/*
* Copyright (C) 2002 - 2005 Tomasz Kojm <tkojm@clamav.net>
* With enhancements from Thomas Lamy <Thomas.Lamy@in-online.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 <stdlib.h>
#include <ctype.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 "htmlnorm.h"
#include "entconv.h"
struct cli_magic_s {
size_t offset;
const char *magic;
size_t length;
const char *descr;
cli_file_t type;
};
struct cli_smagic_s {
const char *sig;
const char *descr;
cli_file_t type;
};
static const struct cli_magic_s cli_magic[] = {
/* Executables */
{0, "MZ", 2, "DOS/W32 executable/library/driver", CL_TYPE_MSEXE},
{0, "\177ELF", 4, "ELF", CL_TYPE_ELF},
/* Archives */
{0, "Rar!", 4, "RAR", CL_TYPE_RAR},
{0, "PK\003\004", 4, "ZIP", CL_TYPE_ZIP},
{0, "PK00PK\003\004", 8, "ZIP", CL_TYPE_ZIP},
{0, "\037\213", 2, "GZip", CL_TYPE_GZ},
{0, "BZh", 3, "BZip", CL_TYPE_BZ},
{0, "SZDD", 4, "compress.exe'd", CL_TYPE_MSSZDD},
{0, "MSCF", 4, "MS CAB", CL_TYPE_MSCAB},
{0, "ITSF", 4, "MS CHM", CL_TYPE_MSCHM},
{8, "\x19\x04\x00\x10", 4, "SIS", CL_TYPE_SIS},
{0, "#@~^", 4, "SCRENC", CL_TYPE_SCRENC},
{0, "(This file must be converted with BinHex 4.0)",
45, "BinHex", CL_TYPE_BINHEX},
/* Mail */
{0, "From ", 5, "MBox", CL_TYPE_MAIL},
{0, "Received: ", 10, "Raw mail", CL_TYPE_MAIL},
{0, "Return-Path: ", 13, "Maildir", CL_TYPE_MAIL},
{0, "Return-path: ", 13, "Maildir", CL_TYPE_MAIL},
{0, "Delivered-To: ", 14, "Mail", CL_TYPE_MAIL},
{0, "X-UIDL: ", 8, "Mail", CL_TYPE_MAIL},
{0, "X-Apparently-To: ", 17, "Mail", CL_TYPE_MAIL},
{0, "X-Envelope-From: ", 17, "Mail", CL_TYPE_MAIL},
{0, "X-Original-To: ", 15, "Mail", CL_TYPE_MAIL},
{0, "X-Symantec-", 11, "Symantec", CL_TYPE_MAIL},
{0, "X-EVS", 5, "EVS mail", CL_TYPE_MAIL},
{0, "X-Real-To: ", 11, "Mail", CL_TYPE_MAIL},
{0, "X-Sieve: ", 9, "Mail", CL_TYPE_MAIL},
{0, ">From ", 6, "Mail", CL_TYPE_MAIL},
{0, "Date: ", 6, "Mail", CL_TYPE_MAIL},
{0, "Message-Id: ", 12, "Mail", CL_TYPE_MAIL},
{0, "Message-ID: ", 12, "Mail", CL_TYPE_MAIL},
{0, "Envelope-to: ", 13, "Mail", CL_TYPE_MAIL},
{0, "Delivery-date: ", 15, "Mail", CL_TYPE_MAIL},
{0, "To: ", 4, "Mail", CL_TYPE_MAIL},
{0, "Subject: ", 9, "Mail", CL_TYPE_MAIL},
{0, "For: ", 5, "Eserv mail", CL_TYPE_MAIL},
{0, "From: ", 6, "Exim mail", CL_TYPE_MAIL},
{0, "v:\015\012Received: ", 14, "VPOP3 Mail (DOS)", CL_TYPE_MAIL},
{0, "v:\012Received: ", 13, "VPOP3 Mail (UNIX)", CL_TYPE_MAIL},
{0, "Hi. This is the qmail-send", 26, "Qmail bounce", CL_TYPE_MAIL},
{0, "\170\237\076\042", 4, "TNEF", CL_TYPE_TNEF},
{0, "begin ", 6, "UUencoded", CL_TYPE_UUENCODED},
{0, "\041\102\104\116", 4, "PST", CL_TYPE_PST},
/* Graphics (may contain exploits against MS systems) */
{0, "GIF", 3, "GIF", CL_TYPE_GRAPHICS},
{0, "BM", 2, "BMP", CL_TYPE_GRAPHICS},
{0, "\377\330\377", 3, "JPEG", CL_TYPE_GRAPHICS},
{6, "JFIF", 4, "JPEG", CL_TYPE_GRAPHICS},
{6, "Exif", 4, "JPEG", CL_TYPE_GRAPHICS},
{0, "\x89PNG", 4, "PNG", CL_TYPE_GRAPHICS},
