Leaked source code of windows server 2003
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

494 lines
12 KiB

//+--------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1996 - 1999
//
// File: base64.cpp
//
// Contents: base64 encode/decode implementation
//
// History: 25-Jul-96 vich created
//
//---------------------------------------------------------------------------
#include <windows.h>
#include <assert.h>
#include <dbgdef.h>
#include "pkifmt.h"
//#define BASE64_STRICT // enforce syntax check on input data
#undef BASE64_STRICT // enforce syntax check on input data
// The following table translates an ascii subset to 6 bit values as follows
// (see RFC 1421 and/or RFC 1521):
//
// input hex (decimal)
// 'A' --> 0x00 (0)
// 'B' --> 0x01 (1)
// ...
// 'Z' --> 0x19 (25)
// 'a' --> 0x1a (26)
// 'b' --> 0x1b (27)
// ...
// 'z' --> 0x33 (51)
// '0' --> 0x34 (52)
// ...
// '9' --> 0x3d (61)
// '+' --> 0x3e (62)
// '/' --> 0x3f (63)
//
// Encoded lines must be no longer than 76 characters.
// The final "quantum" is handled as follows: The translation output shall
// always consist of 4 characters. 'x', below, means a translated character,
// and '=' means an equal sign. 0, 1 or 2 equal signs padding out a four byte
// translation quantum means decoding the four bytes would result in 3, 2 or 1
// unencoded bytes, respectively.
//
// unencoded size encoded data
// -------------- ------------
// 1 byte "xx=="
// 2 bytes "xxx="
// 3 bytes "xxxx"
#define CB_BASE64LINEMAX 64 // others use 64 -- could be up to 76
// Any other (invalid) input character value translates to 0x40 (64)
const BYTE abDecode[256] =
{
/* 00: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* 10: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* 20: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
/* 30: */ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
/* 40: */ 64, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
/* 50: */ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
/* 60: */ 64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
/* 70: */ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64,
/* 80: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* 90: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* a0: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* b0: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* c0: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* d0: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* e0: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
/* f0: */ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
};
const UCHAR abEncode[] =
/* 0 thru 25: */ "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
/* 26 thru 51: */ "abcdefghijklmnopqrstuvwxyz"
/* 52 thru 61: */ "0123456789"
/* 62 and 63: */ "+/";
#define MOD4(x) ((x) & 3)
__inline BOOL
_IsBase64WhiteSpace(
IN TCHAR const ch)
{
return(
ch == TEXT(' ') ||
ch == TEXT('\t') ||
ch == TEXT('\r') ||
ch == TEXT('\n'));
}
DWORD
Base64DecodeA(
IN TCHAR const *pchIn,
IN DWORD cchIn,
OPTIONAL OUT BYTE *pbOut,
IN OUT DWORD *pcbOut)
{
DWORD dwErr;
DWORD cchInDecode, cbOutDecode;
TCHAR const *pchInEnd;
TCHAR const *pchInT;
BYTE *pbOutT;
// Count the translatable characters, skipping whitespace & CR-LF chars.
cchInDecode = 0;
pchInEnd = &pchIn[cchIn];
dwErr = ERROR_INVALID_DATA;
for (pchInT = pchIn; pchInT < pchInEnd; pchInT++)
{
if (sizeof(abDecode) < (unsigned) *pchInT || abDecode[*pchInT] > 63)
{
// Found a non-base64 character. Decide what to do.
DWORD cch;
if (_IsBase64WhiteSpace(*pchInT))
{
continue; // skip all whitespace
}
// The length calculation may stop in the middle of the last
// translation quantum, because the equal sign padding characters
// are treated as invalid input. If the last translation quantum
// is not 4 bytes long, there must be 3, 2 or 1 equal sign(s).
if (0 != cchInDecode)
{
cch = MOD4(cchInDecode);
if (0 != cch)
{
cch = 4 - cch;
while (0 != cch && pchInT < pchInEnd && '=' == *pchInT)
{
pchInT++;
cch--;
}
}
//#ifdef BASE64_STRICT
if (0 == cch)
//#endif
{
break;
}
}
#if DBG
DbgPrintf(
DBG_SS_TRACE,
"Bad base64 data: \"%.*" szFMTTSTR "...\"\n",
min(16, SAFE_SUBTRACT_POINTERS(pchInEnd, pchInT)),
pchInT);
#endif //DBG
goto BadBase64Data;
}
cchInDecode++; // only count valid base64 chars
}
assert(pchInT <= pchInEnd);
#ifdef BASE64_STRICT
if (pchInT < pchInEnd)
{
TCHAR const *pch;
DWORD cchEqual = 0;
for (pch = pchInT; pch < pchInEnd; pch++)
{
if (!_IsBase64WhiteSpace(*pch))
{
// Allow up to 3 extra trailing equal signs.
