/*
* Copyright (C) 2007-2008 Sourcefire, Inc.
*
* Authors: Alberto Wu
*
* 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.
*/
/* FIXME: get a clue about masked stuff */
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_STRING_H
#include <string.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <zlib.h>
#include "inflate64.h"
#if HAVE_BZLIB_H
#include <bzlib.h>
#endif
#include "explode.h"
#include "others.h"
#include "clamav.h"
#include "scanners.h"
#include "matcher.h"
#include "fmap.h"
#define UNZIP_PRIVATE
#include "unzip.h"
static int wrap_inflateinit2(void *a, int b) {
return inflateInit2(a, b);
}
static int unz(uint8_t *src, uint32_t csize, uint32_t usize, uint16_t method, uint16_t flags, unsigned int *fu, cli_ctx *ctx, char *tmpd) {
char name[1024], obuf[BUFSIZ];
char *tempfile = name;
int of, ret=CL_CLEAN;
unsigned int res=1, written=0;
if(tmpd) {
snprintf(name, sizeof(name), "%s"PATHSEP"zip.%03u", tmpd, *fu);
name[sizeof(name)-1]='\0';
} else {
if(!(tempfile = cli_gentemp(ctx->engine->tmpdir))) return CL_EMEM;
}
if((of = open(tempfile, O_RDWR|O_CREAT|O_TRUNC|O_BINARY, S_IRUSR|S_IWUSR))==-1) {
cli_warnmsg("cli_unzip: failed to create temporary file %s\n", tempfile);
if(!tmpd) free(tempfile);
return CL_ECREAT;
}
switch (method) {
case ALG_STORED:
if(csize<usize) {
unsigned int fake = *fu + 1;
cli_dbgmsg("cli_unzip: attempting to inflate stored file with inconsistent size\n");
if ((ret=unz(src, csize, usize, ALG_DEFLATE, 0, &fake, ctx, tmpd))==CL_CLEAN) {
(*fu)++;
res=fake-(*fu);
}
else break;
}
if(res==1) {
if(ctx->engine->maxfilesize && csize > ctx->engine->maxfilesize) {
cli_dbgmsg("cli_unzip: trimming output size to maxfilesize (%lu)\n", (long unsigned int) ctx->engine->maxfilesize);
csize = ctx->engine->maxfilesize;
}
if(cli_writen(of, src, csize)!=(int)csize) ret = CL_EWRITE;
else res=0;
}
break;
case ALG_DEFLATE:
case ALG_DEFLATE64: {
union {
z_stream64 strm64;
z_stream strm;
} strm;
typedef int (*unz_init_) (void *, int);
typedef int (*unz_unz_) (void *, int);
typedef int (*unz_end_) (void *);
unz_init_ unz_init;
unz_unz_ unz_unz;
unz_end_ unz_end;
int wbits;
void **next_in;
void **next_out;
unsigned int *avail_in;
unsigned int *avail_out;
if(method == ALG_DEFLATE64) {
unz_init = (unz_init_)inflate64Init2;
unz_unz = (unz_unz_)inflate64;
unz_end = (unz_end_)inflate64End;
next_in = (void *)&strm.strm64.next_in;
next_out = (void *)&strm.strm64.next_out;
avail_in = &strm.strm64.avail_in;
avail_out = &strm.strm64.avail_out;
wbits=MAX_WBITS64;
} else {
unz_init = (unz_init_)wrap_inflateinit2;
unz_unz = (unz_unz_)inflate;
unz_end = (unz_end_)inflateEnd;
next_in = (void *)&strm.strm.next_in;
next_out = (void *)&strm.strm.next_out;
avail_in = &strm.strm.avail_in;
