50593e02 |
/* |
e1cbc270 |
* Copyright (C) 2013-2019 Cisco Systems, Inc. and/or its affiliates. All rights reserved. |
9eff9418 |
* Copyright (C) 2007-2013 Sourcefire, Inc. |
2023340a |
*
* Authors: Alberto Wu |
50593e02 |
*
* 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
|
f8be651b |
#include "explode.h" |
50593e02 |
#include "others.h"
#include "clamav.h"
#include "scanners.h"
#include "matcher.h" |
774898a7 |
#include "fmap.h" |
20b45621 |
#include "json_api.h" |
50593e02 |
#define UNZIP_PRIVATE
#include "unzip.h"
|
1d3cb0a3 |
// clang-format off
#define ZIP_MAGIC_CENTRAL_DIRECTORY_RECORD_BEGIN (0x02014b50)
#define ZIP_MAGIC_CENTRAL_DIRECTORY_RECORD_END (0x06054b50)
#define ZIP_MAGIC_LOCAL_FILE_HEADER (0x04034b50)
#define ZIP_MAGIC_FILE_BEGIN_SPLIT_OR_SPANNED (0x08074b50)
// clang-format on
|
768d59c7 |
#define ZIP_MAX_NUM_OVERLAPPING_FILES 5 |
23e0b6d3 |
|
288057e9 |
#define ZIP_CRC32(r, c, b, l) \
do { \
r = crc32(~c, b, l); \
r = ~r; \
} while (0) |
a60ec799 |
|
e0c30803 |
#define ZIP_RECORDS_CHECK_BLOCKSIZE 100
struct zip_record { |
768d59c7 |
uint32_t local_header_offset; |
e0c30803 |
uint32_t local_header_size; |
768d59c7 |
uint32_t compressed_size;
uint32_t uncompressed_size;
uint16_t method;
uint16_t flags;
int encrypted; |
e0c30803 |
};
|
288057e9 |
static int wrap_inflateinit2(void *a, int b)
{
return inflateInit2(a, b); |
50593e02 |
}
|
1d3cb0a3 |
/**
* @brief uncompress file from zip
* |
23e0b6d3 |
* @param src pointer to compressed data
* @param csize size of compressed data
* @param usize expected size of uncompressed data
* @param method compression method
* @param flags local header flags
* @param[in,out] num_files_unzipped current number of files that have been unzipped
* @param[in,out] ctx scan context
* @param tmpd temp directory path name
* @param zcb callback function to invoke after extraction (default: scan)
* @return cl_error_t CL_EPARSE = could not apply a password |
1d3cb0a3 |
*/
static cl_error_t unz(
const uint8_t *src,
uint32_t csize,
uint32_t usize,
uint16_t method,
uint16_t flags,
unsigned int *num_files_unzipped,
cli_ctx *ctx,
char *tmpd,
zip_cb zcb) |
288057e9 |
{
char name[1024], obuf[BUFSIZ];
char *tempfile = name; |
1d3cb0a3 |
int out_file, ret = CL_CLEAN; |
6c03dc5d |
int res = 1;
size_t written = 0; |
288057e9 |
if (tmpd) { |
1d3cb0a3 |
snprintf(name, sizeof(name), "%s" PATHSEP "zip.%03u", tmpd, *num_files_unzipped); |
288057e9 |
name[sizeof(name) - 1] = '\0'; |
50593e02 |
} else { |
288057e9 |
if (!(tempfile = cli_gentemp(ctx->engine->tmpdir))) return CL_EMEM;
} |
1d3cb0a3 |
if ((out_file = open(tempfile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR)) == -1) { |
288057e9 |
cli_warnmsg("cli_unzip: failed to create temporary file %s\n", tempfile);
if (!tmpd) free(tempfile);
return CL_ETMPFILE;
}
switch (method) {
case ALG_STORED:
if (csize < usize) { |
1d3cb0a3 |
unsigned int fake = *num_files_unzipped + 1; |
288057e9 |
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, zcb)) == CL_CLEAN) { |
1d3cb0a3 |
(*num_files_unzipped)++;
res = fake - (*num_files_unzipped); |
288057e9 |
} 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;
} |
1d3cb0a3 |
if (cli_writen(out_file, src, csize) != csize) |
288057e9 |
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;
} |
50593e02 |
|
288057e9 |
memset(&strm, 0, sizeof(strm));
*next_in = (void *)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;
} |
1d3cb0a3 |
if (cli_writen(out_file, obuf, sizeof(obuf) - (*avail_out)) != (size_t)(sizeof(obuf) - (*avail_out))) { |
288057e9 |
cli_warnmsg("cli_unzip: falied to write %lu inflated bytes\n", (unsigned long int)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 == Z_BUF_ERROR)) res = 0;
break;
} |
50593e02 |
#if HAVE_BZLIB_H |
c09deba1 |
#ifdef NOBZ2PREFIX |
a622f5f3 |
#define BZ2_bzDecompress bzDecompress
#define BZ2_bzDecompressEnd bzDecompressEnd
#define BZ2_bzDecompressInit bzDecompressInit |
c09deba1 |
#endif
|
288057e9 |
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;
} |
1d3cb0a3 |
if (cli_writen(out_file, obuf, sizeof(obuf) - strm.avail_out) != (size_t)(sizeof(obuf) - strm.avail_out)) { |
288057e9 |
cli_warnmsg("cli_unzip: falied to write %lu bunzipped bytes\n", (long unsigned int)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;
} |
50593e02 |
#endif /* HAVE_BZLIB_H */
|
288057e9 |
case ALG_IMPLODE: {
struct xplstate strm;
strm.next_in = (void *)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;
} |
1d3cb0a3 |
if (cli_writen(out_file, obuf, sizeof(obuf) - strm.avail_out) != (size_t)(sizeof(obuf) - strm.avail_out)) { |
288057e9 |
cli_warnmsg("cli_unzip: falied to write %lu exploded bytes\n", (unsigned long int)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;
} |
f8be651b |
|
288057e9 |
case ALG_LZMA:
/* easy but there's not a single sample in the zoo */ |
50593e02 |
#if !HAVE_BZLIB_H |
288057e9 |
case ALG_BZIP2: |
50593e02 |
#endif |
288057e9 |
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) { |
1d3cb0a3 |
(*num_files_unzipped)++; |
288057e9 |
cli_dbgmsg("cli_unzip: extracted to %s\n", tempfile); |
1d3cb0a3 |
if (lseek(out_file, 0, SEEK_SET) == -1) { |
288057e9 |
cli_dbgmsg("cli_unzip: call to lseek() failed\n");
if (!(tmpd))
free(tempfile); |
1d3cb0a3 |
close(out_file); |
288057e9 |
return CL_ESEEK;
} |
1d3cb0a3 |
ret = zcb(out_file, tempfile, ctx);
close(out_file); |
288057e9 |
if (!ctx->engine->keeptmp)
if (cli_unlink(tempfile)) ret = CL_EUNLINK;
if (!tmpd) free(tempfile);
return ret; |
7e40bab9 |
} |
288057e9 |
|
1d3cb0a3 |
close(out_file); |
288057e9 |
if (!ctx->engine->keeptmp)
if (cli_unlink(tempfile)) ret = CL_EUNLINK;
if (!tmpd) free(tempfile);
cli_dbgmsg("cli_unzip: extraction failed\n"); |
50593e02 |
return ret;
}
|
1ac97cf0 |
/* zip update keys, taken from zip specification */
static inline void zupdatekey(uint32_t key[3], unsigned char input)
{
unsigned char tmp[1];
tmp[0] = input;
ZIP_CRC32(key[0], key[0], tmp, 1);
key[1] = key[1] + (key[0] & 0xff);
key[1] = key[1] * 134775813 + 1;
tmp[0] = key[1] >> 24;
ZIP_CRC32(key[2], key[2], tmp, 1);
}
/* zip init keys */ |
038cb67a |
static inline void zinitkey(uint32_t key[3], struct cli_pwdb *password) |
1ac97cf0 |
{
int i;
|
7cd9337a |
/* initialize keys, these are specified but the zip specification */ |
1ac97cf0 |
key[0] = 305419896L;
key[1] = 591751049L;
key[2] = 878082192L;
/* update keys with password */
for (i = 0; i < password->length; i++) |
288057e9 |
zupdatekey(key, password->passwd[i]); |
1ac97cf0 |
}
/* zip decrypt byte */
static inline unsigned char zdecryptbyte(uint32_t key[3])
{
unsigned short temp;
temp = key[2] | 2;
return ((temp * (temp ^ 1)) >> 8);
}
|
1d3cb0a3 |
/**
* @brief zip decrypt.
