descryptoserviceprovider.cls

这是一个在vb下实现的各种加密程序,可以实现一般的文本加密和文件加密,但是很多算法都是已经被人破解过的.

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "DESCryptoServiceProvider"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
'    CopyRight (c) 2006 Kelly Ethridge
'
'    This file is part of VBCorLib.
'
'    VBCorLib is free software; you can redistribute it and/or modify
'    it under the terms of the GNU Library General Public License as published by
'    the Free Software Foundation; either version 2.1 of the License, or
'    (at your option) any later version.
'
'    VBCorLib is distributed in the hope that it will be useful,
'    but WITHOUT ANY WARRANTY; without even the implied warranty of
'    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
'    GNU Library General Public License for more details.
'
'    You should have received a copy of the GNU Library General Public License
'    along with Foobar; if not, write to the Free Software
'    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
'
'    Module: DESCryptoServiceProvider
'

''
' Defines a wrapper class around a DES cryptographic service provider.
'
' @remarks This provides access to the Windows CryptoAPI cryptography services.
' @see DES
' @include "..\..\..\Includes\DESCryptoServiceProviderExample.txt"
Option Explicit
Implements IObject
Implements SymmetricAlgorithm
Implements DES

Private Const DEF_BLOCKSIZE     As Long = 64
Private Const DEF_MINBLOCKSIZE  As Long = DEF_BLOCKSIZE
Private Const DEF_MAXBLOCKSIZE  As Long = DEF_BLOCKSIZE
Private Const DEF_BLOCKSKIPSIZE As Long = 0
Private Const DEF_FEEDBACKSIZE  As Long = 8
Private Const DEF_MINKEYSIZE    As Long = 64
Private Const DEF_MAXKEYSIZE    As Long = 64
Private Const DEF_KEYSIZE       As Long = DEF_MINKEYSIZE
Private Const DEF_KEYSKIPSIZE   As Long = 0

Private WithEvents mBase As SymmetricAlgorithmBase
Attribute mBase.VB_VarHelpID = -1



''
' Returns the block size, in bits, used by this algorithm.
'
' @return The block size in bits.
' @remarks This will always return 64 bits (8 bytes).
'
Public Property Get BlockSize() As Long
    BlockSize = mBase.BlockSize
End Property

''
' Sets the block size, in bits, used by this algorithm.
'
' @param RHS The new block size in bits.
' @remarks The only valid block size is 64 bits.
'
Public Property Let BlockSize(ByVal RHS As Long)
    mBase.BlockSize = RHS
End Property

''
' Returns a list of legal block sizes.
'
' @return A list of legal block sizes.
' @remarks Only one block size is legal, 64 bits.
'
Public Property Get LegalBlockSizes() As KeySizes()
    LegalBlockSizes = mBase.LegalBlockSizes
End Property

''
' Returns the Feedback Size in bits.
'
' @return The Feedback size in bits.
' @remarks Always returns 64 bits.
'
Public Property Get FeedbackSize() As Long
    FeedbackSize = mBase.FeedbackSize
End Property

''
' Sets the Feedback size in bits.
'
' @param RHS The new feedback size in bits.
' @remarks Only 64 bits is valid.
'
Public Property Let FeedbackSize(ByVal RHS As Long)
    mBase.FeedbackSize = RHS
End Property

''
' Returns the key size in bits.
'
' @Return The key size in bits.
'
Public Property Get KeySize() As Long
    KeySize = mBase.KeySize
End Property

''
' Sets the key size in bits.
'
' @param RHS The new key size in bits.
' @remarks Only 64 bits is supported for DES encryption.
'
Public Property Let KeySize(ByVal RHS As Long)
    mBase.KeySize = RHS
End Property

''
' Returns a list of valid key sizes supported by this algorithm.
'
' @return A list of valid key sizes.
'
Public Property Get LegalKeySizes() As KeySizes()
    LegalKeySizes = mBase.LegalKeySizes
End Property

