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

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/*
* Copyright (C) 2002 - 2004 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 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.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <netinet/in.h>
#if HAVE_MMAP
#if HAVE_SYS_MMAN_H
#include <sys/mman.h>
#else /* HAVE_SYS_MMAN_H */
#undef HAVE_MMAP
#endif
#endif
#include <mspack.h>
#ifdef CL_THREAD_SAFE
# include <pthread.h>
pthread_mutex_t cli_scanrar_mutex = PTHREAD_MUTEX_INITIALIZER;
#endif
int cli_scanrar_inuse = 0;
extern short cli_leavetemps_flag;
extern int cli_mbox(const char *dir, int desc, unsigned int options); /* FIXME */
#include "clamav.h"
#include "others.h"
#include "scanners.h"
#include "matcher-ac.h"
#include "matcher-bm.h"
#include "matcher.h"
#include "unrarlib.h"
#include "ole2_extract.h"
#include "vba_extract.h"
#include "msexpand.h"
#include "chmunpack.h"
#include "pe.h"
#include "filetypes.h"
#include "htmlnorm.h"
#include "untar.h"
#ifdef HAVE_ZLIB_H
#include <zlib.h>
#include <zzip.h>
#endif
#ifdef HAVE_BZLIB_H
#include <bzlib.h>
#endif
#define SCAN_ARCHIVE (options & CL_ARCHIVE)
#define SCAN_MAIL (options & CL_MAIL)
#define SCAN_OLE2 (options & CL_OLE2)
#define SCAN_HTML (options & CL_HTML)
#define SCAN_PE (options & CL_PE)
#define DISABLE_RAR (options & CL_DISABLERAR)
#define DETECT_ENCRYPTED (options & CL_ENCRYPTED)
#define BLOCKMAX (options & CL_BLOCKMAX)
#define MAX_MAIL_RECURSION 15
static int cli_scanfile(const char *filename, const char **virname, unsigned long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec);
#ifdef CL_THREAD_SAFE
static void cli_unlock_mutex(void *mtx)
{
cli_dbgmsg("Pthread cancelled. Unlocking mutex.\n");
pthread_mutex_unlock(mtx);
}
#endif
static int cli_scanrar(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
FILE *tmp = NULL;
int files = 0, fd, ret = CL_CLEAN, afiles;
ArchiveList_struct *rarlist = NULL;
ArchiveList_struct *rarlist_head = NULL;
char *rar_data_ptr;
unsigned long rar_data_size;
cli_dbgmsg("in scanrar()\n");
#ifdef CL_THREAD_SAFE
pthread_cleanup_push(cli_unlock_mutex, &cli_scanrar_mutex);
pthread_mutex_lock(&cli_scanrar_mutex);
cli_scanrar_inuse = 1;
#endif
if(! (afiles = urarlib_list(desc, (ArchiveList_struct *) &rarlist))) {
#ifdef CL_THREAD_SAFE
pthread_mutex_unlock(&cli_scanrar_mutex);
cli_scanrar_inuse = 0;
#endif
return CL_ERAR;
}
cli_dbgmsg("RAR: Number of archived files: %d\n", afiles);
rarlist_head = rarlist;
while(rarlist) {
if(DETECT_ENCRYPTED && (rarlist->item.Flags & 4)) {
files++;
cli_dbgmsg("RAR: Encrypted files found in archive.\n");
lseek(desc, 0, SEEK_SET);
if(cli_scandesc(desc, virname, scanned, root, 0) != CL_VIRUS)
*virname = "Encrypted.RAR";
ret = CL_VIRUS;
break;
}
if(limits) {
if(limits->maxratio && rarlist->item.UnpSize && rarlist->item.PackSize) {
if((unsigned int) rarlist->item.UnpSize / (unsigned int) rarlist->item.PackSize >= limits->maxratio) {
cli_dbgmsg("RAR: Max ratio reached (normal: %d, compressed: %d, max: %ld)\n", (int) rarlist->item.UnpSize, (int) rarlist->item.PackSize, limits->maxratio);
*virname = "Oversized.RAR";
ret = CL_VIRUS;
break;
}
}
if(limits->maxfilesize && (rarlist->item.UnpSize > (unsigned int) limits->maxfilesize)) {
cli_dbgmsg("RAR: %s: Size exceeded (%u, max: %lu)\n", rarlist->item.Name, (unsigned int) rarlist->item.UnpSize, limits->maxfilesize);
rarlist = rarlist->next;
files++;
if(BLOCKMAX) {
*virname = "RAR.ExceededFileSize";
