hmacsha256.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 = "HMACSHA256"
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: HMACSHA256
'

''
' Represents an SHA-256 implementation of the HMAC algorithm.
'
' @remarks Information about HMAC can be found at http://csrc.nist.gov/publications/fips/fips198/fips-198a.pdf
' <p>A Hash-based Message Authentication Code can be used to determine if messages sent over insecure channels
' have been modified. This works by each party at boths ends sharing a secret key used to sign the sent message and
' to also authenticate the received message. If the key were compromised, then the authentication cannot be guaranteed.</p>
'
Option Explicit
Implements IObject
Implements HashAlgorithm
Implements KeyedHashAlgorithm
Implements HMAC
Implements ICryptoTransform


Private mBase As HMACBase



''
' Returns the name of the hash.
'
' @return The name of the hash.
'
Public Property Get HashName() As String
    HashName = mBase.HashName
End Property

''
' Sets the name of the hash.
'
' @param RHS The name of the hash.
'
Public Property Let HashName(ByVal RHS As String)
    mBase.HashName = RHS
End Property

''
' Returns the key being used by the hash.
'
' @return The key being used.
'
Public Property Get Key() As Byte()
    Key = mBase.GetKey
End Property

''
' Sets the key to be used by the hash.
'
' @param RHS The new key value.
'
Public Property Let Key(ByRef RHS() As Byte)
    Call mBase.SetKey(RHS)
End Property

''
' Returns if this service provider can be reused to transfrom more data.
'
' @return Always returns True.
'
Public Property Get CanReuseTransform() As Boolean
    CanReuseTransform = True
End Property

''
' Returns if this transform can operate on multiple blocks at once.
'
' @return Always returns True.
'
Public Property Get CanTransformMultipleBlocks() As Boolean
    CanTransformMultipleBlocks = True
End Property

''
' Returns the computed hash.
'
' @return A 32-byte array containing the hash value.
' @remarks The TransformFinalBlock must be called before accessing
' this property or an InvalidOperationException will be thrown.
'
Public Property Get Hash() As Byte()
    Hash = mBase.Hash
End Property

''
' Returns the size of the computed hash.
'
' @return Always returns 256 bits.
'
Public Property Get HashSize() As Long
    HashSize = 256
End Property

''
' Returns the size of the input block size allowed.
'
' @returns Always returns 1.
' @remarks When calling the TransformBlock method, the InputCount must be zero or a multiple of this value.
'
Public Property Get InputBlockSize() As Long
    InputBlockSize = 1
End Property

''
' Returns the output block size this transform can produce.
'
' @return Always returns 1.
'
Public Property Get OutputBlockSize() As Long
    OutputBlockSize = 1
End Property

''
' Releases any resources.
'
Public Sub Clear()
    Call mBase.Clear
End Sub

''
' Computes a hash value for a source in a single pass.
'
' @param Source This can be either a Byte array or any Stream compatible object.
' @param Index The starting index in the Byte array. This is ignored for Stream objects.
' @param Count The number of bytes in the array to be computed. This is ignored for Stream objects.
' @return A 32-byte hash value.
' @remarks If a Stream object is passed in, then the stream is continuously read and the hash calculated until
' there is no more data left to read from the stream.
'
Public Function ComputeHash(ByRef Source As Variant, Optional ByRef Index As Variant, Optional ByRef Count As Variant) As Byte()
    ComputeHash = mBase.ComputeHash(Source, Index, Count)
End Function

''
' Resets the hashing algorithm to start again.
'
Public Sub Initialize()
    Call mBase.Initialize
End Sub

''
' Computes the hash for the specified block of data.
'
' @param InputBuffer The data to compute the hash from.
' @param InputOffset The starting index in the input data to compute the hash.
' @param InputCount The number of bytes to compute the hash from.
' @param OutputBuffer The array to place the input buffer bytes in.
' @param OutputOffset The starting index to beging copying the bytes to.
' @return The number of bytes processed.
' @remarks The OutputBuffer will contain the same data as the InputBuffer. No hash values are placed in the OutputBuffer.
' <p>If a null array is passed in for the OutputBuffer, then nothing is copied, however, the hash is still computed
' on the InputBuffer data.</p>
'
Public Function TransformBlock(ByRef InputBuffer() As Byte, ByVal InputOffset As Long, ByVal InputCount As Long, ByRef OutputBuffer() As Byte, ByVal OutputOffset As Long) As Long
    TransformBlock = mBase.TransformBlock(InputBuffer, InputOffset, InputCount, OutputBuffer, OutputOffset)
End Function

''
' Processes the final data and retrieves the hash value.
'
' @param InputBuffer The final block of data to compute the hash for.
' @param InputOffset The index in the InputBuffer to begin computing data.
' @param InputCount The number of bytes to be processed.
' @return Returns the section of the InputBuffer that was processed.
' @remarks This does not return the computed hash value. A copy of the data that was
' process is returned. To retrieve the hash value, call the Hash property.
'
Public Function TransformFinalBlock(ByRef InputBuffer() As Byte, ByVal InputOffset As Long, ByVal InputCount As Long) As Byte()
    TransformFinalBlock = mBase.TransformFinalBlock(InputBuffer, InputOffset, InputCount)
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
' obtained from ObjPtr. If a different method needs to be impelmented
' then change the method here in this function.
'
' @return Returns a number identifing this instance.
'
Public Function GetHashCode() As Long
    GetHashCode = ObjPtr(CUnk(Me))
End Function

''
' Returns a string representation of this object instance.
' The default method simply returns the application name
' and class name in which this class resides.
'
' @return Returns a string representation of this instance.
'
Public Function ToString() As String
    ToString = Object.ToString(Me, App)
End Function


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'   Friend Interface
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Friend Sub Init(ByRef Key() As Byte)
    Call mBase.SetKey(Key)
End Sub


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'   Class Events
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Private Sub Class_Initialize()