*
* TODO - search for strong encryption header (0x0017) and handle them
*
* @param src |
23e0b6d3 |
* @param csize size of compressed data; includes the decryption header
* @param usize expected size of uncompressed data |
1d3cb0a3 |
* @param local_header |
23e0b6d3 |
* @param[in,out] num_files_unzipped current number of files that have been unzipped
* @param[in,out] ctx scan context
* @param tmpd temp directory path name
* @param zcb callback function to invoke after extraction (default: scan)
* @return cl_error_t CL_EPARSE = could not apply a password |
1d3cb0a3 |
*/
static inline cl_error_t zdecrypt(
const uint8_t *src,
uint32_t csize,
uint32_t usize,
const uint8_t *local_header,
unsigned int *num_files_unzipped,
cli_ctx *ctx,
char *tmpd,
zip_cb zcb) |
1ac97cf0 |
{ |
6c03dc5d |
cl_error_t ret;
int v = 0;
uint32_t i; |
1ac97cf0 |
uint32_t key[3]; |
1d3cb0a3 |
uint8_t encryption_header[12]; /* encryption header buffer */ |
038cb67a |
struct cli_pwdb *password, *pass_any, *pass_zip; |
1ac97cf0 |
if (!ctx || !ctx->engine) |
288057e9 |
return CL_ENULLARG; |
1ac97cf0 |
|
f5f7b7a1 |
/* dconf */
if (ctx->dconf && !(ctx->dconf->archive & ARCH_CONF_PASSWD)) { |
288057e9 |
cli_dbgmsg("cli_unzip: decrypt - skipping encrypted file\n");
return CL_SUCCESS; |
f5f7b7a1 |
} |
1ac97cf0 |
|
038cb67a |
pass_any = ctx->engine->pwdbs[CLI_PWDB_ANY];
pass_zip = ctx->engine->pwdbs[CLI_PWDB_ZIP]; |
1ac97cf0 |
|
038cb67a |
while (pass_any || pass_zip) { |
288057e9 |
password = pass_zip ? pass_zip : pass_any;
zinitkey(key, password);
/* decrypting the encryption header */ |
1d3cb0a3 |
memcpy(encryption_header, src, SIZEOF_ENCRYPTION_HEADER); |
288057e9 |
|
1d3cb0a3 |
for (i = 0; i < SIZEOF_ENCRYPTION_HEADER; i++) {
encryption_header[i] ^= zdecryptbyte(key);
zupdatekey(key, encryption_header[i]); |
288057e9 |
}
/* verify that the password is correct */ |
1d3cb0a3 |
if (LOCAL_HEADER_version > 20) { /* higher than 2.0 */
uint16_t a = encryption_header[SIZEOF_ENCRYPTION_HEADER - 1]; |
288057e9 |
|
1d3cb0a3 |
if (LOCAL_HEADER_flags & F_USEDD) {
cli_dbgmsg("cli_unzip: decrypt - (v%u) >> 0x%02x 0x%x (moddate)\n", LOCAL_HEADER_version, a, LOCAL_HEADER_mtime);
if (a == ((LOCAL_HEADER_mtime >> 8) & 0xff)) |
288057e9 |
v = 1;
} else { |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: decrypt - (v%u) >> 0x%02x 0x%x (crc32)\n", LOCAL_HEADER_version, a, LOCAL_HEADER_crc32);
if (a == ((LOCAL_HEADER_crc32 >> 24) & 0xff)) |
288057e9 |
v = 1;
}
} else { |
1d3cb0a3 |
uint16_t a = encryption_header[SIZEOF_ENCRYPTION_HEADER - 1], b = encryption_header[SIZEOF_ENCRYPTION_HEADER - 2]; |
288057e9 |
|
1d3cb0a3 |
if (LOCAL_HEADER_flags & F_USEDD) {
cli_dbgmsg("cli_unzip: decrypt - (v%u) >> 0x0000%02x%02x 0x%x (moddate)\n", LOCAL_HEADER_version, a, b, LOCAL_HEADER_mtime);
if ((b | (a << 8)) == (LOCAL_HEADER_mtime & 0xffff)) |
288057e9 |
v = 1;
} else { |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: decrypt - (v%u) >> 0x0000%02x%02x 0x%x (crc32)\n", LOCAL_HEADER_version, encryption_header[SIZEOF_ENCRYPTION_HEADER - 1], encryption_header[SIZEOF_ENCRYPTION_HEADER - 2], LOCAL_HEADER_crc32);
if ((b | (a << 8)) == ((LOCAL_HEADER_crc32 >> 16) & 0xffff)) |
288057e9 |
v = 1;
}
}
if (v) {
char name[1024], obuf[BUFSIZ]; |
6c03dc5d |
char *tempfile = name;
size_t written = 0, total = 0; |
288057e9 |
fmap_t *dcypt_map;
const uint8_t *dcypt_zip; |
1d3cb0a3 |
int out_file; |
288057e9 |
cli_dbgmsg("cli_unzip: decrypt - password [%s] matches\n", password->name);
/* output decrypted data to tempfile */
if (tmpd) { |
1d3cb0a3 |
snprintf(name, sizeof(name), "%s" PATHSEP "zip.decrypt.%03u", tmpd, *num_files_unzipped); |
288057e9 |
name[sizeof(name) - 1] = '\0';
} else {
if (!(tempfile = cli_gentemp(ctx->engine->tmpdir))) return CL_EMEM;
} |
1d3cb0a3 |
if ((out_file = open(tempfile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR)) == -1) { |
288057e9 |
cli_warnmsg("cli_unzip: decrypt - failed to create temporary file %s\n", tempfile);
if (!tmpd) free(tempfile);
return CL_ETMPFILE;
}
for (i = 12; i < csize; i++) {
obuf[written] = src[i] ^ zdecryptbyte(key);
zupdatekey(key, obuf[written]);
written++;
if (written >= BUFSIZ) { |
1d3cb0a3 |
if (cli_writen(out_file, obuf, written) != written) { |
288057e9 |
ret = CL_EWRITE;
