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denyhosts/clamscan/libclamav/matcher.c
aixiao 07f551d5e4 添加病毒扫描
2022-10-22 18:41:00 +08:00

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/*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2007-2013 Sourcefire, Inc.
*
* Authors: Tomasz Kojm
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdbool.h>
#include "clamav.h"
#include "others.h"
#include "matcher-ac.h"
#include "matcher-bm.h"
#include "matcher-pcre.h"
#include "filetypes.h"
#include "matcher.h"
#include "pe.h"
#include "elf.h"
#include "execs.h"
#include "special.h"
#include "scanners.h"
#include "str.h"
#include "default.h"
#include "macho.h"
#include "fmap.h"
#include "pe_icons.h"
#include "regex/regex.h"
#include "filtering.h"
#include "perflogging.h"
#include "bytecode_priv.h"
#include "bytecode_api_impl.h"
#ifdef HAVE_YARA
#include "yara_clam.h"
#include "yara_exec.h"
#endif
#ifdef CLI_PERF_LOGGING
static inline void perf_log_filter(int32_t pos, int32_t length, int8_t trie)
{
cli_perf_log_add(RAW_BYTES_SCANNED, length);
cli_perf_log_add(FILTER_BYTES_SCANNED, length - pos);
cli_perf_log_count2(TRIE_SCANNED, trie, length - pos);
}
static inline int perf_log_tries(int8_t acmode, int8_t bm_called, int32_t length)
{
if (bm_called)
cli_perf_log_add(BM_SCANNED, length);
if (acmode)
cli_perf_log_add(AC_SCANNED, length);
return 0;
}
#else
static inline void perf_log_filter(int32_t pos, uint32_t length, int8_t trie)
{
UNUSEDPARAM(pos);
UNUSEDPARAM(length);
UNUSEDPARAM(trie);
}
static inline int perf_log_tries(int8_t acmode, int8_t bm_called, int32_t length)
{
UNUSEDPARAM(acmode);
UNUSEDPARAM(bm_called);
UNUSEDPARAM(length);
return 0;
}
#endif
static inline cl_error_t matcher_run(const struct cli_matcher *root,
const unsigned char *buffer, uint32_t length,
const char **virname, struct cli_ac_data *mdata,
uint32_t offset,
const struct cli_target_info *tinfo,
cli_file_t ftype,
struct cli_matched_type **ftoffset,
unsigned int acmode,
unsigned int pcremode,
struct cli_ac_result **acres,
fmap_t *map,
struct cli_bm_off *offdata,
struct cli_pcre_off *poffdata,
cli_ctx *ctx)
{
cl_error_t ret, saved_ret = CL_CLEAN;
int32_t pos = 0;
struct filter_match_info info;
uint32_t orig_length, orig_offset;
const unsigned char *orig_buffer;
unsigned int viruses_found = 0;
if (root->filter) {
if (filter_search_ext(root->filter, buffer, length, &info) == -1) {
/* for safety always scan last maxpatlen bytes */
pos = length - root->maxpatlen - 1;
if (pos < 0) pos = 0;
perf_log_filter(pos, length, root->type);
} else {
/* must not cut buffer for 64[4-4]6161, because we must be able to check
* 64! */
pos = info.first_match - root->maxpatlen - 1;
if (pos < 0) pos = 0;
perf_log_filter(pos, length, root->type);
}
} else {
perf_log_filter(0, length, root->type);
}
orig_length = length;
orig_buffer = buffer;
orig_offset = offset;
length -= pos;
buffer += pos;
offset += pos;
if (!root->ac_only) {
perf_log_tries(0, 1, length);
if (root->bm_offmode) {
/* Don't use prefiltering for BM offset mode, since BM keeps tracks
* of offsets itself, and doesn't work if we skip chunks of input
* data */
ret = cli_bm_scanbuff(orig_buffer, orig_length, virname, NULL, root, orig_offset, tinfo, offdata, ctx);
} else {
ret = cli_bm_scanbuff(buffer, length, virname, NULL, root, offset, tinfo, offdata, ctx);
}
if (ret != CL_CLEAN) {
if (ret != CL_VIRUS)
return ret;
/* else (ret == CL_VIRUS) */
if (SCAN_ALLMATCHES)
viruses_found = 1;
else {
ret = cli_append_virus(ctx, *virname);
if (ret != CL_CLEAN)
return ret;
}
}
}
perf_log_tries(acmode, 0, length);
ret = cli_ac_scanbuff(buffer, length, virname, NULL, acres, root, mdata, offset, ftype, ftoffset, acmode, ctx);
if (ret != CL_CLEAN) {
if (ret == CL_VIRUS) {
if (SCAN_ALLMATCHES)
viruses_found = 1;
else {
ret = cli_append_virus(ctx, *virname);
if (ret != CL_CLEAN)
return ret;
}
} else if (ret > CL_TYPENO && acmode & AC_SCAN_VIR)
saved_ret = ret;
else
return ret;
}
if (root->bcomp_metas) {
ret = cli_bcomp_scanbuf(orig_buffer, orig_length, acres, root, mdata, ctx);
if (ret != CL_CLEAN) {
if (ret > CL_TYPENO && acmode & AC_SCAN_VIR)
saved_ret = ret;
else
return ret;
}
}
/* due to logical triggered, pcres cannot be evaluated until after full subsig matching */
/* cannot save pcre execution state without possible evasion; must scan entire buffer */
/* however, scanning the whole buffer may require the whole buffer being loaded into memory */
#if HAVE_PCRE
if (root->pcre_metas) {
int rc;
uint64_t maxfilesize;
if (map && (pcremode == PCRE_SCAN_FMAP)) {
if (offset + length >= map->len) {