{0, "RIFF", 4, "RIFF", CL_TYPE_RIFF},
{0, "RIFX", 4, "RIFX", CL_TYPE_RIFF},
/* Others */
{0, "\320\317\021\340\241\261\032\341", 8, "OLE2 container", CL_TYPE_MSOLE2},
{0, "%PDF-", 5, "PDF document", CL_TYPE_PDF},
{0, "\266\271\254\256\376\377\377\377", 8, "CryptFF", CL_TYPE_CRYPTFF},
{0, "{\\rtf", 5, "RTF", CL_TYPE_RTF},
/* Ignored types */
{0, "\000\000\001\263", 4, "MPEG video stream", CL_TYPE_DATA},
{0, "\000\000\001\272", 4, "MPEG sys stream", CL_TYPE_DATA},
{0, "OggS", 4, "Ogg Stream", CL_TYPE_DATA},
{0, "ID3", 3, "MP3", CL_TYPE_DATA},
{0, "\377\373\220", 3, "MP3", CL_TYPE_DATA},
{0, "%!PS-Adobe-", 11, "PostScript", CL_TYPE_DATA},
{0, "\060\046\262\165\216\146\317", 7, "WMA/WMV/ASF", CL_TYPE_DATA},
{0, ".RMF" , 4, "Real Media File", CL_TYPE_DATA},
{0, NULL, 0, NULL, CL_TYPE_UNKNOWN_DATA}
};
static const struct cli_smagic_s cli_smagic[] = {
/* "\nFrom: " * "\nContent-Type: " */
{"0a46726f6d3a20{-2048}0a436f6e74656e742d547970653a20", "Mail file", CL_TYPE_MAIL},
/* "\nReceived: " * "\nContent-Type: " */
{"0a52656365697665643a20{-2048}0a436f6e74656e742d547970653a20", "Mail file", CL_TYPE_MAIL},
/* "\nReceived: " * "\nContent-type: " */
{"0a52656365697665643a20{-2048}0a436f6e74656e742d747970653a20", "Mail file", CL_TYPE_MAIL},
/* "MIME-Version: " * "\nContent-Type: " */
{"4d494d452d56657273696f6e3a20{-2048}0a436f6e74656e742d547970653a20", "Mail file", CL_TYPE_MAIL},
/* remember the matcher is case sensitive */
{"3c62723e", "HTML data", CL_TYPE_HTML}, /* <br> */
{"3c42723e", "HTML data", CL_TYPE_HTML}, /* <Br> */
{"3c42523e", "HTML data", CL_TYPE_HTML}, /* <BR> */
{"3c703e", "HTML data", CL_TYPE_HTML}, /* <p> */
{"3c503e", "HTML data", CL_TYPE_HTML}, /* <P> */
{"68726566", "HTML data", CL_TYPE_HTML}, /* href */
{"48726566", "HTML data", CL_TYPE_HTML}, /* Href */
{"48524546", "HTML data", CL_TYPE_HTML}, /* HREF */
{"3c68746d6c3e", "HTML data", CL_TYPE_HTML}, /* <html> */
{"3c48544d4c3e", "HTML data", CL_TYPE_HTML}, /* <HTML> */
{"3c48746d6c3e", "HTML data", CL_TYPE_HTML}, /* <Html> */
{"3c686561643e", "HTML data", CL_TYPE_HTML}, /* <head> */
{"3c484541443e", "HTML data", CL_TYPE_HTML}, /* <HEAD> */
{"3c486561643e", "HTML data", CL_TYPE_HTML}, /* <Head> */
{"3c666f6e74", "HTML data", CL_TYPE_HTML}, /* <font */
{"3c466f6e74", "HTML data", CL_TYPE_HTML}, /* <Font */
{"3c464f4e54", "HTML data", CL_TYPE_HTML}, /* <FONT */
{"3c696d67", "HTML data", CL_TYPE_HTML}, /* <img */
{"3c494d47", "HTML data", CL_TYPE_HTML}, /* <IMG */
{"3c496d67", "HTML data", CL_TYPE_HTML}, /* <Img */
{"3c736372697074", "HTML data", CL_TYPE_HTML}, /* <script */
{"3c536372697074", "HTML data", CL_TYPE_HTML}, /* <Script */
{"3c534352495054", "HTML data", CL_TYPE_HTML}, /* <SCRIPT */
{"3c6f626a656374", "HTML data", CL_TYPE_HTML}, /* <object */
{"3c4f626a656374", "HTML data", CL_TYPE_HTML}, /* <Object */
{"3c4f424a454354", "HTML data", CL_TYPE_HTML}, /* <OBJECT */
{"3c696672616d65", "HTML data", CL_TYPE_HTML}, /* <iframe */
