base64.h

BASE64算法及相关介绍； 支持对文件进行编码和对字符串进行编码；

/************************************************
*												*
* CBase64.h									*
* Base 64 de- and encoding class				*
*												*
* ============================================ *
*												*
* This class was written on 28.05.2003			*
* by Jan Raddatz [[e-mail]]			*
*												*
* ============================================ *
*												*
* Copyright (c) by Jan Raddatz					*
* This class was published @ codeguru.com		*
* 28.05.2003									*
*												*
************************************************/

/*----------------------------------------------------------------------------------
@ Base64编码相关

@ Base64是MIME邮件中常用的编码方式之一。它的主要思想是将输入的字符串或数据编码成只含
  有{'A'-'Z', 'a'-'z', '0'-'9', '+', '/'}这64个可打印字符的串，故称为“Base64”。 
  
@ Base64编码的方法是，将输入数据流每次取6 bit，用此6 bit的值(0-63 ; 2^6 = 64)作为索
  引去查表，输出相应字符。这样，每3个字节将编码为4个字符(3×8 → 4×6)；不满4个字符
  的以'='填充。
	
@ 解码时注意：如果对一个编码字符串分多次解码，则需要每次的字符数为4的整数倍。
----------------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------------
// for test

CBase64 m64;
CString strSour, strDest;
CString strFileSour, strFileDest, strFileSwap;

strFileSour = _T("c:\\zxt\\online\\EncodeBufftoFile.txt");
strFileDest = _T("c:\\zxt\\online\\DecodeBufftoFile.txt");

strSour = _T("004abcd");
strDest = _T("1tDQy82ovK/NxTIwMDRhYmNk");


// 测试通过 2004-09-07
// 将字符串编码为文件
m64.EncodeBufftoFile((char *)(LPCTSTR)strSour,
strSour.GetLength()*sizeof(TCHAR),
(LPTSTR)(LPCTSTR)strFileDest);

// 将字符串解码为文件
m64.DecodeBufftoFile((char *)(LPCTSTR)strDest,
(LPTSTR)(LPCTSTR)strFileSour);

// 测试通过 2004-09-07
strFileSour = _T("c:\\zxt\\online\\EncodeFile.txt");
strFileSwap = _T("c:\\zxt\\online\\EncodeSwapFile.txt");
strFileDest = _T("c:\\zxt\\online\\DecodeFile.txt");

// 对文件进行编码
m64.EncodeFile((LPTSTR)(LPCTSTR)strFileSour, (LPTSTR)(LPCTSTR)strFileSwap);
// 对文件进行解码
m64.DecodeFile((LPTSTR)(LPCTSTR)strFileSwap, (LPTSTR)(LPCTSTR)strFileDest);


char buf[100];
char buff[100];
memset(buf, 0, 100);
memset(buff, 0, 100);

// 通过2004-09-07
// 对字符串进行编码
m64.EncodeBuffer((char *)(LPCTSTR)strSour,
strSour.GetLength()*sizeof(TCHAR),
buf);
// 对字符串进行解码
CString strtemp = buf;
m64.DecodeBuffer((char *)(LPCTSTR)strtemp, buff);
CString strtest = buff;
MessageBox(strtest);
--------------------------------------------------------------------------------------*/

#pragma once

#include <afx.h>
#include <stdlib.h>
#include <math.h>
#include <memory.h>
const static unsigned int MAX_LINE_LENGTH = 76;

const static char BASE64_ALPHABET [64] = 
{
	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', //   0 -   9
	'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', //  10 -  19
	'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', //  20 -  29
	'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', //  30 -  39
	'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', //  40 -  49
	'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', //  50 -  59
	'8', '9', '+', '/'								  //  60 -  63
};

const static char BASE64_DEALPHABET [128] = 
{
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0, //   0 -   9
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0, //  10 -  19
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0, //  20 -  29
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0, //  30 -  39
	0,  0,  0, 62,  0,  0,  0, 63, 52, 53, //  40 -  49
	54, 55, 56, 57, 58, 59, 60, 61,  0,  0, //  50 -  59
	0, 61,  0,  0,  0,  0,  1,  2,  3,  4, //  60 -  69
	5,  6,  7,  8,  9, 10, 11, 12, 13, 14, //  70 -  79
	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, //  80 -  89
	25,  0,  0,  0,  0,  0,  0, 26, 27, 28, //  90 -  99
	29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // 100 - 109
	39, 40, 41, 42, 43, 44, 45, 46, 47, 48, // 110 - 119
	49, 50, 51,  0,  0,  0,  0,  0			// 120 - 127
};

enum
{
	UNABLE_TO_OPEN_INPUT_FILE,
	UNABLE_TO_OPEN_OUTPUT_FILE,
	UNABLE_TO_CREATE_OUTPUTBUFFER
};

class CBase64
{
private:	
	
	unsigned int CalculateRecquiredEncodeOutputBufferSize (unsigned int p_InputByteCount);
	unsigned int CalculateRecquiredDecodeOutputBufferSize (char* p_pInputBufferString);
	
	void			EncodeByteTriple  (char* p_pInputBuffer, unsigned int InputCharacters, char* p_pOutputBuffer);
	unsigned int	DecodeByteQuartet (char* p_pInputBuffer, char* p_pOutputBuffer);
	
public:
	
	CBase64 ();
	
	unsigned int CreateMatchingEncodingBuffer (unsigned int p_InputByteCount, char** p_ppEncodingBuffer);
	unsigned int CreateMatchingDecodingBuffer (char* p_pInputBufferString, char** p_ppDecodingBuffer);
	
	void			EncodeBuffer (char* p_pInputBuffer, unsigned int p_InputBufferLength, char*p_pOutputBufferString);
	unsigned int	DecodeBuffer (char* p_pInputBufferString, char* p_pOutputBuffer);
	
	unsigned int EncodeFile (LPTSTR p_pSourceFileName, LPTSTR p_pEncodedFileName);
	unsigned int DecodeFile (LPTSTR p_pSourceFileName, LPTSTR p_pDecodedFileName);
	
	// by wsq
	unsigned int EncodeBufftoFile (char* p_pInputBuffer, unsigned int p_InputBufferLength, LPTSTR p_pEncodedFileName);
	unsigned int DecodeBufftoFile (char* p_pInputBufferString, LPTSTR p_pDecodedFileName);
	
	// by wsq
	unsigned int EncodeFiletoBuff (LPTSTR p_pSourceFileName, char* p_pOutputBuffer);
	unsigned int DecodeFiletoBuff (LPTSTR p_pSourceFileName, char* p_pOutputBuffer);
};