/* check that scanned map does not exceed pcre maxfilesize limit */
maxfilesize = (uint64_t)cl_engine_get_num(ctx->engine, CL_ENGINE_PCRE_MAX_FILESIZE, &rc);
if (rc != CL_SUCCESS)
return rc;
if (maxfilesize && (map->len > maxfilesize)) {
cli_dbgmsg("matcher_run: pcre max filesize (map) exceeded (limit: %llu, needed: %llu)\n",
(long long unsigned)maxfilesize, (long long unsigned)map->len);
return CL_EMAXSIZE;
}
cli_dbgmsg("matcher_run: performing regex matching on full map: %u+%u(%u) >= %zu\n", offset, length, offset + length, map->len);
buffer = fmap_need_off_once(map, 0, map->len);
if (!buffer)
return CL_EMEM;
/* scan the full buffer */
ret = cli_pcre_scanbuf(buffer, map->len, virname, acres, root, mdata, poffdata, ctx);
}
} else if (pcremode == PCRE_SCAN_BUFF) {
/* check that scanned buffer does not exceed pcre maxfilesize limit */
maxfilesize = (uint64_t)cl_engine_get_num(ctx->engine, CL_ENGINE_PCRE_MAX_FILESIZE, &rc);
if (rc != CL_SUCCESS)
return rc;
if (maxfilesize && (length > maxfilesize)) {
cli_dbgmsg("matcher_run: pcre max filesize (buf) exceeded (limit: %llu, needed: %u)\n", (long long unsigned)maxfilesize, length);
return CL_EMAXSIZE;
}
cli_dbgmsg("matcher_run: performing regex matching on buffer with no map: %u+%u(%u)\n", offset, length, offset + length);
/* scan the specified buffer */
ret = cli_pcre_scanbuf(buffer, length, virname, acres, root, mdata, poffdata, ctx);
}
}
#endif /* HAVE_PCRE */
/* end experimental fragment */
if (ctx && !SCAN_ALLMATCHES && ret == CL_VIRUS) {
return cli_append_virus(ctx, *virname);
}
if (ctx && SCAN_ALLMATCHES && viruses_found) {
return CL_VIRUS;
}
if (saved_ret && ret == CL_CLEAN) {
return saved_ret;
}
return ret;
}
cl_error_t cli_scan_buff(const unsigned char *buffer, uint32_t length, uint32_t offset, cli_ctx *ctx, cli_file_t ftype, struct cli_ac_data **acdata)
{
cl_error_t ret = CL_CLEAN;
unsigned int i = 0, j = 0, viruses_found = 0;
struct cli_ac_data mdata;
struct cli_matcher *groot, *troot = NULL;
const char *virname = NULL;
const struct cl_engine *engine = ctx->engine;
if (!engine) {
cli_errmsg("cli_scan_buff: engine == NULL\n");
return CL_ENULLARG;
}
groot = engine->root[0]; /* generic signatures */
if (ftype) {
for (i = 1; i < CLI_MTARGETS; i++) {
for (j = 0; j < cli_mtargets[i].target_count; ++j) {
if (cli_mtargets[i].target[j] == ftype) {
troot = ctx->engine->root[i];
break;
}
}
if (troot) break;
}
}
if (troot) {
if (!acdata && (ret = cli_ac_initdata(&mdata, troot->ac_partsigs, troot->ac_lsigs, troot->ac_reloff_num, CLI_DEFAULT_AC_TRACKLEN)))
return ret;
ret = matcher_run(troot, buffer, length, &virname, acdata ? (acdata[0]) : (&mdata), offset, NULL, ftype, NULL, AC_SCAN_VIR, PCRE_SCAN_BUFF, NULL, ctx->fmap, NULL, NULL, ctx);
if (!acdata)
cli_ac_freedata(&mdata);
if (ret == CL_EMEM)
return ret;
if (ret == CL_VIRUS) {
viruses_found = 1;
if (ctx && !SCAN_ALLMATCHES) {
return ret;
}
}
}
virname = NULL;
if (!acdata && (ret = cli_ac_initdata(&mdata, groot->ac_partsigs, groot->ac_lsigs, groot->ac_reloff_num, CLI_DEFAULT_AC_TRACKLEN)))
return ret;
ret = matcher_run(groot, buffer, length, &virname, acdata ? (acdata[1]) : (&mdata), offset, NULL, ftype, NULL, AC_SCAN_VIR, PCRE_SCAN_BUFF, NULL, ctx->fmap, NULL, NULL, ctx);
if (!acdata)
cli_ac_freedata(&mdata);
if (viruses_found)
return CL_VIRUS;
return ret;
}
/*
* offdata[0]: type
* offdata[1]: offset value
* offdata[2]: max shift
* offdata[3]: section number
*/
cl_error_t cli_caloff(const char *offstr, const struct cli_target_info *info, unsigned int target, uint32_t *offdata, uint32_t *offset_min, uint32_t *offset_max)
{
char offcpy[65];
unsigned int n, val;
char *pt;
if (!info) { /* decode offset string */
if (!offstr) {
cli_errmsg("cli_caloff: offstr == NULL\n");
return CL_ENULLARG;
}
if (!strcmp(offstr, "*")) {
offdata[0] = *offset_max = *offset_min = CLI_OFF_ANY;
return CL_SUCCESS;
}
if (strlen(offstr) > 64) {
cli_errmsg("cli_caloff: Offset string too long\n");
return CL_EMALFDB;
}
strcpy(offcpy, offstr);
if ((pt = strchr(offcpy, ','))) {
if (!cli_isnumber(pt + 1)) {
cli_errmsg("cli_caloff: Invalid offset shift value\n");
return CL_EMALFDB;
}
offdata[2] = atoi(pt + 1);
*pt = 0;
} else {
offdata[2] = 0;
}
*offset_max = *offset_min = CLI_OFF_NONE;
if (!strncmp(offcpy, "EP+", 3) || !strncmp(offcpy, "EP-", 3)) {
if (offcpy[2] == '+')
offdata[0] = CLI_OFF_EP_PLUS;
else
offdata[0] = CLI_OFF_EP_MINUS;
if (!cli_isnumber(&offcpy[3])) {
cli_errmsg("cli_caloff: Invalid offset value\n");
return CL_EMALFDB;
}
offdata[1] = atoi(&offcpy[3]);
} else if (offcpy[0] == 'S') {
if (offcpy[1] == 'E') {
if (!cli_isnumber(&offcpy[2])) {
