/*
* 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 <string.h>
#include <stdlib.h>
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "clamav.h"
#include "filetypes.h"
#include "others.h"
#include "readdb.h"
#include "matcher-ac.h"
#include "str.h"
#include "textdet.h"
#include "default.h"
#include "htmlnorm.h"
#include "entconv.h"
#include "mpool.h"
static const struct ftmap_s {
const char *name;
cli_file_t code;
} ftmap[] = {
{ "CL_TYPE_TEXT_ASCII", CL_TYPE_TEXT_ASCII },
{ "CL_TYPE_TEXT_UTF8", CL_TYPE_TEXT_UTF8 },
{ "CL_TYPE_TEXT_UTF16LE", CL_TYPE_TEXT_UTF16LE },
{ "CL_TYPE_TEXT_UTF16BE", CL_TYPE_TEXT_UTF16BE },
{ "CL_TYPE_BINARY_DATA", CL_TYPE_BINARY_DATA },
{ "CL_TYPE_IGNORED", CL_TYPE_IGNORED },
{ "CL_TYPE_ANY", CL_TYPE_ANY },
{ "CL_TYPE_MSEXE", CL_TYPE_MSEXE },
{ "CL_TYPE_ELF", CL_TYPE_ELF },
{ "CL_TYPE_MACHO", CL_TYPE_MACHO },
{ "CL_TYPE_MACHO_UNIBIN", CL_TYPE_MACHO_UNIBIN },
{ "CL_TYPE_POSIX_TAR", CL_TYPE_POSIX_TAR },
{ "CL_TYPE_OLD_TAR", CL_TYPE_OLD_TAR },
{ "CL_TYPE_CPIO_OLD", CL_TYPE_CPIO_OLD },
{ "CL_TYPE_CPIO_ODC", CL_TYPE_CPIO_ODC },
{ "CL_TYPE_CPIO_NEWC", CL_TYPE_CPIO_NEWC },
{ "CL_TYPE_CPIO_CRC", CL_TYPE_CPIO_CRC },
{ "CL_TYPE_GZ", CL_TYPE_GZ },
{ "CL_TYPE_ZIP", CL_TYPE_ZIP },
{ "CL_TYPE_BZ", CL_TYPE_BZ },
{ "CL_TYPE_RAR", CL_TYPE_RAR },
{ "CL_TYPE_ARJ", CL_TYPE_ARJ },
{ "CL_TYPE_MSSZDD", CL_TYPE_MSSZDD },
{ "CL_TYPE_MSOLE2", CL_TYPE_MSOLE2 },
{ "CL_TYPE_MSCAB", CL_TYPE_MSCAB },
{ "CL_TYPE_MSCHM", CL_TYPE_MSCHM },
{ "CL_TYPE_SIS", CL_TYPE_SIS },
{ "CL_TYPE_SCRENC", CL_TYPE_SCRENC },
{ "CL_TYPE_GRAPHICS", CL_TYPE_GRAPHICS },
{ "CL_TYPE_RIFF", CL_TYPE_RIFF },
{ "CL_TYPE_BINHEX", CL_TYPE_BINHEX },
{ "CL_TYPE_TNEF", CL_TYPE_TNEF },
{ "CL_TYPE_CRYPTFF", CL_TYPE_CRYPTFF },
{ "CL_TYPE_PDF", CL_TYPE_PDF },
{ "CL_TYPE_UUENCODED", CL_TYPE_UUENCODED },
{ "CL_TYPE_HTML_UTF16", CL_TYPE_HTML_UTF16 },
{ "CL_TYPE_SCRIPT", CL_TYPE_SCRIPT },
{ "CL_TYPE_RTF", CL_TYPE_RTF },
{ "CL_TYPE_HTML", CL_TYPE_HTML },
{ "CL_TYPE_MAIL", CL_TYPE_MAIL },
{ "CL_TYPE_SFX", CL_TYPE_SFX },
{ "CL_TYPE_ZIPSFX", CL_TYPE_ZIPSFX },
{ "CL_TYPE_RARSFX", CL_TYPE_RARSFX },
{ "CL_TYPE_CABSFX", CL_TYPE_CABSFX },
{ "CL_TYPE_ARJSFX", CL_TYPE_ARJSFX },
{ "CL_TYPE_NULSFT", CL_TYPE_NULSFT },
{ "CL_TYPE_AUTOIT", CL_TYPE_AUTOIT },
{ "CL_TYPE_ISHIELD_MSI", CL_TYPE_ISHIELD_MSI },
{ "CL_TYPE_7Z", CL_TYPE_7Z },
{ NULL, CL_TYPE_IGNORED }
};
cli_file_t cli_ftcode(const char *name)
{
unsigned int i;
for(i = 0; ftmap[i].name; i++)
if(!strcmp(ftmap[i].name, name))
return ftmap[i].code;
return CL_TYPE_ERROR;
}
void cli_ftfree(const struct cl_engine *engine)
{
struct cli_ftype *ftypes=engine->ftypes, *pt;
while(ftypes) {
pt = ftypes;
ftypes = ftypes->next;
mpool_free(engine->mempool, pt->magic);
mpool_free(engine->mempool, pt->tname);
mpool_free(engine->mempool, pt);
}
}
cli_file_t cli_filetype(const unsigned char *buf, size_t buflen, const struct cl_engine *engine)
{
struct cli_ftype *ftype = engine->ftypes;
while(ftype) {
if(ftype->offset + ftype->length <= buflen) {
if(!memcmp(buf + ftype->offset, ftype->magic, ftype->length)) {
cli_dbgmsg("Recognized %s file\n", ftype->tname);
return ftype->type;
}
}
ftype = ftype->next;
}
return cli_texttype(buf, buflen);
}
int is_tar(unsigned char *buf, unsigned int nbytes);