avail_out = &strm.strm.avail_out;
wbits=MAX_WBITS;
}
memset(&strm, 0, sizeof(strm));
*next_in = src;
*next_out = obuf;
*avail_in = csize;
*avail_out = sizeof(obuf);
if (unz_init(&strm, -wbits)!=Z_OK) {
cli_dbgmsg("cli_unzip: zinit failed\n");
break;
}
while(1) {
while((res = unz_unz(&strm, Z_NO_FLUSH))==Z_OK) {};
if(*avail_out!=sizeof(obuf)) {
written+=sizeof(obuf)-(*avail_out);
if(ctx->engine->maxfilesize && written > ctx->engine->maxfilesize) {
cli_dbgmsg("cli_unzip: trimming output size to maxfilesize (%lu)\n", (long unsigned int) ctx->engine->maxfilesize);
res = Z_STREAM_END;
break;
}
if(cli_writen(of, obuf, sizeof(obuf)-(*avail_out)) != (int)(sizeof(obuf)-(*avail_out))) {
cli_warnmsg("cli_unzip: falied to write %lu inflated bytes\n", sizeof(obuf)-(*avail_out));
ret = CL_EWRITE;
res = 100;
break;
}
*next_out = obuf;
*avail_out = sizeof(obuf);
continue;
}
break;
}
unz_end(&strm);
if (res == Z_STREAM_END) res=0;
break;
}
#if HAVE_BZLIB_H
#ifdef NOBZ2PREFIX
#define BZ2_bzDecompress bzDecompress
#define BZ2_bzDecompressEnd bzDecompressEnd
#define BZ2_bzDecompressInit bzDecompressInit
#endif
case ALG_BZIP2: {
bz_stream strm;
memset(&strm, 0, sizeof(strm));
strm.next_in = (char *)src;
strm.next_out = obuf;
strm.avail_in = csize;
strm.avail_out = sizeof(obuf);
if (BZ2_bzDecompressInit(&strm, 0, 0)!=BZ_OK) {
cli_dbgmsg("cli_unzip: bzinit failed\n");
break;
}
while((res = BZ2_bzDecompress(&strm))==BZ_OK || res==BZ_STREAM_END) {
if(strm.avail_out!=sizeof(obuf)) {
written+=sizeof(obuf)-strm.avail_out;
if(ctx->engine->maxfilesize && written > ctx->engine->maxfilesize) {
cli_dbgmsg("cli_unzip: trimming output size to maxfilesize (%lu)\n", (unsigned long int) ctx->engine->maxfilesize);
res = BZ_STREAM_END;
break;
}
if(cli_writen(of, obuf, sizeof(obuf)-strm.avail_out) != (int)(sizeof(obuf)-strm.avail_out)) {
cli_warnmsg("cli_unzip: falied to write %lu bunzipped bytes\n", sizeof(obuf)-strm.avail_out);
ret = CL_EWRITE;
res = 100;
break;
}
strm.next_out = obuf;
strm.avail_out = sizeof(obuf);
if (res == BZ_OK) continue; /* after returning BZ_STREAM_END once, decompress returns an error */
}
break;
}
BZ2_bzDecompressEnd(&strm);
if (res == BZ_STREAM_END) res=0;
break;
}
#endif /* HAVE_BZLIB_H */
case ALG_IMPLODE: {
struct xplstate strm;
strm.next_in = src;
strm.next_out = (uint8_t *)obuf;
strm.avail_in = csize;
strm.avail_out = sizeof(obuf);
if (explode_init(&strm, flags)!=EXPLODE_OK) {
cli_dbgmsg("cli_unzip: explode_init() failed\n");
break;
}
while((res = explode(&strm))==EXPLODE_OK) {
if(strm.avail_out!=sizeof(obuf)) {
written+=sizeof(obuf)-strm.avail_out;
if(ctx->engine->maxfilesize && written > ctx->engine->maxfilesize) {