{"3c494652414d45", "HTML data", CL_TYPE_HTML}, /* <IFRAME */
{"3c7461626c65", "HTML data", CL_TYPE_HTML}, /* <table */
{"3c5441424c45", "HTML data", CL_TYPE_HTML}, /* <TABLE */
{"526172211a0700", "RAR-SFX", CL_TYPE_RARSFX},
{"504b0304", "ZIP-SFX", CL_TYPE_ZIPSFX},
{"4d534346", "CAB-SFX", CL_TYPE_CABSFX},
{"efbeadde4e756c6c736f6674496e7374", "NSIS", CL_TYPE_NULSFT},
{"4d5a{180-300}50450000", "PE", CL_TYPE_MSEXE},
{NULL, NULL, CL_TYPE_UNKNOWN_DATA}
};
static char internat[256] = {
/* TODO: Remember to buy a beer to Joerg Wunsch <joerg@FreeBSD.ORG> */
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, /* 0x0X */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, /* 0x1X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x2X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x3X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x4X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x5X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x6X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, /* 0x7X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x8X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0x9X */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0xaX */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0xbX */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0xcX */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0xdX */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 0xeX */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 /* 0xfX */
};
cli_file_t cli_filetype(const unsigned char *buf, size_t buflen)
{
int i, text = 1, len;
for(i = 0; cli_magic[i].magic; i++) {
if(buflen >= cli_magic[i].offset+cli_magic[i].length) {
if(memcmp(buf+cli_magic[i].offset, cli_magic[i].magic, cli_magic[i].length) == 0) {
cli_dbgmsg("Recognized %s file\n", cli_magic[i].descr);
return cli_magic[i].type;
}
}
}
/* improve or drop this code
* https://wwws.clamav.net/bugzilla/show_bug.cgi?id=373
*
buflen < 25 ? (len = buflen) : (len = 25);
for(i = 0; i < len; i++)
if(!iscntrl(buf[i]) && !isprint(buf[i]) && !internat[buf[i] & 0xff]) {
text = 0;
break;
}
*/
return text ? CL_TYPE_UNKNOWN_TEXT : CL_TYPE_UNKNOWN_DATA;
}
int is_tar(unsigned char *buf, unsigned int nbytes);
cli_file_t cli_filetype2(int desc, const struct cl_engine *engine)
{
unsigned char smallbuff[MAGIC_BUFFER_SIZE + 1], *decoded, *bigbuff;
int bread, sret;
cli_file_t ret = CL_TYPE_UNKNOWN_DATA;
struct cli_matcher *root;
struct cli_ac_data mdata;
memset(smallbuff, 0, sizeof(smallbuff));
if((bread = read(desc, smallbuff, MAGIC_BUFFER_SIZE)) > 0)
ret = cli_filetype(smallbuff, bread);
if(engine && ret == CL_TYPE_UNKNOWN_TEXT) {
root = engine->root[0];
if(!root)
return ret;
if(cli_ac_initdata(&mdata, root->ac_partsigs, AC_DEFAULT_TRACKLEN))
return ret;
sret = cli_ac_scanbuff(smallbuff, bread, NULL, engine->root[0], &mdata, 1, 0, 0, -1, NULL);
cli_ac_freedata(&mdata);
