ClamAV is an open source (GPLv2) anti-virus toolkit.
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clamav/clamav-devel/libclamav/msexpand.c

158 lines
3.4 KiB

/*
* msexpand: Microsoft "compress.exe/expand.exe" compatible decompressor
*
* Copyright (c) 2000 Martin Hinner <mhi@penguin.cz>
* Algorithm & data structures by M. Winterhoff <100326.2776@compuserve.com>
*
* Corrected and adapted to ClamAV by Tomasz Kojm <tkojm@clamav.net>
*
* 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include "cltypes.h"
#include "others.h"
int cli_msexpand(FILE *in, FILE *out)
{
int bits, ch, i, j, len, mask;
unsigned char *buffer;
uint32_t magic1, magic2, magic3, filesize;
uint16_t reserved;
if(fread(&magic1, sizeof(magic1), 1, in) != 1) {
return -1;
}
#if WORDS_BIGENDIAN == 1
if(magic1 == 0x535A4444L)
#else
if(magic1 == 0x44445A53L)
#endif
{
if(fread(&magic2, sizeof(magic2), 1, in) != 1) {
return -1;
}
if(fread(&reserved, sizeof(reserved), 1, in) != 1) {
return -1;
}
if(fread(&filesize, sizeof(filesize), 1, in) != 1) {
return -1;
}
#if WORDS_BIGENDIAN == 1
if(magic2 != 0x88F02733L)
#else
if(magic2 != 0x3327F088L)
#endif
{
cli_warnmsg("msexpand: Not a MS-compressed file\n");
return -1;
}
} else
#if WORDS_BIGENDIAN == 1
if(magic1 == 0x4B57414AL)
#else
if(magic1 == 0x4A41574BL)
#endif
{
if(fread(&magic2, sizeof(magic2), 1, in) != 1) {
return -1;
}
if(fread(&magic3, sizeof(magic3), 1, in) != 1) {
return -1;
}
if(fread(&reserved, sizeof(reserved), 1, in) != 1) {
return -1;
}
#if WORDS_BIGENDIAN == 1
if(magic2 != 0x88F027D1L || magic3 != 0x03001200L)
#else
if(magic2 != 0xD127F088L || magic3 != 0x00120003L)
#endif
{
cli_warnmsg("msexpand: Not a MS-compressed file\n");
return -1;
}
cli_warnmsg("msexpand: unsupported version 6.22\n");
return -1;
} else {
cli_warnmsg("msexpand: Not a MS-compressed file\n");
return -1;
}
if((buffer = (unsigned char *) cli_calloc(4096, sizeof(char))) == NULL) {
cli_errmsg("msexpand: Can't allocate memory\n");
return -1;
}
i = 4096 - 16;
while (1) {
if((bits = fgetc(in)) == EOF)
break;
for(mask = 0x01; mask & 0xFF; mask <<= 1) {
if(!(bits & mask)) {
if((j = fgetc(in)) == EOF)
break;
len = fgetc(in);
j += (len & 0xF0) << 4;
len = (len & 15) + 3;
while(len--) {
buffer[i] = buffer[j];
if(fwrite(&buffer[i], sizeof(unsigned char), 1, out) != 1) {
free(buffer);
return -1;
}
j++;
j %= 4096;
i++;
i %= 4096;
}
} else {
if((ch = fgetc(in)) == EOF)
break;
buffer[i] = ch;
if(fwrite(&buffer[i], sizeof(unsigned char), 1, out) != 1) {
free(buffer);
return -1;
}
i++;
i %= 4096;
}
}
}
free(buffer);
return 0;
}