cli_errmsg("cli_caloff: Invalid section number\n");
return CL_EMALFDB;
}
offdata[0] = CLI_OFF_SE;
offdata[3] = atoi(&offcpy[2]);
} else if (!strncmp(offstr, "SL+", 3)) {
offdata[0] = CLI_OFF_SL_PLUS;
if (!cli_isnumber(&offcpy[3])) {
cli_errmsg("cli_caloff: Invalid offset value\n");
return CL_EMALFDB;
}
offdata[1] = atoi(&offcpy[3]);
} else if (sscanf(offcpy, "S%u+%u", &n, &val) == 2) {
offdata[0] = CLI_OFF_SX_PLUS;
offdata[1] = val;
offdata[3] = n;
} else {
cli_errmsg("cli_caloff: Invalid offset string\n");
return CL_EMALFDB;
}
} else if (!strncmp(offcpy, "EOF-", 4)) {
offdata[0] = CLI_OFF_EOF_MINUS;
if (!cli_isnumber(&offcpy[4])) {
cli_errmsg("cli_caloff: Invalid offset value\n");
return CL_EMALFDB;
}
offdata[1] = atoi(&offcpy[4]);
} else if (!strncmp(offcpy, "VI", 2)) {
/* versioninfo */
offdata[0] = CLI_OFF_VERSION;
} else if (strchr(offcpy, '$')) {
if (sscanf(offcpy, "$%u$", &n) != 1) {
cli_errmsg("cli_caloff: Invalid macro($) in offset: %s\n", offcpy);
return CL_EMALFDB;
}
if (n >= 32) {
cli_errmsg("cli_caloff: at most 32 macro groups supported\n");
return CL_EMALFDB;
}
offdata[0] = CLI_OFF_MACRO;
offdata[1] = n;
} else {
offdata[0] = CLI_OFF_ABSOLUTE;
if (!cli_isnumber(offcpy)) {
cli_errmsg("cli_caloff: Invalid offset value\n");
return CL_EMALFDB;
}
*offset_min = offdata[1] = atoi(offcpy);
*offset_max = *offset_min + offdata[2];
}
if (offdata[0] != CLI_OFF_ANY && offdata[0] != CLI_OFF_ABSOLUTE &&
offdata[0] != CLI_OFF_EOF_MINUS && offdata[0] != CLI_OFF_MACRO) {
if (target != 1 && target != 6 && target != 9) {
cli_errmsg("cli_caloff: Invalid offset type for target %u\n", target);
return CL_EMALFDB;
}
}
} else {
/* calculate relative offsets */
*offset_min = CLI_OFF_NONE;
if (offset_max)
*offset_max = CLI_OFF_NONE;
if (info->status == -1) {
// If the executable headers weren't parsed successfully then we
// can't process any ndb/ldb EOF-n/EP+n/EP-n/Sx+n/SEx/SL+n subsigs
return CL_SUCCESS;
}
switch (offdata[0]) {
case CLI_OFF_EOF_MINUS:
*offset_min = info->fsize - offdata[1];
break;
case CLI_OFF_EP_PLUS:
*offset_min = info->exeinfo.ep + offdata[1];
break;
case CLI_OFF_EP_MINUS:
*offset_min = info->exeinfo.ep - offdata[1];
break;
case CLI_OFF_SL_PLUS:
*offset_min = info->exeinfo.sections[info->exeinfo.nsections - 1].raw + offdata[1];
break;
case CLI_OFF_SX_PLUS:
if (offdata[3] >= info->exeinfo.nsections)
*offset_min = CLI_OFF_NONE;
else
*offset_min = info->exeinfo.sections[offdata[3]].raw + offdata[1];
break;
case CLI_OFF_SE:
if (offdata[3] >= info->exeinfo.nsections) {
*offset_min = CLI_OFF_NONE;
} else {
*offset_min = info->exeinfo.sections[offdata[3]].raw;
if (offset_max)
*offset_max = *offset_min + info->exeinfo.sections[offdata[3]].rsz + offdata[2];
// TODO offdata[2] == MaxShift. Won't this make offset_max
// extend beyond the end of the section? This doesn't seem like
// what we want...
}
break;
case CLI_OFF_VERSION:
if (offset_max)
*offset_min = *offset_max = CLI_OFF_ANY;
break;
default:
cli_errmsg("cli_caloff: Not a relative offset (type: %u)\n", offdata[0]);
return CL_EARG;
}
if (offset_max && *offset_max == CLI_OFF_NONE && *offset_min != CLI_OFF_NONE)
*offset_max = *offset_min + offdata[2];
}
return CL_SUCCESS;
}
void cli_targetinfo_init(struct cli_target_info *info)
{
if (NULL == info) {
return;
}
info->status = 0;
cli_exe_info_init(&(info->exeinfo), 0);
}
void cli_targetinfo(struct cli_target_info *info, unsigned int target, cli_ctx *ctx)
{
int (*einfo)(cli_ctx *, struct cli_exe_info *) = NULL;
info->fsize = ctx->fmap->len;
if (target == 1)
einfo = cli_pe_targetinfo;
else if (target == 6)
einfo = cli_elfheader;
else if (target == 9)
einfo = cli_machoheader;
else
return;
if (einfo(ctx, &info->exeinfo))
info->status = -1;
else
info->status = 1;
}
void cli_targetinfo_destroy(struct cli_target_info *info)
{
if (NULL == info) {
return;
}
cli_exe_info_destroy(&(info->exeinfo));
info->status = 0;
}
cl_error_t cli_check_fp(cli_ctx *ctx, const char *vname)
{
cl_error_t status = CL_VIRUS;
char md5[33];
unsigned int i;
const char *virname = NULL;
fmap_t *map;
int32_t stack_index;
const char *ptr;
uint8_t shash1[SHA1_HASH_SIZE * 2 + 1];
uint8_t shash256[SHA256_HASH_SIZE * 2 + 1];
int have_sha1, have_sha256;
unsigned char *digest;
size_t size;
stack_index = (int32_t)ctx->recursion_level;
while (stack_index >= 0) {
map = ctx->recursion_stack[stack_index].fmap;
if (CL_SUCCESS != fmap_get_MD5(map, &digest)) {
cli_dbgmsg("cli_check_fp: Failed to get a hash for the map at stack index # %u\n", stack_index);
stack_index--;
continue;
}
size = map->len;
/*
* First, check the MD5 digest.
* MD5 is default, so it always exists.
