/* Copyright (C) 2007-2022 Open Information Security Foundation * * You can copy, redistribute or modify this Program 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 * version 2 along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. */ /** * \file * * \author Victor Julien * \author Pablo Rincon * */ #include "suricata-common.h" #include "threads.h" #include "decode.h" #include "detect.h" #include "detect-parse.h" #include "detect-content.h" #include "detect-engine.h" #include "detect-engine-mpm.h" #include "detect-engine-state.h" #include "detect-engine-file.h" #include "detect-engine-prefilter.h" #include "detect-engine-content-inspection.h" #include "flow.h" #include "flow-var.h" #include "flow-util.h" #include "util-debug.h" #include "util-spm-bm.h" #include "util-unittest.h" #include "util-unittest-helper.h" #include "util-profiling.h" #include "app-layer.h" #include "app-layer-htp.h" #include "stream-tcp.h" #include "detect-filename.h" #include "app-layer-parser.h" typedef struct DetectFilenameData { uint8_t *name; /** name of the file to match */ BmCtx *bm_ctx; /** BM context */ uint16_t len; /** name length */ uint32_t flags; } DetectFilenameData; static int DetectFilenameMatch (DetectEngineThreadCtx *, Flow *, uint8_t, File *, const Signature *, const SigMatchCtx *); static int DetectFilenameSetup (DetectEngineCtx *, Signature *, const char *); static int DetectFilenameSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str); #ifdef UNITTESTS static void DetectFilenameRegisterTests(void); #endif static void DetectFilenameFree(DetectEngineCtx *, void *); static int g_file_match_list_id = 0; static int g_file_name_buffer_id = 0; static int PrefilterMpmFilenameRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistery *mpm_reg, int list_id); static uint8_t DetectEngineInspectFilename(DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, const DetectEngineAppInspectionEngine *engine, const Signature *s, Flow *f, uint8_t flags, void *alstate, void *txv, uint64_t tx_id); /** * \brief Registration function for keyword: filename */ void DetectFilenameRegister(void) { sigmatch_table[DETECT_FILENAME].name = "filename"; sigmatch_table[DETECT_FILENAME].desc = "match on the file name"; sigmatch_table[DETECT_FILENAME].url = "/rules/file-keywords.html#filename"; sigmatch_table[DETECT_FILENAME].FileMatch = DetectFilenameMatch; sigmatch_table[DETECT_FILENAME].Setup = DetectFilenameSetup; sigmatch_table[DETECT_FILENAME].Free = DetectFilenameFree; #ifdef UNITTESTS sigmatch_table[DETECT_FILENAME].RegisterTests = DetectFilenameRegisterTests; #endif sigmatch_table[DETECT_FILENAME].flags = SIGMATCH_QUOTES_OPTIONAL|SIGMATCH_HANDLE_NEGATION; sigmatch_table[DETECT_FILENAME].alternative = DETECT_FILE_NAME; sigmatch_table[DETECT_FILE_NAME].name = "file.name"; sigmatch_table[DETECT_FILE_NAME].desc = "sticky buffer to match on the file name"; sigmatch_table[DETECT_FILE_NAME].url = "/rules/file-keywords.html#filename"; sigmatch_table[DETECT_FILE_NAME].Setup = DetectFilenameSetupSticky; sigmatch_table[DETECT_FILE_NAME].flags = SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER; DetectAppLayerInspectEngineRegister2("files", ALPROTO_HTTP1, SIG_FLAG_TOSERVER, HTP_REQUEST_BODY, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2("files", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT, HTP_RESPONSE_BODY, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2( "files", ALPROTO_SMTP, SIG_FLAG_TOSERVER, 0, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2( "files", ALPROTO_NFS, SIG_FLAG_TOSERVER, 0, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2( "files", ALPROTO_NFS, SIG_FLAG_TOCLIENT, 0, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2( "files", ALPROTO_FTPDATA, SIG_FLAG_TOSERVER, 0, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2( "files", ALPROTO_FTPDATA, SIG_FLAG_TOCLIENT, 0, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2( "files", ALPROTO_SMB, SIG_FLAG_TOSERVER, 0, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2( "files", ALPROTO_SMB, SIG_FLAG_TOCLIENT, 