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denyhosts/clamscan/libclamav/ishield.c

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添加病毒扫描
2022-10-22 18:41:00 +08:00
/*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2009-2013 Sourcefire, Inc.
*
* Authors: aCaB <acab@clamav.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.
*/
/* common routines to deal with installshield archives and installers */
#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 <limits.h>
#if HAVE_STRINGS_H
#include <strings.h>
#endif
#if defined(HAVE_MMAP) && defined(HAVE_SYS_MMAN_H)
#include <sys/mman.h>
#endif
#include <zlib.h>
#include "clamav.h"
#include "scanners.h"
#include "others.h"
#include "fmap.h"
#include "ishield.h"
#ifndef LONG_MAX
#define LONG_MAX ((-1UL) >> 1)
#endif
#ifndef HAVE_ATTRIB_PACKED
#define __attribute__(x)
#endif
#ifdef HAVE_PRAGMA_PACK
#pragma pack(1)
#endif
#ifdef HAVE_PRAGMA_PACK_HPPA
#pragma pack 1
#endif
/* PACKED things go here */
struct IS_HDR {
uint32_t magic;
uint32_t unk1; /* version ??? */
uint32_t unk2; /* ??? */
uint32_t data_off;
uint32_t data_sz; /* ??? */
} __attribute__((packed));
struct IS_FB {
char fname[0x104]; /* MAX_PATH */
uint32_t unk1; /* 6 */
uint32_t unk2;
uint64_t csize;
uint32_t unk3;
uint32_t unk4; /* 1 */
uint32_t unk5;
uint32_t unk6;
uint32_t unk7;
uint32_t unk8;
uint32_t unk9;
uint32_t unk10;
uint32_t unk11;
} __attribute__((packed));
struct IS_COMPONENT {
uint32_t str_name_off;
uint32_t unk_str1_off;
uint32_t unk_str2_off;
uint16_t unk_flags;
uint32_t unk_str3_off;
uint32_t unk_str4_off;
uint16_t ordinal_id;
uint32_t str_shortname_off;
uint32_t unk_str6_off;
uint32_t unk_str7_off;
uint32_t unk_str8_off;
char guid1[16];
char guid2[16];
uint32_t unk_str9_off;
char unk1[3];
uint16_t unk_flags2;
uint32_t unk3[5];
uint32_t unk_str10_off;
uint32_t unk4[4];
uint16_t unk5;
uint16_t sub_comp_cnt;
uint32_t sub_comp_offs_array;
uint32_t next_comp_off;
uint32_t unk_str11_off;
uint32_t unk_str12_off;
uint32_t unk_str13_off;
uint32_t unk_str14_off;
uint32_t str_next1_off;
uint32_t str_next2_off;
} __attribute__((packed));
struct IS_INSTTYPEHDR {
uint32_t unk1;
uint32_t cnt;
uint32_t off;
} __attribute__((packed));
struct IS_INSTTYPEITEM {
uint32_t str_name1_off;
uint32_t str_name2_off;
uint32_t str_name3_off;
uint32_t cnt;
uint32_t off;
} __attribute__((packed));
struct IS_OBJECTS {
/* 200 */ uint32_t strings_off;
/* 204 */ uint32_t zero1;
/* 208 */ uint32_t comps_off;
/* 20c */ uint32_t dirs_off;
/* 210 */ uint32_t zero2;
/* 214 */ uint32_t unk1, unk2; /* 0x4a636 304694 uguali - NOT AN OFFSET! */
/* 21c */ uint32_t dirs_cnt;
/* 220 */ uint32_t zero3;
/* 224 */ uint32_t dirs_sz; /* dirs_cnt * 4 */