cli_file_t cli_filetype2(fmap_t *map, const struct cl_engine *engine)
{
unsigned char *buff, *decoded;
int bread = MIN(map->len, MAGIC_BUFFER_SIZE), sret;
cli_file_t ret = CL_TYPE_BINARY_DATA;
struct cli_matcher *root;
struct cli_ac_data mdata;
if(!engine) {
cli_errmsg("cli_filetype2: engine == NULL\n");
return CL_TYPE_ERROR;
}
buff = fmap_need_off_once(map, 0, bread);
if(!buff)
return CL_TYPE_ERROR;
ret = cli_filetype(buff, bread, engine);
if(ret == CL_TYPE_BINARY_DATA) {
switch(is_tar(buff, bread)) {
case 1:
cli_dbgmsg("Recognized old fashioned tar file\n");
return CL_TYPE_OLD_TAR;
case 2:
cli_dbgmsg("Recognized POSIX tar file\n");
return CL_TYPE_POSIX_TAR;
}
}
if(ret >= CL_TYPE_TEXT_ASCII && ret <= CL_TYPE_BINARY_DATA) {
/* HTML files may contain special characters and could be
* misidentified as BINARY_DATA by cli_filetype()
*/
root = engine->root[0];
if(!root)
return ret;
if(cli_ac_initdata(&mdata, root->ac_partsigs, root->ac_lsigs, root->ac_reloff_num, CLI_DEFAULT_AC_TRACKLEN))
return ret;
sret = cli_ac_scanbuff(buff, bread, NULL, NULL, NULL, engine->root[0], &mdata, 0, ret, NULL, AC_SCAN_FT, NULL);
cli_ac_freedata(&mdata);
if(sret >= CL_TYPENO) {
ret = sret;
} else {
if(cli_ac_initdata(&mdata, root->ac_partsigs, root->ac_lsigs, root->ac_reloff_num, CLI_DEFAULT_AC_TRACKLEN))
return ret;
decoded = (unsigned char *) cli_utf16toascii((char *) buff, bread);
if(decoded) {
sret = cli_ac_scanbuff(decoded, bread / 2, NULL, NULL, NULL, engine->root[0], &mdata, 0, CL_TYPE_TEXT_ASCII, NULL, AC_SCAN_FT, NULL);
free(decoded);
if(sret == CL_TYPE_HTML)
ret = CL_TYPE_HTML_UTF16;
}
cli_ac_freedata(&mdata);
if((((struct cli_dconf*) engine->dconf)->phishing & PHISHING_CONF_ENTCONV) && ret != CL_TYPE_HTML_UTF16) {
const char* encoding;
/* check if we can autodetect this encoding.
* If we can't don't try to detect HTML sig, since
* we just tried that above, and failed */
if((encoding = encoding_detect_bom(buff, bread))) {
unsigned char decodedbuff[(MAGIC_BUFFER_SIZE+1)*2];
m_area_t in_area, out_area;
memset(decodedbuff, 0, sizeof(decodedbuff));
in_area.buffer = (unsigned char *) buff;
in_area.length = bread;
in_area.offset = 0;
out_area.buffer = decodedbuff;
out_area.length = sizeof(decodedbuff);
out_area.offset = 0;
/* in htmlnorm we simply skip over \0 chars, and that allows to parse HTML in any unicode
* (multibyte characters will not be exactly handled, but that is not a problem).
* However when detecting whether a file is HTML or not, we need exact conversion.
* (just eliminating zeros and matching would introduce false positives */
if(encoding_normalize_toascii(&in_area, encoding, &out_area) >= 0 && out_area.length > 0) {
if(cli_ac_initdata(&mdata, root->ac_partsigs, root->ac_lsigs, root->ac_reloff_num, CLI_DEFAULT_AC_TRACKLEN))
return ret;
if(out_area.length > 0) {
sret = cli_ac_scanbuff(decodedbuff, out_area.length, NULL, NULL, NULL, engine->root[0], &mdata, 0, 0, NULL, AC_SCAN_FT, NULL); /* FIXME: can we use CL_TYPE_TEXT_ASCII instead of 0? */
if(sret == CL_TYPE_HTML) {
cli_dbgmsg("cli_filetype2: detected HTML signature in Unicode file\n");
/* htmlnorm is able to handle any unicode now, since it skips null chars */
ret = CL_TYPE_HTML;
}
}
cli_ac_freedata(&mdata);
}
}
}
}
}
return ret;
}