0, DetectFileInspectGeneric, NULL); //this is used by filestore DetectAppLayerInspectEngineRegister2("files", ALPROTO_HTTP2, SIG_FLAG_TOSERVER, HTTP2StateDataClient, DetectFileInspectGeneric, NULL); DetectAppLayerInspectEngineRegister2("files", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT, HTTP2StateDataServer, DetectFileInspectGeneric, NULL); g_file_match_list_id = DetectBufferTypeGetByName("files"); AppProto protos_ts[] = { ALPROTO_HTTP1, ALPROTO_SMTP, ALPROTO_FTP, ALPROTO_FTPDATA, ALPROTO_SMB, ALPROTO_NFS, 0 }; AppProto protos_tc[] = { ALPROTO_HTTP1, ALPROTO_FTP, ALPROTO_FTPDATA, ALPROTO_SMB, ALPROTO_NFS, 0 }; for (int i = 0; protos_ts[i] != 0; i++) { DetectAppLayerInspectEngineRegister2("file.name", protos_ts[i], SIG_FLAG_TOSERVER, 0, DetectEngineInspectFilename, NULL); DetectAppLayerMpmRegister2("file.name", SIG_FLAG_TOSERVER, 2, PrefilterMpmFilenameRegister, NULL, protos_ts[i], 0); } for (int i = 0; protos_tc[i] != 0; i++) { DetectAppLayerInspectEngineRegister2("file.name", protos_tc[i], SIG_FLAG_TOCLIENT, 0, DetectEngineInspectFilename, NULL); DetectAppLayerMpmRegister2("file.name", SIG_FLAG_TOCLIENT, 2, PrefilterMpmFilenameRegister, NULL, protos_tc[i], 0); } DetectBufferTypeSetDescriptionByName("file.name", "file name"); DetectBufferTypeSupportsMultiInstance("file.name"); g_file_name_buffer_id = DetectBufferTypeGetByName("file.name"); SCLogDebug("registering filename rule option"); return; } /** * \brief match the specified filename * * \param t thread local vars * \param det_ctx pattern matcher thread local data * \param f *LOCKED* flow * \param flags direction flags * \param file file being inspected * \param s signature being inspected * \param m sigmatch that we will cast into DetectFilenameData * * \retval 0 no match * \retval 1 match */ static int DetectFilenameMatch (DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags, File *file, const Signature *s, const SigMatchCtx *m) { SCEnter(); int ret = 0; DetectFilenameData *filename = (DetectFilenameData *)m; if (file->name == NULL) SCReturnInt(0); if (BoyerMooreNocase(filename->name, filename->len, file->name, file->name_len, filename->bm_ctx) != NULL) { #ifdef DEBUG if (SCLogDebugEnabled()) { char *name = SCMalloc(filename->len + 1); if (name != NULL) { memcpy(name, filename->name, filename->len); name[filename->len] = '\0'; SCLogDebug("will look for filename %s", name); SCFree(name); } } #endif if (!(filename->flags & DETECT_CONTENT_NEGATED)) { ret = 1; } } else if (filename->flags & DETECT_CONTENT_NEGATED) { SCLogDebug("negated match"); ret = 1; } SCReturnInt(ret); } /** * \brief Parse the filename keyword * * \param de_ctx Pointer to the detection engine context * \param idstr Pointer to the user provided option * * \retval filename pointer to DetectFilenameData on success * \retval NULL on failure */ static DetectFilenameData *DetectFilenameParse (DetectEngineCtx *de_ctx, const char *str, bool negate) { DetectFilenameData *filename = SCCalloc(1, sizeof(DetectFilenameData)); if (unlikely(filename == NULL)) return NULL; if (DetectContentDataParse ("filename", str, &filename->name, &filename->len) == -1) { goto error; } filename->bm_ctx = BoyerMooreNocaseCtxInit(filename->name, filename->len); if (filename->bm_ctx == NULL) { goto error; } if (negate) { filename->flags |= DETECT_CONTENT_NEGATED; } SCLogDebug("flags %02X", filename->flags); if (filename->flags & DETECT_CONTENT_NEGATED) { SCLogDebug("negated filename"); } #ifdef DEBUG if (SCLogDebugEnabled()) { char *name = SCMalloc(filename->len + 1); if (name != NULL) { memcpy(name, filename->name, filename->len); name[filename->len] = '\0'; SCLogDebug("will look for filename %s", name); SCFree(name); } } #endif return filename; error: DetectFilenameFree(de_ctx, filename); return NULL; } /** * \brief this function is used to parse filename options * \brief into the current signature * * \param de_ctx pointer to the Detection Engine Context * \param s pointer to the Current Signature * \param str pointer to the user provided "filename" option * * \retval 0 on Success * \retval -1 on Failure */ static int DetectFilenameSetup (DetectEngineCtx *de_ctx, Signature *s, const char *str) { DetectFilenameData *filename = NULL; SigMatch *sm = NULL; filename = DetectFilenameParse(de_ctx, str, s->init_data->negated); if (filename == NULL) goto error; /* Okay so far so good, lets get this into a SigMatch * and put it in the Signature. */ sm = SigMatchAlloc(); if (sm == NULL) goto error; sm->type = DETECT_FILENAME; sm->ctx = (void *)filename; SigMatchAppendSMToList(s, sm, g_file_match_list_id); s->file_flags |= (FILE_SIG_NEED_FILE|FILE_SIG_NEED_FILENAME); return 0; error: if (filename != NULL) DetectFilenameFree(de_ctx, filename); if (sm != NULL) SCFree(sm); return -1; } /** * \brief this function will free memory associated with DetectFilenameData * * \param filename pointer to DetectFilenameData */ static void DetectFilenameFree(DetectEngineCtx *de_ctx, void *ptr) { if (ptr != NULL) { DetectFilenameData *filename = (DetectFilenameData *)ptr; if (filename->bm_ctx != NULL) { BoyerMooreCtxDeInit(filename->bm_ctx); } if (filename->name != NULL) SCFree(filename->name); SCFree(filename); } } /* file.name implementation */ /** * \brief this function setup the file.data keyword used in the rule * * \param de_ctx Pointer to the Detection Engine Context * \param s Pointer to the Signature to which the current keyword belongs * \param str Should hold an empty string always * * \retval 0 On success */ static int DetectFilenameSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str) { if (DetectBufferSetActiveList(de_ctx, s, g_file_name_buffer_id) < 0) return -1; s->file_flags |= (FILE_SIG_NEED_FILE | FILE_SIG_NEED_FILENAME); return 0; } static InspectionBuffer *FilenameGetDataCallback(DetectEngineThreadCtx *det_ctx, const DetectEngineTransforms *transforms, Flow *f, uint8_t flow_flags, File *cur_file, int list_id, int local_file_id) { SCEnter(); InspectionBuffer *buffer = InspectionBufferMultipleForListGet(det_ctx, list_id, local_file_id); if (buffer == NULL) return NULL; if (buffer->initialized) return buffer; const uint8_t *data = cur_file->name; uint32_t data_len = cur_file->name_len; InspectionBufferSetupMulti(buffer, transforms, data, data_len); SCReturnPtr(buffer, "InspectionBuffer"); } static uint8_t DetectEngineInspectFilename(DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, const DetectEngineAppInspectionEngine *engine, const Signature *s, Flow *f, uint8_t flags, void *alstate, void *txv, uint64_t tx_id) { const DetectEngineTransforms *transforms = NULL; if (!engine->mpm) { transforms = engine->v2.transforms; } AppLayerGetFileState files = AppLayerParserGetTxFiles(f, alstate, txv, flags); FileContainer *ffc = files.fc; if (ffc == NULL) { return DETECT_ENGINE_INSPECT_SIG_CANT_MATCH_FILES; } uint8_t r = DETECT_ENGINE_INSPECT_SIG_NO_MATCH; int local_file_id = 0; for (File *file = ffc->head; file != NULL; file = file->next) { InspectionBuffer *buffer = FilenameGetDataCallback( det_ctx, transforms, f, flags, file, engine->sm_list, local_file_id); if (buffer == NULL) continue; det_ctx->buffer_offset = 0; det_ctx->discontinue_matching = 0; det_ctx->inspection_recursion_counter = 0; int match = DetectEngineContentInspection(de_ctx, det_ctx, s, engine->smd, NULL, f, (uint8_t *)buffer->inspect, buffer->inspect_len, buffer->inspect_offset, DETECT_CI_FLAGS_SINGLE, DETECT_ENGINE_CONTENT_INSPECTION_MODE_STATE); if (match == 1) { return DETECT_ENGINE_INSPECT_SIG_MATCH; } else { r = DETECT_ENGINE_INSPECT_SIG_CANT_MATCH_FILES; } local_file_id++; } return r; } typedef struct PrefilterMpmFilename { int list_id; const MpmCtx *mpm_ctx; const DetectEngineTransforms *transforms; } PrefilterMpmFilename; /** \brief Filedata Filedata Mpm prefilter callback * * \param det_ctx detection engine thread ctx * \param p packet to inspect * \param f flow to inspect * \param txv tx to inspect * \param pectx inspection context */ static void PrefilterTxFilename(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p, Flow *f, void *txv, const uint64_t idx, const AppLayerTxData *txd, const uint8_t flags) { SCEnter(); if (!AppLayerParserHasFilesInDir(txd, flags)) return; const PrefilterMpmFilename *ctx = (const PrefilterMpmFilename *)pectx; const MpmCtx *mpm_ctx = ctx->mpm_ctx; const int list_id = ctx->list_id; AppLayerGetFileState files = AppLayerParserGetTxFiles(f, f->alstate, txv, flags); FileContainer *ffc = files.fc; if (ffc != NULL) { int local_file_id = 0; for (File *file = ffc->head; file != NULL; file = file->next) { InspectionBuffer *buffer = FilenameGetDataCallback( det_ctx, ctx->transforms, f, flags, file, list_id, local_file_id); if (buffer == NULL) continue; if (buffer->inspect_len >= mpm_ctx->minlen) { (void)mpm_table[mpm_ctx->mpm_type].Search(mpm_ctx, &det_ctx->mtcu, &det_ctx->pmq, buffer->inspect, buffer->inspect_len); PREFILTER_PROFILING_ADD_BYTES(det_ctx, buffer->inspect_len); } local_file_id++; } } } static void PrefilterMpmFilenameFree(void *ptr) { SCFree(ptr); } static int PrefilterMpmFilenameRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistery *mpm_reg, int list_id) { PrefilterMpmFilename *pectx = SCCalloc(1, sizeof(*pectx)); if (pectx == NULL) return -1; pectx->list_id = list_id; pectx->mpm_ctx = mpm_ctx; pectx->transforms = &mpm_reg->transforms; return PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxFilename, mpm_reg->app_v2.alproto, mpm_reg->app_v2.tx_min_progress, pectx, PrefilterMpmFilenameFree, mpm_reg->pname); } #ifdef UNITTESTS /* UNITTESTS */ /** * \test Test parser accepting valid rules and rejecting invalid rules */ static int DetectFilenameSignatureParseTest01(void) { FAIL_IF_NOT(UTHParseSignature("alert http any any -> any any (flow:to_client; file.name; content:\"abc\"; sid:1;)", true)); FAIL_IF_NOT(UTHParseSignature("alert http any any -> any any (flow:to_client; file.name; content:\"abc\"; nocase; sid:1;)", true)); FAIL_IF_NOT(UTHParseSignature("alert http any any -> any any (flow:to_client; file.name; content:\"abc\"; endswith; sid:1;)", true)); FAIL_IF_NOT(UTHParseSignature("alert http any any -> any any (flow:to_client; file.name; content:\"abc\"; startswith; sid:1;)", true)); FAIL_IF_NOT(UTHParseSignature("alert http any any -> any any (flow:to_client; file.name; content:\"abc\"; startswith; endswith; sid:1;)", true)); FAIL_IF_NOT(UTHParseSignature("alert http any any -> any any (flow:to_client; file.name; bsize:10; sid:1;)", true)); FAIL_IF_NOT(UTHParseSignature("alert http any any -> any any (flow:to_client; file.name; content:\"abc\"; rawbytes; sid:1;)", false)); FAIL_IF_NOT(UTHParseSignature("alert tcp any any -> any any (flow:to_client; file.name; sid:1;)", false)); //FAIL_IF_NOT(UTHParseSignature("alert tls any any -> any any (flow:to_client; file.name; content:\"abc\"; sid:1;)", false)); PASS; } /** * \test DetectFilenameTestParse01 */ static int DetectFilenameTestParse01 (void) { DetectFilenameData *dnd = DetectFilenameParse(NULL, "secret.pdf", false); FAIL_IF_NULL(dnd); DetectFilenameFree(NULL, dnd); PASS; } /** * \test DetectFilenameTestParse02 */ static int DetectFilenameTestParse02 (void) { DetectFilenameData *dnd = DetectFilenameParse(NULL, "backup.tar.gz", false); FAIL_IF_NULL(dnd); FAIL_IF_NOT(dnd->len == 13); FAIL_IF_NOT(memcmp(dnd->name, "backup.tar.gz", 13) == 0); DetectFilenameFree(NULL, dnd); PASS; } /** * \test DetectFilenameTestParse03 */ static int DetectFilenameTestParse03 (void) { DetectFilenameData *dnd = DetectFilenameParse(NULL, "cmd.exe", false); FAIL_IF_NULL(dnd); FAIL_IF_NOT(dnd->len == 7); FAIL_IF_NOT(memcmp(dnd->name, "cmd.exe", 7) == 0); DetectFilenameFree(NULL, dnd); PASS; } /** * \brief this function registers unit tests for DetectFilename */ void DetectFilenameRegisterTests(void) { UtRegisterTest("DetectFilenameSignatureParseTest01", DetectFilenameSignatureParseTest01); UtRegisterTest("DetectFilenameTestParse01", DetectFilenameTestParse01); UtRegisterTest("DetectFilenameTestParse02", DetectFilenameTestParse02); UtRegisterTest("DetectFilenameTestParse03", DetectFilenameTestParse03); } #endif /* UNITTESTS */