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[VB6] Рассчет хеша MD5
30.12.2017
21:28
Раздел: VBScript

1. Код на основе API функций библиотеки cryptdll.
Примечание: начиная с Vista эти функции продублированы в ntdll.dll (недокументированная возможность).

Код (vb.net):

Option Explicit
Private Type MD5_CTX
  i(1 To 2) As Long
  buf(1 To 4) As Long
  inp(1 To 64) As Byte
  digest(1 To 16) As Byte
End Type
Private Declare Sub MD5Init Lib "cryptdll" (Context As MD5_CTX)
Private Declare Sub MD5Update Lib "cryptdll" (Context As MD5_CTX, ByVal strInput As String, ByVal lLen As Long)
Private Declare Sub MD5Final Lib "cryptdll" (Context As MD5_CTX)
Private Sub Command1_Click()
    MsgBox CalcMD5("C:\Win32_BIOS.txt")
    MsgBox CalcMD5_String("C:\Win32_BIOS.txt")
End Sub
Private Function CalcMD5_String(strBuffer As String) As String
    Dim myContext As MD5_CTX
    Dim result As String
    Dim lp As Long
    Dim MD5 As String
    MD5Init myContext
    MD5Update myContext, strBuffer, Len(strBuffer)
    MD5Final myContext
    result = StrConv(myContext.digest, vbUnicode)
   
    For lp = 1 To Len(result)
            CalcMD5_String = CalcMD5_String & Right("00" & Hex(Asc(Mid(result, lp, 1))), 2)
    Next
End Function
Private Function CalcMD5(strFilename As String) As String
    Dim strBuffer As String
    Dim myContext As MD5_CTX
    Dim result As String
    Dim lp As Long
    Dim MD5 As String
    strBuffer = Space(FileLen(strFilename))
    Open strFilename For Binary Access Read As #1
        Get #1, , strBuffer
    Close #1
    MD5Init myContext
    MD5Update myContext, strBuffer, Len(strBuffer)
    MD5Final myContext
    result = StrConv(myContext.digest, vbUnicode)
   
    For lp = 1 To Len(result)
            CalcMD5 = CalcMD5 & Right("00" & Hex(Asc(Mid(result, lp, 1))), 2)
    Next
   
End Function




2. Чисто математическая реализация. Автор: Robert Hubley

Код (vb.net):