if (TEXT('=') == *pch && 3 > cchEqual)
{
cchEqual++;
continue;
}
#if DBG
DbgPrintf(DBG_SS_TRACE,
"Bad trailing base64 data: \"%.*" szFMTTSTR "...\"\n",
min(16, SAFE_SUBTRACT_POINTERS(pchInEnd, pch)),
pch);
#endif //DBG
goto BadTrailingBase64Data;
}
}
#if DBG
if (0 != cchEqual)
{
DbgPrintf(DBG_SS_TRACE,
"Ignored trailing base64 data: \"%.*" szFMTTSTR "\"\n",
cchEqual,
TEXT("==="));
}
#endif //DBG
}
#endif
pchInEnd = pchInT; // don't process any trailing stuff again
// We know how many translatable characters are in the input buffer, so now
// set the output buffer size to three bytes for every four (or fraction of
// four) input bytes. Compensate for a fractional translation quantum.
cbOutDecode = ((cchInDecode + 3) >> 2) * 3;
switch (cchInDecode % 4)
{
case 1:
case 2:
cbOutDecode -= 2;
break;
case 3:
cbOutDecode--;
break;
}
pbOutT = pbOut;
if (NULL == pbOut)
{
pbOutT += cbOutDecode;
}
else
{
// Decode one quantum at a time: 4 bytes ==> 3 bytes
//assert(cbOutDecode <= *pcbOut);
if (cbOutDecode > *pcbOut)
{
*pcbOut = cbOutDecode;
dwErr = ERROR_MORE_DATA;
goto MoreDataError;
}
pchInT = pchIn;
while (cchInDecode > 0)
{
DWORD i;
BYTE ab4[4];
ZeroMemory(ab4, sizeof(ab4));
for (i = 0; i < min(sizeof(ab4)/sizeof(ab4[0]), cchInDecode); i++)
{
while (
sizeof(abDecode) > (unsigned) *pchInT &&
63 < abDecode[*pchInT])
{
pchInT++;
}
assert(pchInT < pchInEnd);
ab4[i] = (BYTE) *pchInT++;
}
// Translate 4 input characters into 6 bits each, and deposit the
// resulting 24 bits into 3 output bytes by shifting as appropriate.
// out[0] = in[0]:in[1] 6:2
// out[1] = in[1]:in[2] 4:4
// out[2] = in[2]:in[3] 2:6
*pbOutT++ =
(BYTE) ((abDecode[ab4[0]] << 2) | (abDecode[ab4[1]] >> 4));
if (i > 2)
{
*pbOutT++ =
(BYTE) ((abDecode[ab4[1]] << 4) | (abDecode[ab4[2]] >> 2));
}
if (i > 3)
{
*pbOutT++ = (BYTE) ((abDecode[ab4[2]] << 6) | abDecode[ab4[3]]);
}
cchInDecode -= i;
}
assert((DWORD) (pbOutT - pbOut) <= cbOutDecode);
}
*pcbOut = SAFE_SUBTRACT_POINTERS(pbOutT, pbOut);
dwErr = ERROR_SUCCESS;
ErrorReturn:
return dwErr;
SET_ERROR(MoreDataError, dwErr)
SET_ERROR(BadBase64Data, dwErr)
#ifdef BASE64_STRICT
SET_ERROR(BadTrailingBase64Data, dwErr)
#endif
}
// Encode a BYTE array into a Base64 text string.
// Use CR-LF pairs for line breaks, unless CRYPT_STRING_NOCR is set.
// Do not '\0' terminate the text string -- that's handled by the caller.
// Do not add -----BEGIN/END headers -- that's also handled by the caller.