/* 228 */ uint32_t files_cnt;
/* 22c */ uint32_t dir_sz2; /* same as dirs_sz ?? */
/* 230 */ uint16_t unk5; /* 1 - comp count ?? */
/* 232 */ uint32_t insttype_off;
/* 234 */ uint16_t zero4;
/* 238 */ uint32_t zero5;
/* 23c */ uint32_t unk7; /* 0xd0 - 208 */
/* 240 */ uint16_t unk8;
/* 242 */ uint32_t unk9;
/* 246 */ uint32_t unk10;
} __attribute__((packed));
struct IS_FILEITEM {
uint16_t flags; /* 0 = EXTERNAL | 4 = INTERNAL | 8 = NAME_fuckup_rare | c = name_fuckup_common */
uint64_t size;
uint64_t csize;
uint64_t stream_off;
uint8_t md5[16];
uint64_t versioninfo_id;
uint32_t zero1;
uint32_t zero2;
uint32_t str_name_off;
uint16_t dir_id;
uint32_t unk13; /* 0, 20, 21 ??? */
uint32_t unk14; /* timestamp ??? */
uint32_t unk15; /* begins with 1 then 2 but not the cab# ??? */
uint32_t prev_dup_id; /* msvcrt #38(0, 97, 2) #97(38, 1181, 3) ... , 0, 1) */
uint32_t next_dup_id;
uint8_t flag_has_dup; /* HAS_NEXT = 2 | HAS_BOTH = 3 | HAS_PREV = 1 */
uint16_t datafile_id;
} __attribute__((packed));
#ifdef HAVE_PRAGMA_PACK
#pragma pack()
#endif
#ifdef HAVE_PRAGMA_PACK_HPPA
#pragma pack
#endif
static int is_dump_and_scan(cli_ctx *ctx, off_t off, size_t fsize);
static const uint8_t skey[] = {0xec, 0xca, 0x79, 0xf8}; /* ~0x13, ~0x35, ~0x86, ~0x07 */
/* Extracts the content of MSI based IS */
int cli_scanishield_msi(cli_ctx *ctx, off_t off)
{
const uint8_t *buf;
unsigned int fcount, scanned = 0;
int ret;
fmap_t *map = ctx->fmap;
cli_dbgmsg("in ishield-msi\n");
if (!(buf = fmap_need_off_once(map, off, 0x20))) {
cli_dbgmsg("ishield-msi: short read for header\n");
return CL_CLEAN;
}
off += 0x20;
if (cli_readint32(buf + 8) | cli_readint32(buf + 0xc) | cli_readint32(buf + 0x10) | cli_readint32(buf + 0x14) | cli_readint32(buf + 0x18) | cli_readint32(buf + 0x1c))
return CL_CLEAN;
if (!(fcount = cli_readint32(buf))) {
cli_dbgmsg("ishield-msi: no files?\n");
return CL_CLEAN;
}
while (fcount--) {
struct IS_FB fb;
uint8_t obuf[BUFSIZ], *key = (uint8_t *)&fb.fname;
char *filename = NULL;
char *tempfile;
unsigned int i, lameidx = 0, keylen;
int ofd;
uint64_t csize;
z_stream z;
if (fmap_readn(map, &fb, off, sizeof(fb)) != sizeof(fb)) {
cli_dbgmsg("ishield-msi: short read for fileblock\n");
return CL_CLEAN;
}
off += sizeof(fb);
fb.fname[sizeof(fb.fname) - 1] = '\0';
csize = le64_to_host(fb.csize);
if (!CLI_ISCONTAINED_0_TO(map->len, off, csize)) {
cli_dbgmsg("ishield-msi: next stream is out of file, giving up\n");
return CL_CLEAN;
}
if (ctx->engine->maxfilesize && csize > ctx->engine->maxfilesize) {
cli_dbgmsg("ishield-msi: skipping stream due to size limits (%lu vs %lu)\n", (unsigned long int)csize, (unsigned long int)ctx->engine->maxfilesize);
off += csize;
continue;
}
keylen = strlen((const char *)key);
