123 lines
3.7 KiB
C++
123 lines
3.7 KiB
C++
/*--------------------------------------------------------------------------*
|
|
*
|
|
* Microsoft Windows
|
|
* Copyright (C) Microsoft Corporation, 1999 - 1999
|
|
*
|
|
* File: base64.cpp
|
|
*
|
|
* Contents: Implements encoding / decoding table for base64 format
|
|
*
|
|
* History: 17-Dec-99 audriusz Created
|
|
*
|
|
*--------------------------------------------------------------------------*/
|
|
|
|
#include <windows.h>
|
|
#include <comdef.h>
|
|
#include <memory.h>
|
|
#include "base64.h"
|
|
|
|
/*+-------------------------------------------------------------------------*
|
|
*
|
|
* TABLE base64_table::_six2pr64
|
|
*
|
|
* PURPOSE: for conversion from binary to base64
|
|
*
|
|
*+-------------------------------------------------------------------------*/
|
|
BYTE base64_table::_six2pr64[64] =
|
|
{
|
|
'A','B','C','D','E','F','G','H','I','J','K','L','M',
|
|
'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
|
|
'a','b','c','d','e','f','g','h','i','j','k','l','m',
|
|
'n','o','p','q','r','s','t','u','v','w','x','y','z',
|
|
'0','1','2','3','4','5','6','7','8','9','+','/'
|
|
};
|
|
|
|
/*+-------------------------------------------------------------------------*
|
|
*
|
|
* TABLE base64_table::_six2pr64
|
|
*
|
|
* PURPOSE: for conversion from base64 to binary
|
|
* [filled by base64_table::base64_table()]
|
|
*
|
|
*+-------------------------------------------------------------------------*/
|
|
BYTE base64_table::_pr2six[256];
|
|
|
|
/*+-------------------------------------------------------------------------*
|
|
*
|
|
* METHOD: base64_table::base64_table
|
|
*
|
|
* PURPOSE: c-tor. fills the table
|
|
*
|
|
*+-------------------------------------------------------------------------*/
|
|
base64_table::base64_table()
|
|
{
|
|
memset(_pr2six,-1,sizeof(_pr2six));
|
|
// Build up the reverse index from base64 characters to values
|
|
for (int i = 0; i < sizeof(_six2pr64)/sizeof(_six2pr64[0]); i++)
|
|
_pr2six[_six2pr64[i]] = (BYTE)i;
|
|
}
|
|
|
|
/*+-------------------------------------------------------------------------*
|
|
*
|
|
* METHOD: base64_table::decode
|
|
*
|
|
* PURPOSE: decodes 0-3 bytes of data ( as much as available )
|
|
*
|
|
*+-------------------------------------------------------------------------*/
|
|
bool base64_table::decode(LPCOLESTR &src, BYTE * &dest)
|
|
{
|
|
BYTE Inputs[4] = { 0, 0, 0, 0 };
|
|
int nChars = 0;
|
|
// force table initialization on first call
|
|
static base64_table table_init;
|
|
|
|
// collect 4 characters if possible.
|
|
while (*src && *src != '=' && nChars < 4)
|
|
{
|
|
BYTE bt = table_init.map2six(static_cast<BYTE>(*src++));
|
|
if (bt != 0xff)
|
|
Inputs[nChars++] = bt;
|
|
}
|
|
|
|
dest += table_init.decode4(Inputs, nChars, dest);
|
|
|
|
return (nChars == 4);
|
|
}
|
|
|
|
|
|
/*+-------------------------------------------------------------------------*
|
|
*
|
|
* METHOD: base64_table::encode
|
|
*
|
|
* PURPOSE: encodes 1-3 bytes of data. pads if the last set
|
|
*
|
|
*+-------------------------------------------------------------------------*/
|
|
void base64_table::encode(const BYTE * &src, DWORD &cbInput, LPOLESTR &dest)
|
|
{
|
|
BYTE chr0 = src[0];
|
|
BYTE chr1 = cbInput > 1 ? src[1] : 0;
|
|
BYTE chr2 = cbInput > 2 ? src[2] : 0;
|
|
*(dest++) = _six2pr64[chr0 >> 2]; // c1
|
|
*(dest++) = _six2pr64[((chr0 << 4) & 060) | ((chr1 >> 4) & 017)]; // c2
|
|
*(dest++) = _six2pr64[((chr1 << 2) & 074) | ((chr2 >> 6) & 03) ]; // c3
|
|
*(dest++) = _six2pr64[chr2 & 077]; // c4
|
|
src += 3;
|
|
|
|
if (cbInput == 1)
|
|
{
|
|
*(dest-1) = '=';
|
|
*(dest-2) = '=';
|
|
cbInput = 0;
|
|
}
|
|
else if (cbInput == 2)
|
|
{
|
|
*(dest-1) = '=';
|
|
cbInput = 0;
|
|
}
|
|
else
|
|
cbInput -= 3;
|
|
|
|
if (!cbInput)
|
|
*dest = 0;
|
|
}
|