ret = CL_VIRUS;
break;
}
continue;
}
if(limits->maxfiles && (files > limits->maxfiles)) {
cli_dbgmsg("RAR: Files limit reached (max: %d)\n", limits->maxfiles);
if(BLOCKMAX) {
*virname = "RAR.ExceededFilesLimit";
ret = CL_VIRUS;
break;
}
break;
}
}
if(!(rarlist->item.FileAttr & RAR_FENTRY_ATTR_DIRECTORY)) {
rarlist = rarlist->next;
files++;
continue;
}
if((tmp = tmpfile()) == NULL) {
cli_dbgmsg("RAR: Can't generate temporary file.\n");
#ifdef CL_THREAD_SAFE
pthread_mutex_unlock(&cli_scanrar_mutex);
cli_scanrar_inuse = 0;
#endif
return CL_ETMPFILE;
}
fd = fileno(tmp);
if( urarlib_get(&rar_data_ptr, &rar_data_size, rarlist->item.Name, desc, "clam")) {
cli_dbgmsg("RAR: Extracted: %s, size: %lu\n", rarlist->item.Name, rar_data_size);
if(fwrite(rar_data_ptr, 1, rar_data_size, tmp) != rar_data_size) {
cli_dbgmsg("RAR: Can't write to file.\n");
fclose(tmp);
tmp = NULL;
ret = CL_ERAR;
if(rar_data_ptr) {
free(rar_data_ptr);
rar_data_ptr = NULL;
}
break;
}
if(rar_data_ptr) {
free(rar_data_ptr);
rar_data_ptr = NULL;
}
if(fflush(tmp) != 0) {
cli_dbgmsg("RAR: fflush() failed: %s\n", strerror(errno));
fclose(tmp);
urarlib_freelist(rarlist_head);
#ifdef CL_THREAD_SAFE
pthread_mutex_unlock(&cli_scanrar_mutex);
cli_scanrar_inuse = 0;
#endif
return CL_EFSYNC;
}
lseek(fd, 0, SEEK_SET);
if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, arec, mrec)) == CL_VIRUS ) {
cli_dbgmsg("RAR: Infected with %s\n", *virname);
fclose(tmp);
urarlib_freelist(rarlist);
#ifdef CL_THREAD_SAFE
pthread_mutex_unlock(&cli_scanrar_mutex);
cli_scanrar_inuse = 0;
#endif
return ret;
}
} else {
cli_dbgmsg("RAR: Can't decompress file %s\n", rarlist->item.Name);
fclose(tmp);
tmp = NULL;
ret = CL_ERAR; /* WinRAR 3.0 ? */
break;
}
fclose(tmp);
tmp = NULL;
rarlist = rarlist->next;
files++;
}
urarlib_freelist(rarlist_head);
#ifdef CL_THREAD_SAFE
pthread_mutex_unlock(&cli_scanrar_mutex);
cli_scanrar_inuse = 0;
pthread_cleanup_pop(0);
#endif
cli_dbgmsg("RAR: Exit code: %d\n", ret);
return ret;
}
#ifdef HAVE_ZLIB_H
static int cli_scanzip(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
ZZIP_DIR *zdir;
ZZIP_DIRENT zdirent;
ZZIP_FILE *zfp;
FILE *tmp = NULL;
char *buff;
int fd, bytes, files = 0, ret = CL_CLEAN;
struct stat source;
zzip_error_t err;
cli_dbgmsg("in scanzip()\n");
if((zdir = zzip_dir_fdopen(dup(desc), &err)) == NULL) {
cli_dbgmsg("Zip: Not supported file format ?.\n");
cli_dbgmsg("Zip: zzip_dir_fdopen() return code: %d\n", err);
/* no return with CL_EZIP due to password protected zips */
return CL_CLEAN;
}
fstat(desc, &source);
if(!(buff = (char *) cli_malloc(FILEBUFF))) {
cli_dbgmsg("Zip: unable to malloc(%d)\n", FILEBUFF);
zzip_dir_close(zdir);
return CL_EMEM;
}
while(zzip_dir_read(zdir, &zdirent)) {
if(!zdirent.d_name || !strlen(zdirent.d_name)) { /* Mimail fix */
cli_dbgmsg("Zip: strlen(zdirent.d_name) == %d\n", strlen(zdirent.d_name));
*virname = "Suspected.Zip";
ret = CL_VIRUS;
break;
}
cli_dbgmsg("Zip: %s, compressed: %u, normal: %u, ratio: %d (max: %d)\n", zdirent.d_name, zdirent.d_csize, zdirent.st_size, zdirent.st_size / (zdirent.d_csize+1), limits ? limits->maxratio : -1 );
if(!zdirent.st_size) { /* omit directories and empty files */
files++;
continue;
}
/* work-around for problematic zips (zziplib crashes with them) */
if(zdirent.d_csize <= 0 || zdirent.st_size < 0) {
files++;
cli_dbgmsg("Zip: Malformed archive detected.\n");
/* ret = CL_EMALFZIP; */
/* report it as a virus */
*virname = "Suspected.Zip";
ret = CL_VIRUS;
break;
}