if (!keylen) return CL_CLEAN;
filename = cli_strdup((const char *)key);
/* FIXMEISHIELD: cleanup the spam below */
cli_dbgmsg("ishield-msi: File %s (csize: %llx, unk1:%x unk2:%x unk3:%x unk4:%x unk5:%x unk6:%x unk7:%x unk8:%x unk9:%x unk10:%x unk11:%x)\n", key, (long long)csize, fb.unk1, fb.unk2, fb.unk3, fb.unk4, fb.unk5, fb.unk6, fb.unk7, fb.unk8, fb.unk9, fb.unk10, fb.unk11);
if (!(tempfile = cli_gentemp(ctx->sub_tmpdir))) {
if (NULL != filename) {
free(filename);
}
return CL_EMEM;
}
if ((ofd = open(tempfile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR)) < 0) {
cli_dbgmsg("ishield-msi: failed to create file %s\n", tempfile);
free(tempfile);
if (NULL != filename) {
free(filename);
}
return CL_ECREAT;
}
for (i = 0; i < keylen; i++)
key[i] ^= skey[i & 3];
memset(&z, 0, sizeof(z));
inflateInit(&z);
ret = CL_SUCCESS;
while (csize) {
uint8_t buf2[BUFSIZ];
z.avail_in = MIN(csize, sizeof(buf2));
if (fmap_readn(map, buf2, off, z.avail_in) != z.avail_in) {
cli_dbgmsg("ishield-msi: premature EOS or read fail\n");
break;
}
off += z.avail_in;
for (i = 0; i < z.avail_in; i++, lameidx++) {
uint8_t c = buf2[i];
c = (c >> 4) | (c << 4);
c ^= key[(lameidx & 0x3ff) % keylen];
buf2[i] = c;
}
csize -= z.avail_in;
z.next_in = buf2;
do {
int inf;
z.avail_out = sizeof(obuf);
z.next_out = obuf;
inf = inflate(&z, 0);
if (inf != Z_OK && inf != Z_STREAM_END && inf != Z_BUF_ERROR) {
cli_dbgmsg("ishield-msi: bad stream\n");
csize = 0;
off += csize;
break;
}
if (cli_writen(ofd, obuf, sizeof(obuf) - z.avail_out) == (size_t)-1) {
ret = CL_EWRITE;
csize = 0;
break;
}
if (ctx->engine->maxfilesize && z.total_out > ctx->engine->maxfilesize) {
cli_dbgmsg("ishield-msi: trimming output file due to size limits (%lu vs %lu)\n", z.total_out, (unsigned long int)ctx->engine->maxfilesize);
off += csize;
csize = 0;
break;
}
} while (!z.avail_out);
}
inflateEnd(&z);
if (ret == CL_SUCCESS) {
cli_dbgmsg("ishield-msi: extracted to %s\n", tempfile);
if (lseek(ofd, 0, SEEK_SET) == -1) {
cli_dbgmsg("ishield-msi: call to lseek() failed\n");
ret = CL_ESEEK;
}
ret = cli_magic_scan_desc(ofd, tempfile, ctx, filename);
}
close(ofd);
if (!ctx->engine->keeptmp) {
if (cli_unlink(tempfile)) {
ret = CL_EUNLINK;
}
}
free(tempfile);
if (NULL != filename) {
free(filename);
}
if (ret != CL_CLEAN)
return ret;
scanned++;
if (ctx->engine->maxfiles && scanned >= ctx->engine->maxfiles) {
cli_dbgmsg("ishield-msi: File limit reached (max: %u)\n", ctx->engine->maxfiles);
return CL_EMAXFILES;
}
}
return CL_CLEAN;
}
struct IS_CABSTUFF {
struct CABARRAY {
unsigned int cabno;
off_t off;
size_t sz;
} * cabs;
off_t hdr;
size_t hdrsz;
unsigned int cabcnt;
};
static void md5str(uint8_t *sum);
