VB中實(shí)現(xiàn)MD5加密

使用方法：

msgbox DigestStrToHexStr("111")

源代碼:

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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