TripleDESCryptoServiceProvider Class
Updated: March 2012
Defines a wrapper object to access the cryptographic service provider (CSP) version of the TripleDES algorithm. This class cannot be inherited.
System.Security.Cryptography.SymmetricAlgorithm
System.Security.Cryptography.TripleDES
System.Security.Cryptography.TripleDESCryptoServiceProvider
Assembly: mscorlib (in mscorlib.dll)
The TripleDESCryptoServiceProvider type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | TripleDESCryptoServiceProvider | Initializes a new instance of the TripleDESCryptoServiceProvider class. |
| Name | Description | |
|---|---|---|
![]() | BlockSize | Gets or sets the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.) |
![]() | FeedbackSize | Gets or sets the feedback size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.) |
![]() | IV | Gets or sets the initialization vector (IV) for the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | Key | Gets or sets the secret key for the TripleDES algorithm. (Inherited from TripleDES.) |
![]() | KeySize | Gets or sets the size, in bits, of the secret key used by the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | LegalBlockSizes | Gets the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | LegalKeySizes | Gets the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | Mode | Gets or sets the mode for operation of the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | Padding | Gets or sets the padding mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
| Name | Description | |
|---|---|---|
![]() | Clear | Releases all resources used by the SymmetricAlgorithm class. (Inherited from SymmetricAlgorithm.) |
![]() | CreateDecryptor | Creates a symmetric decryptor object with the current Key property and initialization vector (IV). (Inherited from SymmetricAlgorithm.) |
![]() | CreateDecryptor(Byte(), Byte()) | Creates a symmetric TripleDES decryptor object with the specified key (Key) and initialization vector (IV). (Overrides SymmetricAlgorithm.CreateDecryptor(Byte(), Byte()).) |
![]() | CreateEncryptor | Creates a symmetric encryptor object with the current Key property and initialization vector (IV). (Inherited from SymmetricAlgorithm.) |
![]() | CreateEncryptor(Byte(), Byte()) | Creates a symmetric TripleDES encryptor object with the specified key (Key) and initialization vector (IV). (Overrides SymmetricAlgorithm.CreateEncryptor(Byte(), Byte()).) |
![]() | Dispose | Releases all resources used by the current instance of the SymmetricAlgorithm class. (Inherited from SymmetricAlgorithm.) |
![]() | Dispose(Boolean) | Releases the unmanaged resources used by the SymmetricAlgorithm and optionally releases the managed resources. (Inherited from SymmetricAlgorithm.) |
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GenerateIV | Generates a random initialization vector (IV) to use for the algorithm. (Overrides SymmetricAlgorithm.GenerateIV.) |
![]() | GenerateKey | Generates a random Key to be used for the algorithm. (Overrides SymmetricAlgorithm.GenerateKey.) |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
![]() | ValidKeySize | Determines whether the specified key size is valid for the current algorithm. (Inherited from SymmetricAlgorithm.) |
| Name | Description | |
|---|---|---|
![]() | BlockSizeValue | Represents the block size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.) |
![]() | FeedbackSizeValue | Represents the feedback size, in bits, of the cryptographic operation. (Inherited from SymmetricAlgorithm.) |
![]() | IVValue | Represents the initialization vector (IV) for the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | KeySizeValue | Represents the size, in bits, of the secret key used by the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | KeyValue | Represents the secret key for the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | LegalBlockSizesValue | Specifies the block sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | LegalKeySizesValue | Specifies the key sizes, in bits, that are supported by the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | ModeValue | Represents the cipher mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
![]() | PaddingValue | Represents the padding mode used in the symmetric algorithm. (Inherited from SymmetricAlgorithm.) |
This algorithm supports key lengths from 128 bits to 192 bits in increments of 64 bits.
A newer symmetric encryption algorithm, Advanced Encryption Standard (AES), is available. Consider using the AesCryptoServiceProvider class instead of the TripleDESCryptoServiceProvider class.
The following code example creates a TripleDESCryptoServiceProvider object and uses it to encrypt and decrypt data in a file.
Imports System.Security.Cryptography Imports System.Text Imports System.IO Module TrippleDESCSPSample Sub Main() Try ' Create a new TripleDESCryptoServiceProvider object ' to generate a key and initialization vector (IV). Dim tDESalg As New TripleDESCryptoServiceProvider ' 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, tDESalg.Key, tDESalg.IV) ' Decrypt the text from a file using the file name, key, and IV. Dim Final As String = DecryptTextFromFile(FileName, tDESalg.Key, tDESalg.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 TripleDESCryptoServiceProvider().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 TripleDESCryptoServiceProvider().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 creates a TripleDESCryptoServiceProvider object and uses it to encrypt and decrypt data in memory.
Imports System.Security.Cryptography Imports System.Text Imports System.IO Module TrippleDESCSPSample Sub Main() Try ' Create a new TripleDESCryptoServiceProvider object ' to generate a key and initialization vector (IV). Dim tDESalg As New TripleDESCryptoServiceProvider ' 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, tDESalg.Key, tDESalg.IV) ' Decrypt the buffer back to a string. Dim Final As String = DecryptTextFromMemory(Data, tDESalg.Key, tDESalg.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 TripleDESCryptoServiceProvider().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 TripleDESCryptoServiceProvider().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
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.