static int is_parse_hdr(cli_ctx *ctx, struct IS_CABSTUFF *c);
static int is_extract_cab(cli_ctx *ctx, uint64_t off, uint64_t size, uint64_t csize);
/* Extract the content of older (non-MSI) IS */
int cli_scanishield(cli_ctx *ctx, off_t off, size_t sz)
{
const char *fname, *path, *version, *strsz, *data;
char *eostr;
int ret = CL_CLEAN;
long fsize;
off_t coff = off;
struct IS_CABSTUFF c = {NULL, -1, 0, 0};
fmap_t *map = ctx->fmap;
unsigned fc = 0;
int virus_found = 0;
while (ret == CL_CLEAN) {
fname = fmap_need_offstr(map, coff, 2048);
if (!fname) break;
coff += strlen(fname) + 1;
path = fmap_need_offstr(map, coff, 2048);
if (!path) break;
coff += strlen(path) + 1;
version = fmap_need_offstr(map, coff, 2048);
if (!version) break;
coff += strlen(version) + 1;
strsz = fmap_need_offstr(map, coff, 2048);
if (!strsz) break;
coff += strlen(strsz) + 1;
data = &strsz[strlen(strsz) + 1];
fsize = strtol(strsz, &eostr, 10);
if (fsize < 0 || fsize == LONG_MAX ||
!*strsz || !eostr || eostr == strsz || *eostr ||
(unsigned long)fsize >= sz ||
(size_t)(data - fname) >= sz - fsize) break;
cli_dbgmsg("ishield: @%lx found file %s (%s) - version %s - size %lu\n", (unsigned long int)coff, fname, path, version, (unsigned long int)fsize);
if (cli_matchmeta(ctx, fname, fsize, fsize, 0, fc++, 0, NULL) == CL_VIRUS) {
if (!SCAN_ALLMATCHES) {
ret = CL_VIRUS;
break;
}
ret = CL_CLEAN;
virus_found = 1;
}
sz -= (data - fname) + fsize;
if (!strncasecmp(fname, "data", 4)) {
long cabno;
if (!strcasecmp(fname + 4, "1.hdr")) {
if (c.hdr == -1) {
cli_dbgmsg("ishield: added data1.hdr to array\n");
c.hdr = coff;
c.hdrsz = fsize;
coff += fsize;
continue;
}
cli_warnmsg("ishield: got multiple header files\n");
}
cabno = strtol(fname + 4, &eostr, 10);
if (cabno > 0 && cabno < 65536 && fname[4] && eostr && eostr != &fname[4] && !strcasecmp(eostr, ".cab")) {
unsigned int i;
for (i = 0; i < c.cabcnt && i != c.cabs[i].cabno; i++) {
}
if (i == c.cabcnt) {
c.cabcnt++;
if (!(c.cabs = cli_realloc2(c.cabs, sizeof(struct CABARRAY) * c.cabcnt))) {
ret = CL_EMEM;
break;
}
cli_dbgmsg("ishield: added data%lu.cab to array\n", cabno);
c.cabs[i].cabno = cabno;
c.cabs[i].off = coff;
c.cabs[i].sz = fsize;
coff += fsize;
continue;
}
cli_warnmsg("ishield: got multiple data%lu.cab files\n", cabno);
}
}
fmap_unneed_ptr(map, fname, data - fname);
ret = is_dump_and_scan(ctx, coff, fsize);
coff += fsize;
}
if (ret == CL_CLEAN && (c.cabcnt || c.hdr != -1)) {
if ((ret = is_parse_hdr(ctx, &c)) == CL_CLEAN) {
unsigned int i;
if (c.hdr != -1) {
cli_dbgmsg("ishield: scanning data1.hdr\n");
ret = is_dump_and_scan(ctx, c.hdr, c.hdrsz);
}
for (i = 0; i < c.cabcnt && ret == CL_CLEAN; i++) {
cli_dbgmsg("ishield: scanning data%u.cab\n", c.cabs[i].cabno);
