VB中实现MD5加密

东坡下载 2010年10月14日 14:28:11

      使用方法:

      msgbox DigestStrToHexStr("111")

      源代码:

      -----------剪切线------------------------------------------------------------

      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