*/
if (cli_hm_scan(digest, size, &virname, ctx->engine->hm_fp, CLI_HASH_MD5) == CL_VIRUS) {
cli_dbgmsg("cli_check_fp(md5): Found false positive detection (fp sig: %s), size: %d\n", virname, (int)size);
return CL_CLEAN;
} else if (cli_hm_scan_wild(digest, &virname, ctx->engine->hm_fp, CLI_HASH_MD5) == CL_VIRUS) {
cli_dbgmsg("cli_check_fp(md5): Found false positive detection (fp sig: %s), size: *\n", virname);
return CL_CLEAN;
}
if (cli_debug_flag || ctx->engine->cb_hash) {
const char *name = ctx->recursion_stack[stack_index].fmap->name;
const char *type = cli_ftname(ctx->recursion_stack[stack_index].type);
for (i = 0; i < 16; i++)
sprintf(md5 + i * 2, "%02x", digest[i]);
md5[32] = 0;
cli_dbgmsg("FP SIGNATURE: %s:%u:%s # Name: %s, Type: %s\n",
md5, (unsigned int)size, vname ? vname : "Name", name ? name : "n/a", type);
}
have_sha1 = cli_hm_have_size(ctx->engine->hm_fp, CLI_HASH_SHA1, size) || cli_hm_have_wild(ctx->engine->hm_fp, CLI_HASH_SHA1) || cli_hm_have_size(ctx->engine->hm_fp, CLI_HASH_SHA1, 1);
have_sha256 = cli_hm_have_size(ctx->engine->hm_fp, CLI_HASH_SHA256, size) || cli_hm_have_wild(ctx->engine->hm_fp, CLI_HASH_SHA256);
if (have_sha1 || have_sha256) {
if ((ptr = fmap_need_off_once(map, 0, size))) {
if (have_sha1) {
cl_sha1(ptr, size, &shash1[SHA1_HASH_SIZE], NULL);
if (cli_hm_scan(&shash1[SHA1_HASH_SIZE], size, &virname, ctx->engine->hm_fp, CLI_HASH_SHA1) == CL_VIRUS) {
cli_dbgmsg("cli_check_fp(sha1): Found false positive detection (fp sig: %s)\n", virname);
return CL_CLEAN;
}
if (cli_hm_scan_wild(&shash1[SHA1_HASH_SIZE], &virname, ctx->engine->hm_fp, CLI_HASH_SHA1) == CL_VIRUS) {
cli_dbgmsg("cli_check_fp(sha1): Found false positive detection (fp sig: %s)\n", virname);
return CL_CLEAN;
}
/* See whether the hash matches those loaded in from .cat files
* (associated with the .CAB file type) */
if (cli_hm_scan(&shash1[SHA1_HASH_SIZE], 1, &virname, ctx->engine->hm_fp, CLI_HASH_SHA1) == CL_VIRUS) {
cli_dbgmsg("cli_check_fp(sha1): Found .CAB false positive detection via catalog file\n");
return CL_CLEAN;
}
}
if (have_sha256) {
cl_sha256(ptr, size, &shash256[SHA256_HASH_SIZE], NULL);
if (cli_hm_scan(&shash256[SHA256_HASH_SIZE], size, &virname, ctx->engine->hm_fp, CLI_HASH_SHA256) == CL_VIRUS) {
cli_dbgmsg("cli_check_fp(sha256): Found false positive detection (fp sig: %s)\n", virname);
return CL_CLEAN;
}
if (cli_hm_scan_wild(&shash256[SHA256_HASH_SIZE], &virname, ctx->engine->hm_fp, CLI_HASH_SHA256) == CL_VIRUS) {
cli_dbgmsg("cli_check_fp(sha256): Found false positive detection (fp sig: %s)\n", virname);
return CL_CLEAN;
}
/* See whether the hash matches those loaded in from .cat files
* (associated with the .CAB file type) */
if (cli_hm_scan(&shash256[SHA256_HASH_SIZE], 1, &virname, ctx->engine->hm_fp, CLI_HASH_SHA256) == CL_VIRUS) {
cli_dbgmsg("cli_check_fp(sha256): Found .CAB false positive detection via catalog file\n");
return CL_CLEAN;
}
}
}
}
#ifdef HAVE__INTERNAL__SHA_COLLECT
if (SCAN_DEV_COLLECT_SHA && (ctx->sha_collect > 0)) {
if ((ptr = fmap_need_off_once(map, 0, size))) {
if (!have_sha256)
cl_sha256(ptr, size, shash256 + SHA256_HASH_SIZE, NULL);
for (i = 0; i < SHA256_HASH_SIZE; i++)
sprintf((char *)shash256 + i * 2, "%02x", shash256[SHA256_HASH_SIZE + i]);
if (!have_sha1)
cl_sha1(ptr, size, shash1 + SHA1_HASH_SIZE);
for (i = 0; i < SHA1_HASH_SIZE; i++)
sprintf((char *)shash1 + i * 2, "%02x", shash1[SHA1_HASH_SIZE + i]);
if (NULL == ctx->target_filepath) {
cli_errmsg("COLLECT:%s:%s:%u:%s:%s\n", shash256, shash1, size, vname ? vname : "noname", "NO_IDEA");
} else {
cli_errmsg("COLLECT:%s:%s:%u:%s:%s\n", shash256, shash1, size, vname ? vname : "noname", ctx->target_filepath);
}
} else
cli_errmsg("can't compute sha\n!");
ctx->sha_collect = -1;
}
#endif
if (ctx->engine->cb_hash)
ctx->engine->cb_hash(fmap_fd(ctx->fmap), size, (const unsigned char *)md5, vname ? vname : "noname", ctx->cb_ctx);
if (ctx->engine->cb_stats_add_sample) {
stats_section_t sections;
memset(&sections, 0x00, sizeof(stats_section_t));
if (!(ctx->engine->engine_options & ENGINE_OPTIONS_DISABLE_PE_STATS) &&
!(ctx->engine->dconf->stats & (DCONF_STATS_DISABLED | DCONF_STATS_PE_SECTION_DISABLED)))
cli_genhash_pe(ctx, CL_GENHASH_PE_CLASS_SECTION, 1, &sections);
// TODO We probably only want to call cb_stats_add_sample when
// sections.section != NULL... leaving as is for now
ctx->engine->cb_stats_add_sample(vname ? vname : "noname", digest, size, &sections, ctx->engine->stats_data);
if (sections.sections) {
free(sections.sections);
}
}
stack_index -= 1;
}
return status;
}
static cl_error_t matchicon(cli_ctx *ctx, struct cli_exe_info *exeinfo, const char *grp1, const char *grp2)
{
icon_groupset iconset;
if (!ctx ||
!ctx->engine ||
!ctx->engine->iconcheck ||
!ctx->engine->iconcheck->group_counts[0] ||
!ctx->engine->iconcheck->group_counts[1] ||
!exeinfo->res_addr) return CL_CLEAN;
if (!(ctx->dconf->pe & PE_CONF_MATCHICON))
return CL_CLEAN;
cli_icongroupset_init(&iconset);
cli_icongroupset_add(grp1 ? grp1 : "*", &iconset, 0, ctx);
cli_icongroupset_add(grp2 ? grp2 : "*", &iconset, 1, ctx);