ret = is_dump_and_scan(ctx, c.cabs[i].off, c.cabs[i].sz);
}
} else if (ret == CL_BREAK)
ret = CL_CLEAN;
}
if (c.cabs) free(c.cabs);
if (virus_found != 0)
return CL_VIRUS;
return ret;
}
/* Utility func to scan a fd @ a given offset and size */
static int is_dump_and_scan(cli_ctx *ctx, off_t off, size_t fsize)
{
char *fname;
const char *buf;
int ofd, ret = CL_CLEAN;
fmap_t *map = ctx->fmap;
if (!fsize) {
cli_dbgmsg("ishield: skipping empty file\n");
return CL_CLEAN;
}
if (!(fname = cli_gentemp(ctx->sub_tmpdir)))
return CL_EMEM;
if ((ofd = open(fname, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR)) < 0) {
cli_errmsg("ishield: failed to create file %s\n", fname);
free(fname);
return CL_ECREAT;
}
while (fsize) {
size_t rd = MIN(fsize, map->pgsz);
if (!(buf = fmap_need_off_once(map, off, rd))) {
cli_dbgmsg("ishield: read error\n");
ret = CL_EREAD;
break;
}
if (cli_writen(ofd, buf, rd) != rd) {
ret = CL_EWRITE;
break;
}
fsize -= rd;
off += rd;
}
if (!fsize) {
cli_dbgmsg("ishield: extracted to %s\n", fname);
if (lseek(ofd, 0, SEEK_SET) == -1) {
cli_dbgmsg("ishield: call to lseek() failed\n");
ret = CL_ESEEK;
}
ret = cli_magic_scan_desc(ofd, fname, ctx, NULL);
}
close(ofd);
if (!ctx->engine->keeptmp)
if (cli_unlink(fname)) ret = CL_EUNLINK;
free(fname);
return ret;
}
/* Process data1.hdr and extracts all the available files from dataX.cab */
static int is_parse_hdr(cli_ctx *ctx, struct IS_CABSTUFF *c)
{
uint32_t h1_data_off, objs_files_cnt, objs_dirs_off;
unsigned int off, i, scanned = 0;
int ret = CL_BREAK;
char hash[33], *hdr;
fmap_t *map = ctx->fmap;
const struct IS_HDR *h1;
struct IS_OBJECTS *objs;
/* struct IS_INSTTYPEHDR *typehdr; -- UNUSED */
if (!c->hdr || !c->hdrsz || !c->cabcnt) {
cli_dbgmsg("is_parse_hdr: inconsistent hdr, maybe a false match\n");
return CL_CLEAN;
}
if (!(h1 = fmap_need_off(map, c->hdr, c->hdrsz))) {
cli_dbgmsg("is_parse_hdr: not enough room for H1\n");
return CL_CLEAN;
}
hdr = (char *)h1;
h1_data_off = le32_to_host(h1->data_off);
objs = (struct IS_OBJECTS *)fmap_need_ptr(map, hdr + h1_data_off, sizeof(*objs));
if (!objs) {
cli_dbgmsg("is_parse_hdr: not enough room for OBJECTS\n");
return CL_CLEAN;
}
cli_dbgmsg("is_parse_hdr: magic %x, unk1 %x, unk2 %x, data_off %x, data_sz %x\n",
h1->magic, h1->unk1, h1->unk2, h1_data_off, h1->data_sz);
if (le32_to_host(h1->magic) != 0x28635349) {
cli_dbgmsg("is_parse_hdr: bad magic. wrong version?\n");
return CL_CLEAN;
}
fmap_unneed_ptr(map, h1, sizeof(*h1));
/* cli_errmsg("COMPONENTS\n"); */
/* off = le32_to_host(objs->comps_off) + h1_data_off; */
/* for(i=1; ; i++) { */
/* struct IS_COMPONENT *cmp = (struct IS_COMPONENT *)(hdr + off); */
/* if(!CLI_ISCONTAINED(hdr, c->hdrsz, ((char *)cmp), sizeof(*cmp))) { */
