/* Hashes a file onto the provided buffer and looks it up the cache.
Returns CL_VIRUS if found, CL_CLEAN if not FIXME or a recoverable error,
and returns CL_EREAD if unrecoverable */
int cache_check(unsigned char *hash, cli_ctx *ctx) {
fmap_t *map;
size_t todo, at = 0;
void *hashctx;
int ret;
if(!ctx || !ctx->engine || !ctx->engine->cache)
return CL_VIRUS;
if (ctx->engine->engine_options & ENGINE_OPTIONS_DISABLE_CACHE) {
cli_dbgmsg("cache_check: Caching disabled. Returning CL_VIRUS.\n");
return CL_VIRUS;
}
map = *ctx->fmap;
todo = map->len;
hashctx = cl_hash_init("md5");
if (!(hashctx))
return CL_VIRUS;
while(todo) {
const void *buf;
size_t readme = todo < FILEBUFF ? todo : FILEBUFF;
if(!(buf = fmap_need_off_once(map, at, readme))) {
cl_hash_destroy(hashctx);
return CL_EREAD;
}
todo -= readme;
at += readme;
if (cl_update_hash(hashctx, (void *)buf, readme)) {
cl_hash_destroy(hashctx);
cli_errmsg("cache_check: error reading while generating hash!\n");
return CL_EREAD;
}
}
cl_finish_hash(hashctx, hash);
ret = cache_lookup_hash(hash, map->len, ctx->engine->cache, ctx->recursion);
cli_dbgmsg("cache_check: %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x is %s\n", hash[0], hash[1], hash[2], hash[3], hash[4], hash[5], hash[6], hash[7], hash[8], hash[9], hash[10], hash[11], hash[12], hash[13], hash[14], hash[15], (ret == CL_VIRUS) ? "negative" : "positive");
return ret;
}
int cache_get_MD5(unsigned char *hash, cli_ctx *ctx)
{
fmap_t *map;
size_t todo, at = 0;
void *hashctx;
map = *ctx->fmap;
todo = map->len;
hashctx = cl_hash_init("md5");
if (!(hashctx))
return CL_VIRUS;
while(todo) {
const void *buf;
size_t readme = todo < FILEBUFF ? todo : FILEBUFF;
if(!(buf = fmap_need_off_once(map, at, readme))) {
cl_hash_destroy(hashctx);
return CL_EREAD;
}
todo -= readme;
at += readme;
if (cl_update_hash(hashctx, (void *)buf, readme)) {
cl_hash_destroy(hashctx);
cli_errmsg("cache_check: error reading while generating hash!\n");
return CL_EREAD;
}
}
cl_finish_hash(hashctx, hash);
return CL_CLEAN;
}
static void cli_tgzload_cleanup(int comp, struct cli_dbio *dbio, int fdd)
{
cli_dbgmsg("in cli_tgzload_cleanup()\n");
if(comp) {
gzclose(dbio->gzs);
dbio->gzs = NULL;
}
else {
fclose(dbio->fs);
dbio->fs = NULL;
}
if(dbio->buf != NULL) {
free(dbio->buf);
dbio->buf = NULL;
}
if (dbio->hashctx) {
cl_hash_destroy(dbio->hashctx);
dbio->hashctx = NULL;
}
}
int cli_fmap_scandesc(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;
int ret = CL_CLEAN, type = CL_CLEAN, bytes, compute_hash[CLI_HASH_AVAIL_TYPES];
unsigned int i = 0, j = 0, bm_offmode = 0;
uint32_t maxpatlen, 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;
fmap_t *map = *ctx->fmap;
struct cli_matcher *hdb, *fp;
const char *virname = NULL;
uint32_t viruses_found = 0;
void *md5ctx, *sha1ctx, *sha256ctx;
if(!ctx->engine) {
cli_errmsg("cli_scandesc: 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(&info, i, map);
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))) {
if(info.exeinfo.section)
free(info.exeinfo.section);
cli_hashset_destroy(&info.exeinfo.vinfo);
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);
if(info.exeinfo.section)
free(info.exeinfo.section);
cli_hashset_destroy(&info.exeinfo.vinfo);
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);
}
if(info.exeinfo.section)
free(info.exeinfo.section);
cli_hashset_destroy(&info.exeinfo.vinfo);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
}
if(troot->bm_offmode) {
if(map->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);
if(info.exeinfo.section)
free(info.exeinfo.section);
cli_hashset_destroy(&info.exeinfo.vinfo);
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);
if(info.exeinfo.section)
free(info.exeinfo.section);
cli_hashset_destroy(&info.exeinfo.vinfo);
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, map->len) || cli_hm_have_size(fp, CLI_HASH_MD5, map->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, map->len) || cli_hm_have_wild(hdb, CLI_HASH_SHA1)
|| cli_hm_have_size(fp, CLI_HASH_SHA1, map->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, map->len) || cli_hm_have_wild(hdb, CLI_HASH_SHA256)
|| cli_hm_have_size(fp, CLI_HASH_SHA256, map->len) || cli_hm_have_wild(fp, CLI_HASH_SHA256)) {
compute_hash[CLI_HASH_SHA256] = 1;
} else {
compute_hash[CLI_HASH_SHA256] = 0;
}
}
while(offset < map->len) {
bytes = MIN(map->len - offset, SCANBUFF);
if(!(buff = fmap_need_off_once(map, 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, map, bm_offmode ? &toff : NULL, &tpoff, ctx);
if (virname) {
/* virname already appended by matcher_run */
viruses_found = 1;
}
if((ret == CL_VIRUS && !SCAN_ALL) || 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);
if(info.exeinfo.section)
free(info.exeinfo.section);
cli_hashset_destroy(&info.exeinfo.vinfo);
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, map, NULL, &gpoff, ctx);
if (virname) {
/* virname already appended by matcher_run */
viruses_found = 1;
}
if((ret == CL_VIRUS && !SCAN_ALL) || 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);
}
if(info.exeinfo.section)
free(info.exeinfo.section);
cli_hashset_destroy(&info.exeinfo.vinfo);
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
return ret;
} else if((acmode & AC_SCAN_FT) && 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], map->len, &virname, hdb, hashtype)) == CL_VIRUS) {
found += 1;
}
if(!found || SCAN_ALL) {
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], map->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;
cli_append_virus(ctx, virname);
if (!SCAN_ALL)
break;
virname = NULL;
}
/* If matched size-agnostic hash ... */
if (found > 1) {
viruses_found = 1;
cli_append_virus(ctx, virname_w);
if (!SCAN_ALL)
break;
}
}
}
cl_hash_destroy(md5ctx);
cl_hash_destroy(sha1ctx);
cl_hash_destroy(sha256ctx);
if(troot) {
if(ret != CL_VIRUS || SCAN_ALL)
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_ALL)
ret = cli_exp_eval(ctx, groot, &gdata, &info, (const char *)refhash);
cli_ac_freedata(&gdata);
cli_pcre_freeoff(&gpoff);
}
if(info.exeinfo.section)
free(info.exeinfo.section);
cli_hashset_destroy(&info.exeinfo.vinfo);
if (SCAN_ALL && viruses_found)
return CL_VIRUS;
if(ret == CL_VIRUS)
return CL_VIRUS;
return (acmode & AC_SCAN_FT) ? type : CL_CLEAN;
}
