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

115 lines
2.6 KiB

/*
* Copyright (C) 2004 trog@uncon.org
*
* 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 of the License, 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 <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "clamav.h"
#include "others.h"
int cli_check_mydoom_log(int desc, const char **virname)
{
int32_t record[8], check;
int i, retval=CL_VIRUS, j;
cli_dbgmsg("in cli_check_mydoom_log()\n");
/* Check upto the first five records in the file */
for (j=0 ; j<5 ; j++) {
if (cli_readn(desc, &record, 32) != 32) {
break;
}
/* Decode the key */
record[0] = ~ntohl(record[0]);
cli_dbgmsg("Mydoom: key: %lu\n", record[0]);
check = 0;
for (i=1 ; i<8; i++) {
record[i] = ntohl(record[i]) ^ record[0];
check += record[i];
}
cli_dbgmsg("Mydoom: check: %lu\n", ~check);
if ((~check) != record[0]) {
return CL_CLEAN;
}
}
if (j < 2) {
retval = CL_CLEAN;
} else if (retval==CL_VIRUS) {
if(virname)
*virname = "Worm.Mydoom.M.log";
}
return retval;
}
int cli_check_jpeg_exploit(int fd)
{
unsigned char buffer[4];
off_t offset;
int retval;
cli_dbgmsg("in cli_check_jpeg_exploit()\n");
if (cli_readn(fd, buffer, 2) != 2) {
return 0;
}
if ((buffer[0] != 0xff) || (buffer[1] != 0xd8)) {
return 0;
}
for (;;) {
if ((retval=cli_readn(fd, buffer, 4)) != 4) {
return 0;
}
/* Check for multiple 0xFF values, we need to skip them */
if ((buffer[0] == 0xff) && (buffer[1] == 0xff)) {
lseek(fd, -3, SEEK_CUR);
continue;
}
if ((buffer[0] == 0xff) && (buffer[1] == 0xfe)) {
if (buffer[2] == 0x00) {
if ((buffer[3] == 0x00) || (buffer[3] == 0x01)) {
return 1;
}
}
}
if (buffer[0] != 0xff) {
return -1;
}
if (buffer[1] == 0xda) {
/* End of Image marker */
return 0;
}
offset = ((unsigned int) buffer[2] << 8) + buffer[3];
if (offset < 2) {
return 2;
}
offset -= 2;
offset += lseek(fd, 0, SEEK_CUR);
if (lseek(fd, offset, SEEK_SET) != offset) {
return -1;
}
}
}