return cli_scanicon(&iconset, ctx, exeinfo);
}
int32_t cli_bcapi_matchicon(struct cli_bc_ctx *ctx, const uint8_t *grp1, int32_t grp1len,
const uint8_t *grp2, int32_t grp2len)
{
cl_error_t ret;
char group1[128], group2[128];
const char **oldvirname;
struct cli_exe_info info;
// TODO This isn't a good check, since EP will be zero for DLLs and
// (assuming pedata->ep is populated from exeinfo->pe) non-zero for
// some MachO and ELF executables
if (!ctx->hooks.pedata->ep) {
cli_dbgmsg("bytecode: matchicon only works with PE files\n");
return -1;
}
if ((size_t)grp1len > sizeof(group1) - 1 ||
(size_t)grp2len > sizeof(group2) - 1)
return -1;
oldvirname = ((cli_ctx *)ctx->ctx)->virname;
((cli_ctx *)ctx->ctx)->virname = NULL;
memcpy(group1, grp1, grp1len);
memcpy(group2, grp2, grp2len);
group1[grp1len] = 0;
group2[grp2len] = 0;
memset(&info, 0, sizeof(info));
if (ctx->bc->kind == BC_PE_UNPACKER || ctx->bc->kind == BC_PE_ALL) {
if (le16_to_host(ctx->hooks.pedata->file_hdr.Characteristics) & 0x2000 ||
!ctx->hooks.pedata->dirs[2].Size)
info.res_addr = 0;
else
info.res_addr = le32_to_host(ctx->hooks.pedata->dirs[2].VirtualAddress);
} else
info.res_addr = ctx->resaddr; /* from target_info */
info.sections = (struct cli_exe_section *)ctx->sections;
info.nsections = ctx->hooks.pedata->nsections;
info.hdr_size = ctx->hooks.pedata->hdr_size;
cli_dbgmsg("bytecode matchicon %s %s\n", group1, group2);
ret = matchicon(ctx->ctx, &info, group1[0] ? group1 : NULL,
group2[0] ? group2 : NULL);
((cli_ctx *)ctx->ctx)->virname = oldvirname;
return (int32_t)ret;
}
cl_error_t cli_scan_desc(int desc, cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struct cli_matched_type **ftoffset, unsigned int acmode, struct cli_ac_result **acres, const char *name)
{
cl_error_t status = CL_CLEAN;
int empty;
fmap_t *new_map = NULL;
fmap_t *map = ctx->fmap; /* Store off the parent fmap for easy reference */
new_map = fmap_check_empty(desc, 0, 0, &empty, name);
if (NULL == new_map) {
if (!empty) {
cli_dbgmsg("cli_scan_desc: Failed to allocate new map for file descriptor scan.\n");
status = CL_EMEM;
}
goto done;
}
status = cli_recursion_stack_push(ctx, new_map, ftype, true); /* Perform scan with child fmap */
if (CL_SUCCESS != status) {
cli_dbgmsg("cli_scan_desc: Failed to scan fmap.\n");
goto done;
}
status = cli_scan_fmap(ctx, ftype, ftonly, ftoffset, acmode, acres, NULL);
map->dont_cache_flag = ctx->fmap->dont_cache_flag; /* Set the parent layer's "don't cache" flag to match the child.
TODO: This may not be needed since `emax_reached()` should've
already done that for us. */
(void)cli_recursion_stack_pop(ctx); /* Restore the parent fmap */
done:
if (NULL != new_map) {
funmap(new_map);
}
return status;
}
static int intermediates_eval(cli_ctx *ctx, struct cli_ac_lsig *ac_lsig)
{
uint32_t i, icnt = ac_lsig->tdb.intermediates[0];
// -1 is the deepest layer (the current layer), so we start at -2, which is the first ancestor
int32_t j = -2;
if (ctx->recursion_level < icnt)
return 0;
for (i = icnt; i > 0; i--) {
if (ac_lsig->tdb.intermediates[i] == CL_TYPE_ANY)
continue;
if (ac_lsig->tdb.intermediates[i] != cli_recursion_stack_get_type(ctx, j--))
return 0;
}
return 1;
}
static cl_error_t lsig_eval(cli_ctx *ctx, struct cli_matcher *root, struct cli_ac_data *acdata, struct cli_target_info *target_info, const char *hash, uint32_t lsid)
{
cl_error_t status = CL_CLEAN;
unsigned evalcnt = 0;
uint64_t evalids = 0;
fmap_t *new_map = NULL;
struct cli_ac_lsig *ac_lsig = root->ac_lsigtable[lsid];
char *exp = ac_lsig->u.logic;
char *exp_end = exp + strlen(exp);
status = cli_ac_chkmacro(root, acdata, lsid);
if (status != CL_SUCCESS)
return status;
if (cli_ac_chklsig(exp, exp_end, acdata->lsigcnt[lsid], &evalcnt, &evalids, 0) == 1) {
if (ac_lsig->tdb.container && ac_lsig->tdb.container[0] != cli_recursion_stack_get_type(ctx, -2))
goto done;
if (ac_lsig->tdb.intermediates && !intermediates_eval(ctx, ac_lsig))
goto done;
if (ac_lsig->tdb.filesize && (ac_lsig->tdb.filesize[0] > ctx->fmap->len || ac_lsig->tdb.filesize[1] < ctx->fmap->len))
goto done;
if (ac_lsig->tdb.ep || ac_lsig->tdb.nos) {
if (!target_info || target_info->status != 1)
goto done;
if (ac_lsig->tdb.ep && (ac_lsig->tdb.ep[0] > target_info->exeinfo.ep || ac_lsig->tdb.ep[1] < target_info->exeinfo.ep))
goto done;
if (ac_lsig->tdb.nos && (ac_lsig->tdb.nos[0] > target_info->exeinfo.nsections || ac_lsig->tdb.nos[1] < target_info->exeinfo.nsections))
goto done;
}
if (hash && ac_lsig->tdb.handlertype) {
if (0 != memcmp(ctx->handlertype_hash, hash, 16)) {
/*
* Create an fmap window into our current fmap using the original offset & length, and rescan as the new type
*
* TODO: Unsure if creating an fmap is the right move, or if we should rescan with the current fmap as-is,
* since it's not really a container so much as it is type reassignment. This new fmap layer protect agains
* a possible infinite loop by applying the scan recursion limit, but maybe there's a better way?
* Testing with both HandlerType type reassignment sigs + Container/Intermediates sigs should indicate if
* a change is needed.