/* cli_dbgmsg("is_extract: not enough room for COMPONENT\n"); */
/* free(hdr); */
/* return CL_CLEAN; */
/* } */
/* cli_errmsg("%06u\t%s\n", i, &hdr[le32_to_host(cmp->str_name_off) + h1_data_off]); */
/* spam_strarray(hdr, h1_data_off + cmp->sub_comp_offs_array, h1_data_off, cmp->sub_comp_cnt); */
/* if(!cmp->next_comp_off) break; */
/* off = le32_to_host(cmp->next_comp_off) + h1_data_off; */
/* } */
/* cli_errmsg("DIRECTORIES (%u)", le32_to_host(objs->dirs_cnt)); */
objs_dirs_off = le32_to_host(objs->dirs_off);
/* spam_strarray(hdr, h1_data_off + objs_dirs_off, h1_data_off + objs_dirs_off, objs->dirs_cnt); */
/* typehdr = (struct INSTTYPEHDR *)&hdr[h1_data_off + le32_to_host(objs->insttype_off)]; */
/* printf("INSTTYPES (unk1: %d)\n-----------\n", typehdr->unk1); */
/* off = typehdr->off + h1_data_off; */
/* for(i=1; i<=typehdr->cnt; i++) { */
/* uint32_t x = *(uint32_t *)(&hdr[off]); */
/* struct INSTTYPEITEM *item = (struct INSTTYPEITEM *)&hdr[x + h1_data_off]; */
/* printf("%06u\t%s\t aka %s\taka %s\n", i, &hdr[item->str_name1_off + h1_data_off], &hdr[item->str_name2_off + h1_data_off], &hdr[item->str_name3_off + h1_data_off]); */
/* printf("components:\n"); */
/* spam_strarray(hdr, h1_data_off + item->off, h1_data_off, item->cnt); */
/* off+=4; */
/* } */
/* dir = &hdr[*(uint32_t *)(&hdr[h1_data_off + objs_dirs_off + 4 * file->dir_id]) + h1_data_off + objs_dirs_off] */
objs_files_cnt = le32_to_host(objs->files_cnt);
off = h1_data_off + objs_dirs_off + le32_to_host(objs->dir_sz2);
fmap_unneed_ptr(map, objs, sizeof(*objs));
for (i = 0; i < objs_files_cnt; i++) {
struct IS_FILEITEM *file = (struct IS_FILEITEM *)fmap_need_off(map, c->hdr + off, sizeof(*file));
if (file) {
const char *emptyname = "", *dir_name = emptyname, *file_name = emptyname;
uint32_t dir_rel = h1_data_off + objs_dirs_off + 4 * le32_to_host(file->dir_id); /* rel off of dir entry from array of rel ptrs */
uint32_t file_rel = objs_dirs_off + h1_data_off + le32_to_host(file->str_name_off); /* rel off of fname */
uint64_t file_stream_off, file_size, file_csize;
uint16_t cabno;
memcpy(hash, file->md5, 16);
md5str((uint8_t *)hash);
if (fmap_need_ptr_once(map, &hdr[dir_rel], 4)) {
dir_rel = cli_readint32(&hdr[dir_rel]) + h1_data_off + objs_dirs_off;
if (fmap_need_str(map, &hdr[dir_rel], c->hdrsz - dir_rel))
dir_name = &hdr[dir_rel];
}
if (fmap_need_str(map, &hdr[file_rel], c->hdrsz - file_rel))
file_name = &hdr[file_rel];
file_stream_off = le64_to_host(file->stream_off);
file_size = le64_to_host(file->size);
file_csize = le64_to_host(file->csize);
cabno = le16_to_host(file->datafile_id);
switch (le16_to_host(file->flags)) {
case 0:
/* FIXMEISHIELD: for FS scan ? */