if(limits && limits->maxratio > 0 && ((unsigned) zdirent.st_size / (unsigned) zdirent.d_csize) >= limits->maxratio) {
*virname = "Oversized.Zip";
ret = CL_VIRUS;
break;
}
if(DETECT_ENCRYPTED && (zdirent.d_flags & 1 )) {
files++;
cli_dbgmsg("Zip: Encrypted files found in archive.\n");
lseek(desc, 0, SEEK_SET);
if(cli_scandesc(desc, virname, scanned, root, 0) != CL_VIRUS)
*virname = "Encrypted.Zip";
ret = CL_VIRUS;
break;
}
if(limits) {
if(limits->maxfilesize && (zdirent.st_size > limits->maxfilesize)) {
cli_dbgmsg("Zip: %s: Size exceeded (%d, max: %ld)\n", zdirent.d_name, zdirent.st_size, limits->maxfilesize);
files++;
/* ret = CL_EMAXSIZE; */
if(BLOCKMAX) {
*virname = "Zip.ExceededFileSize";
ret = CL_VIRUS;
break;
}
continue; /* continue scanning */
}
if(limits->maxfiles && (files > limits->maxfiles)) {
cli_dbgmsg("Zip: Files limit reached (max: %d)\n", limits->maxfiles);
if(BLOCKMAX) {
*virname = "Zip.ExceededFilesLimit";
ret = CL_VIRUS;
break;
}
break;
}
}
/* generate temporary file and get its descriptor */
if((tmp = tmpfile()) == NULL) {
cli_dbgmsg("Zip: Can't generate tmpfile().\n");
ret = CL_ETMPFILE;
break;
}
if((zfp = zzip_file_open(zdir, zdirent.d_name, 0)) == NULL) {
cli_dbgmsg("Zip: Can't open file %s\n", zdirent.d_name);
ret = CL_EZIP;
break;
}
while((bytes = zzip_file_read(zfp, buff, FILEBUFF)) > 0) {
if(fwrite(buff, 1, bytes, tmp) != (size_t) bytes) {
cli_dbgmsg("Zip: Can't write to file.\n");
zzip_file_close(zfp);
zzip_dir_close(zdir);
fclose(tmp);
free(buff);
return CL_EZIP;
}
}
zzip_file_close(zfp);
if(fflush(tmp) != 0) {
cli_dbgmsg("Zip: fflush() failed: %s\n", strerror(errno));
ret = CL_EFSYNC;
break;
}
fd = fileno(tmp);
lseek(fd, 0, SEEK_SET);
if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, arec, mrec)) == CL_VIRUS ) {
cli_dbgmsg("Zip: Infected with %s\n", *virname);
ret = CL_VIRUS;
break;
} else if(ret == CL_EMALFZIP) {
/*
* The trick with detection of ZoD only works with higher (>= 5)
* recursion limit level.
*/
cli_dbgmsg("Zip: Malformed Zip file, scanning stopped.\n");
*virname = "Suspected.Zip";
ret = CL_VIRUS;
break;
}
if (tmp) {
fclose(tmp);
tmp = NULL;
}
files++;
}
zzip_dir_close(zdir);
if (tmp) {
fclose(tmp);
tmp = NULL;
}
free(buff);
return ret;
}
static int cli_scangzip(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
int fd, bytes, ret = CL_CLEAN;
long int size = 0;
char *buff;
FILE *tmp = NULL;
gzFile gd;
cli_dbgmsg("in cli_scangzip()\n");
if((gd = gzdopen(dup(desc), "rb")) == NULL) {
cli_dbgmsg("GZip: Can't open descriptor %d\n", desc);
return CL_EGZIP;
}
if((tmp = tmpfile()) == NULL) {
cli_dbgmsg("GZip: Can't generate temporary file.\n");
gzclose(gd);
return CL_ETMPFILE;
}
fd = fileno(tmp);
if(!(buff = (char *) cli_malloc(FILEBUFF))) {
cli_dbgmsg("GZip: Unable to malloc %d bytes.\n", FILEBUFF);
gzclose(gd);
return CL_EMEM;
}
while((bytes = gzread(gd, buff, FILEBUFF)) > 0) {
size += bytes;
if(limits)
if(limits->maxfilesize && (size + FILEBUFF > limits->maxfilesize)) {
cli_dbgmsg("GZip: Size exceeded (stopped at %ld, max: %ld)\n", size, limits->maxfilesize);
/* ret = CL_EMAXSIZE; */
break;
}
if(cli_writen(fd, buff, bytes) != bytes) {
cli_dbgmsg("GZip: Can't write to file.\n");
fclose(tmp);
gzclose(gd);
free(buff);
return CL_EGZIP;
}
}
free(buff);
gzclose(gd);
if(fsync(fd) == -1) {
cli_dbgmsg("GZip: Can't synchronise descriptor %d\n", fd);
fclose(tmp);
return CL_EFSYNC;
}
lseek(fd, 0, SEEK_SET);
if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, arec, mrec)) == CL_VIRUS ) {