*/
new_map = fmap_duplicate(ctx->fmap, 0, ctx->fmap->len, ctx->fmap->name);
if (NULL == new_map) {
status = CL_EMEM;
cli_dbgmsg("Failed to duplicate the current fmap for a re-scan as a different type.\n");
goto done;
}
memcpy(ctx->handlertype_hash, hash, 16);
status = cli_recursion_stack_push(ctx, new_map, ac_lsig->tdb.handlertype[0], true); /* Perform scan with child fmap */
if (CL_SUCCESS != status) {
cli_dbgmsg("Failed to re-scan fmap as a new type.\n");
goto done;
}
status = cli_magic_scan(ctx, ac_lsig->tdb.handlertype[0]);
(void)cli_recursion_stack_pop(ctx); /* Restore the parent fmap */
if (CL_VIRUS == status) {
status = CL_VIRUS;
goto done;
}
goto done;
}
}
if (ac_lsig->tdb.icongrp1 || ac_lsig->tdb.icongrp2) {
if (!target_info || target_info->status != 1) {
goto done;
}
if (CL_VIRUS == matchicon(ctx, &target_info->exeinfo, ac_lsig->tdb.icongrp1, ac_lsig->tdb.icongrp2)) {
if (!ac_lsig->bc_idx) {
status = cli_append_virus(ctx, ac_lsig->virname);
if (status != CL_CLEAN) {
goto done;
}
} else if (CL_VIRUS == cli_bytecode_runlsig(ctx, target_info, &ctx->engine->bcs, ac_lsig->bc_idx, acdata->lsigcnt[lsid], acdata->lsigsuboff_first[lsid], ctx->fmap)) {
status = CL_VIRUS;
goto done;
}
}
goto done;
}
if (!ac_lsig->bc_idx) {
status = cli_append_virus(ctx, ac_lsig->virname);
if (status != CL_CLEAN) {
goto done;
}
}
if (CL_VIRUS == cli_bytecode_runlsig(ctx, target_info, &ctx->engine->bcs, ac_lsig->bc_idx, acdata->lsigcnt[lsid], acdata->lsigsuboff_first[lsid], ctx->fmap)) {
status = CL_VIRUS;
goto done;
}
}
done:
if (NULL != new_map) {
free_duplicate_fmap(new_map);
}
return status;
}
#ifdef HAVE_YARA
static cl_error_t yara_eval(cli_ctx *ctx, struct cli_matcher *root, struct cli_ac_data *acdata, struct cli_target_info *target_info, const char *hash, uint32_t lsid)
{
struct cli_ac_lsig *ac_lsig = root->ac_lsigtable[lsid];
cl_error_t rc;
YR_SCAN_CONTEXT context;
(void)hash;
memset(&context, 0, sizeof(YR_SCAN_CONTEXT));
context.fmap = ctx->fmap;
context.file_size = ctx->fmap->len;
if (target_info != NULL) {
if (target_info->status == 1)
context.entry_point = target_info->exeinfo.ep;
}
rc = yr_execute_code(ac_lsig, acdata, &context, 0, 0);
if (rc == CL_VIRUS) {
if (ac_lsig->flag & CLI_LSIG_FLAG_PRIVATE) {
rc = CL_CLEAN;
} else {
rc = cli_append_virus(ctx, ac_lsig->virname);
}
}
return rc;
}
#endif
cl_error_t cli_exp_eval(cli_ctx *ctx, struct cli_matcher *root, struct cli_ac_data *acdata, struct cli_target_info *target_info, const char *hash)
{
uint8_t viruses_found = 0;
uint32_t i;
cl_error_t rc = CL_SUCCESS;
for (i = 0; i < root->ac_lsigs; i++) {
if (root->ac_lsigtable[i]->type == CLI_LSIG_NORMAL)
rc = lsig_eval(ctx, root, acdata, target_info, hash, i);
#ifdef HAVE_YARA
else if (root->ac_lsigtable[i]->type == CLI_YARA_NORMAL || root->ac_lsigtable[i]->type == CLI_YARA_OFFSET)
rc = yara_eval(ctx, root, acdata, target_info, hash, i);
#endif
if (rc == CL_VIRUS) {
viruses_found = 1;
if (SCAN_ALLMATCHES)
continue;
break;
}
}
if (viruses_found)
return CL_VIRUS;
return CL_CLEAN;
}
cl_error_t cli_scan_fmap(cli_ctx *ctx, cli_file_t ftype, uint8_t ftonly, struct cli_matched_type **ftoffset, unsigned int acmode, struct cli_ac_result **acres, unsigned char *refhash)
{
const unsigned char *buff;
cl_error_t ret = CL_CLEAN, type = CL_CLEAN;
int compute_hash[CLI_HASH_AVAIL_TYPES];
unsigned int i = 0, j = 0, bm_offmode = 0;
uint32_t maxpatlen, bytes, offset = 0;
struct cli_ac_data gdata, tdata;
struct cli_bm_off toff;
struct cli_pcre_off gpoff, tpoff;
unsigned char digest[CLI_HASH_AVAIL_TYPES][32];
struct cli_matcher *groot = NULL, *troot = NULL;
struct cli_target_info info;
struct cli_matcher *hdb, *fp;
const char *virname;
uint32_t viruses_found = 0;
void *md5ctx, *sha1ctx, *sha256ctx;
if (!ctx->engine) {
cli_errmsg("cli_scan_fmap: engine == NULL\n");
return CL_ENULLARG;
}
md5ctx = cl_hash_init("md5");
if (!(md5ctx))
return CL_EMEM;
sha1ctx = cl_hash_init("sha1");
if (!(sha1ctx)) {
cl_hash_destroy(md5ctx);
return CL_EMEM;
}
sha256ctx = cl_hash_init("sha256");
if (!(sha256ctx)) {
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
return CL_EMEM;
}
if (!ftonly)
groot = ctx->engine->root[0]; /* generic signatures */
if (ftype) {
for (i = 1; i < CLI_MTARGETS; i++) {
for (j = 0; j < cli_mtargets[i].target_count; ++j) {
if (cli_mtargets[i].target[j] == ftype) {
troot = ctx->engine->root[i];
break;
}
}
if (troot) break;
}
}
if (ftonly) {
if (!troot) {
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return CL_CLEAN;
}
maxpatlen = troot->maxpatlen;
} else {
if (troot)
maxpatlen = MAX(troot->maxpatlen, groot->maxpatlen);
else
maxpatlen = groot->maxpatlen;
}
cli_targetinfo_init(&info);
cli_targetinfo(&info, i, ctx);
if (-1 == info.status) {
cli_dbgmsg("cli_scan_fmap: Failed to successfully parse the executable header. "
"Scan features will be disabled, such as "
"NDB/LDB subsigs using EOF-n/EP+n/EP-n/Sx+n/SEx/SL+n, "
"fuzzy icon matching, "
"MDB/IMP sigs, "
"and bytecode sigs that require exe metadata\n");
}
/* If it's a PE, check the Authenticode header. This would be more
* appropriate in cli_scanpe, but scanraw->cli_scan_fmap gets
* called first for PEs, and we want to determine the whitelist/blacklist
* status early on so we can skip things like embedded PE extraction
* (which is broken for signed binaries within signed binaries).
*
* If we want to add support for more signature parsing in the future
* (Ex: MachO sigs), do that here too.