cli_dbgmsg("cli_unzip: trimming output size to maxfilesize (%lu)\n", (unsigned long int) ctx->engine->maxfilesize);
res = 0;
break;
}
if(cli_writen(of, obuf, sizeof(obuf)-strm.avail_out) != (int)(sizeof(obuf)-strm.avail_out)) {
cli_warnmsg("cli_unzip: falied to write %lu exploded bytes\n", sizeof(obuf)-strm.avail_out);
ret = CL_EWRITE;
res = 100;
break;
}
strm.next_out = (uint8_t *)obuf;
strm.avail_out = sizeof(obuf);
continue;
}
break;
}
break;
}
case ALG_LZMA:
/* easy but there's not a single sample in the zoo */
#if !HAVE_BZLIB_H
case ALG_BZIP2:
#endif
case ALG_SHRUNK:
case ALG_REDUCE1:
case ALG_REDUCE2:
case ALG_REDUCE3:
case ALG_REDUCE4:
case ALG_TOKENZD:
case ALG_OLDTERSE:
case ALG_RSVD1:
case ALG_RSVD2:
case ALG_RSVD3:
case ALG_RSVD4:
case ALG_RSVD5:
case ALG_NEWTERSE:
case ALG_LZ77:
case ALG_WAVPACK:
case ALG_PPMD:
cli_dbgmsg("cli_unzip: unsupported method (%d)\n", method);
break;
default:
cli_dbgmsg("cli_unzip: unknown method (%d)\n", method);
break;
}
if(!res) {
(*fu)++;
cli_dbgmsg("cli_unzip: extracted to %s\n", tempfile);
lseek(of, 0, SEEK_SET);
ret = cli_magic_scandesc(of, ctx);
close(of);
if(!ctx->engine->keeptmp)
if(cli_unlink(tempfile)) ret = CL_EUNLINK;
if(!tmpd) free(tempfile);
return ret;
}
close(of);
if(!ctx->engine->keeptmp)
if(cli_unlink(tempfile)) ret = CL_EUNLINK;
if(!tmpd) free(tempfile);
cli_dbgmsg("cli_unzip: extraction failed\n");
return ret;
}
static unsigned int lhdr(fmap_t *map, uint32_t loff,uint32_t zsize, unsigned int *fu, unsigned int fc, uint8_t *ch, int *ret, cli_ctx *ctx, char *tmpd, int detect_encrypted) {
uint8_t *lh, *zip;
char name[256];
uint32_t csize, usize;
if(!(lh = fmap_need_off(map, loff, SIZEOF_LH))) {
cli_dbgmsg("cli_unzip: lh - out of file\n");
return 0;
}
if(LH_magic != 0x04034b50) {
if (!ch) cli_dbgmsg("cli_unzip: lh - wrkcomplete\n");
else cli_dbgmsg("cli_unzip: lh - bad magic\n");
fmap_unneed_off(map, loff, SIZEOF_LH);
return 0;
}
zip = lh + SIZEOF_LH;
zsize-=SIZEOF_LH;
if(zsize<=LH_flen) {
cli_dbgmsg("cli_unzip: lh - fname out of file\n");
fmap_unneed_off(map, loff, SIZEOF_LH);
return 0;
}
if(ctx->engine->cdb || cli_debug_flag) {
uint32_t nsize = (LH_flen>=sizeof(name))?sizeof(name)-1:LH_flen;
char *src;
if(nsize && (src = fmap_need_ptr_once(map, zip, nsize))) {
memcpy(name, zip, nsize);
name[nsize]='\0';
} else
name[0] = '\0';
}
zip+=LH_flen;
zsize-=LH_flen;
cli_dbgmsg("cli_unzip: lh - ZMDNAME:%d:%s:%u:%u:%x:%u:%u:%u\n", ((LH_flags & F_ENCR)!=0), name, LH_usize, LH_csize, LH_crc32, LH_method, fc, ctx->recursion);
/* ZMDfmt virname:encrypted(0-1):filename(exact|*):usize(exact|*):csize(exact|*):crc32(exact|*):method(exact|*):fileno(exact|*):maxdepth(exact|*) */
if(cli_matchmeta(ctx, name, LH_csize, LH_usize, (LH_flags & F_ENCR)!=0, fc, LH_crc32, NULL) == CL_VIRUS) {