cli_dbgmsg("GZip: Infected with %s\n", *virname);
fclose(tmp);
return CL_VIRUS;
}
fclose(tmp);
return ret;
}
#endif
#ifdef HAVE_BZLIB_H
#ifdef NOBZ2PREFIX
#define BZ2_bzReadOpen bzReadOpen
#define BZ2_bzReadClose bzReadClose
#define BZ2_bzRead bzRead
#endif
static int cli_scanbzip(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
int fd, bytes, ret = CL_CLEAN, bzerror = 0;
short memlim = 0;
long int size = 0;
char *buff;
FILE *fs, *tmp = NULL;
BZFILE *bfd;
if((fs = fdopen(dup(desc), "rb")) == NULL) {
cli_dbgmsg("Bzip: Can't open descriptor %d.\n", desc);
return CL_EBZIP;
}
if(limits)
if(limits->archivememlim)
memlim = 1;
if((bfd = BZ2_bzReadOpen(&bzerror, fs, 0, memlim, NULL, 0)) == NULL) {
cli_dbgmsg("Bzip: Can't initialize bzip2 library (descriptor: %d).\n", desc);
fclose(fs);
return CL_EBZIP;
}
if((tmp = tmpfile()) == NULL) {
cli_dbgmsg("Bzip: Can't generate temporary file.\n");
BZ2_bzReadClose(&bzerror, bfd);
fclose(fs);
return CL_ETMPFILE;
}
fd = fileno(tmp);
if(!(buff = (char *) malloc(FILEBUFF))) {
cli_dbgmsg("Bzip: Unable to malloc %d bytes.\n", FILEBUFF);
fclose(tmp);
fclose(fs);
BZ2_bzReadClose(&bzerror, bfd);
return CL_EMEM;
}
while((bytes = BZ2_bzRead(&bzerror, bfd, buff, FILEBUFF)) > 0) {
size += bytes;
if(limits)
if(limits->maxfilesize && (size + FILEBUFF > limits->maxfilesize)) {
cli_dbgmsg("Bzip: Size exceeded (stopped at %ld, max: %ld)\n", size, limits->maxfilesize);
/* ret = CL_EMAXSIZE; */
break;
}
if(cli_writen(fd, buff, bytes) != bytes) {
cli_dbgmsg("Bzip: Can't write to file.\n");
BZ2_bzReadClose(&bzerror, bfd);
fclose(tmp);
free(buff);
fclose(fs);
return CL_EGZIP;
}
}
free(buff);
BZ2_bzReadClose(&bzerror, bfd);
if(fsync(fd) == -1) {
cli_dbgmsg("Bzip: Synchronisation failed for descriptor %d\n", fd);
fclose(tmp);
fclose(fs);
return CL_EFSYNC;
}
lseek(fd, 0, SEEK_SET);
if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, arec, mrec)) == CL_VIRUS ) {
cli_dbgmsg("Bzip: Infected with %s\n", *virname);
}
fclose(tmp);
fclose(fs);
return ret;
}
#endif
static int cli_scanmscomp(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
int fd, ret = CL_CLEAN;
FILE *tmp = NULL, *in;
cli_dbgmsg("in cli_scanmscomp()\n");
if((in = fdopen(dup(desc), "rb")) == NULL) {
cli_dbgmsg("SZDD: Can't open descriptor %d\n", desc);
return CL_EMSCOMP;
}
if((tmp = tmpfile()) == NULL) {
cli_dbgmsg("SZDD: Can't generate temporary file.\n");
fclose(in);
return CL_ETMPFILE;
}
if(cli_msexpand(in, tmp) == -1) {
cli_dbgmsg("SZDD: msexpand failed.\n");
return CL_EMSCOMP;
}
fclose(in);
if(fflush(tmp)) {
cli_dbgmsg("SZDD: fflush() failed.\n");
fclose(tmp);
return CL_EFSYNC;
}
fd = fileno(tmp);
lseek(fd, 0, SEEK_SET);
if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, arec, mrec)) == CL_VIRUS) {
cli_dbgmsg("SZDD: Infected with %s\n", *virname);
fclose(tmp);
return CL_VIRUS;
}
fclose(tmp);
return ret;
}
static int cli_scanmscab(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
struct mscab_decompressor *cabd = NULL;
struct mscabd_cabinet *base, *cab;
struct mscabd_file *file;
const char *tmpdir;
char *tempname;
int ret = CL_CLEAN;
cli_dbgmsg("in cli_scanmscab()\n");
if((cabd = mspack_create_cab_decompressor(NULL)) == NULL) {
cli_dbgmsg("MSCAB: Can't create libmspack CAB decompressor\n");
return CL_EMSCAB;
}
if((base = cabd->dsearch(cabd, desc)) == NULL) {
cli_dbgmsg("MSCAB: I/O error or no valid cabinets found\n");
mspack_destroy_cab_decompressor(cabd);
return CL_EMSCAB;
}
if((tmpdir = getenv("TMPDIR")) == NULL)
#ifdef P_tmpdir