goto zd_clean;
}
total += written;
written = 0;
}
}
if (written) { |
1d3cb0a3 |
if (cli_writen(out_file, obuf, written) != written) { |
288057e9 |
ret = CL_EWRITE;
goto zd_clean;
}
total += written;
written = 0;
}
|
6c03dc5d |
cli_dbgmsg("cli_unzip: decrypt - decrypted %zu bytes to %s\n", total, tempfile); |
288057e9 |
/* decrypt data to new fmap -> buffer */ |
1d3cb0a3 |
if (!(dcypt_map = fmap(out_file, 0, total))) { |
288057e9 |
cli_warnmsg("cli_unzip: decrypt - failed to create fmap on decrypted file %s\n", tempfile);
ret = CL_EMAP;
goto zd_clean;
}
if (!(dcypt_zip = fmap_need_off_once(dcypt_map, 0, total))) {
cli_warnmsg("cli_unzip: decrypt - failed to acquire buffer on decrypted file %s\n", tempfile);
funmap(dcypt_map);
ret = CL_EREAD;
goto zd_clean;
}
/* call unz on decrypted output */ |
1d3cb0a3 |
ret = unz(dcypt_zip, csize - SIZEOF_ENCRYPTION_HEADER, usize, LOCAL_HEADER_method, LOCAL_HEADER_flags, num_files_unzipped, ctx, tmpd, zcb); |
288057e9 |
/* clean-up and return */
funmap(dcypt_map);
zd_clean: |
1d3cb0a3 |
close(out_file); |
288057e9 |
if (!ctx->engine->keeptmp) |
202a5dae |
if (cli_unlink(tempfile)) { |
288057e9 |
if (!tmpd) free(tempfile);
return CL_EUNLINK;
} |
1ac97cf0 |
if (!tmpd) free(tempfile); |
288057e9 |
return ret;
} |
1ac97cf0 |
|
288057e9 |
if (pass_zip)
pass_zip = pass_zip->next;
else
pass_any = pass_any->next; |
1ac97cf0 |
}
|
0b119e6f |
cli_dbgmsg("cli_unzip: decrypt - skipping encrypted file, no valid passwords\n"); |
1ac97cf0 |
return CL_SUCCESS;
}
|
1d3cb0a3 |
/**
* @brief Parse, extract, and scan a file using the local file header.
* |
e0c30803 |
* Usage of the `record` parameter will alter behavior so it only collect file record metadata and does not extract or scan any files.
* |
23e0b6d3 |
* @param map fmap for the file
* @param loff offset of the local file header
* @param zsize size of the zip file
* @param[in,out] num_files_unzipped current number of files that have been unzipped
* @param file_count current number of files that have been discovered
* @param central_header offset of central directory header
* @param[out] ret The status code
* @param[in,out] ctx scan context
* @param tmpd temp directory path name
* @param detect_encrypted bool: if encrypted files should raise heuristic alert
* @param zcb callback function to invoke after extraction (default: scan) |
e0c30803 |
* @param record (optional) a pointer to a struct to store file record information. |
23e0b6d3 |
* @return unsigned int returns the size of the file header + file data, so zip file can be indexed without the central directory |
1d3cb0a3 |
*/
static unsigned int parse_local_file_header(
fmap_t *map,
uint32_t loff,
uint32_t zsize,
unsigned int *num_files_unzipped,
unsigned int file_count,
const uint8_t *central_header, /* pointer to central header. */
cl_error_t *ret,
cli_ctx *ctx,
char *tmpd,
int detect_encrypted, |
23e0b6d3 |
zip_cb zcb, |
e0c30803 |
struct zip_record *record) |
288057e9 |
{ |
1d3cb0a3 |
const uint8_t *local_header, *zip; |
288057e9 |
char name[256];
uint32_t csize, usize;
int virus_found = 0;
|
1d3cb0a3 |
if (!(local_header = fmap_need_off(map, loff, SIZEOF_LOCAL_HEADER))) {
cli_dbgmsg("cli_unzip: local header - out of file\n"); |
288057e9 |
return 0;
} |
1d3cb0a3 |
if (LOCAL_HEADER_magic != ZIP_MAGIC_LOCAL_FILE_HEADER) {
if (!central_header)
cli_dbgmsg("cli_unzip: local header - wrkcomplete\n"); |
288057e9 |
else |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: local header - bad magic\n");
fmap_unneed_off(map, loff, SIZEOF_LOCAL_HEADER); |
288057e9 |
return 0;
}
|
1d3cb0a3 |
zip = local_header + SIZEOF_LOCAL_HEADER;
zsize -= SIZEOF_LOCAL_HEADER; |
288057e9 |
|
1d3cb0a3 |
if (zsize <= LOCAL_HEADER_flen) {
cli_dbgmsg("cli_unzip: local header - fname out of file\n");
fmap_unneed_off(map, loff, SIZEOF_LOCAL_HEADER); |
288057e9 |
return 0;
}
if (ctx->engine->cdb || cli_debug_flag) { |
1d3cb0a3 |
uint32_t nsize = (LOCAL_HEADER_flen >= sizeof(name)) ? sizeof(name) - 1 : LOCAL_HEADER_flen; |
288057e9 |
const char *src;
if (nsize && (src = fmap_need_ptr_once(map, zip, nsize))) {
memcpy(name, zip, nsize);
name[nsize] = '\0';
} else
name[0] = '\0';
} |
1d3cb0a3 |
zip += LOCAL_HEADER_flen;
zsize -= LOCAL_HEADER_flen; |
288057e9 |
|
1d3cb0a3 |