*ret = CL_VIRUS;
return 0;
}
if(LH_flags & F_MSKED) {
cli_dbgmsg("cli_unzip: lh - header has got unusable masked data\n");
/* FIXME: need to find/craft a sample */
fmap_unneed_off(map, loff, SIZEOF_LH);
return 0;
}
if(detect_encrypted && (LH_flags & F_ENCR) && DETECT_ENCRYPTED) {
cli_dbgmsg("cli_unzip: Encrypted files found in archive.\n");
cli_append_virus(ctx, "Heuristics.Encrypted.Zip");
*ret = CL_VIRUS;
fmap_unneed_off(map, loff, SIZEOF_LH);
return 0;
}
if(LH_flags & F_USEDD) {
cli_dbgmsg("cli_unzip: lh - has data desc\n");
if(!ch) {
fmap_unneed_off(map, loff, SIZEOF_LH);
return 0;
}
else { usize = CH_usize; csize = CH_csize; }
} else { usize = LH_usize; csize = LH_csize; }
if(zsize<=LH_elen) {
cli_dbgmsg("cli_unzip: lh - extra out of file\n");
fmap_unneed_off(map, loff, SIZEOF_LH);
return 0;
}
zip+=LH_elen;
zsize-=LH_elen;
if (!csize) { /* FIXME: what's used for method0 files? csize or usize? Nothing in the specs, needs testing */
cli_dbgmsg("cli_unzip: lh - skipping empty file\n");
} else {
if(zsize<csize) {
cli_dbgmsg("cli_unzip: lh - stream out of file\n");
fmap_unneed_off(map, loff, SIZEOF_LH);
return 0;
}
if(LH_flags & F_ENCR) {
cli_dbgmsg("cli_unzip: lh - skipping encrypted file\n");
} else {
if(fmap_need_ptr_once(map, zip, csize))
*ret = unz(zip, csize, usize, LH_method, LH_flags, fu, ctx, tmpd);
}
zip+=csize;
zsize-=csize;
}
fmap_unneed_off(map, loff, SIZEOF_LH); /* unneed now. block is guaranteed to exists till the next need */
if(LH_flags & F_USEDD) {
if(zsize<12) {
cli_dbgmsg("cli_unzip: lh - data desc out of file\n");
return 0;
}
zsize-=12;
if(fmap_need_ptr_once(map, zip, 4)) {
if(cli_readint32(zip)==0x08074b50) {
if(zsize<4) {
cli_dbgmsg("cli_unzip: lh - data desc out of file\n");
return 0;
}
zip+=4;
}
}
zip+=12;
}
return zip-lh;
}
static unsigned int chdr(fmap_t *map, uint32_t coff, uint32_t zsize, unsigned int *fu, unsigned int fc, int *ret, cli_ctx *ctx, char *tmpd) {
char name[256];
int last = 0;
uint8_t *ch;
if(!(ch = fmap_need_off(map, coff, SIZEOF_CH)) || CH_magic != 0x02014b50) {
if(ch) fmap_unneed_ptr(map, ch, SIZEOF_CH);
cli_dbgmsg("cli_unzip: ch - wrkcomplete\n");
return 0;
}
coff+=SIZEOF_CH;
cli_dbgmsg("cli_unzip: ch - flags %x - method %x - csize %x - usize %x - flen %x - elen %x - clen %x - disk %x - off %x\n", CH_flags, CH_method, CH_csize, CH_usize, CH_flen, CH_elen, CH_clen, CH_dsk, CH_off);
if(zsize-coff<=CH_flen) {
cli_dbgmsg("cli_unzip: ch - fname out of file\n");
last=1;
}
if(cli_debug_flag && !last) {
unsigned int size = (CH_flen>=sizeof(name))?sizeof(name)-1:CH_flen;
char *src = fmap_need_off_once(map, coff, size);
if(src) {
memcpy(name, src, size);
name[size]='\0';
cli_dbgmsg("cli_unzip: ch - fname: %s\n", name);
}
}
