DESCryptoServiceProvider

Implements:

Public:

Properties:

Name	Description
BlockSize (get)	Returns the block size, in bits, used by this algorithm.
BlockSize (let)	Sets the block size, in bits, used by this algorithm.
FeedbackSize (get)	Returns the Feedback Size in bits.
FeedbackSize (let)	Sets the Feedback size in bits.
IV (get)	Returns the Initialization Vector.
IV (let)	Sets the Initialization Vector to be used.
Key (get)	Returns the current secret key.
Key (let)	Sets the secret key.
KeySize (get)	Returns the key size in bits.
KeySize (let)	Sets the key size in bits.
LegalBlockSizes (get)	Returns a list of legal block sizes.
LegalKeySizes (get)	Returns a list of valid key sizes supported by this algorithm.
Mode (get)	Returns the Cipher mode this algorithm will use.
Mode (let)	Sets the Cipher mode this algorithm will use.
Padding (get)	Returns the padding mode being used.
Padding (let)	Sets the padding mode to be used.

Methods:

Name	Description
Clear	Clears the Key and IV arrays.
CreateDecryptor	Returns a new cipher used to decrypt data.
CreateEncryptor	Returns a new cipher used to encrypt data.
Equals	This function determines if the value passed in is the same as the current object instance. Meaning, are the Value and this object the same object in memory.
GenerateIV	Generates a random IV array to use.
GenerateKey	Generates a random key to be used.
GetHashCode	Returns a psuedo-unique number used to help identify this object in memory. The current method is to return the value obtained from ObjPtr. If a different method needs to be impelmented then change the method here in this function.
ToString	Returns a string representation of this object instance. The default method simply returns the application name and class name in which this class resides.
ValidKeySize	Tests if a specific bit length is valid for a key.

Remarks

This example shows a very simple method of encrypting then decrypting a String value.

Private Sub Main()
    ' Create a new DES key.
    Dim Key As New DESCryptoServiceProvider

    ' Encrypt a string to a byte array.
    Dim Buffer() As Byte
    Buffer = Encrypt("This is some plaintext!", Key)

    ' Decrypt the byte array back to a string.
    Dim PlainText As String
    PlainText = Decrypt(Buffer, Key)

    ' Display the PlainText value to the console.
    Console.WriteLine PlainText
    Console.ReadKey
End Sub Main


' Encrypt the string.
Private Function Encrypt(ByVal PlainText As String, ByVal Key As SymmetricAlgorithm) As Byte()
    Dim Buffer() As Byte
    Buffer = StrConv(PlainText, vbFromUnicode)

    Dim Encryptor As ICryptoTransform
    Set Encryptor = Key.CreateEncryptor
    Encrypt = Encryptor.TransformFinalBlock(Buffer, 0, cArray.GetLength(Buffer))
End Function


' Decrypt the byte array.
Public Function Decrypt(ByRef CypherText() As Byte, ByVal Key As SymmetricAlgorithm) As String
    Dim Decryptor As ICryptoTransform
    Set Decryptor = Key.CreateDecryptor

    Dim Buffer() As Byte
    Buffer = Decryptor.TransformFinalBlock(CypherText, 0, cArray.GetLength(CypherText))
    Decrypt = StrConv(Buffer, vbUnicode)
End Function

See Also

Project CorLib Overview

Class DESCryptoServiceProvider Overview

DES