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "MD5_Hash"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Option Explicit
'/******************************************************************************
' *  Copyright (C) 2000 by Robert Hubley.                                      *
' *  All rights reserved.                                                      *
' *                                                                            *
' *  This software is provided ``AS IS'' and any express or implied            *
' *  warranties, including, but not limited to, the implied warranties of      *
' *  merchantability and fitness for a particular purpose, are disclaimed.     *
' *  In no event shall the authors be liable for any direct, indirect,         *
' *  incidental, special, exemplary, or consequential damages (including, but  *
' *  not limited to, procurement of substitute goods or services; loss of use, *
' *  data, or profits; or business interruption) however caused and on any     *
' *  theory of liability, whether in contract, strict liability, or tort       *
' *  (including negligence or otherwise) arising in any way out of the use of  *
' *  this software, even if advised of the possibility of such damage.         *
' *                                                                            *
' ******************************************************************************
'
'  CLASS: MD5
'
'  DESCRIPTION:
'     This is a class which encapsulates a set of MD5 Message Digest functions.
'     MD5 algorithm produces a 128 bit digital fingerprint (signature) from an
'     dataset of arbitrary length.  For details see RFC 1321 (summarized below).
'     This implementation is derived from the RSA Data Security, Inc. MD5 Message-Digest
'     algorithm reference implementation (originally written in C)
'
'  AUTHOR:
'     Robert M. Hubley 12/1999
'
'
'  NOTES:
'      Network Working Group                                    R. Rivest
'      Request for Comments: 1321     MIT Laboratory for Computer Science
'                                             and RSA Data Security, Inc.
'                                                              April 1992
'
'
'                           The MD5 Message-Digest Algorithm
'
'      Summary
'
'         This document describes the MD5 message-digest algorithm. The
'         algorithm takes as input a message of arbitrary length and produces
'         as output a 128-bit "fingerprint" or "message digest" of the input.
'         It is conjectured that it is computationally infeasible to produce
'         two messages having the same message digest, or to produce any
'         message having a given prespecified target message digest. The MD5
'         algorithm is intended for digital signature applications, where a
'         large file must be "compressed" in a secure manner before being
'         encrypted with a private (secret) key under a public-key cryptosystem
'         such as RSA.
'
'         The MD5 algorithm is designed to be quite fast on 32-bit machines. In
'         addition, the MD5 algorithm does not require any large substitution
'         tables; the algorithm can be coded quite compactly.
'
'         The MD5 algorithm is an extension of the MD4 message-digest algorithm
'         1,2]. MD5 is slightly slower than MD4, but is more "conservative" in
'         design. MD5 was designed because it was felt that MD4 was perhaps
'         being adopted for use more quickly than justified by the existing
'         critical review; because MD4 was designed to be exceptionally fast,
'         it is "at the edge" in terms of risking successful cryptanalytic
'         attack. MD5 backs off a bit, giving up a little in speed for a much
'         greater likelihood of ultimate security. It incorporates some
'         suggestions made by various reviewers, and contains additional
'         optimizations. The MD5 algorithm is being placed in the public domain
'         for review and possible adoption as a standard.
'
'         RFC Author:
'         Ronald L.Rivest
'         Massachusetts Institute of Technology
'         Laboratory for Computer Science
'         NE43 -324545    Technology Square
'         Cambridge, MA  02139-1986
'         Phone: (617) 253-5880
'         EMail:    Rivest@ theory.lcs.mit.edu
'
'
'
'  CHANGE HISTORY:
'
'     0.1.0  RMH    1999/12/29      Original version
'
'
'=
'= Class Constants
'=
Private Const OFFSET_4 = 4294967296#
Private Const MAXINT_4 = 2147483647
Private Const S11 = 7
Private Const S12 = 12
Private Const S13 = 17
Private Const S14 = 22
Private Const S21 = 5
Private Const S22 = 9
Private Const S23 = 14
Private Const S24 = 20
Private Const S31 = 4
Private Const S32 = 11
Private Const S33 = 16
Private Const S34 = 23
Private Const S41 = 6
Private Const S42 = 10
Private Const S43 = 15
Private Const S44 = 21
'=
'= Class Variables
'=
Private state(4) As Long
Private ByteCounter As Long
Private ByteBuffer(63) As Byte
'=
'= Class Properties
'=
Property Get RegisterA() As String
    RegisterA = state(1)
End Property
Property Get RegisterB() As String
    RegisterB = state(2)
End Property
Property Get RegisterC() As String
    RegisterC = state(3)
End Property
Property Get RegisterD() As String
    RegisterD = state(4)
End Property
'=
'= Class Functions
'=
'
' Function to quickly digest a file into a hex string
'
Public Function DigestFileToHexStr(FileName As String) As String
    Open FileName For Binary Access Read As #1
    MD5Init
    Do While Not EOF(1)
        Get #1, , ByteBuffer
        If Loc(1) < LOF(1) Then
            ByteCounter = ByteCounter + 64
            MD5Transform ByteBuffer
        End If
    Loop
    ByteCounter = ByteCounter + (LOF(1) Mod 64)
    Close #1
    MD5Final
    DigestFileToHexStr = GetValues
End Function
'
' Function to digest a text string and output the result as a string
' of hexadecimal characters.
'
Public Function DigestStrToHexStr(SourceString As String) As String
    MD5Init
    MD5Update Len(SourceString), StringToArray(SourceString)
    MD5Final
    DigestStrToHexStr = GetValues
End Function
'
' A utility function which converts a string into an array of
' bytes.
'
Private Function StringToArray(InString As String) As Byte()
    Dim i As Integer
    Dim bytBuffer() As Byte
    ReDim bytBuffer(Len(InString))
    For i = 0 To Len(InString) - 1
        bytBuffer(i) = Asc(Mid(InString, i + 1, 1))
    Next i
    StringToArray = bytBuffer
End Function
'
' Concatenate the four state vaules into one string
'
Public Function GetValues() As String
    GetValues = LongToString(state(1)) & LongToString(state(2)) & LongToString(state(3)) &
LongToString(state(4))
End Function
'
' Convert a Long to a Hex string
'
Private Function LongToString(Num As Long) As String
        Dim a As Byte
        Dim b As Byte
        Dim c As Byte
        Dim d As Byte
       
        a = Num And &HFF&
        If a < 16 Then
            LongToString = "0" & Hex(a)
        Else
            LongToString = Hex(a)
        End If
             
        b = (Num And &HFF00&) \ 256
        If b < 16 Then
            LongToString = LongToString & "0" & Hex(b)
        Else
            LongToString = LongToString & Hex(b)
        End If
       
        c = (Num And &HFF0000) \ 65536
        If c < 16 Then
            LongToString = LongToString & "0" & Hex(c)
        Else
            LongToString = LongToString & Hex(c)
        End If
     