tmpdir = P_tmpdir;
#else
tmpdir = "/tmp";
#endif
for(cab = base; cab; cab = cab->next) {
for(file = cab->files; file; file = file->next) {
tempname = cli_gentemp(tmpdir);
cli_dbgmsg("MSCAB: Extracting data to %s\n", tempname);
if(cabd->extract(cabd, file, tempname)) {
cli_dbgmsg("MSCAB: libmscab error code: %d\n", cabd->last_error(cabd));
} else {
ret = cli_scanfile(tempname, virname, scanned, root, limits, options, arec, mrec);
}
if(!cli_leavetemps_flag)
unlink(tempname);
free(tempname);
if(ret == CL_VIRUS)
break;
}
if(ret == CL_VIRUS)
break;
}
cabd->close(cabd, base);
mspack_destroy_cab_decompressor(cabd);
return ret;
}
static int cli_scanhtml(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
unsigned char *membuff, *newbuff, *newbuff2;
struct stat statbuf;
int ret;
#ifdef HAVE_MMAP
cli_dbgmsg("in cli_scanhtml()\n");
if(fstat(desc, &statbuf) != 0) {
cli_dbgmsg("HTML: Can't stat descriptor %d\n", desc);
return CL_EIO;
}
if(limits && limits->maxfilesize && (statbuf.st_size > limits->maxfilesize)) {
cli_dbgmsg("HTML: Size exceeded (%d, max: %ld)\n", statbuf.st_size, limits->maxfilesize);
return CL_CLEAN;
}
membuff = mmap(NULL, statbuf.st_size, PROT_READ, MAP_PRIVATE, desc, 0);
/* TODO: do file operations if mmap fails */
if(membuff == MAP_FAILED) {
cli_dbgmsg("HTML: mmap failed\n");
return CL_EMEM;
}
newbuff = html_normalize(membuff, statbuf.st_size);
if(newbuff) {
newbuff2 = remove_html_comments(newbuff);
free(newbuff);
newbuff = remove_html_char_ref(newbuff2);
free(newbuff2);
/* Normalise a second time as the above can leave inconsistent white
* space
*/
newbuff2 = html_normalize(newbuff, strlen(newbuff));
free(newbuff);
newbuff = newbuff2;
}
ret = cl_scanbuff(newbuff, strlen(newbuff), virname, root);
free(newbuff);
munmap(membuff, statbuf.st_size);
return ret;
#else /* FIXME */
return CL_CLEAN;
#endif
}
static int cli_scan_mydoom_log(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
int32_t record[8], check;
int i, retval=CL_VIRUS, j;
cli_dbgmsg("in 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;
}
static int cli_scandir(const char *dirname, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
DIR *dd;
struct dirent *dent;
struct stat statbuf;
char *fname;
if((dd = opendir(dirname)) != NULL) {
while((dent = readdir(dd))) {
#ifndef C_INTERIX
if(dent->d_ino)
#endif
{
if(strcmp(dent->d_name, ".") && strcmp(dent->d_name, "..")) {
/* build the full name */
fname = cli_calloc(strlen(dirname) + strlen(dent->d_name) + 2, sizeof(char));
sprintf(fname, "%s/%s", dirname, dent->d_name);
/* stat the file */
if(lstat(fname, &statbuf) != -1) {
if(S_ISDIR(statbuf.st_mode) && !S_ISLNK(statbuf.st_mode)) {
if (cli_scandir(fname, virname, scanned, root, limits, options, arec, mrec) == CL_VIRUS) {
free(fname);
closedir(dd);
return CL_VIRUS;
}
} else
if(S_ISREG(statbuf.st_mode))
if(cli_scanfile(fname, virname, scanned, root, limits, options, arec, mrec) == CL_VIRUS) {
free(fname);
closedir(dd);
return CL_VIRUS;
}
}
free(fname);
}
}
}
} else {
cli_dbgmsg("ScanDir: Can't open directory %s.\n", dirname);
return CL_EOPEN;
}
closedir(dd);
return 0;
}
static int cli_vba_scandir(const char *dirname, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
int ret = CL_CLEAN, i, fd, data_len;
vba_project_t *vba_project;
DIR *dd;
struct dirent *dent;
struct stat statbuf;
char *fname, *fullname;
unsigned char *data;
cli_dbgmsg("VBADir: %s\n", dirname);
if((vba_project = (vba_project_t *) vba56_dir_read(dirname))) {