''
' Returns the Cipher mode this algorithm will use.
'
' @return The Cipher mode.
'
Public Property Get Mode() As CipherMode
    Mode = mBase.Mode
End Property

''
' Sets the Cipher mode this algorithm will use.
'
' @param RHS The cipher mode to use.
'
Public Property Let Mode(ByVal RHS As CipherMode)
    mBase.Mode = RHS
End Property

''
' Returns the padding mode being used.
'
' @return The current padding mode.
'
Public Property Get Padding() As PaddingMode
    Padding = mBase.Padding
End Property

''
' Sets the padding mode to be used.
'
' @param RHS The new padding mode.
'
Public Property Let Padding(ByVal RHS As PaddingMode)
    mBase.Padding = RHS
End Property

''
' Returns the current secret key.
'
' @return The secret key.
' @remarks If no key has been set, then a new random key will be generated.
'
Public Property Get Key() As Byte()
    Key = mBase.GetKey
End Property

''
' Sets the secret key.
'
' @param RHS The new secret key.
' @param The key must be a valid key length. Currently only 64 bits (8 bytes) is supported.
'
Public Property Let Key(ByRef RHS() As Byte)
    Call mBase.SetKey(RHS)
End Property

''
' Generates a random key to be used.
'
Public Sub GenerateKey()
    Call mBase.GenerateKey
End Sub

''
' Returns the Initialization Vector.
'
' @return The Initialization Vector.
' @remarks If no IV has been set, then a new random IV will be generated.
'
Public Property Get IV() As Byte()
    IV = mBase.GetIV
End Property

''
' Sets the Initialization Vector to be used.
'
' @param RHS The new IV to use.
' @remarks The array must be 8 bytes in length.
'
Public Property Let IV(ByRef RHS() As Byte)
    Call mBase.SetIV(RHS)
End Property

''
' Generates a random IV array to use.
'
Public Sub GenerateIV()
    Call mBase.GenerateIV
End Sub

''
' Clears the Key and IV arrays.
'
Public Sub Clear()
    Call mBase.Clear
End Sub

''
' Tests if a specific bit length is valid for a key.
'
' @param BitLength The number of bits to test for.
' @return Return True if the number of bits is supported, False otherwise.
' @remarks Only 64bits (8 bytes) is supported.
'
Public Function ValidKeySize(ByVal BitLength As Long) As Boolean
    ValidKeySize = mBase.ValidKeySize(BitLength)
End Function

''
' Returns a new cipher used to encrypt data.
'
' @param RgbKey A supplied byte array used as the secret key.
' @param RgbIV A supplied byte array used for the Initialization Vector (IV).
' @return An ICryptoTransform object used to encrypt data.
' @remarks Both parameters must be either supplied or missing. A single parameter will throw an exception.
' <p>If no parameters are supplied then the key and IV will be retrieved through the Key and IV properties.</p>
'
Public Function CreateEncryptor(Optional ByRef RgbKey As Variant, Optional ByRef RgbIV As Variant) As ICryptoTransform
    Set CreateEncryptor = CreateCipher(RgbKey, RgbIV, True)
End Function

''
' Returns a new cipher used to decrypt data.
'
' @param RgbKey A supplied byte array used as the secret key.
' @param RgbIV A supplied byte array used for the Initialization Vector (IV).
' @return An ICryptoTransform object used to dencrypt data.
' @remarks Both parameters must be either supplied or missing. A single parameter will throw an exception.
' <p>If no parameters are supplied then the key and IV will be retrieved through the Key and IV properties.</p>
'
Public Function CreateDecryptor(Optional ByRef RgbKey As Variant, Optional ByRef RgbIV As Variant) As ICryptoTransform
    Set CreateDecryptor = CreateCipher(RgbKey, RgbIV, False)
End Function

''
' 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.
'
' @param Value The value to compare against this instance.
' @return Returns True if the values are the same.
'
Public Function Equals(ByRef Value As Variant) As Boolean
    Equals = Object.Equals(Me, Value)
End Function

''
' Returns a psuedo-unique number used to help identify this
' object in memory. The current method is to return the value