        If Num < 0 Then
            d = ((Num And &H7F000000) \ 16777216) Or &H80&
        Else
            d = (Num And &HFF000000) \ 16777216
        End If
       
        If d < 16 Then
            LongToString = LongToString & "0" & Hex(d)
        Else
            LongToString = LongToString & Hex(d)
        End If
   
End Function
'
' Initialize the class
'   This must be called before a digest calculation is started
'
Public Sub MD5Init()
    ByteCounter = 0
    state(1) = UnsignedToLong(1732584193#)
    state(2) = UnsignedToLong(4023233417#)
    state(3) = UnsignedToLong(2562383102#)
    state(4) = UnsignedToLong(271733878#)
End Sub
'
' MD5 Final
'
Public Sub MD5Final()
    Dim dblBits As Double
   
    Dim padding(72) As Byte
    Dim lngBytesBuffered As Long
   
    padding(0) = &H80
   
    dblBits = ByteCounter * 8
   
    ' Pad out
    lngBytesBuffered = ByteCounter Mod 64
    If lngBytesBuffered <= 56 Then
        MD5Update 56 - lngBytesBuffered, padding
    Else
        MD5Update 120 - ByteCounter, padding
    End If
   
   
    padding(0) = UnsignedToLong(dblBits) And &HFF&
    padding(1) = UnsignedToLong(dblBits) \ 256 And &HFF&
    padding(2) = UnsignedToLong(dblBits) \ 65536 And &HFF&
    padding(3) = UnsignedToLong(dblBits) \ 16777216 And &HFF&
    padding(4) = 0
    padding(5) = 0
    padding(6) = 0
    padding(7) = 0
   
    MD5Update 8, padding
End Sub
'
' Break up input stream into 64 byte chunks
'
Public Sub MD5Update(InputLen As Long, InputBuffer() As Byte)
    Dim II As Integer
    Dim i As Integer
    Dim j As Integer
    Dim k As Integer
    Dim lngBufferedBytes As Long
    Dim lngBufferRemaining As Long
    Dim lngRem As Long
   
    lngBufferedBytes = ByteCounter Mod 64
    lngBufferRemaining = 64 - lngBufferedBytes
    ByteCounter = ByteCounter + InputLen
    ' Use up old buffer results first
    If InputLen >= lngBufferRemaining Then
        For II = 0 To lngBufferRemaining - 1
            ByteBuffer(lngBufferedBytes + II) = InputBuffer(II)
        Next II
        MD5Transform ByteBuffer
       
        lngRem = (InputLen) Mod 64
        ' The transfer is a multiple of 64 lets do some transformations
        For i = lngBufferRemaining To InputLen - II - lngRem Step 64
            For j = 0 To 63
                ByteBuffer(j) = InputBuffer(i + j)
            Next j
            MD5Transform ByteBuffer
        Next i
        lngBufferedBytes = 0
    Else
      i = 0
    End If
   
    ' Buffer any remaining input
    For k = 0 To InputLen - i - 1
        ByteBuffer(lngBufferedBytes + k) = InputBuffer(i + k)
    Next k
   
End Sub
'
' MD5 Transform
'
Private Sub MD5Transform(Buffer() As Byte)
    Dim x(16) As Long
    Dim a As Long
    Dim b As Long
    Dim c As Long
    Dim d As Long
   
    a = state(1)
    b = state(2)
    c = state(3)
    d = state(4)
   
    Decode 64, x, Buffer
    ' Round 1
    FF a, b, c, d, x(0), S11, -680876936
    FF d, a, b, c, x(1), S12, -389564586
    FF c, d, a, b, x(2), S13, 606105819
    FF b, c, d, a, x(3), S14, -1044525330
    FF a, b, c, d, x(4), S11, -176418897
    FF d, a, b, c, x(5), S12, 1200080426
    FF c, d, a, b, x(6), S13, -1473231341
    FF b, c, d, a, x(7), S14, -45705983
    FF a, b, c, d, x(8), S11, 1770035416
    FF d, a, b, c, x(9), S12, -1958414417
    FF c, d, a, b, x(10), S13, -42063
    FF b, c, d, a, x(11), S14, -1990404162
    FF a, b, c, d, x(12), S11, 1804603682
    FF d, a, b, c, x(13), S12, -40341101
    FF c, d, a, b, x(14), S13, -1502002290
    FF b, c, d, a, x(15), S14, 1236535329
   