cli_dbgmsg("is_parse_hdr: skipped external file:%s\\%s (size: %llu csize: %llu md5:%s)\n",
dir_name,
file_name,
(long long)file_size, (long long)file_csize, hash);
break;
case 4:
cli_dbgmsg("is_parse_hdr: file %s\\%s (size: %llu csize: %llu md5:%s offset:%llx (data%u.cab) 13:%x 14:%x 15:%x)\n",
dir_name,
file_name,
(long long)file_size, (long long)file_csize, hash, (long long)file_stream_off,
cabno, file->unk13, file->unk14, file->unk15);
if (file->flag_has_dup & 1)
cli_dbgmsg("is_parse_hdr: not scanned (dup)\n");
else {
if (file_size) {
unsigned int j;
int cabret = CL_CLEAN;
if (ctx->engine->maxfilesize && file_csize > ctx->engine->maxfilesize) {
cli_dbgmsg("is_parse_hdr: skipping file due to size limits (%lu vs %lu)\n", (unsigned long int)file_csize, (unsigned long int)ctx->engine->maxfilesize);
break;
}
for (j = 0; j < c->cabcnt && c->cabs[j].cabno != cabno; j++) {
}
if (j != c->cabcnt) {
if (CLI_ISCONTAINED(c->cabs[j].off, c->cabs[j].sz, file_stream_off + c->cabs[j].off, file_csize)) {
scanned++;
if (ctx->engine->maxfiles && scanned >= ctx->engine->maxfiles) {
cli_dbgmsg("is_parse_hdr: File limit reached (max: %u)\n", ctx->engine->maxfiles);
if (file_name != emptyname)
fmap_unneed_ptr(map, (void *)file_name, strlen(file_name) + 1);
if (dir_name != emptyname)
fmap_unneed_ptr(map, (void *)dir_name, strlen(dir_name) + 1);
return CL_EMAXFILES;
}
cabret = is_extract_cab(ctx, file_stream_off + c->cabs[j].off, file_size, file_csize);
} else {
ret = CL_CLEAN;
cli_dbgmsg("is_parse_hdr: stream out of file\n");
}
} else {
ret = CL_CLEAN;
cli_dbgmsg("is_parse_hdr: data%u.cab not available\n", cabno);
}
if (cabret == CL_BREAK) {
ret = CL_CLEAN;
cabret = CL_CLEAN;
}
if (cabret != CL_CLEAN) {
if (file_name != emptyname)
fmap_unneed_ptr(map, (void *)file_name, strlen(file_name) + 1);
if (dir_name != emptyname)
fmap_unneed_ptr(map, (void *)dir_name, strlen(dir_name) + 1);
return cabret;
}
} else {
cli_dbgmsg("is_parse_hdr: skipped empty file\n");
}
}
break;
default:
cli_dbgmsg("is_parse_hdr: skipped unknown file entry %u\n", i);
}
if (file_name != emptyname)
fmap_unneed_ptr(map, (void *)file_name, strlen(file_name) + 1);
if (dir_name != emptyname)
fmap_unneed_ptr(map, (void *)dir_name, strlen(dir_name) + 1);
fmap_unneed_ptr(map, file, sizeof(*file));
} else {
ret = CL_CLEAN;
cli_dbgmsg("is_parse_hdr: FILEITEM out of bounds\n");
}
off += sizeof(*file);
}
return ret;
}
static void md5str(uint8_t *sum)
{
int i;
for (i = 15; i >= 0; i--) {
uint8_t lo = (sum[i] & 0xf), hi = (sum[i] >> 4);
lo += '0' + (lo > 9) * '\'';
hi += '0' + (hi > 9) * '\'';
sum[i * 2 + 1] = lo;
sum[i * 2] = hi;
}
sum[32] = '\0';
}
#define IS_CABBUFSZ 65536
static int is_extract_cab(cli_ctx *ctx, uint64_t off, uint64_t size, uint64_t csize)