DWORD
Base64EncodeA(
IN BYTE const *pbIn,
IN DWORD cbIn,
IN DWORD Flags,
OPTIONAL OUT TCHAR *pchOut,
IN OUT DWORD *pcchOut)
{
DWORD dwErr;
TCHAR *pchOutT;
DWORD cchOutEncode;
BOOL fNoCR = 0 != (CRYPT_STRING_NOCR & Flags);
// Allocate enough memory for full final translation quantum.
cchOutEncode = ((cbIn + 2) / 3) * 4;
// and enough for CR-LF pairs for every CB_BASE64LINEMAX character line.
cchOutEncode +=
(fNoCR? 1 : 2) *
((cchOutEncode + CB_BASE64LINEMAX - 1) / CB_BASE64LINEMAX);
pchOutT = pchOut;
if (NULL == pchOut)
{
pchOutT += cchOutEncode;
//printf("cchOut: =%x Computed=%x\n", (DWORD) (pchOutT - pchOut), cchOutEncode);
}
else
{
DWORD cCol;
if (cchOutEncode > *pcchOut)
{
*pcchOut = cchOutEncode;
dwErr = ERROR_MORE_DATA;
goto MoreDataError;
}
cCol = 0;
while ((long) cbIn > 0) // signed comparison -- cbIn can wrap
{
BYTE ab3[3];
if (cCol == CB_BASE64LINEMAX/4)
{
cCol = 0;
if (!fNoCR)
{
*pchOutT++ = '\r';
}
*pchOutT++ = '\n';
}
cCol++;
ZeroMemory(ab3, sizeof(ab3));
ab3[0] = *pbIn++;
if (cbIn > 1)
{
ab3[1] = *pbIn++;
if (cbIn > 2)
{
ab3[2] = *pbIn++;
}
}
*pchOutT++ = abEncode[ab3[0] >> 2];
*pchOutT++ = abEncode[((ab3[0] << 4) | (ab3[1] >> 4)) & 0x3f];
*pchOutT++ = (cbIn > 1)?
abEncode[((ab3[1] << 2) | (ab3[2] >> 6)) & 0x3f] : '=';
*pchOutT++ = (cbIn > 2)? abEncode[ab3[2] & 0x3f] : '=';
cbIn -= 3;
}
// Append CR-LF only if there was input data
if (pchOutT != pchOut)
{
if (!fNoCR)
{
*pchOutT++ = '\r';
}
*pchOutT++ = '\n';
}
//printf("cchOut: Actual=%x Computed=%x Buffer=%x\n", (DWORD) (pchOutT - pchOut), cchOutEncode, *pcchOut);
assert((DWORD) (pchOutT - pchOut) == cchOutEncode);
}
*pcchOut = SAFE_SUBTRACT_POINTERS(pchOutT, pchOut);
dwErr = ERROR_SUCCESS;
ErrorReturn:
return dwErr;
SET_ERROR(MoreDataError, dwErr)
}
DWORD
Base64EncodeW(
IN BYTE const *pbIn,
IN DWORD cbIn,
IN DWORD Flags,
OUT WCHAR *wszOut,
OUT DWORD *pcchOut)
{
DWORD cchOut;
CHAR *pch = NULL;
DWORD cch;
DWORD err;
assert(pcchOut != NULL);
// only want to know how much to allocate
// we know all base64 char map 1-1 with unicode
if (wszOut == NULL)
{
// get the number of characters
*pcchOut = 0;
err = Base64EncodeA(pbIn, cbIn, Flags, NULL, pcchOut);
}
// otherwise we have an output buffer
else {
// char count is the same be it ascii or unicode,
cchOut = *pcchOut;
cch = 0;
err = ERROR_OUTOFMEMORY;
pch = (CHAR *) malloc(cchOut);
if (NULL != pch)
{
err = Base64EncodeA(pbIn, cbIn, Flags, pch, &cchOut);
if (ERROR_SUCCESS == err)
{
// should not fail!
cch = MultiByteToWideChar(0, 0, pch, cchOut, wszOut, *pcchOut);
// check to make sure we did not fail
assert(*pcchOut == 0 || cch != 0);
}
}
}
if(pch != NULL)
free(pch);
return(err);
}
DWORD
Base64DecodeW(
IN const WCHAR * wszIn,
IN DWORD cch,
OUT BYTE *pbOut,
OUT DWORD *pcbOut)
{
CHAR *pch;
DWORD err = ERROR_SUCCESS;
// in all cases we need to convert to an ascii string
// we know the ascii string is less
if ((pch = (CHAR *) malloc(cch)) == NULL)
{
err = ERROR_OUTOFMEMORY;
}
// we know no base64 wide char map to more than 1 ascii char
else if (WideCharToMultiByte(0, 0, wszIn, cch, pch, cch, NULL, NULL) == 0)
{
err = ERROR_NO_DATA;
}
// get the length of the buffer
else if (pbOut == NULL)
{
*pcbOut = 0;
err = Base64Decode(pch, cch, NULL, pcbOut);
}
// otherwise fill in the buffer
else {
err = Base64Decode(pch, cch, pbOut, pcbOut);
}
if(pch != NULL)
free(pch);
return(err);
}