*
* One benefit of not continuing on to scan files with trusted signatures
* is that the bytes associated with the exe won't get counted against the
* scansize limits, which means we have an increased chance of catching
* malware in container types (NSIS, iShield, etc.) where the file size is
* large. A common case where this occurs is installers that embed one
* or more of the various Microsoft Redistributable Setup packages. These
* can easily be 5 MB or more in size, and might appear before malware
* does in a given sample.
*/
if (1 == info.status && i == 1) {
ret = cli_check_auth_header(ctx, &(info.exeinfo));
if ((ret == CL_VIRUS || ret == CL_VERIFIED) && !SCAN_ALLMATCHES) {
cli_targetinfo_destroy(&info);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
}
ret = CL_CLEAN;
}
if (!ftonly) {
if ((ret = cli_ac_initdata(&gdata, groot->ac_partsigs, groot->ac_lsigs, groot->ac_reloff_num, CLI_DEFAULT_AC_TRACKLEN)) ||
(ret = cli_ac_caloff(groot, &gdata, &info))) {
cli_targetinfo_destroy(&info);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
}
if ((ret = cli_pcre_recaloff(groot, &gpoff, &info, ctx))) {
cli_ac_freedata(&gdata);
cli_targetinfo_destroy(&info);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
}
}
if (troot) {
if ((ret = cli_ac_initdata(&tdata, troot->ac_partsigs, troot->ac_lsigs, troot->ac_reloff_num, CLI_DEFAULT_AC_TRACKLEN)) ||
(ret = cli_ac_caloff(troot, &tdata, &info))) {
if (!ftonly) {
cli_ac_freedata(&gdata);
cli_pcre_freeoff(&gpoff);
}
cli_targetinfo_destroy(&info);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
}
if (troot->bm_offmode) {
if (ctx->fmap->len >= CLI_DEFAULT_BM_OFFMODE_FSIZE) {
if ((ret = cli_bm_initoff(troot, &toff, &info))) {
if (!ftonly) {
cli_ac_freedata(&gdata);
cli_pcre_freeoff(&gpoff);
}
cli_ac_freedata(&tdata);
cli_targetinfo_destroy(&info);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
}
bm_offmode = 1;
}
}
if ((ret = cli_pcre_recaloff(troot, &tpoff, &info, ctx))) {
if (!ftonly) {
cli_ac_freedata(&gdata);
cli_pcre_freeoff(&gpoff);
}
cli_ac_freedata(&tdata);
if (bm_offmode)
cli_bm_freeoff(&toff);
cli_targetinfo_destroy(&info);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
}
}
hdb = ctx->engine->hm_hdb;
fp = ctx->engine->hm_fp;
if (!ftonly && hdb) {
if (!refhash) {
if (cli_hm_have_size(hdb, CLI_HASH_MD5, ctx->fmap->len) ||
cli_hm_have_size(fp, CLI_HASH_MD5, ctx->fmap->len) ||
cli_hm_have_wild(hdb, CLI_HASH_MD5) ||
cli_hm_have_wild(fp, CLI_HASH_MD5)) {
compute_hash[CLI_HASH_MD5] = 1;
} else {
compute_hash[CLI_HASH_MD5] = 0;
}
} else {
compute_hash[CLI_HASH_MD5] = 0;
memcpy(digest[CLI_HASH_MD5], refhash, 16);
}
if (cli_hm_have_size(hdb, CLI_HASH_SHA1, ctx->fmap->len) ||
cli_hm_have_wild(hdb, CLI_HASH_SHA1) ||
cli_hm_have_size(fp, CLI_HASH_SHA1, ctx->fmap->len) ||
cli_hm_have_wild(fp, CLI_HASH_SHA1)) {
compute_hash[CLI_HASH_SHA1] = 1;
} else {
compute_hash[CLI_HASH_SHA1] = 0;
}
if (cli_hm_have_size(hdb, CLI_HASH_SHA256, ctx->fmap->len) ||
cli_hm_have_wild(hdb, CLI_HASH_SHA256) ||
cli_hm_have_size(fp, CLI_HASH_SHA256, ctx->fmap->len) ||
cli_hm_have_wild(fp, CLI_HASH_SHA256)) {
compute_hash[CLI_HASH_SHA256] = 1;
} else {
compute_hash[CLI_HASH_SHA256] = 0;
}
}
while (offset < ctx->fmap->len) {
bytes = MIN(ctx->fmap->len - offset, SCANBUFF);
if (!(buff = fmap_need_off_once(ctx->fmap, offset, bytes)))
break;
if (ctx->scanned)
*ctx->scanned += bytes / CL_COUNT_PRECISION;
if (troot) {
virname = NULL;
ret = matcher_run(troot, buff, bytes, &virname, &tdata, offset, &info, ftype, ftoffset, acmode, PCRE_SCAN_FMAP, acres, ctx->fmap, bm_offmode ? &toff : NULL, &tpoff, ctx);
if (virname) {
/* virname already appended by matcher_run */
viruses_found = 1;
}
if ((ret == CL_VIRUS && !SCAN_ALLMATCHES) || ret == CL_EMEM) {
if (!ftonly) {
cli_ac_freedata(&gdata);
cli_pcre_freeoff(&gpoff);
}
cli_ac_freedata(&tdata);
if (bm_offmode)
cli_bm_freeoff(&toff);
cli_pcre_freeoff(&tpoff);
cli_targetinfo_destroy(&info);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
}
}
if (!ftonly) {
virname = NULL;
ret = matcher_run(groot, buff, bytes, &virname, &gdata, offset, &info, ftype, ftoffset, acmode, PCRE_SCAN_FMAP, acres, ctx->fmap, NULL, &gpoff, ctx);
if (virname) {
/* virname already appended by matcher_run */
viruses_found = 1;
}
if ((ret == CL_VIRUS && !SCAN_ALLMATCHES) || ret == CL_EMEM) {
cli_ac_freedata(&gdata);
cli_pcre_freeoff(&gpoff);
if (troot) {
cli_ac_freedata(&tdata);
if (bm_offmode)
cli_bm_freeoff(&toff);
cli_pcre_freeoff(&tpoff);
}
cli_targetinfo_destroy(&info);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
} else if ((acmode & AC_SCAN_FT) && ((cli_file_t)ret >= CL_TYPENO)) {
if (ret > type)
type = ret;
}
/* if (bytes <= (maxpatlen * (offset!=0))), it means the last window finished the file hashing *
* since the last window is responsible for adding intersection between windows (maxpatlen) */
