int cli_checkfp(unsigned char *digest, size_t size, cli_ctx *ctx)
{
char md5[33];
unsigned int i;
const char *virname=NULL;
fmap_t *map;
const char *ptr;
uint8_t shash1[SHA1_HASH_SIZE*2+1];
uint8_t shash256[SHA256_HASH_SIZE*2+1];
int have_sha1, have_sha256, do_dsig_check = 1;
stats_section_t sections;
if(cli_hm_scan(digest, size, &virname, ctx->engine->hm_fp, CLI_HASH_MD5) == CL_VIRUS) {
cli_dbgmsg("cli_checkfp(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_checkfp(md5): Found false positive detection (fp sig: %s), size: *\n", virname);
return CL_CLEAN;
}
if(cli_debug_flag || ctx->engine->cb_hash) {
for(i = 0; i < 16; i++)
sprintf(md5 + i * 2, "%02x", digest[i]);
md5[32] = 0;
cli_dbgmsg("FP SIGNATURE: %s:%u:%s\n", md5, (unsigned int) size,
cli_get_last_virus(ctx) ? cli_get_last_virus(ctx) : "Name");
}
if(cli_get_last_virus(ctx))
do_dsig_check = strncmp("W32S.", cli_get_last_virus(ctx), 5);
map = *ctx->fmap;
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) && do_dsig_check);
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_checkfp(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_checkfp(sha1): Found false positive detection (fp sig: %s)\n", virname);
return CL_CLEAN;
}
if(do_dsig_check && cli_hm_scan(&shash1[SHA1_HASH_SIZE], 1, &virname, ctx->engine->hm_fp, CLI_HASH_SHA1) == CL_VIRUS) {
cli_dbgmsg("cli_checkfp(sha1): Found 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_checkfp(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_checkfp(sha256): Found false positive detection (fp sig: %s)\n", virname);
return CL_CLEAN;
}
}
}
}
#ifdef HAVE__INTERNAL__SHA_COLLECT
if((ctx->options & CL_SCAN_INTERNAL_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]);
cli_errmsg("COLLECT:%s:%s:%u:%s:%s\n", shash256, shash1, size, cli_get_last_virus(ctx), ctx->entry_filename);
} else
cli_errmsg("can't compute sha\n!");
ctx->sha_collect = -1;
}
#endif
memset(§ions, 0x00, sizeof(stats_section_t));
if(do_dsig_check || ctx->engine->cb_stats_add_sample) {
uint32_t flags = (do_dsig_check ? CL_CHECKFP_PE_FLAG_AUTHENTICODE : 0);
if (!(ctx->engine->engine_options & ENGINE_OPTIONS_DISABLE_PE_STATS) && !(ctx->engine->dconf->stats & (DCONF_STATS_DISABLED | DCONF_STATS_PE_SECTION_DISABLED)))
flags |= CL_CHECKFP_PE_FLAG_STATS;
switch(cli_checkfp_pe(ctx, shash1, §ions, flags)) {
case CL_CLEAN:
cli_dbgmsg("cli_checkfp(pe): PE file whitelisted due to valid embedded digital signature\n");
return CL_CLEAN;
case CL_VIRUS:
if(cli_hm_scan(shash1, 2, &virname, ctx->engine->hm_fp, CLI_HASH_SHA1) == CL_VIRUS) {
cli_dbgmsg("cli_checkfp(pe): PE file whitelisted by catalog file\n");
return CL_CLEAN;
}
}
}
if (ctx->engine->cb_hash)
ctx->engine->cb_hash(fmap_fd(*ctx->fmap), size, (const unsigned char *)md5, cli_get_last_virus(ctx), ctx->cb_ctx);
if (ctx->engine->cb_stats_add_sample)
ctx->engine->cb_stats_add_sample(cli_get_last_virus(ctx), digest, size, §ions, ctx->engine->stats_data);
if (sections.sections)
free(sections.sections);
return CL_VIRUS;
}
int cli_checkfp(unsigned char *digest, size_t size, cli_ctx *ctx)
{
char md5[33];
unsigned int i;
const char *virname;
SHA1Context sha1;
SHA256_CTX sha256;
fmap_t *map;
const char *ptr;
