DESCryptoServiceProvider.CreateEncryptor Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Creates a symmetric encryptor object.
Overloads
| CreateEncryptor() |
Creates a symmetric encryptor object with the current Key property and initialization vector (IV). |
| CreateEncryptor(Byte[], Byte[]) |
Creates a symmetric Data Encryption Standard (DES) encryptor object with the specified key (Key) and initialization vector (IV). |
CreateEncryptor()
public:
override System::Security::Cryptography::ICryptoTransform ^ CreateEncryptor();public override System.Security.Cryptography.ICryptoTransform CreateEncryptor();override this.CreateEncryptor : unit -> System.Security.Cryptography.ICryptoTransformPublic Overrides Function CreateEncryptor () As ICryptoTransformReturns
A symmetric encryptor object.
Remarks
If the current Key property is null, the GenerateKey method is called to create a new random Key. If the current IV property is null, the GenerateIV method is called to create a new random IV.
Use the CreateDecryptor overload with the same signature to decrypt the result of this method.
Applies to
CreateEncryptor(Byte[], Byte[])
public:
override System::Security::Cryptography::ICryptoTransform ^ CreateEncryptor(cli::array <System::Byte> ^ rgbKey, cli::array <System::Byte> ^ rgbIV);public override System.Security.Cryptography.ICryptoTransform CreateEncryptor(byte[] rgbKey, byte[]? rgbIV);public override System.Security.Cryptography.ICryptoTransform CreateEncryptor(byte[] rgbKey, byte[] rgbIV);override this.CreateEncryptor : byte[] * byte[] -> System.Security.Cryptography.ICryptoTransformPublic Overrides Function CreateEncryptor (rgbKey As Byte(), rgbIV As Byte()) As ICryptoTransformParameters
- rgbKey
- Byte[]
The secret key to use for the symmetric algorithm.
- rgbIV
- Byte[]
The initialization vector to use for the symmetric algorithm.
Returns
A symmetric DES encryptor object.
Exceptions
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.
Examples
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;
}
}
}
Imports System.Security.Cryptography
Imports System.Text
Imports System.IO
Module DESCSPSample
Sub Main()
Try
' Create a new DESCryptoServiceProvider object
' to generate a key and initialization vector (IV).
Dim DESalg As New DESCryptoServiceProvider
' Create a string to encrypt.
Dim sData As String = "Here is some data to encrypt."
Dim FileName As String = "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.
Dim Final As String = DecryptTextFromFile(FileName, DESalg.Key, DESalg.IV)
' Display the decrypted string to the console.
Console.WriteLine(Final)
Catch e As Exception
Console.WriteLine(e.Message)
End Try
End Sub
Sub EncryptTextToFile(ByVal Data As String, ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte)
Try
' Create or open the specified file.
Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)
' Create a CryptoStream using the FileStream
' and the passed key and initialization vector (IV).
Dim cStream As New CryptoStream(fStream, _
New DESCryptoServiceProvider().CreateEncryptor(Key, IV), _
CryptoStreamMode.Write)
' Create a StreamWriter using the CryptoStream.
Dim sWriter As 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 e As CryptographicException
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
Catch e As UnauthorizedAccessException
Console.WriteLine("A file error occurred: {0}", e.Message)
End Try
End Sub
Function DecryptTextFromFile(ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte) As String
Try
' Create or open the specified file.
Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)
' Create a CryptoStream using the FileStream
' and the passed key and initialization vector (IV).
Dim cStream As New CryptoStream(fStream, _
New DESCryptoServiceProvider().CreateDecryptor(Key, IV), _
CryptoStreamMode.Read)
' Create a StreamReader using the CryptoStream.
Dim sReader As New StreamReader(cStream)
' Read the data from the stream
' to decrypt it.
Dim val As String = sReader.ReadLine()
' Close the streams and
' close the file.
sReader.Close()
cStream.Close()
fStream.Close()
' Return the string.
Return val
Catch e As CryptographicException
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
Return Nothing
Catch e As UnauthorizedAccessException
Console.WriteLine("A file error occurred: {0}", e.Message)
Return Nothing
End Try
End Function
End Module
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;
}
}
}
Imports System.Security.Cryptography
Imports System.Text
Imports System.IO
Module DESCSPSample
Sub Main()
Try
' Create a new DESCryptoServiceProvider object
' to generate a key and initialization vector (IV).
Dim DESalg As New DESCryptoServiceProvider
' Create a string to encrypt.
Dim sData As String = "Here is some data to encrypt."
' Encrypt the string to an in-memory buffer.
Dim Data As Byte() = EncryptTextToMemory(sData, DESalg.Key, DESalg.IV)
' Decrypt the buffer back to a string.
Dim Final As String = DecryptTextFromMemory(Data, DESalg.Key, DESalg.IV)
' Display the decrypted string to the console.
Console.WriteLine(Final)
Catch e As Exception
Console.WriteLine(e.Message)
End Try
End Sub
Function EncryptTextToMemory(ByVal Data As String, ByVal Key() As Byte, ByVal IV() As Byte) As Byte()
Try
' Create a MemoryStream.
Dim mStream As New MemoryStream
' Create a CryptoStream using the MemoryStream
' and the passed key and initialization vector (IV).
Dim cStream As New CryptoStream(mStream, _
New DESCryptoServiceProvider().CreateEncryptor(Key, IV), _
CryptoStreamMode.Write)
' Convert the passed string to a byte array.
Dim toEncrypt As Byte() = 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.
Dim ret As Byte() = mStream.ToArray()
' Close the streams.
cStream.Close()
mStream.Close()
' Return the encrypted buffer.
Return ret
Catch e As CryptographicException
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
Return Nothing
End Try
End Function
Function DecryptTextFromMemory(ByVal Data() As Byte, ByVal Key() As Byte, ByVal IV() As Byte) As String
Try
' Create a new MemoryStream using the passed
' array of encrypted data.
Dim msDecrypt As New MemoryStream(Data)
' Create a CryptoStream using the MemoryStream
' and the passed key and initialization vector (IV).
Dim csDecrypt As New CryptoStream(msDecrypt, _
New DESCryptoServiceProvider().CreateDecryptor(Key, IV), _
CryptoStreamMode.Read)
' Create buffer to hold the decrypted data.
Dim fromEncrypt(Data.Length - 1) As Byte
' 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 e As CryptographicException
Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
Return Nothing
End Try
End Function
End Module
Remarks
Use the CreateDecryptor overload with the same parameters to decrypt the result of this method.