for(i = 0; i < vba_project->count; i++) {
fullname = (char *) cli_malloc(strlen(vba_project->dir) + strlen(vba_project->name[i]) + 2);
sprintf(fullname, "%s/%s", vba_project->dir, vba_project->name[i]);
fd = open(fullname, O_RDONLY);
if(fd == -1) {
cli_dbgmsg("VBADir: Can't open file %s\n", fullname);
free(fullname);
ret = CL_EOPEN;
break;
}
free(fullname);
cli_dbgmsg("VBADir: Decompress VBA project '%s'\n", vba_project->name[i]);
data = (unsigned char *) vba_decompress(fd, vba_project->offset[i], &data_len);
close(fd);
if(!data) {
cli_dbgmsg("VBADir: WARNING: VBA project '%s' decompressed to NULL\n", vba_project->name[i]);
} else {
if(cl_scanbuff(data, data_len, virname, root) == CL_VIRUS) {
free(data);
ret = CL_VIRUS;
break;
}
free(data);
}
}
for(i = 0; i < vba_project->count; i++)
free(vba_project->name[i]);
free(vba_project->name);
free(vba_project->dir);
free(vba_project->offset);
free(vba_project);
} else if ((fullname = ppt_vba_read(dirname))) {
if(cli_scandir(fullname, virname, scanned, root, limits, options, arec, mrec) == CL_VIRUS) {
ret = CL_VIRUS;
}
cli_rmdirs(fullname);
free(fullname);
} else if ((vba_project = (vba_project_t *) wm_dir_read(dirname))) {
for (i = 0; i < vba_project->count; i++) {
fullname = (char *) cli_malloc(strlen(vba_project->dir) + strlen(vba_project->name[i]) + 2);
sprintf(fullname, "%s/%s", vba_project->dir, vba_project->name[i]);
fd = open(fullname, O_RDONLY);
if(fd == -1) {
cli_dbgmsg("VBADir: Can't open file %s\n", fullname);
free(fullname);
ret = CL_EOPEN;
break;
}
free(fullname);
cli_dbgmsg("VBADir: Decompress WM project '%s' macro:%d key:%d\n", vba_project->name[i], i, vba_project->key[i]);
data = (unsigned char *) wm_decrypt_macro(fd, vba_project->offset[i], vba_project->length[i], vba_project->key[i]);
close(fd);
if(!data) {
cli_dbgmsg("VBADir: WARNING: WM project '%s' macro %d decrypted to NULL\n", vba_project->name[i], i);
} else {
if(cl_scanbuff(data, vba_project->length[i], virname, root) == CL_VIRUS) {
free(data);
ret = CL_VIRUS;
break;
}
free(data);
}
}
for(i = 0; i < vba_project->count; i++)
free(vba_project->name[i]);
free(vba_project->key);
free(vba_project->length);
free(vba_project->offset);
free(vba_project->name);
free(vba_project->dir);
free(vba_project);
}
if(ret != CL_CLEAN)
return ret;
if((dd = opendir(dirname)) != NULL) {
while((dent = readdir(dd))) {
#ifndef C_INTERIX
if(dent->d_ino)
#endif
{
if(strcmp(dent->d_name, ".") && strcmp(dent->d_name, "..")) {
/* build the full name */
fname = cli_calloc(strlen(dirname) + strlen(dent->d_name) + 2, sizeof(char));
sprintf(fname, "%s/%s", dirname, dent->d_name);
/* stat the file */
if(lstat(fname, &statbuf) != -1) {
if(S_ISDIR(statbuf.st_mode) && !S_ISLNK(statbuf.st_mode))
if (cli_vba_scandir(fname, virname, scanned, root, limits, options, arec, mrec) == CL_VIRUS) {
ret = CL_VIRUS;
free(fname);
break;
}
}
free(fname);
}
}
}
} else {
cli_dbgmsg("VBADir: Can't open directory %s.\n", dirname);
return CL_EOPEN;
}
closedir(dd);
return ret;
}
static int cli_scanole2(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
const char *tmpdir;
char *dir;
int ret = CL_CLEAN;
cli_dbgmsg("in cli_scanole2()\n");
if((tmpdir = getenv("TMPDIR")) == NULL)
#ifdef P_tmpdir
tmpdir = P_tmpdir;
#else
tmpdir = "/tmp";
#endif
/* generate the temporary directory */
dir = cli_gentemp(tmpdir);
if(mkdir(dir, 0700)) {
cli_dbgmsg("OLE2: Can't create temporary directory %s\n", dir);
return CL_ETMPDIR;
}
if((ret = cli_ole2_extract(desc, dir, limits))) {