    ' Round 2
    GG a, b, c, d, x(1), S21, -165796510
    GG d, a, b, c, x(6), S22, -1069501632
    GG c, d, a, b, x(11), S23, 643717713
    GG b, c, d, a, x(0), S24, -373897302
    GG a, b, c, d, x(5), S21, -701558691
    GG d, a, b, c, x(10), S22, 38016083
    GG c, d, a, b, x(15), S23, -660478335
    GG b, c, d, a, x(4), S24, -405537848
    GG a, b, c, d, x(9), S21, 568446438
    GG d, a, b, c, x(14), S22, -1019803690
    GG c, d, a, b, x(3), S23, -187363961
    GG b, c, d, a, x(8), S24, 1163531501
    GG a, b, c, d, x(13), S21, -1444681467
    GG d, a, b, c, x(2), S22, -51403784
    GG c, d, a, b, x(7), S23, 1735328473
    GG b, c, d, a, x(12), S24, -1926607734
   
    ' Round 3
    HH a, b, c, d, x(5), S31, -378558
    HH d, a, b, c, x(8), S32, -2022574463
    HH c, d, a, b, x(11), S33, 1839030562
    HH b, c, d, a, x(14), S34, -35309556
    HH a, b, c, d, x(1), S31, -1530992060
    HH d, a, b, c, x(4), S32, 1272893353
    HH c, d, a, b, x(7), S33, -155497632
    HH b, c, d, a, x(10), S34, -1094730640
    HH a, b, c, d, x(13), S31, 681279174
    HH d, a, b, c, x(0), S32, -358537222
    HH c, d, a, b, x(3), S33, -722521979
    HH b, c, d, a, x(6), S34, 76029189
    HH a, b, c, d, x(9), S31, -640364487
    HH d, a, b, c, x(12), S32, -421815835
    HH c, d, a, b, x(15), S33, 530742520
    HH b, c, d, a, x(2), S34, -995338651
   
    ' Round 4
    II a, b, c, d, x(0), S41, -198630844
    II d, a, b, c, x(7), S42, 1126891415
    II c, d, a, b, x(14), S43, -1416354905
    II b, c, d, a, x(5), S44, -57434055
    II a, b, c, d, x(12), S41, 1700485571
    II d, a, b, c, x(3), S42, -1894986606
    II c, d, a, b, x(10), S43, -1051523
    II b, c, d, a, x(1), S44, -2054922799
    II a, b, c, d, x(8), S41, 1873313359
    II d, a, b, c, x(15), S42, -30611744
    II c, d, a, b, x(6), S43, -1560198380
    II b, c, d, a, x(13), S44, 1309151649
    II a, b, c, d, x(4), S41, -145523070
    II d, a, b, c, x(11), S42, -1120210379
    II c, d, a, b, x(2), S43, 718787259
    II b, c, d, a, x(9), S44, -343485551
   
   
    state(1) = LongOverflowAdd(state(1), a)
    state(2) = LongOverflowAdd(state(2), b)
    state(3) = LongOverflowAdd(state(3), c)
    state(4) = LongOverflowAdd(state(4), d)
'  /* Zeroize sensitive information.
'*/
'  MD5_memset ((POINTER)x, 0, sizeof (x));
   
End Sub
Private Sub Decode(Length As Integer, OutputBuffer() As Long, InputBuffer() As Byte)
    Dim intDblIndex As Integer
    Dim intByteIndex As Integer
    Dim dblSum As Double
   
