patternbasedgenerator.cpp

来自「一款密码保险箱源码」· C++ 代码 · 共 165 行

/*
  KeePass Password Safe - The Open-Source Password Manager
  Copyright (C) 2003-2007 Dominik Reichl <[e-mail]>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program 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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "StdAfx.h"
#include "PatternBasedGenerator.h"
#include "../Util/StrUtil.h"

#define PBG_RANDOM_BUFFER_SIZE 1024

PWG_ERROR PbgGenerate(std::vector<WCHAR>& vOutBuffer,
	const PW_GEN_SETTINGS_EX* pSettings, CNewRandom* pRandomSource)
{
	ASSERT(pSettings != NULL);
	if(pSettings == NULL) return PWGE_NULL_PTR;
	ASSERT(pRandomSource != NULL);
	if(pRandomSource == NULL) return PWGE_NULL_PTR;

	DWORD dwOutBufPos = 0;

	DWORD dwRandomPos = 0;
	BYTE pbRandom[PBG_RANDOM_BUFFER_SIZE];
	pRandomSource->GetRandomBuffer(pbRandom, PBG_RANDOM_BUFFER_SIZE);

	PbgWString strOrgPattern = pSettings->strPattern;
	PbgWString strExpPattern = PbgExpandPattern(strOrgPattern);

	WCharStream csPattern(strExpPattern.c_str());
	WCHAR ch = csPattern.ReadChar();

	PwCharSet pwCustomCharSet;
	BOOL bInCharSetDef = FALSE;

	while(ch != 0)
	{
		PwCharSet pwCurrentCharSet;
		BOOL bGenerateChar = FALSE;

		if(ch == L'\\')
		{
			ch = csPattern.ReadChar();
			if(ch == 0) // Backslash at the end
			{
				PbgAppendChar(vOutBuffer, L'\\', dwOutBufPos);
				break;
			}

			if(bInCharSetDef == FALSE)
				PbgAppendChar(vOutBuffer, ch, dwOutBufPos);
			else
				pwCustomCharSet.Add(ch);
		}
		else if(ch == '[')
		{
			pwCustomCharSet.Clear();
			bInCharSetDef = TRUE;
		}
		else if(ch == ']')
		{
			pwCurrentCharSet.Add(pwCustomCharSet.ToString().c_str());

			bInCharSetDef = FALSE;
			bGenerateChar = TRUE;
		}
		else if(bInCharSetDef == TRUE)
		{
			if(pwCustomCharSet.AddCharSet(ch) == false)
				pwCustomCharSet.Add(ch);
		}
		else if(pwCurrentCharSet.AddCharSet(ch) == false)
			PbgAppendChar(vOutBuffer, ch, dwOutBufPos);
		else bGenerateChar = TRUE;
		
		if(bGenerateChar == TRUE)
		{
			PwgPrepareCharSet(&pwCurrentCharSet, pSettings);

			if(pwCurrentCharSet.Size() == 0) return PWGE_TOO_FEW_CHARACTERS;

			UINT64 uIndex = *(UINT64 *)&pbRandom[dwRandomPos];

			dwRandomPos += sizeof(UINT64);
			if(dwRandomPos == PBG_RANDOM_BUFFER_SIZE)
			{
				pRandomSource->GetRandomBuffer(pbRandom, PBG_RANDOM_BUFFER_SIZE);
				dwRandomPos = 0;
			}

			uIndex %= static_cast<UINT64>(pwCurrentCharSet.Size());

			WCHAR wch = pwCurrentCharSet.GetAt(static_cast<DWORD>(uIndex));
			PbgAppendChar(vOutBuffer, wch, dwOutBufPos);
		}

		ch = csPattern.ReadChar();
	}

	PbgAppendChar(vOutBuffer, 0, dwOutBufPos);
	PbgAppendChar(vOutBuffer, 0, dwOutBufPos);

	for(DWORD iRem = dwOutBufPos; iRem < vOutBuffer.size(); ++iRem)
	{
		vOutBuffer[iRem] = 0; // Set the rest to zero
	}

	if(pSettings->bPatternPermute != FALSE)
		PwgShufflePassword(vOutBuffer, pRandomSource);

	return PWGE_SUCCESS;
}

PbgWString PbgExpandPattern(const PbgWString& strPattern)
{
	PbgWString str = strPattern;

	while(true)
	{
		PbgWString::size_type nOpen = str.find(L'{');
		PbgWString::size_type nClose = str.find('}');

		if((nOpen == PbgWString::npos) || (nClose == PbgWString::npos) ||
			(!(nOpen >= 0)) || (nOpen > nClose))
			break;

		PbgWString strCount = str.substr(nOpen + 1, nClose - nOpen - 1);
		str.erase(nOpen, nClose - nOpen + 1);

		long lRepeat = _wtol(strCount.c_str());
		if((lRepeat >= 0) && (nOpen >= 1))
		{
			if(lRepeat == 0)
				str.erase(nOpen - 1, 1);
			else
				str.insert(nOpen, lRepeat - 1, str[nOpen - 1]);
		}
	}

	return str;
}

void PbgAppendChar(std::vector<WCHAR>& vOutBuffer, WCHAR wch, DWORD& rdwPos)
{
	if(rdwPos < vOutBuffer.size())
		vOutBuffer[rdwPos] = wch;
	else
		vOutBuffer.push_back(wch);

	++rdwPos;
}