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/*
* Copyright (C) 2015 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2007-2008 Sourcefire, Inc.
*
* Authors: Tomasz Kojm
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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 Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <stdio.h>
#include <stddef.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include "clamav.h"
#include "cltypes.h"
#include "others.h"
#include "msexpand.h"
#include "fmap.h"
#ifndef HAVE_ATTRIB_PACKED
#define __attribute__(x)
#endif
#ifdef HAVE_PRAGMA_PACK
#pragma pack(1)
#endif
#ifdef HAVE_PRAGMA_PACK_HPPA
#pragma pack 1
#endif
#define EC32(x) le32_to_host(x)
#define EC16(x) le16_to_host(x)
#define MAGIC1 0x44445a53
#define MAGIC2 0x3327f088
#define MAGIC3 0x0041
struct msexp_hdr {
uint32_t magic1;
uint32_t magic2;
uint16_t magic3;
uint32_t fsize;
} __attribute__((packed));
#ifdef HAVE_PRAGMA_PACK
#pragma pack()
#endif
#ifdef HAVE_PRAGMA_PACK_HPPA
#pragma pack
#endif
#define B_SIZE 4096
#define RW_SIZE 2048
#define READBYTES \
rbytes = MIN(RW_SIZE, map->len - cur_off); \
if(!rbytes) \
break; \
rbuff = fmap_need_off_once(map, cur_off, rbytes); \
if(!rbuff) \
return CL_EREAD; \
cur_off += rbytes; \
r = 0;
#define WRITEBYTES \
ret = cli_writen(ofd, wbuff, w); \
if(ret == -1 || (unsigned int) ret != w) \
return CL_EWRITE; \
wbytes += w; \
if(wbytes >= fsize) \
return CL_SUCCESS; \
w = 0;
int cli_msexpand(cli_ctx *ctx, int ofd)
{
const struct msexp_hdr *hdr;
uint8_t i, mask, bits;
unsigned char buff[B_SIZE], wbuff[RW_SIZE];
const unsigned char *rbuff;
unsigned int j = B_SIZE - 16, k, l, r = 0, w = 0, rbytes = 0, wbytes = 0;
fmap_t *map = *ctx->fmap;
off_t cur_off = sizeof(*hdr);
unsigned int fsize;
int ret;
if(!(hdr = fmap_need_off_once(map, 0, sizeof(*hdr))))
return CL_EREAD;
if(EC32(hdr->magic1) != MAGIC1 || EC32(hdr->magic2) != MAGIC2 || EC16(hdr->magic3) != MAGIC3) {
cli_dbgmsg("MSEXPAND: Not supported file format\n");
return CL_EFORMAT;
}
fsize = EC32(hdr->fsize);
cli_dbgmsg("MSEXPAND: File size from header: %u\n", fsize);
if(cli_checklimits("MSEXPAND", ctx, fsize, 0, 0)!=CL_CLEAN)
return CL_SUCCESS;
memset(buff, 0, B_SIZE);
while(1) {
if(!rbytes || (r == rbytes)) {
READBYTES;
}
bits = rbuff[r]; r++;
mask = 1;
for(i = 0; i < 8; i++) {
if(bits & mask) {
if(r == rbytes) {
READBYTES;
}
if(w == RW_SIZE) {
WRITEBYTES;
}
wbuff[w] = buff[j] = rbuff[r];
r++; w++;
j++; j %= B_SIZE;
} else {
if(r == rbytes) {
READBYTES;
}
k = rbuff[r]; r++;
if(r == rbytes) {
READBYTES;
}
l = rbuff[r]; r++;
k += (l & 0xf0) << 4;
l = (l & 0x0f) + 3;
while(l--) {
if(w == RW_SIZE) {
WRITEBYTES;
}
wbuff[w] = buff[j] = buff[k];
w++;
k++; k %= B_SIZE;
j++; j %= B_SIZE;
}
}
mask *= 2;
}
}
if(w) {
WRITEBYTES;
}
return CL_SUCCESS;
}
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