cli_dbgmsg("cli_unzip: local header - ZMDNAME:%d:%s:%u:%u:%x:%u:%u:%u\n",
((LOCAL_HEADER_flags & F_ENCR) != 0), name, LOCAL_HEADER_usize, LOCAL_HEADER_csize, LOCAL_HEADER_crc32, LOCAL_HEADER_method, file_count, ctx->recursion); |
288057e9 |
/* ZMDfmt virname:encrypted(0-1):filename(exact|*):usize(exact|*):csize(exact|*):crc32(exact|*):method(exact|*):fileno(exact|*):maxdepth(exact|*) */
|
1d3cb0a3 |
/* Scan file header metadata. */
if (cli_matchmeta(ctx, name, LOCAL_HEADER_csize, LOCAL_HEADER_usize, (LOCAL_HEADER_flags & F_ENCR) != 0, file_count, LOCAL_HEADER_crc32, NULL) == CL_VIRUS) { |
288057e9 |
*ret = CL_VIRUS;
if (!SCAN_ALLMATCHES)
return 0;
virus_found = 1;
}
|
1d3cb0a3 |
if (LOCAL_HEADER_flags & F_MSKED) {
cli_dbgmsg("cli_unzip: local header - header has got unusable masked data\n"); |
288057e9 |
/* FIXME: need to find/craft a sample */ |
1d3cb0a3 |
fmap_unneed_off(map, loff, SIZEOF_LOCAL_HEADER); |
288057e9 |
return 0;
}
|
1d3cb0a3 |
if (detect_encrypted && (LOCAL_HEADER_flags & F_ENCR) && SCAN_HEURISTIC_ENCRYPTED_ARCHIVE) { |
288057e9 |
cli_dbgmsg("cli_unzip: Encrypted files found in archive.\n");
*ret = cli_append_virus(ctx, "Heuristics.Encrypted.Zip");
if ((*ret == CL_VIRUS && !SCAN_ALLMATCHES) || *ret != CL_CLEAN) { |
1d3cb0a3 |
fmap_unneed_off(map, loff, SIZEOF_LOCAL_HEADER); |
288057e9 |
return 0;
}
virus_found = 1;
}
|
1d3cb0a3 |
if (LOCAL_HEADER_flags & F_USEDD) {
cli_dbgmsg("cli_unzip: local header - has data desc\n");
if (!central_header) {
fmap_unneed_off(map, loff, SIZEOF_LOCAL_HEADER); |
288057e9 |
return 0;
} else { |
1d3cb0a3 |
usize = CENTRAL_HEADER_usize;
csize = CENTRAL_HEADER_csize; |
288057e9 |
}
} else { |
1d3cb0a3 |
usize = LOCAL_HEADER_usize;
csize = LOCAL_HEADER_csize; |
288057e9 |
}
|
1d3cb0a3 |
if (zsize <= LOCAL_HEADER_elen) {
cli_dbgmsg("cli_unzip: local header - extra out of file\n");
fmap_unneed_off(map, loff, SIZEOF_LOCAL_HEADER); |
7a307529 |
return 0;
} |
1d3cb0a3 |
zip += LOCAL_HEADER_elen;
zsize -= LOCAL_HEADER_elen; |
288057e9 |
if (!csize) { /* FIXME: what's used for method0 files? csize or usize? Nothing in the specs, needs testing */ |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: local header - skipping empty file\n"); |
288057e9 |
} else {
if (zsize < csize) { |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: local header - stream out of file\n");
fmap_unneed_off(map, loff, SIZEOF_LOCAL_HEADER); |
288057e9 |
return 0;
} |
23e0b6d3 |
|
e0c30803 |
/* Don't actually unzip if we're just collecting the file record information (offset, sizes) */
if (NULL == record) {
if (LOCAL_HEADER_flags & F_ENCR) {
if (fmap_need_ptr_once(map, zip, csize))
*ret = zdecrypt(zip, csize, usize, local_header, num_files_unzipped, ctx, tmpd, zcb);
} else {
if (fmap_need_ptr_once(map, zip, csize))
*ret = unz(zip, csize, usize, LOCAL_HEADER_method, LOCAL_HEADER_flags, num_files_unzipped, ctx, tmpd, zcb);
} |
768d59c7 |
} else {
record->local_header_offset = loff;
record->local_header_size = zip - local_header;
record->compressed_size = csize;
record->uncompressed_size = usize;
record->method = LOCAL_HEADER_method;
record->flags = LOCAL_HEADER_flags;
record->encrypted = (LOCAL_HEADER_flags & F_ENCR) ? 1 : 0; |
288057e9 |
} |
768d59c7 |
|
288057e9 |
zip += csize;
zsize -= csize;
}
if (virus_found != 0)
*ret = CL_VIRUS;
|
1d3cb0a3 |
fmap_unneed_off(map, loff, SIZEOF_LOCAL_HEADER); /* unneed now. block is guaranteed to exists till the next need */
if (LOCAL_HEADER_flags & F_USEDD) { |
288057e9 |
if (zsize < 12) { |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: local header - data desc out of file\n"); |
288057e9 |
return 0;
}
zsize -= 12;
if (fmap_need_ptr_once(map, zip, 4)) { |
1d3cb0a3 |
if (cli_readint32(zip) == ZIP_MAGIC_FILE_BEGIN_SPLIT_OR_SPANNED) { |
288057e9 |
if (zsize < 4) { |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: local header - data desc out of file\n"); |
288057e9 |
return 0;
}
zip += 4;
}
}
zip += 12;
} |
1d3cb0a3 |
return zip - local_header; |
50593e02 |
}
|
1d3cb0a3 |
/**
* @brief Parse, extract, and scan a file by iterating the central directory.
* |
e0c30803 |
* Usage of the `record` parameter will alter behavior so it only collect file record metadata and does not extract or scan any files.
