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denyhosts/clamav/libclamav/cpio.c

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C
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/*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2009-2013 Sourcefire, Inc.
*
* Authors: 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 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 <string.h>
#include <ctype.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "clamav.h"
#include "others.h"
#include "cpio.h"
#include "scanners.h"
#include "matcher.h"
struct cpio_hdr_old {
uint16_t magic;
uint16_t dev;
uint16_t ino;
uint16_t mode;
uint16_t uid;
uint16_t gid;
uint16_t nlink;
uint16_t rdev;
uint16_t mtime[2];
uint16_t namesize;
uint16_t filesize[2];
};
struct cpio_hdr_odc {
char magic[6];
char dev[6];
char ino[6];
char mode[6];
char uid[6];
char gid[6];
char nlink[6];
char rdev[6];
char mtime[11];
char namesize[6];
char filesize[11];
};
struct cpio_hdr_newc {
char magic[6];
char ino[8];
char mode[8];
char uid[8];
char gid[8];
char nlink[8];
char mtime[8];
char filesize[8];
char devmajor[8];
char devminor[8];
char rdevmajor[8];
char rdevminor[8];
char namesize[8];
char check[8];
};
#define EC16(v, conv) (conv ? cbswap16(v) : v)
static void sanitname(char *name)
{
while (*name) {
if (!isascii(*name) || strchr("%\\\t\n\r", *name))
*name = '_';
name++;
}
}
cl_error_t cli_scancpio_old(cli_ctx *ctx)
{
cl_error_t status = CL_SUCCESS;
struct cpio_hdr_old hdr_old;
char *fmap_name = NULL;
char name[513];
unsigned int file = 0, trailer = 0;
uint32_t filesize, namesize, hdr_namesize;
int conv;
size_t pos = 0;
memset(name, 0, sizeof(name));
while (fmap_readn(ctx->fmap, &hdr_old, pos, sizeof(hdr_old)) == sizeof(hdr_old)) {
pos += sizeof(hdr_old);
if (!hdr_old.magic && trailer) {
status = CL_SUCCESS;
goto done;
}
if (hdr_old.magic == 070707) {
conv = 0;
} else if (hdr_old.magic == 0143561) {
conv = 1;
} else {
cli_dbgmsg("cli_scancpio_old: Invalid magic number\n");
status = CL_EFORMAT;
goto done;
}
cli_dbgmsg("CPIO: -- File %u --\n", ++file);
if (hdr_old.namesize) {
hdr_namesize = EC16(hdr_old.namesize, conv);
namesize = MIN(sizeof(name), hdr_namesize);
if (fmap_readn(ctx->fmap, &name, pos, namesize) != namesize) {
cli_dbgmsg("cli_scancpio_old: Can't read file name\n");
status = CL_EFORMAT;
goto done;
}
pos += namesize;
name[namesize - 1] = 0;
sanitname(name);
cli_dbgmsg("CPIO: Name: %s\n", name);
if (!strcmp(name, "TRAILER!!!")) {
trailer = 1;
}
if (namesize < hdr_namesize) {
if (hdr_namesize % 2) {
hdr_namesize++;
}
pos += hdr_namesize - namesize;
} else if (hdr_namesize % 2) {
pos++;
}
fmap_name = name;
}
filesize = (uint32_t)((uint32_t)EC16(hdr_old.filesize[0], conv) << 16 | EC16(hdr_old.filesize[1], conv));
cli_dbgmsg("CPIO: Filesize: %u\n", filesize);
if (!filesize)
continue;
status = cli_matchmeta(ctx, name, filesize, filesize, 0, file, 0, NULL);
if (status != CL_SUCCESS) {
goto done;
}
if ((EC16(hdr_old.mode, conv) & 0170000) != 0100000) {
cli_dbgmsg("CPIO: Not a regular file, skipping\n");
} else {
status = cli_magic_scan_nested_fmap_type(ctx->fmap, pos, filesize, ctx, CL_TYPE_ANY, fmap_name, LAYER_ATTRIBUTES_NONE);
if (status != CL_SUCCESS) {
goto done;
}
}
if (filesize % 2) {
filesize++;
}
pos += filesize;
}
done:
return status;
}
cl_error_t cli_scancpio_odc(cli_ctx *ctx)
{
cl_error_t status = CL_SUCCESS;
struct cpio_hdr_odc hdr_odc;
char name[513] = {0}, buff[12] = {0};
unsigned int file = 0, trailer = 0;
uint32_t filesize = 0, namesize = 0, hdr_namesize = 0;
size_t pos = 0;
memset(&hdr_odc, 0, sizeof(hdr_odc));
