
            Console.WriteLine("A file error occurred: {0}", e.Message);
        }

    }

    public static string DecryptTextFromFile(String FileName, byte[] Key, byte[] IV)
    {
        try
        {
            // Create or open the specified file. 
            FileStream fStream = File.Open(FileName, FileMode.OpenOrCreate);
  
            // Create a CryptoStream using the FileStream 
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(fStream, 
                new DESCryptoServiceProvider().CreateDecryptor(Key,IV), 
                CryptoStreamMode.Read); 

            // Create a StreamReader using the CryptoStream.
            StreamReader sReader = new StreamReader(cStream);

            // Read the data from the stream 
            // to decrypt it.
            string val = sReader.ReadLine();
    
            // Close the streams and
            // close the file.
            sReader.Close();
            cStream.Close();
            fStream.Close();

            // Return the string. 
            return val;
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }
        catch(UnauthorizedAccessException  e)
        {
            Console.WriteLine("A file error occurred: {0}", e.Message);
            return null;
        }
    }
}

import System.*;
import System.Security.Cryptography.*;
import System.Text.*;
import System.IO.*;

class DESCSPSample
{
    public static void main(String[] args)
    {
        try {
            // Create a new DESCryptoServiceProvider object
            // to generate a key and initialization vector (iv).
            DESCryptoServiceProvider desAlg = new DESCryptoServiceProvider();

            // Create a string to encrypt.
            String sData = "Here is some data to encrypt.";
            String fileName = "CText.txt";

            // Encrypt text to a file using the file name, key, and iv.
            EncryptTextToFile(sData, fileName, desAlg.get_Key(), desAlg.get_IV());

            // Decrypt the text from a file using the file name, key, and iv.
            String strFinal = DecryptTextFromFile(fileName, desAlg.get_Key(), 
                desAlg.get_IV());

            // Display the decrypted string to the console.
            Console.WriteLine(strFinal);
        }
        catch (System.Exception e) {
            Console.WriteLine(e.get_Message());
        }
    } //main

    public static void EncryptTextToFile(String desAlg, String fileName, 
        ubyte key[], ubyte iv[])
    {
        try {
            // Create or open the specified file.
            FileStream fStream = File.Open(fileName, FileMode.OpenOrCreate);

            // Create a CryptoStream using the FileStream 
            // and the passed key and initialization vector (iv).
            CryptoStream cStream = new CryptoStream(fStream, 
                (new DESCryptoServiceProvider()).CreateEncryptor(key, iv), 
                CryptoStreamMode.Write);

            // Create a StreamWriter using the CryptoStream.
            StreamWriter sWriter = new StreamWriter(cStream);

            // Write the data to the stream 
            // to encrypt it.
            sWriter.WriteLine(desAlg);

            // Close the streams and
            // close the file.
            sWriter.Close();
            cStream.Close();
            fStream.Close();
        }
        catch (CryptographicException e) {
            Console.WriteLine("A Cryptographic error occurred: {0}", 
                e.get_Message());
        }
        catch (UnauthorizedAccessException e) {
            Console.WriteLine("A file error occurred: {0}", 
                e.get_Message());
        }
    } //EncryptTextToFile

    public static String DecryptTextFromFile(String fileName, ubyte key[], 
        ubyte iv[])
    {
        try {
            // Create or open the specified file. 
            FileStream fStream = File.Open(fileName, FileMode.OpenOrCreate);

            // Create a CryptoStream using the FileStream 
            // and the passed key and initialization vector (iv).
            CryptoStream cStream = new CryptoStream(fStream, 
                (new DESCryptoServiceProvider()).CreateDecryptor(key, iv), 
                CryptoStreamMode.Read);

            // Create a StreamReader using the CryptoStream.
            StreamReader sReader = new StreamReader(cStream);

            // Read the data from the stream 
            // to decrypt it.
            String val = sReader.ReadLine();

            // Close the streams and
            // close the file.
            sReader.Close();
            cStream.Close();
            fStream.Close();

            // Return the string. 
            return val;
        }
        catch (CryptographicException e) {
            Console.WriteLine("A Cryptographic error occurred: {0}", 
                e.get_Message());
            return null;
        }
        catch (UnauthorizedAccessException e) {
            Console.WriteLine("A file error occurred: {0}", 
                e.get_Message());
            return null;
        }
    } //DecryptTextFromFile
} //DESCSPSample

The following code example shows how to create and use a DESCryptoServiceProvider object to encrypt and decrypt data in memory.

using System;
using System.Security.Cryptography;
using System.Text;
using System.IO;

class DESCSPSample
{
    static void Main()
    {
        try
        {
            // Create a new DESCryptoServiceProvider object
            // to generate a key and initialization vector (IV).
            DESCryptoServiceProvider DESalg = new DESCryptoServiceProvider();

            // Create a string to encrypt.
            string sData = "Here is some data to encrypt.";

            // Encrypt the string to an in-memory buffer.
            byte[] Data = EncryptTextToMemory(sData, DESalg.Key, DESalg.IV);

            // Decrypt the buffer back to a string.
            string Final = DecryptTextFromMemory(Data, DESalg.Key, DESalg.IV);
            
            // Display the decrypted string to the console.
            Console.WriteLine(Final);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
       
    }

    public static byte[] EncryptTextToMemory(string Data,  byte[] Key, byte[] IV)
    {
        try
        {
            // Create a MemoryStream.
            MemoryStream mStream = new MemoryStream();

            // Create a CryptoStream using the MemoryStream 
            // and the passed key and initialization vector (IV).
            CryptoStream cStream = new CryptoStream(mStream, 
                new DESCryptoServiceProvider().CreateEncryptor(Key, IV), 
                CryptoStreamMode.Write);

            // Convert the passed string to a byte array.
            byte[] toEncrypt = new ASCIIEncoding().GetBytes(Data);

            // Write the byte array to the crypto stream and flush it.
            cStream.Write(toEncrypt, 0, toEncrypt.Length);
            cStream.FlushFinalBlock();
        
            // Get an array of bytes from the 
            // MemoryStream that holds the 
            // encrypted data.
            byte[] ret = mStream.ToArray();

            // Close the streams.
            cStream.Close();
            mStream.Close();

            // Return the encrypted buffer.
            return ret;
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }

    }

    public static string DecryptTextFromMemory(byte[] Data,  byte[] Key, byte[] IV)
    {
        try
        {
            // Create a new MemoryStream using the passed 
            // array of encrypted data.
            MemoryStream msDecrypt = new MemoryStream(Data);

            // Create a CryptoStream using the MemoryStream 
            // and the passed key and initialization vector (IV).
            CryptoStream csDecrypt = new CryptoStream(msDecrypt, 
                new DESCryptoServiceProvider().CreateDecryptor(Key, IV), 
                CryptoStreamMode.Read);

            // Create buffer to hold the decrypted data.
            byte[] fromEncrypt = new byte[Data.Length];

            // Read the decrypted data out of the crypto stream
            // and place it into the temporary buffer.
            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);

            //Convert the buffer into a string and return it.
            return new ASCIIEncoding().GetString(fromEncrypt);
        }
        catch(CryptographicException e)
        {
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message);
            return null;
        }
    }
}

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0

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