* |
23e0b6d3 |
* @param map fmap for the file
* @param coff offset of the file header in the central directory
* @param zsize size of the zip file
* @param[in,out] num_files_unzipped current number of files that have been unzipped
* @param file_count current number of files that have been discovered
* @param[out] ret The status code
* @param[in,out] ctx scan context
* @param tmpd temp directory path name
* @param requests (optional) structure use to search the zip for files by name |
e0c30803 |
* @param record (optional) a pointer to a struct to store file record information. |
768d59c7 |
* @return unsigned int returns the size of the file header in the central directory, or 0 if no more files |
1d3cb0a3 |
*/ |
e0c30803 |
static unsigned int
parse_central_directory_file_header( |
1d3cb0a3 |
fmap_t *map,
uint32_t coff,
uint32_t zsize,
unsigned int *num_files_unzipped,
unsigned int file_count,
cl_error_t *ret,
cli_ctx *ctx,
char *tmpd, |
23e0b6d3 |
struct zip_requests *requests, |
e0c30803 |
struct zip_record *record) |
288057e9 |
{
char name[256];
int last = 0; |
1d3cb0a3 |
const uint8_t *central_header; |
288057e9 |
int virus_found = 0;
|
1d3cb0a3 |
if (!(central_header = fmap_need_off(map, coff, SIZEOF_CENTRAL_HEADER)) || CENTRAL_HEADER_magic != ZIP_MAGIC_CENTRAL_DIRECTORY_RECORD_BEGIN) {
if (central_header) fmap_unneed_ptr(map, central_header, SIZEOF_CENTRAL_HEADER);
cli_dbgmsg("cli_unzip: central header - wrkcomplete\n"); |
288057e9 |
return 0;
} |
1d3cb0a3 |
coff += SIZEOF_CENTRAL_HEADER; |
288057e9 |
|
1d3cb0a3 |
cli_dbgmsg("cli_unzip: central header - flags %x - method %x - csize %x - usize %x - flen %x - elen %x - clen %x - disk %x - off %x\n",
CENTRAL_HEADER_flags, CENTRAL_HEADER_method, CENTRAL_HEADER_csize, CENTRAL_HEADER_usize, CENTRAL_HEADER_flen, CENTRAL_HEADER_extra_len, CENTRAL_HEADER_comment_len, CENTRAL_HEADER_disk_num, CENTRAL_HEADER_off); |
288057e9 |
|
1d3cb0a3 |
if (zsize - coff <= CENTRAL_HEADER_flen) {
cli_dbgmsg("cli_unzip: central header - fname out of file\n"); |
288057e9 |
last = 1;
}
name[0] = '\0';
if (!last) { |
1d3cb0a3 |
unsigned int size = (CENTRAL_HEADER_flen >= sizeof(name)) ? sizeof(name) - 1 : CENTRAL_HEADER_flen; |
288057e9 |
const char *src = fmap_need_off_once(map, coff, size);
if (src) {
memcpy(name, src, size);
name[size] = '\0'; |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: central header - fname: %s\n", name); |
288057e9 |
}
} |
1d3cb0a3 |
coff += CENTRAL_HEADER_flen; |
288057e9 |
/* requests do not supply a ctx; also prevent multiple scans */ |
1d3cb0a3 |
if (ctx && cli_matchmeta(ctx, name, CENTRAL_HEADER_csize, CENTRAL_HEADER_usize, (CENTRAL_HEADER_flags & F_ENCR) != 0, file_count, CENTRAL_HEADER_crc32, NULL) == CL_VIRUS) |
288057e9 |
virus_found = 1;
|
1d3cb0a3 |
if (zsize - coff <= CENTRAL_HEADER_extra_len && !last) {
cli_dbgmsg("cli_unzip: central header - extra out of file\n"); |
288057e9 |
last = 1;
} |
1d3cb0a3 |
coff += CENTRAL_HEADER_extra_len; |
288057e9 |
|
1d3cb0a3 |
if (zsize - coff < CENTRAL_HEADER_comment_len && !last) {
cli_dbgmsg("cli_unzip: central header - comment out of file\n"); |
288057e9 |
last = 1;
} |
1d3cb0a3 |
coff += CENTRAL_HEADER_comment_len; |
288057e9 |
if (!requests) { |
1d3cb0a3 |
if (CENTRAL_HEADER_off < zsize - SIZEOF_LOCAL_HEADER) { |
23e0b6d3 |
parse_local_file_header(map,
CENTRAL_HEADER_off,
zsize - CENTRAL_HEADER_off,
num_files_unzipped,
file_count,
central_header,
ret,
ctx,
tmpd,
1,
zip_scan_cb, |
e0c30803 |
record); |
23e0b6d3 |
} else { |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: central header - local hdr out of file\n"); |
23e0b6d3 |
} |
288057e9 |
} else {
int i;
size_t len;
if (!last) {
for (i = 0; i < requests->namecnt; ++i) { |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: central header - checking for %i: %s\n", i, requests->names[i]); |
288057e9 |
len = MIN(sizeof(name) - 1, requests->namelens[i]);
if (!strncmp(requests->names[i], name, len)) {
requests->match = 1;
requests->found = i; |
1d3cb0a3 |
requests->loff = CENTRAL_HEADER_off; |
288057e9 |
}
}
}
}
if (virus_found == 1)
*ret = CL_VIRUS; |
1d3cb0a3 |
fmap_unneed_ptr(map, central_header, SIZEOF_CENTRAL_HEADER); |
288057e9 |
return (last ? 0 : coff); |
50593e02 |
}
|
e0c30803 |
/**
* @brief Sort zip_record structures based on local file offset.
*
* @param first
* @param second
* @return int 1 if first record's offset is higher than second's.
* @return int 0 if first and second reocrd offsets are equal.
* @return int -1 if first record's offset is less than second's.
*/
static int sort_by_file_offset(const void *first, const void *second)
{
const struct zip_record *a = (const struct zip_record *)first;
const struct zip_record *b = (const struct zip_record *)second;
/* Avoid return x - y, which can cause undefined behaviour
because of signed integer overflow. */ |
768d59c7 |
if (a->local_header_offset < b->local_header_offset) |
e0c30803 |
return -1; |
768d59c7 |
else if (a->local_header_offset > b->local_header_offset) |
e0c30803 |
return 1;
return 0;
}
/** |
768d59c7 |
* @brief Create a catalogue of the central directory. |
e0c30803 |
* |
768d59c7 |
* This function indexes every file in the central directory.
* It creates a zip record catalogue and sorts them by file entry offset. |
e0c30803 |
* Then it iterates the sorted file records looking for overlapping files.
* |
768d59c7 |
* The caller is responsible for freeing the catalogue.
* The catalogue may contain duplicate items, which should be skipped.
*
* @param ctx The scanning context
* @param map The file map
* @param fsize The file size
* @param coff The central directory offset
* @param[out] catalogue A catalogue of zip_records found in the central directory.
* @param[out] num_records The number of records in the catalogue. |
e0c30803 |
* @return cl_error_t CL_CLEAN if no overlapping files
* @return cl_error_t CL_VIRUS if overlapping files and heuristic alerts are enabled
* @return cl_error_t CL_EFORMAT if overlapping files and heuristic alerts are disabled
* @return cl_error_t CL_ETIMEOUT if the scan time limit is exceeded.
* @return cl_error_t CL_EMEM for memory allocation errors.