{
const uint8_t *inbuf;
uint8_t *outbuf;
char *tempfile;
int ofd, ret = CL_CLEAN;
z_stream z;
uint64_t outsz = 0;
int success = 0;
fmap_t *map = ctx->fmap;
if (!(outbuf = cli_malloc(IS_CABBUFSZ))) {
cli_errmsg("is_extract_cab: Unable to allocate memory for outbuf\n");
return CL_EMEM;
}
if (!(tempfile = cli_gentemp(ctx->sub_tmpdir))) {
free(outbuf);
return CL_EMEM;
}
if ((ofd = open(tempfile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR)) < 0) {
cli_errmsg("is_extract_cab: failed to create file %s\n", tempfile);
free(tempfile);
free(outbuf);
return CL_ECREAT;
}
while (csize) {
uint16_t chunksz;
success = 0;
if (csize < 2) {
cli_dbgmsg("is_extract_cab: no room for chunk size\n");
break;
}
csize -= 2;
if (!(inbuf = fmap_need_off_once(map, off, 2))) {
cli_dbgmsg("is_extract_cab: short read for chunk size\n");
break;
}
off += 2;
chunksz = inbuf[0] | (inbuf[1] << 8);
if (!chunksz) {
cli_dbgmsg("is_extract_cab: zero sized chunk\n");
continue;
}
if (csize < chunksz) {
cli_dbgmsg("is_extract_cab: chunk is bigger than csize\n");
break;
}
csize -= chunksz;
if (!(inbuf = fmap_need_off_once(map, off, chunksz))) {
cli_dbgmsg("is_extract_cab: short read for chunk\n");
break;
}
off += chunksz;
memset(&z, 0, sizeof(z));
inflateInit2(&z, -MAX_WBITS);
z.next_in = (uint8_t *)inbuf;
z.avail_in = chunksz;
while (1) {
int zret;
z.next_out = outbuf;
z.avail_out = IS_CABBUFSZ;
zret = inflate(&z, 0);
if (zret == Z_OK || zret == Z_STREAM_END || zret == Z_BUF_ERROR) {
unsigned int umpd = IS_CABBUFSZ - z.avail_out;
if (cli_writen(ofd, outbuf, umpd) != umpd)
break;
outsz += umpd;
if (zret == Z_STREAM_END || z.avail_out == IS_CABBUFSZ /* FIXMEISHIELD: is the latter ok? */) {
success = 1;
break;
}
if (ctx->engine->maxfilesize && z.total_out > ctx->engine->maxfilesize) {
cli_dbgmsg("ishield_extract_cab: trimming output file due to size limits (%lu vs %lu)\n", z.total_out, (unsigned long int)ctx->engine->maxfilesize);
success = 1;
outsz = size;
break;
}
continue;
}
cli_dbgmsg("is_extract_cab: file decompression failed with %d\n", zret);
break;
}
inflateEnd(&z);
if (!success) break;
}
free(outbuf);
if (success) {
if (outsz != size)
cli_dbgmsg("is_extract_cab: extracted %llu bytes to %s, expected %llu, scanning anyway.\n", (long long)outsz, tempfile, (long long)size);
else
cli_dbgmsg("is_extract_cab: extracted to %s\n", tempfile);
if (lseek(ofd, 0, SEEK_SET) == -1)
cli_dbgmsg("is_extract_cab: call to lseek() failed\n");
ret = cli_magic_scan_desc(ofd, tempfile, ctx, NULL);
}
close(ofd);
if (!ctx->engine->keeptmp)
if (cli_unlink(tempfile)) ret = CL_EUNLINK;
free(tempfile);
return success ? ret : CL_BREAK;
}
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