cli_dbgmsg("OLE2: %s\n", cl_strerror(ret));
cli_rmdirs(dir);
free(dir);
return ret;
}
if((ret = cli_vba_scandir(dir, virname, scanned, root, limits, options, arec, mrec)) != CL_VIRUS) {
if(cli_scandir(dir, virname, scanned, root, limits, options, arec, mrec) == CL_VIRUS) {
ret = CL_VIRUS;
}
}
cli_rmdirs(dir);
free(dir);
return ret;
}
static int cli_scantar(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
const char *tmpdir;
char *dir;
int ret = CL_CLEAN;
cli_dbgmsg("in cli_scantar()\n");
if((tmpdir = getenv("TMPDIR")) == NULL)
#ifdef P_tmpdir
tmpdir = P_tmpdir;
#else
tmpdir = "/tmp";
#endif
/* generate temporary directory */
dir = cli_gentemp(tmpdir);
if(mkdir(dir, 0700)) {
cli_errmsg("Tar: Can't create temporary directory %s\n", dir);
return CL_ETMPDIR;
}
if((ret = cli_untar(dir, desc)))
cli_dbgmsg("Tar: %s\n", cl_strerror(ret));
else
ret = cli_scandir(dir, virname, scanned, root, limits, options, arec, mrec);
if(!cli_leavetemps_flag)
cli_rmdirs(dir);
free(dir);
return ret;
}
static int cli_scanmschm(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
const char *tmpdir;
char *tempname;
int ret = CL_CLEAN;
cli_dbgmsg("in cli_scanmschm()\n");
if((tmpdir = getenv("TMPDIR")) == NULL)
#ifdef P_tmpdir
tmpdir = P_tmpdir;
#else
tmpdir = "/tmp";
#endif
tempname = cli_gentemp(tmpdir);
if(mkdir(tempname, 0700)) {
cli_dbgmsg("CHM: Can't create temporary directory %s\n", tempname);
return CL_ETMPDIR;
}
if(chm_unpack(desc, tempname))
ret = cli_scandir(tempname, virname, scanned, root, limits, options, arec, mrec);
if(!cli_leavetemps_flag)
cli_rmdirs(tempname);
free(tempname);
return ret;
}
static int cli_scanmail(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
const char *tmpdir;
char *dir;
int ret;
cli_dbgmsg("Starting cli_scanmail(), mrec == %d, arec == %d\n", *mrec, *arec);
if((tmpdir = getenv("TMPDIR")) == NULL)
#ifdef P_tmpdir
tmpdir = P_tmpdir;
#else
tmpdir = "/tmp";
#endif
/* generate the temporary directory */
dir = cli_gentemp(tmpdir);
if(mkdir(dir, 0700)) {
cli_dbgmsg("Mail: Can't create temporary directory %s\n", dir);
return CL_ETMPDIR;
}
/*
* Extract the attachments into the temporary directory
*/
ret = cli_mbox(dir, desc, options);
/* FIXME: check mbox return code */
ret = cli_scandir(dir, virname, scanned, root, limits, options, arec, mrec);
cli_rmdirs(dir);
free(dir);
return ret;
}
int cli_magic_scandesc(int desc, const char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
char magic[MAGIC_BUFFER_SIZE + 1];
int ret = CL_CLEAN, nret;
int bread = 0;
cli_file_t type;
if(!root) {
cli_errmsg("CRITICAL: root == NULL\n");
return -1;
}
if(!options) { /* raw mode (stdin, etc.) */
cli_dbgmsg("Raw mode: no support for archives.\n");
if((ret = cli_scandesc(desc, virname, scanned, root, 0) == CL_VIRUS))
cli_dbgmsg("%s found in descriptor %d\n", *virname, desc);
return ret;
}
if(SCAN_ARCHIVE && limits && limits->maxreclevel)
if(*arec > limits->maxreclevel) {
cli_dbgmsg("Archive recursion limit exceeded (arec == %d).\n", *arec);
/* return CL_EMAXREC; */
return CL_CLEAN;
}
if(SCAN_MAIL)
if(*mrec > MAX_MAIL_RECURSION) {
cli_dbgmsg("Mail recursion level exceeded (mrec == %d).\n", *mrec);
/* return CL_EMAXREC; */
return CL_CLEAN;
}
lseek(desc, 0, SEEK_SET);
memset(magic, 0, sizeof(magic));
if((bread = read(desc, magic, MAGIC_BUFFER_SIZE)) == -1) {
cli_dbgmsg("Can't read from descriptor %d\n");
return CL_EIO;
} else if(bread < 2) {
/* short read - no need to do magic */
return CL_CLEAN;
}
lseek(desc, 0, SEEK_SET);
type = cli_filetype(magic, bread);