*/ |
768d59c7 |
cl_error_t index_the_central_directory(
cli_ctx *ctx,
fmap_t *map,
uint32_t fsize,
uint32_t coff,
struct zip_record **catalogue,
size_t *num_records) |
e0c30803 |
{
cl_error_t status = CL_CLEAN;
cl_error_t ret = CL_CLEAN;
|
768d59c7 |
size_t num_record_blocks = 0;
size_t index = 0;
|
e0c30803 |
struct zip_record *zip_catalogue = NULL;
size_t records_count = 0; |
768d59c7 |
struct zip_record *curr_record = NULL;
struct zip_record *prev_record = NULL;
uint32_t num_overlapping_files = 0; |
e0c30803 |
|
768d59c7 |
if (NULL == catalogue || NULL == num_records) {
cli_errmsg("index_the_central_directory: Invalid NULL arguments\n");
goto done;
}
*catalogue = NULL;
*num_records = 0; |
e0c30803 |
zip_catalogue = (struct zip_record *)cli_malloc(sizeof(struct zip_record) * ZIP_RECORDS_CHECK_BLOCKSIZE);
if (NULL == zip_catalogue) {
status = CL_EMEM;
goto done;
}
num_record_blocks = 1;
memset(zip_catalogue, 0, sizeof(struct zip_record) * ZIP_RECORDS_CHECK_BLOCKSIZE);
cli_dbgmsg("cli_unzip: checking for non-recursive zip bombs...\n");
while (0 != (coff = parse_central_directory_file_header(map,
coff,
fsize,
NULL, // num_files_unziped not required
index + 1,
&ret,
ctx,
NULL, // tmpd not required
NULL, |
768d59c7 |
&(zip_catalogue[records_count])))) { |
e0c30803 |
index++;
if (cli_checktimelimit(ctx) != CL_SUCCESS) {
cli_dbgmsg("cli_unzip: Time limit reached (max: %u)\n", ctx->engine->maxscantime);
status = CL_ETIMEOUT;
goto done;
}
/* stop checking file entries if we'll exceed maxfiles */
if (ctx->engine->maxfiles && records_count >= ctx->engine->maxfiles) {
cli_dbgmsg("cli_unzip: Files limit reached (max: %u)\n", ctx->engine->maxfiles);
break;
}
records_count++;
if (records_count % ZIP_RECORDS_CHECK_BLOCKSIZE == 0) {
cli_dbgmsg(" cli_unzip: Exceeded zip record block size, allocating more space...\n");
/* allocate more space for zip records */
if (sizeof(struct zip_record) * ZIP_RECORDS_CHECK_BLOCKSIZE * (num_record_blocks + 1) <
sizeof(struct zip_record) * ZIP_RECORDS_CHECK_BLOCKSIZE * (num_record_blocks)) {
cli_errmsg("cli_unzip: Number of file records in zip will exceed the max for current architecture (integer overflow)\n");
status = CL_EFORMAT;
goto done;
}
zip_catalogue = cli_realloc2(zip_catalogue, sizeof(struct zip_record) * ZIP_RECORDS_CHECK_BLOCKSIZE * (num_record_blocks + 1));
if (NULL == zip_catalogue) {
status = CL_EMEM;
goto done;
}
num_record_blocks++;
/* zero out the memory for the new records */ |
768d59c7 |
memset(&(zip_catalogue[records_count]), 0, sizeof(struct zip_record) * (ZIP_RECORDS_CHECK_BLOCKSIZE * num_record_blocks - records_count)); |
e0c30803 |
}
}
|
768d59c7 |
if (records_count > 1) {
/*
* Sort the records by local file offset
*/
cli_qsort(zip_catalogue, records_count, sizeof(struct zip_record), sort_by_file_offset);
/*
* Detect overlapping files.
*/
for (index = 1; index < records_count; index++) {
prev_record = &(zip_catalogue[index - 1]);
curr_record = &(zip_catalogue[index]);
/* Check for integer overflow in 32bit size & offset values */
if ((UINT32_MAX - (prev_record->local_header_size + prev_record->compressed_size) < prev_record->local_header_offset) ||
(UINT32_MAX - (curr_record->local_header_size + curr_record->compressed_size) < curr_record->local_header_offset)) {
cli_dbgmsg("cli_unzip: Integer overflow detected; invalid data sizes in zip file headers.\n");
status = CL_EFORMAT;
goto done;
} |
e0c30803 |
|
768d59c7 |
if (((curr_record->local_header_offset >= prev_record->local_header_offset) && (curr_record->local_header_offset < prev_record->local_header_offset + prev_record->local_header_size + prev_record->compressed_size)) ||
((prev_record->local_header_offset >= curr_record->local_header_offset) && (prev_record->local_header_offset < curr_record->local_header_offset + curr_record->local_header_size + curr_record->compressed_size))) {
/* Overlapping file detected */
num_overlapping_files++; |
e0c30803 |
|
768d59c7 |
if ((curr_record->local_header_offset == prev_record->local_header_offset) &&
(curr_record->local_header_size == prev_record->local_header_size) &&
(curr_record->compressed_size == prev_record->compressed_size)) {
cli_dbgmsg("cli_unzip: Ignoring duplicate file entry @ 0x%x.\n", curr_record->local_header_offset); |
e0c30803 |
} else { |
768d59c7 |
cli_dbgmsg("cli_unzip: Overlapping files detected.\n");
cli_dbgmsg(" previous file end: %u\n", prev_record->local_header_offset + prev_record->local_header_size + prev_record->compressed_size);
cli_dbgmsg(" current file start: %u\n", curr_record->local_header_offset);
if (ZIP_MAX_NUM_OVERLAPPING_FILES < num_overlapping_files) {
if (SCAN_HEURISTICS) {
status = cli_append_virus(ctx, "Heuristics.Zip.OverlappingFiles");
} else {
status = CL_EFORMAT;
}
goto done;
} |
e0c30803 |
}
}
|
768d59c7 |
if (cli_checktimelimit(ctx) != CL_SUCCESS) {
cli_dbgmsg("cli_unzip: Time limit reached (max: %u)\n", ctx->engine->maxscantime);
status = CL_ETIMEOUT;
goto done;
} |
e0c30803 |
}
}
|
768d59c7 |
*catalogue = zip_catalogue;
*num_records = records_count;
status = CL_SUCCESS;
|
e0c30803 |
done:
|
768d59c7 |
if (CL_SUCCESS != status) {
if (NULL != zip_catalogue) {
free(zip_catalogue);
zip_catalogue = NULL;
} |
e0c30803 |
}
return status;
}
|
1d3cb0a3 |
cl_error_t cli_unzip(cli_ctx *ctx) |
288057e9 |
{ |
1d3cb0a3 |
unsigned int file_count = 0, num_files_unzipped = 0;
cl_error_t ret = CL_CLEAN; |
288057e9 |
uint32_t fsize, lhoff = 0, coff = 0;
fmap_t *map = *ctx->fmap; |
e0c30803 |
char *tmpd = NULL; |
288057e9 |
const char *ptr;
int virus_found = 0; |
20b45621 |
#if HAVE_JSON |
288057e9 |
int toval = 0; |
20b45621 |
#endif |
768d59c7 |
struct zip_record *zip_catalogue = NULL;
size_t records_count = 0;
size_t i; |
50593e02 |
|
288057e9 |
cli_dbgmsg("in cli_unzip\n");
fsize = (uint32_t)map->len;
if (sizeof(off_t) != sizeof(uint32_t) && (size_t)fsize != map->len) {
cli_dbgmsg("cli_unzip: file too big\n"); |
e0c30803 |
ret = CL_CLEAN;
goto done; |
288057e9 |
} |
1d3cb0a3 |
if (fsize < SIZEOF_CENTRAL_HEADER) { |
288057e9 |
cli_dbgmsg("cli_unzip: file too short\n"); |
e0c30803 |
ret = CL_CLEAN;
goto done; |
288057e9 |
}
if (!(tmpd = cli_gentemp(ctx->engine->tmpdir))) { |
e0c30803 |
ret = CL_ETMPDIR;
goto done; |
288057e9 |
}
if (mkdir(tmpd, 0700)) {
cli_dbgmsg("cli_unzip: Can't create temporary directory %s\n", tmpd); |
e0c30803 |
ret = CL_ETMPDIR;
goto done; |
288057e9 |
}
for (coff = fsize - 22; coff > 0; coff--) { /* sizeof(EOC)==22 */
if (!(ptr = fmap_need_off_once(map, coff, 20)))
continue; |
1d3cb0a3 |
if (cli_readint32(ptr) == ZIP_MAGIC_CENTRAL_DIRECTORY_RECORD_END) { |
288057e9 |
uint32_t chptr = cli_readint32(&ptr[16]); |
1d3cb0a3 |
if (!CLI_ISCONTAINED(0, fsize, chptr, SIZEOF_CENTRAL_HEADER)) continue; |
288057e9 |
coff = chptr;
break;
}
}
if (coff) { |
1d3cb0a3 |
cli_dbgmsg("cli_unzip: central directory header offset: @%x\n", coff); |
e0c30803 |
|
768d59c7 |
/*
* Index the central directory first.