    intDblIndex = 0
    For intByteIndex = 0 To Length - 1 Step 4
        dblSum = InputBuffer(intByteIndex) + _
                                    InputBuffer(intByteIndex + 1) * 256# + _
                                    InputBuffer(intByteIndex + 2) * 65536# + _
                                    InputBuffer(intByteIndex + 3) * 16777216#
        OutputBuffer(intDblIndex) = UnsignedToLong(dblSum)
        intDblIndex = intDblIndex + 1
    Next intByteIndex
End Sub
'
' FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
' Rotation is separate from addition to prevent recomputation.
'
Private Function FF(a As Long, _
                    b As Long, _
                    c As Long, _
                    d As Long, _
                    x As Long, _
                    s As Long, _
                    ac As Long) As Long
    a = LongOverflowAdd4(a, (b And c) Or (Not (b) And d), x, ac)
    a = LongLeftRotate(a, s)
    a = LongOverflowAdd(a, b)
End Function
Private Function GG(a As Long, _
                    b As Long, _
                    c As Long, _
                    d As Long, _
                    x As Long, _
                    s As Long, _
                    ac As Long) As Long
    a = LongOverflowAdd4(a, (b And d) Or (c And Not (d)), x, ac)
    a = LongLeftRotate(a, s)
    a = LongOverflowAdd(a, b)
End Function
Private Function HH(a As Long, _
                    b As Long, _
                    c As Long, _
                    d As Long, _
                    x As Long, _
                    s As Long, _
                    ac As Long) As Long
    a = LongOverflowAdd4(a, b Xor c Xor d, x, ac)
    a = LongLeftRotate(a, s)
    a = LongOverflowAdd(a, b)
End Function
Private Function II(a As Long, _
                    b As Long, _
                    c As Long, _
                    d As Long, _
                    x As Long, _
                    s As Long, _
                    ac As Long) As Long
    a = LongOverflowAdd4(a, c Xor (b Or Not (d)), x, ac)
    a = LongLeftRotate(a, s)
    a = LongOverflowAdd(a, b)
End Function
'
' Rotate a long to the right
'
Function LongLeftRotate(value As Long, bits As Long) As Long
    Dim lngSign As Long
    Dim lngI As Long
    bits = bits Mod 32
    If bits = 0 Then LongLeftRotate = value: Exit Function
    For lngI = 1 To bits
        lngSign = value And &HC0000000
        value = (value And &H3FFFFFFF) * 2
        value = value Or ((lngSign < 0) And 1) Or (CBool(lngSign And _
                &H40000000) And &H80000000)
    Next
    LongLeftRotate = value
End Function
'
' Function to add two unsigned numbers together as in C.
' Overflows are ignored!
'
Private Function LongOverflowAdd(Val1 As Long, Val2 As Long) As Long
    Dim lngHighWord As Long
    Dim lngLowWord As Long
    Dim lngOverflow As Long
    lngLowWord = (Val1 And &HFFFF&) + (Val2 And &HFFFF&)
    lngOverflow = lngLowWord \ 65536
    lngHighWord = (((Val1 And &HFFFF0000) \ 65536) + ((Val2 And &HFFFF0000) \ 65536) + lngOverflow) And
&HFFFF&
    LongOverflowAdd = UnsignedToLong((lngHighWord * 65536#) + (lngLowWord And &HFFFF&))
End Function
'
' Function to add two unsigned numbers together as in C.
' Overflows are ignored!
'
Private Function LongOverflowAdd4(Val1 As Long, Val2 As Long, val3 As Long, val4 As Long) As Long
    Dim lngHighWord As Long
    Dim lngLowWord As Long
    Dim lngOverflow As Long
    lngLowWord = (Val1 And &HFFFF&) + (Val2 And &HFFFF&) + (val3 And &HFFFF&) + (val4 And &HFFFF&)
    lngOverflow = lngLowWord \ 65536
    lngHighWord = (((Val1 And &HFFFF0000) \ 65536) + _
                   ((Val2 And &HFFFF0000) \ 65536) + _
                   ((val3 And &HFFFF0000) \ 65536) + _
                   ((val4 And &HFFFF0000) \ 65536) + _
                   lngOverflow) And &HFFFF&
    LongOverflowAdd4 = UnsignedToLong((lngHighWord * 65536#) + (lngLowWord And &HFFFF&))
End Function
'
' Convert an unsigned double into a long
'
Private Function UnsignedToLong(value As Double) As Long
        If value < 0 Or value >= OFFSET_4 Then Error 6 ' Overflow
        If value <= MAXINT_4 Then
          UnsignedToLong = value
        Else
          UnsignedToLong = value - OFFSET_4
        End If
      End Function
'
' Convert a long to an unsigned Double
'
Private Function LongToUnsigned(value As Long) As Double
        If value < 0 Then
          LongToUnsigned = value + OFFSET_4
        Else
          LongToUnsigned = value
        End If
End Function

Так же в этом разделе:
 
MyTetra Share v.0.52
Яндекс индекс цитирования