if (hdb && (bytes > (maxpatlen * (offset != 0)))) {
const void *data = buff + maxpatlen * (offset != 0);
uint32_t data_len = bytes - maxpatlen * (offset != 0);
if (compute_hash[CLI_HASH_MD5])
cl_update_hash(md5ctx, (void *)data, data_len);
if (compute_hash[CLI_HASH_SHA1])
cl_update_hash(sha1ctx, (void *)data, data_len);
if (compute_hash[CLI_HASH_SHA256])
cl_update_hash(sha256ctx, (void *)data, data_len);
}
}
if (bytes < SCANBUFF)
break;
offset += bytes - maxpatlen;
}
if (!ftonly && hdb) {
enum CLI_HASH_TYPE hashtype, hashtype2;
if (compute_hash[CLI_HASH_MD5]) {
cl_finish_hash(md5ctx, digest[CLI_HASH_MD5]);
md5ctx = NULL;
}
if (refhash)
compute_hash[CLI_HASH_MD5] = 1;
if (compute_hash[CLI_HASH_SHA1]) {
cl_finish_hash(sha1ctx, digest[CLI_HASH_SHA1]);
sha1ctx = NULL;
}
if (compute_hash[CLI_HASH_SHA256]) {
cl_finish_hash(sha256ctx, digest[CLI_HASH_SHA256]);
sha256ctx = NULL;
}
virname = NULL;
for (hashtype = CLI_HASH_MD5; hashtype < CLI_HASH_AVAIL_TYPES; hashtype++) {
const char *virname_w = NULL;
int found = 0;
/* If no hash, skip to next type */
if (!compute_hash[hashtype])
continue;
/* Do hash scan */
if ((ret = cli_hm_scan(digest[hashtype], ctx->fmap->len, &virname, hdb, hashtype)) == CL_VIRUS) {
found += 1;
}
if (!found || SCAN_ALLMATCHES) {
if ((ret = cli_hm_scan_wild(digest[hashtype], &virname_w, hdb, hashtype)) == CL_VIRUS)
found += 2;
}
/* If found, do immediate hash-only FP check */
if (found && fp) {
for (hashtype2 = CLI_HASH_MD5; hashtype2 < CLI_HASH_AVAIL_TYPES; hashtype2++) {
if (!compute_hash[hashtype2])
continue;
if (cli_hm_scan(digest[hashtype2], ctx->fmap->len, NULL, fp, hashtype2) == CL_VIRUS) {
found = 0;
ret = CL_CLEAN;
break;
} else if (cli_hm_scan_wild(digest[hashtype2], NULL, fp, hashtype2) == CL_VIRUS) {
found = 0;
ret = CL_CLEAN;
break;
}
}
}
/* If matched size-based hash ... */
if (found % 2) {
viruses_found = 1;
ret = cli_append_virus(ctx, virname);
if (!SCAN_ALLMATCHES || ret != CL_CLEAN)
break;
virname = NULL;
}
/* If matched size-agnostic hash ... */
if (found > 1) {
viruses_found = 1;
ret = cli_append_virus(ctx, virname_w);
if (!SCAN_ALLMATCHES || ret != CL_CLEAN)
break;
}
}
}
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
if (troot) {
if (ret != CL_VIRUS || SCAN_ALLMATCHES)
ret = cli_exp_eval(ctx, troot, &tdata, &info, (const char *)refhash);
if (ret == CL_VIRUS)
viruses_found++;
cli_ac_freedata(&tdata);
if (bm_offmode)
cli_bm_freeoff(&toff);
cli_pcre_freeoff(&tpoff);
}
if (groot) {
if (ret != CL_VIRUS || SCAN_ALLMATCHES)
ret = cli_exp_eval(ctx, groot, &gdata, &info, (const char *)refhash);
cli_ac_freedata(&gdata);
cli_pcre_freeoff(&gpoff);
}
cli_targetinfo_destroy(&info);
if (SCAN_ALLMATCHES && viruses_found) {
return CL_VIRUS;
}
if (ret == CL_VIRUS) {
return CL_VIRUS;
}
return (acmode & AC_SCAN_FT) ? type : CL_CLEAN;
}
#define CDBRANGE(field, val) \
if (field[0] != CLI_OFF_ANY) { \
if (field[0] == field[1] && field[0] != val) \
continue; \
else if (field[0] != field[1] && ((field[0] && field[0] > val) || \
(field[1] && field[1] < val))) \
continue; \
}
cl_error_t cli_matchmeta(cli_ctx *ctx, const char *fname, size_t fsizec, size_t fsizer, int encrypted, unsigned int filepos, int res1, void *res2)
{
const struct cli_cdb *cdb;
unsigned int viruses_found = 0;
cl_error_t ret = CL_CLEAN;
cli_dbgmsg("CDBNAME:%s:%llu:%s:%llu:%llu:%d:%u:%u:%p\n",
cli_ftname(cli_recursion_stack_get_type(ctx, -1)), (long long unsigned)fsizec, fname, (long long unsigned)fsizec, (long long unsigned)fsizer,
encrypted, filepos, res1, res2);
if (ctx->engine && ctx->engine->cb_meta)
if (ctx->engine->cb_meta(cli_ftname(cli_recursion_stack_get_type(ctx, -1)), fsizec, fname, fsizer, encrypted, filepos, ctx->cb_ctx) == CL_VIRUS) {
cli_dbgmsg("inner file blocked by callback: %s\n", fname);
ret = cli_append_virus(ctx, "Detected.By.Callback");
viruses_found++;
if (!SCAN_ALLMATCHES || ret != CL_CLEAN)
return ret;
}
if (!ctx->engine || !(cdb = ctx->engine->cdb))
return CL_CLEAN;
do {
if (cdb->ctype != CL_TYPE_ANY && cdb->ctype != cli_recursion_stack_get_type(ctx, -1))
continue;
if (cdb->encrypted != 2 && cdb->encrypted != encrypted)
continue;
if (cdb->res1 && (cdb->ctype == CL_TYPE_ZIP || cdb->ctype == CL_TYPE_RAR) && cdb->res1 != res1)
continue;
CDBRANGE(cdb->csize, cli_recursion_stack_get_size(ctx, -1));
CDBRANGE(cdb->fsizec, fsizec);
CDBRANGE(cdb->fsizer, fsizer);
CDBRANGE(cdb->filepos, filepos);
if (cdb->name.re_magic && (!fname || cli_regexec(&cdb->name, fname, 0, NULL, 0) == REG_NOMATCH))
continue;
ret = cli_append_virus(ctx, cdb->virname);
viruses_found++;
if (!SCAN_ALLMATCHES || ret != CL_CLEAN)
return ret;
} while ((cdb = cdb->next));
if (SCAN_ALLMATCHES && viruses_found)
return CL_VIRUS;
return CL_CLEAN;
}
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