*/
ret = index_the_central_directory(
ctx,
map,
fsize,
coff,
&zip_catalogue,
&records_count); |
e0c30803 |
if (CL_SUCCESS != ret) {
goto done;
}
|
768d59c7 |
/*
* Then decrypt/unzip & scan each unique file entry.
*/
for (i = 0; i < records_count; i++) {
const uint8_t *compressed_data = NULL;
if ((i > 0) &&
(zip_catalogue[i].local_header_offset == zip_catalogue[i - 1].local_header_offset) &&
(zip_catalogue[i].local_header_size == zip_catalogue[i - 1].local_header_size) &&
(zip_catalogue[i].compressed_size == zip_catalogue[i - 1].compressed_size)) {
/* Duplicate file entry, skip. */
cli_dbgmsg("cli_unzip: Skipping unzipping of duplicate file entry: @ 0x%x\n", zip_catalogue[i].local_header_offset);
continue;
}
compressed_data = fmap_need_off(map, zip_catalogue[i].local_header_offset + zip_catalogue[i].local_header_size, SIZEOF_LOCAL_HEADER);
if (zip_catalogue[i].encrypted) {
if (fmap_need_ptr_once(map, compressed_data, zip_catalogue[i].compressed_size))
ret = zdecrypt(
compressed_data,
zip_catalogue[i].compressed_size,
zip_catalogue[i].uncompressed_size,
fmap_need_off(map, zip_catalogue[i].local_header_offset, SIZEOF_LOCAL_HEADER),
&num_files_unzipped,
ctx,
tmpd,
zip_scan_cb);
} else {
if (fmap_need_ptr_once(map, compressed_data, zip_catalogue[i].compressed_size))
ret = unz(
compressed_data,
zip_catalogue[i].compressed_size,
zip_catalogue[i].uncompressed_size,
zip_catalogue[i].method,
zip_catalogue[i].flags,
&num_files_unzipped,
ctx,
tmpd,
zip_scan_cb);
}
|
1d3cb0a3 |
file_count++;
if (ctx->engine->maxfiles && num_files_unzipped >= ctx->engine->maxfiles) { |
288057e9 |
cli_dbgmsg("cli_unzip: Files limit reached (max: %u)\n", ctx->engine->maxfiles);
ret = CL_EMAXFILES;
} |
23e0b6d3 |
|
b056e8e4 |
if (cli_checktimelimit(ctx) != CL_SUCCESS) {
cli_dbgmsg("cli_unzip: Time limit reached (max: %u)\n", ctx->engine->maxscantime);
ret = CL_ETIMEOUT;
}
|
20b45621 |
#if HAVE_JSON |
288057e9 |
if (cli_json_timeout_cycle_check(ctx, &toval) != CL_SUCCESS) {
ret = CL_ETIMEOUT;
} |
20b45621 |
#endif |
288057e9 |
if (ret != CL_CLEAN) { |
e0c30803 |
if (ret == CL_VIRUS && SCAN_ALLMATCHES) { |
288057e9 |
ret = CL_CLEAN;
virus_found = 1; |
e0c30803 |
} else { |
288057e9 |
break; |
e0c30803 |
} |
288057e9 |
}
} |
e0c30803 |
} else { |
288057e9 |
cli_dbgmsg("cli_unzip: central not found, using localhdrs\n"); |
e0c30803 |
}
if (virus_found == 1) { |
288057e9 |
ret = CL_VIRUS; |
e0c30803 |
} |
1d3cb0a3 |
if (num_files_unzipped <= (file_count / 4)) { /* FIXME: make up a sane ratio or remove the whole logic */
file_count = 0;
while ((ret == CL_CLEAN) &&
(lhoff < fsize) && |
23e0b6d3 |
(0 != (coff = parse_local_file_header(map,
lhoff,
fsize - lhoff,
&num_files_unzipped,
file_count + 1,
NULL,
&ret,
ctx,
tmpd,
1,
zip_scan_cb,
NULL)))) { |
1d3cb0a3 |
file_count++; |
288057e9 |
lhoff += coff;
if (SCAN_ALLMATCHES && ret == CL_VIRUS) {
ret = CL_CLEAN;
virus_found = 1;
} |
1d3cb0a3 |
if (ctx->engine->maxfiles && num_files_unzipped >= ctx->engine->maxfiles) { |
288057e9 |
cli_dbgmsg("cli_unzip: Files limit reached (max: %u)\n", ctx->engine->maxfiles);
ret = CL_EMAXFILES;
} |
20b45621 |
#if HAVE_JSON |
288057e9 |
if (cli_json_timeout_cycle_check(ctx, &toval) != CL_SUCCESS) {
ret = CL_ETIMEOUT;
} |
20b45621 |
#endif |
288057e9 |
} |
50593e02 |
}
|
e0c30803 |
done: |
768d59c7 |
if (NULL != zip_catalogue) {
free(zip_catalogue);
zip_catalogue = NULL;
}
|
e0c30803 |
if (NULL != tmpd) {
if (!ctx->engine->keeptmp) {
cli_rmdirs(tmpd);
}
free(tmpd);
} |
50593e02 |
|
288057e9 |
if (ret == CL_CLEAN && virus_found)
ret = CL_VIRUS; |
92e0ae15 |
|
288057e9 |
return ret; |
50593e02 |
}
|
1d3cb0a3 |
cl_error_t unzip_single_internal(cli_ctx *ctx, off_t local_header_offset, zip_cb zcb) |
c8c878f9 |
{ |
1d3cb0a3 |
cl_error_t ret = CL_CLEAN;
unsigned int num_files_unzipped = 0; |
288057e9 |
uint32_t fsize;
fmap_t *map = *ctx->fmap;
cli_dbgmsg("in cli_unzip_single\n"); |
1d3cb0a3 |
fsize = (uint32_t)(map->len - local_header_offset);