uint8_t shash1[SHA1_HASH_SIZE*2+1];
uint8_t shash256[SHA256_HASH_SIZE*2+1];
int have_sha1, have_sha256, do_dsig_check = 1;
if(cli_hm_scan(digest, size, &virname, ctx->engine->hm_fp, CLI_HASH_MD5) == CL_VIRUS) {
cli_dbgmsg("cli_checkfp(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_checkfp(md5): Found false positive detection (fp sig: %s), size: *\n", virname);
return CL_CLEAN;
}
if(cli_debug_flag || ctx->engine->cb_hash) {
for(i = 0; i < 16; i++)
sprintf(md5 + i * 2, "%02x", digest[i]);
md5[32] = 0;
cli_dbgmsg("FP SIGNATURE: %s:%u:%s\n", md5, (unsigned int) size,
cli_get_last_virus(ctx) ? cli_get_last_virus(ctx) : "Name");
}
if(cli_get_last_virus(ctx))
do_dsig_check = strncmp("W32S.", cli_get_last_virus(ctx), 5);
map = *ctx->fmap;
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) && do_dsig_check);
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) {
SHA1Init(&sha1);
SHA1Update(&sha1, ptr, size);
SHA1Final(&sha1, &shash1[SHA1_HASH_SIZE]);
if(cli_hm_scan(&shash1[SHA1_HASH_SIZE], size, &virname, ctx->engine->hm_fp, CLI_HASH_SHA1) == CL_VIRUS) {
cli_dbgmsg("cli_checkfp(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_checkfp(sha1): Found false positive detection (fp sig: %s)\n", virname);
return CL_CLEAN;
}
if(do_dsig_check && cli_hm_scan(&shash1[SHA1_HASH_SIZE], 1, &virname, ctx->engine->hm_fp, CLI_HASH_SHA1) == CL_VIRUS) {
cli_dbgmsg("cli_checkfp(sha1): Found false positive detection via catalog file\n");
return CL_CLEAN;
}
}
if(have_sha256) {
sha256_init(&sha256);
sha256_update(&sha256, ptr, size);
sha256_final(&sha256, &shash256[SHA256_HASH_SIZE]);
if(cli_hm_scan(&shash256[SHA256_HASH_SIZE], size, &virname, ctx->engine->hm_fp, CLI_HASH_SHA256) == CL_VIRUS) {
cli_dbgmsg("cli_checkfp(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_checkfp(sha256): Found false positive detection (fp sig: %s)\n", virname);
return CL_CLEAN;
}
}
}
}
#ifdef HAVE__INTERNAL__SHA_COLLECT
if((ctx->options & CL_SCAN_INTERNAL_COLLECT_SHA) && ctx->sha_collect>0) {
if((ptr = fmap_need_off_once(map, 0, size))) {
if(!have_sha256) {
sha256_init(&sha256);
sha256_update(&sha256, ptr, size);
sha256_final(&sha256, &shash256[SHA256_HASH_SIZE]);
}
for(i=0; i<SHA256_HASH_SIZE; i++)
sprintf((char *)shash256+i*2, "%02x", shash256[SHA256_HASH_SIZE+i]);
if(!have_sha1) {
SHA1Init(&sha1);
SHA1Update(&sha1, ptr, size);
SHA1Final(&sha1, &shash1[SHA1_HASH_SIZE]);
}
for(i=0; i<SHA1_HASH_SIZE; i++)
sprintf((char *)shash1+i*2, "%02x", shash1[SHA1_HASH_SIZE+i]);
cli_errmsg("COLLECT:%s:%s:%u:%s:%s\n", shash256, shash1, size, cli_get_last_virus(ctx), ctx->entry_filename);
} else
cli_errmsg("can't compute sha\n!");
ctx->sha_collect = -1;
}
#endif
if(do_dsig_check) {
switch(cli_checkfp_pe(ctx, shash1)) {
case CL_CLEAN:
cli_dbgmsg("cli_checkfp(pe): PE file whitelisted due to valid embedded digital signature\n");
return CL_CLEAN;
case CL_VIRUS:
if(cli_hm_scan(shash1, 2, &virname, ctx->engine->hm_fp, CLI_HASH_SHA1) == CL_VIRUS) {
cli_dbgmsg("cli_checkfp(pe): PE file whitelisted by catalog file\n");
return CL_CLEAN;
}
}
}
if (ctx->engine->cb_hash)
ctx->engine->cb_hash(fmap_fd(*ctx->fmap), size, md5, cli_get_last_virus(ctx), ctx->cb_ctx);
return CL_VIRUS;
}