while (fmap_readn(ctx->fmap, &hdr_odc, pos, sizeof(hdr_odc)) == sizeof(hdr_odc)) {
pos += sizeof(hdr_odc);
if (!hdr_odc.magic[0] && trailer) {
status = CL_SUCCESS;
goto done;
}
if (strncmp(hdr_odc.magic, "070707", 6)) {
cli_dbgmsg("cli_scancpio_odc: Invalid magic string\n");
status = CL_EFORMAT;
goto done;
}
cli_dbgmsg("CPIO: -- File %u --\n", ++file);
strncpy(buff, hdr_odc.namesize, 6);
buff[6] = 0;
if (sscanf(buff, "%o", &hdr_namesize) != 1) {
cli_dbgmsg("cli_scancpio_odc: Can't convert name size\n");
status = CL_EFORMAT;
goto done;
}
if (hdr_namesize) {
namesize = MIN(sizeof(name), hdr_namesize);
if (fmap_readn(ctx->fmap, &name, pos, namesize) != namesize) {
cli_dbgmsg("cli_scancpio_odc: Can't read file name\n");
status = CL_EFORMAT;
goto done;
}
pos += namesize;
name[namesize - 1] = 0;
sanitname(name);
cli_dbgmsg("CPIO: Name: %s\n", name);
if (!strcmp(name, "TRAILER!!!")) {
trailer = 1;
}
if (namesize < hdr_namesize) {
pos += hdr_namesize - namesize;
}
}
strncpy(buff, hdr_odc.filesize, 11);
buff[11] = 0;
if (sscanf(buff, "%o", &filesize) != 1) {
cli_dbgmsg("cli_scancpio_odc: Can't convert file size\n");
status = CL_EFORMAT;
goto done;
}
cli_dbgmsg("CPIO: Filesize: %u\n", filesize);
if (!filesize) {
continue;
}
status = cli_matchmeta(ctx, name, filesize, filesize, 0, file, 0, NULL);
if (status == CL_VIRUS) {
goto done;
}
status = cli_magic_scan_nested_fmap_type(ctx->fmap, pos, filesize, ctx, CL_TYPE_ANY, name, LAYER_ATTRIBUTES_NONE);
if (status != CL_SUCCESS) {
goto done;
}
pos += filesize;
}
done:
return status;
}
cl_error_t cli_scancpio_newc(cli_ctx *ctx, int crc)
{
cl_error_t status = CL_SUCCESS;
struct cpio_hdr_newc hdr_newc;
char name[513], buff[9];
unsigned int file = 0, trailer = 0;
uint32_t filesize, namesize, hdr_namesize, pad;
size_t pos = 0;
memset(name, 0, 513);
while (fmap_readn(ctx->fmap, &hdr_newc, pos, sizeof(hdr_newc)) == sizeof(hdr_newc)) {
pos += sizeof(hdr_newc);
if (!hdr_newc.magic[0] && trailer) {
status = CL_SUCCESS;
goto done;
}
if ((!crc && strncmp(hdr_newc.magic, "070701", 6)) || (crc && strncmp(hdr_newc.magic, "070702", 6))) {
cli_dbgmsg("cli_scancpio_newc: Invalid magic string\n");
status = CL_EFORMAT;
goto done;
}
cli_dbgmsg("CPIO: -- File %u --\n", ++file);
strncpy(buff, hdr_newc.namesize, 8);
buff[8] = 0;
if (sscanf(buff, "%x", &hdr_namesize) != 1) {
cli_dbgmsg("cli_scancpio_newc: Can't convert name size\n");
status = CL_EFORMAT;
goto done;
}
if (hdr_namesize) {
namesize = MIN(sizeof(name), hdr_namesize);
if (fmap_readn(ctx->fmap, &name, pos, namesize) != namesize) {
cli_dbgmsg("cli_scancpio_newc: Can't read file name\n");
status = CL_EFORMAT;
goto done;
}
pos += namesize;
name[namesize - 1] = 0;
sanitname(name);
cli_dbgmsg("CPIO: Name: %s\n", name);
if (!strcmp(name, "TRAILER!!!")) {
trailer = 1;
}
pad = (4 - (sizeof(hdr_newc) + hdr_namesize) % 4) % 4;
if (namesize < hdr_namesize) {
if (pad) {
hdr_namesize += pad;
}
pos += hdr_namesize - namesize;
} else if (pad) {
pos += pad;
}
}
strncpy(buff, hdr_newc.filesize, 8);
buff[8] = 0;
if (sscanf(buff, "%x", &filesize) != 1) {
cli_dbgmsg("cli_scancpio_newc: Can't convert file size\n");
status = CL_EFORMAT;
goto done;
}
cli_dbgmsg("CPIO: Filesize: %u\n", filesize);
if (!filesize) {
continue;
}
status = cli_matchmeta(ctx, name, filesize, filesize, 0, file, 0, NULL);
if (status == CL_VIRUS) {
goto done;
}
status = cli_magic_scan_nested_fmap_type(ctx->fmap, pos, filesize, ctx, CL_TYPE_ANY, name, LAYER_ATTRIBUTES_NONE);
if (status != CL_SUCCESS) {
goto done;
}
if ((pad = filesize % 4)) {
filesize += (4 - pad);
}
pos += filesize;
}
done:
return status;
}
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