if ((local_header_offset < 0) ||
((size_t)local_header_offset > map->len) ||
((sizeof(off_t) != sizeof(uint32_t)) && ((size_t)fsize != map->len - local_header_offset))) {
|
288057e9 |
cli_dbgmsg("cli_unzip: bad offset\n");
return CL_CLEAN;
} |
1d3cb0a3 |
if (fsize < SIZEOF_LOCAL_HEADER) { |
288057e9 |
cli_dbgmsg("cli_unzip: file too short\n");
return CL_CLEAN;
}
|
23e0b6d3 |
parse_local_file_header(map,
local_header_offset,
fsize,
&num_files_unzipped,
0,
NULL,
&ret,
ctx,
NULL,
0,
zcb,
NULL); |
288057e9 |
return ret; |
50593e02 |
} |
c8c878f9 |
|
1d3cb0a3 |
cl_error_t cli_unzip_single(cli_ctx *ctx, off_t local_header_offset) |
288057e9 |
{ |
1d3cb0a3 |
return unzip_single_internal(ctx, local_header_offset, zip_scan_cb); |
c8c878f9 |
}
|
1d3cb0a3 |
cl_error_t unzip_search_add(struct zip_requests *requests, const char *name, size_t nlen) |
c8c80ddf |
{
cli_dbgmsg("in unzip_search_add\n");
if (requests->namecnt >= MAX_ZIP_REQUESTS) {
cli_dbgmsg("DEBUGGING MESSAGE GOES HERE!\n");
return CL_BREAK;
}
cli_dbgmsg("unzip_search_add: adding %s (len %llu)\n", name, (long long unsigned)nlen);
|
288057e9 |
requests->names[requests->namecnt] = name; |
c8c80ddf |
requests->namelens[requests->namecnt] = nlen;
requests->namecnt++;
return CL_SUCCESS;
}
|
1d3cb0a3 |
cl_error_t unzip_search(cli_ctx *ctx, fmap_t *map, struct zip_requests *requests) |
c8c878f9 |
{ |
1d3cb0a3 |
unsigned int file_count = 0;
fmap_t *zmap = map; |
c8c878f9 |
size_t fsize;
uint32_t coff = 0;
const char *ptr; |
1d3cb0a3 |
cl_error_t ret = CL_CLEAN; |
20b45621 |
#if HAVE_JSON
uint32_t toval = 0;
#endif |
c8c878f9 |
cli_dbgmsg("in unzip_search\n"); |
c8c80ddf |
if ((!ctx && !map) || !requests) { |
c8c878f9 |
return CL_ENULLARG;
}
|
c8c80ddf |
/* get priority to given map over *ctx->fmap */
if (ctx && !map)
zmap = *ctx->fmap;
fsize = zmap->len; |
288057e9 |
if (sizeof(off_t) != sizeof(uint32_t) && fsize != zmap->len) { |
c8c878f9 |
cli_dbgmsg("unzip_search: file too big\n");
return CL_CLEAN;
} |
1d3cb0a3 |
if (fsize < SIZEOF_CENTRAL_HEADER) { |
c8c878f9 |
cli_dbgmsg("unzip_search: file too short\n");
return CL_CLEAN;
}
|
288057e9 |
for (coff = fsize - 22; coff > 0; coff--) { /* sizeof(EOC)==22 */
if (!(ptr = fmap_need_off_once(zmap, coff, 20))) |
c8c878f9 |
continue; |
1d3cb0a3 |
if (cli_readint32(ptr) == ZIP_MAGIC_CENTRAL_DIRECTORY_RECORD_END) { |
c8c878f9 |
uint32_t chptr = cli_readint32(&ptr[16]); |
1d3cb0a3 |
if (!CLI_ISCONTAINED(0, fsize, chptr, SIZEOF_CENTRAL_HEADER)) continue; |
288057e9 |
coff = chptr; |
c8c878f9 |
break;
}
}
|
288057e9 |
if (coff) { |
1d3cb0a3 |
cli_dbgmsg("unzip_search: central directory header offset: @%x\n", coff); |
23e0b6d3 |
while (ret == CL_CLEAN && (coff = parse_central_directory_file_header(zmap,
coff,
fsize,
NULL,
file_count + 1,
&ret,
ctx,
NULL,
requests,
NULL))) { |
c8c80ddf |
if (requests->match) { |
288057e9 |
ret = CL_VIRUS; |
c8c878f9 |
}
|
1d3cb0a3 |
file_count++;
if (ctx && ctx->engine->maxfiles && file_count >= ctx->engine->maxfiles) { |
c8c878f9 |
cli_dbgmsg("cli_unzip: Files limit reached (max: %u)\n", ctx->engine->maxfiles); |
288057e9 |
ret = CL_EMAXFILES; |
c8c878f9 |
} |
20b45621 |
#if HAVE_JSON |
c8c80ddf |
if (ctx && cli_json_timeout_cycle_check(ctx, (int *)(&toval)) != CL_SUCCESS) { |
288057e9 |
ret = CL_ETIMEOUT; |
20b45621 |
}
#endif |
c8c878f9 |
}
} else {
cli_dbgmsg("unzip_search: cannot locate central directory\n");
}
return ret;
}
|
1d3cb0a3 |
cl_error_t unzip_search_single(cli_ctx *ctx, const char *name, size_t nlen, uint32_t *loff) |
c8c80ddf |
{
struct zip_requests requests; |
1d3cb0a3 |
cl_error_t ret; |
c8c80ddf |
cli_dbgmsg("in unzip_search_single\n");
if (!ctx) {
return CL_ENULLARG;
}
memset(&requests, 0, sizeof(struct zip_requests));
if ((ret = unzip_search_add(&requests, name, nlen)) != CL_SUCCESS) {
return ret;
}
if ((ret = unzip_search(ctx, NULL, &requests)) == CL_VIRUS) {
*loff = requests.loff;
}
return ret;
} |