if(sret >= CL_TYPENO) {
ret = sret;
} else {
if(cli_ac_initdata(&mdata, root->ac_partsigs, AC_DEFAULT_TRACKLEN))
return ret;
decoded = (unsigned char *) cli_utf16toascii((char *) smallbuff, bread);
if(decoded) {
sret = cli_ac_scanbuff(decoded, strlen((char *) decoded), NULL, engine->root[0], &mdata, 1, 0, 0, -1, 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) {
struct entity_conv conv;
const size_t conv_size = 2*bread < 256 ? 256 : 2*bread;
if(init_entity_converter(&conv,UNKNOWN,conv_size) == 0) {
int end = 0;
m_area_t area;
area.buffer = (unsigned char *) smallbuff;
area.length = bread;
area.offset = 0;
while(!end) {
if(cli_ac_initdata(&mdata, root->ac_partsigs, AC_DEFAULT_TRACKLEN))
return ret;
decoded = encoding_norm_readline(&conv, NULL, &area, bread);
if(decoded) {
sret = cli_ac_scanbuff(decoded, strlen((const char *) decoded), NULL, engine->root[0], &mdata, 1, 0, 0, -1, NULL);
free(decoded);
if(sret == CL_TYPE_HTML) {
ret = CL_TYPE_HTML;
end = 1;
}
} else
end = 1;
cli_ac_freedata(&mdata);
}
entity_norm_done(&conv);
} else {
cli_warnmsg("cli_filetype2: Error initializing entity converter\n");
}
}
}
}
if(ret == CL_TYPE_UNKNOWN_DATA || ret == CL_TYPE_UNKNOWN_TEXT) {
if(!(bigbuff = (unsigned char *) cli_calloc(37638 + 1, sizeof(unsigned char))))
return ret;
lseek(desc, 0, SEEK_SET);
if((bread = read(desc, bigbuff, 37638)) > 0) {
bigbuff[bread] = 0;
switch(is_tar(bigbuff, bread)) {
case 1:
ret = CL_TYPE_OLD_TAR;
cli_dbgmsg("Recognized old fashioned tar file\n");
break;
case 2:
ret = CL_TYPE_POSIX_TAR;
cli_dbgmsg("Recognized POSIX tar file\n");
break;
}
}
if(ret == CL_TYPE_UNKNOWN_DATA || ret == CL_TYPE_UNKNOWN_TEXT) {
if(!memcmp(bigbuff + 32769, "CD001" , 5) || !memcmp(bigbuff + 37633, "CD001" , 5)) {
cli_dbgmsg("Recognized ISO 9660 CD-ROM data\n");
ret = CL_TYPE_DATA;
} else if(!memcmp(bigbuff + 32776, "CDROM" , 5)) {
cli_dbgmsg("Recognized High Sierra CD-ROM data\n");
ret = CL_TYPE_DATA;
}
}
free(bigbuff);
}
return ret;
}
int cli_addtypesigs(struct cl_engine *engine)
{
int i, ret;
struct cli_matcher *root;
if(!engine->root[0]) {
cli_dbgmsg("cli_addtypesigs: Need to allocate AC trie in engine->root[0]\n");
root = engine->root[0] = (struct cli_matcher *) cli_calloc(1, sizeof(struct cli_matcher));
if(!root) {
cli_errmsg("cli_addtypesigs: Can't initialise AC pattern matcher\n");
return CL_EMEM;
}
if((ret = cli_ac_init(root, AC_DEFAULT_MIN_DEPTH, AC_DEFAULT_MAX_DEPTH))) {
/* No need to free previously allocated memory here - all engine
* elements will be properly freed by cl_free()
*/
cli_errmsg("cli_addtypesigs: Can't initialise AC pattern matcher\n");
return ret;
}
} else {
root = engine->root[0];
}
for(i = 0; cli_smagic[i].sig; i++) {
if((ret = cli_parse_add(root, cli_smagic[i].descr, cli_smagic[i].sig, cli_smagic[i].type, NULL, 0))) {
cli_errmsg("cli_addtypesigs: Problem adding signature for %s\n", cli_smagic[i].descr);
return ret;
}
}
return 0;
}