coff+=CH_flen;
if(zsize-coff<=CH_elen && !last) {
cli_dbgmsg("cli_unzip: ch - extra out of file\n");
last=1;
}
coff+=CH_elen;
if(zsize-coff<CH_clen && !last) {
cli_dbgmsg("cli_unzip: ch - comment out of file\n");
last = 1;
}
coff+=CH_clen;
if(CH_off<zsize-SIZEOF_LH) {
lhdr(map, CH_off, zsize-CH_off, fu, fc, ch, ret, ctx, tmpd, 1);
} else cli_dbgmsg("cli_unzip: ch - local hdr out of file\n");
fmap_unneed_ptr(map, ch, SIZEOF_CH);
return last?0:coff;
}
int cli_unzip(cli_ctx *ctx) {
unsigned int fc=0, fu=0;
int ret=CL_CLEAN;
uint32_t fsize, lhoff = 0, coff = 0;
fmap_t *map = *ctx->fmap;
char *tmpd, *ptr;
cli_dbgmsg("in cli_unzip\n");
fsize = (uint32_t)map->len;
if(sizeof(off_t)!=sizeof(uint32_t) && (off_t)fsize!=map->len) {
cli_dbgmsg("cli_unzip: file too big\n");
return CL_CLEAN;
}
if (fsize < SIZEOF_CH) {
cli_dbgmsg("cli_unzip: file too short\n");
return CL_CLEAN;
}
if (!(tmpd = cli_gentemp(ctx->engine->tmpdir))) {
return CL_ETMPDIR;
}
if (mkdir(tmpd, 0700)) {
cli_dbgmsg("cli_unzip: Can't create temporary directory %s\n", tmpd);
free(tmpd);
return CL_ETMPDIR;
}
for(coff=fsize-22 ; coff>0 ; coff--) { /* sizeof(EOC)==22 */
if(!(ptr = fmap_need_off_once(map, coff, 20)))
continue;
if(cli_readint32(ptr)==0x06054b50) {
uint32_t chptr = cli_readint32(&ptr[16]);
if(!CLI_ISCONTAINED(0, fsize, chptr, SIZEOF_CH)) continue;
coff=chptr;
break;
}
}
if(coff) {
cli_dbgmsg("cli_unzip: central @%x\n", coff);
while(ret==CL_CLEAN && (coff=chdr(map, coff, fsize, &fu, fc+1, &ret, ctx, tmpd))) {
fc++;
if (ctx->engine->maxfiles && fu>=ctx->engine->maxfiles) {
cli_dbgmsg("cli_unzip: Files limit reached (max: %u)\n", ctx->engine->maxfiles);
ret=CL_EMAXFILES;
}
}
} else cli_dbgmsg("cli_unzip: central not found, using localhdrs\n");
if(fu<=(fc/4)) { /* FIXME: make up a sane ratio or remove the whole logic */
fc = 0;
while (ret==CL_CLEAN && lhoff<fsize && (coff=lhdr(map, lhoff, fsize-lhoff, &fu, fc+1, NULL, &ret, ctx, tmpd, 1))) {
fc++;
lhoff+=coff;
if (ctx->engine->maxfiles && fu>=ctx->engine->maxfiles) {
cli_dbgmsg("cli_unzip: Files limit reached (max: %u)\n", ctx->engine->maxfiles);
ret=CL_EMAXFILES;
}
}
}
if (!ctx->engine->keeptmp) cli_rmdirs(tmpd);
free(tmpd);
return ret;
}
int cli_unzip_single(cli_ctx *ctx, off_t lhoffl) {
int ret=CL_CLEAN;
unsigned int fu=0;
uint32_t fsize;
fmap_t *map = *ctx->fmap;
cli_dbgmsg("in cli_unzip_single\n");
fsize = (uint32_t)(map->len - lhoffl);
if (lhoffl<0 || lhoffl>map->len || (sizeof(off_t)!=sizeof(uint32_t) && (off_t)fsize!=map->len - lhoffl)) {
cli_dbgmsg("cli_unzip: bad offset\n");
return CL_CLEAN;
}
if (fsize < SIZEOF_LH) {
cli_dbgmsg("cli_unzip: file too short\n");
return CL_CLEAN;
}
lhdr(map, lhoffl, fsize, &fu, 0, NULL, &ret, ctx, NULL, 0);
return ret;
}