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Smiley MD5-Algorithmus in VB(A)
Hier ist eine fertige Klasse (in ein Klassenmodul einfügen!)



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 = 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







Gruß aus dem Norden
Reinhard


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