type == CL_MAILFILE ? (*mrec)++ : (*arec)++;
switch(type) {
case CL_RARFILE:
if(!DISABLE_RAR && SCAN_ARCHIVE && !cli_scanrar_inuse)
ret = cli_scanrar(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_ZIPFILE:
if(SCAN_ARCHIVE)
ret = cli_scanzip(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_GZFILE:
if(SCAN_ARCHIVE)
ret = cli_scangzip(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_BZFILE:
#ifdef HAVE_BZLIB_H
if(SCAN_ARCHIVE)
ret = cli_scanbzip(desc, virname, scanned, root, limits, options, arec, mrec);
#endif
break;
case CL_MSCFILE:
if(SCAN_ARCHIVE)
ret = cli_scanmscomp(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_MSCABFILE:
if(SCAN_ARCHIVE)
ret = cli_scanmscab(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_MAILFILE:
if(SCAN_MAIL)
ret = cli_scanmail(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_MSCHMFILE:
if(SCAN_ARCHIVE)
ret = cli_scanmschm(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_OLE2FILE:
if(SCAN_OLE2)
ret = cli_scanole2(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_TARFILE:
if(SCAN_ARCHIVE)
ret = cli_scantar(desc, virname, scanned, root, limits, options, arec, mrec);
break;
case CL_DATAFILE:
/* it could be a false positive and a standard DOS .COM file */
{
struct stat s;
if(fstat(desc, &s) == 0 && S_ISREG(s.st_mode) && s.st_size < 65536)
type = CL_UNKNOWN_DATA_TYPE;
}
case CL_UNKNOWN_DATA_TYPE:
ret = cli_scan_mydoom_log(desc, virname, scanned, root, limits, options, arec, mrec);
break;
default:
break;
}
type == CL_MAILFILE ? (*mrec)-- : (*arec)--;
if(type != CL_DATAFILE && ret != CL_VIRUS) { /* scan the raw file */
int typerec;
type == CL_UNKNOWN_TEXT_TYPE ? (typerec = 1) : (typerec = 0);
lseek(desc, 0, SEEK_SET);
if((nret = cli_scandesc(desc, virname, scanned, root, typerec)) == CL_VIRUS) {
cli_dbgmsg("%s found in descriptor %d.\n", *virname, desc);
return CL_VIRUS;
} else if(nret >= CL_TYPENO) {
lseek(desc, 0, SEEK_SET);
switch(nret) {
case CL_HTMLFILE:
if(SCAN_HTML)
if(cli_scanhtml(desc, virname, scanned, root, limits, options, arec, mrec) == CL_VIRUS)
return CL_VIRUS;
break;
case CL_MAILFILE:
if(SCAN_MAIL)
if(cli_scanmail(desc, virname, scanned, root, limits, options, arec, mrec) == CL_VIRUS)
return CL_VIRUS;
break;
}
}
}
(*arec)++;
lseek(desc, 0, SEEK_SET);
switch(type) {
/* Due to performance reasons all executables were first scanned
* in raw mode. Now we will try to unpack them
*/
case CL_DOSEXE:
if(SCAN_PE)
ret = cli_scanpe(desc, virname, scanned, root, limits, options, arec, mrec);
break;
default:
break;
}
(*arec)--;
return ret;
}
int cl_scandesc(int desc, const char **virname, unsigned long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options)
{
int arec = 0, mrec = 0;
return cli_magic_scandesc(desc, virname, scanned, root, limits, options, &arec, &mrec);
}
static int cli_scanfile(const char *filename, const char **virname, unsigned long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *arec, int *mrec)
{
int fd, ret;
/* internal version of cl_scanfile with arec/mrec preserved */
if((fd = open(filename, O_RDONLY)) == -1)
return CL_EOPEN;
ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, arec, mrec);
close(fd);
return ret;
}
int cl_scanfile(const char *filename, const char **virname, unsigned long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options)
{
int fd, ret;
if((fd = open(filename, O_RDONLY)) == -1)
return CL_EOPEN;
ret = cl_scandesc(fd, virname, scanned, root, limits, options);
close(fd);
return ret;
}