/* Copyright (C) 2007-2010 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 * * Implements the tls.version keyword */ #include "suricata-common.h" #include "threads.h" #include "debug.h" #include "decode.h" #include "detect.h" #include "detect-parse.h" #include "detect-engine.h" #include "detect-engine-mpm.h" #include "detect-engine-state.h" #include "flow.h" #include "flow-var.h" #include "flow-util.h" #include "util-debug.h" #include "util-unittest.h" #include "util-unittest-helper.h" #include "app-layer.h" #include "app-layer-parser.h" #include "app-layer-ssl.h" #include "detect-tls-version.h" #include "stream-tcp.h" /** * \brief Regex for parsing "id" option, matching number or "number" */ #define PARSE_REGEX "^\\s*([A-z0-9\\.]+|\"[A-z0-9\\.]+\")\\s*$" static pcre *parse_regex; static pcre_extra *parse_regex_study; int DetectTlsVersionMatch (ThreadVars *, DetectEngineThreadCtx *, Flow *, uint8_t, void *, Signature *, SigMatch *); static int DetectTlsVersionSetup (DetectEngineCtx *, Signature *, char *); void DetectTlsVersionRegisterTests(void); void DetectTlsVersionFree(void *); /** * \brief Registration function for keyword: tls.version */ void DetectTlsVersionRegister (void) { sigmatch_table[DETECT_AL_TLS_VERSION].name = "tls.version"; sigmatch_table[DETECT_AL_TLS_VERSION].desc = "match on TLS/SSL version"; sigmatch_table[DETECT_AL_TLS_VERSION].url = "https://redmine.openinfosecfoundation.org/projects/suricata/wiki/TLS-keywords#tlsversion"; sigmatch_table[DETECT_AL_TLS_VERSION].Match = NULL; sigmatch_table[DETECT_AL_TLS_VERSION].AppLayerMatch = DetectTlsVersionMatch; sigmatch_table[DETECT_AL_TLS_VERSION].alproto = ALPROTO_TLS; sigmatch_table[DETECT_AL_TLS_VERSION].Setup = DetectTlsVersionSetup; sigmatch_table[DETECT_AL_TLS_VERSION].Free = DetectTlsVersionFree; sigmatch_table[DETECT_AL_TLS_VERSION].RegisterTests = DetectTlsVersionRegisterTests; const char *eb; int eo; int opts = 0; SCLogDebug("registering tls.version rule option"); parse_regex = pcre_compile(PARSE_REGEX, opts, &eb, &eo, NULL); if (parse_regex == NULL) { SCLogError(SC_ERR_PCRE_COMPILE, "Compile of \"%s\" failed at offset %" PRId32 ": %s", PARSE_REGEX, eo, eb); goto error; } parse_regex_study = pcre_study(parse_regex, 0, &eb); if (eb != NULL) { SCLogError(SC_ERR_PCRE_STUDY, "pcre study failed: %s", eb); goto error; } return; error: return; } /** * \brief match the specified version on a tls session * * \param t pointer to thread vars * \param det_ctx pointer to the pattern matcher thread * \param p pointer to the current packet * \param m pointer to the sigmatch that we will cast into DetectTlsVersionData * * \retval 0 no match * \retval 1 match */ int DetectTlsVersionMatch (ThreadVars *t, DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags, void *state, Signature *s, SigMatch *m) { SCEnter(); DetectTlsVersionData *tls_data = (DetectTlsVersionData *)m->ctx; SSLState *ssl_state = (SSLState *)state; if (ssl_state == NULL) { SCLogDebug("no tls state, no match"); SCReturnInt(0); } int ret = 0; SCLogDebug("looking for tls_data->ver 0x%02X (flags 0x%02X)", tls_data->ver, flags); if (flags & STREAM_TOCLIENT) { SCLogDebug("server (toclient) version is 0x%02X", ssl_state->server_connp.version); if (tls_data->ver == ssl_state->server_connp.version) ret = 1; } else if (flags & STREAM_TOSERVER) { SCLogDebug("client (toserver) version is 0x%02X", ssl_state->client_connp.version); if (tls_data->ver == ssl_state->client_connp.version) ret = 1; } SCReturnInt(ret); } /** * \brief This function is used to parse IPV4 ip_id passed via keyword: "id" * * \param idstr Pointer to the user provided id option * * \retval id_d pointer to DetectTlsVersionData on success * \retval NULL on failure */ DetectTlsVersionData *DetectTlsVersionParse (char *str) { uint16_t temp; DetectTlsVersionData *tls = NULL; #define MAX_SUBSTRINGS 30 int ret = 0, res = 0; int ov[MAX_SUBSTRINGS]; ret = pcre_exec(parse_regex, parse_regex_study, str, strlen(str), 0, 0, ov, MAX_SUBSTRINGS); if (ret < 1 || ret > 3) { SCLogError(SC_ERR_PCRE_MATCH, "invalid tls.version option"); goto error; } if (ret > 1) { const char *str_ptr; char *orig; char *tmp_str; res = pcre_get_substring((char *)str, ov, MAX_SUBSTRINGS, 1, &str_ptr); if (res < 0) { SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre_get_substring failed"); goto error; } /* We have a correct id option */ tls = SCMalloc(sizeof(DetectTlsVersionData)); if (unlikely(tls == NULL)) goto error; orig = SCStrdup((char*)str_ptr); if (unlikely(orig == NULL)) { goto error; } tmp_str=orig; /* Let's see if we need to scape "'s */ if (tmp_str[0] == '"') { tmp_str[strlen(tmp_str) - 1] = '\0'; tmp_str += 1; } if (strcmp("1.0", tmp_str) == 0) { temp = TLS_VERSION_10; } else if (strcmp("1.1", tmp_str) == 0) { temp = TLS_VERSION_11; } else if (strcmp("1.2", tmp_str) == 0) { temp = TLS_VERSION_12; } else { SCLogError(SC_ERR_INVALID_VALUE, "Invalid value"); goto error; } tls->ver = temp; SCFree(orig); SCLogDebug("will look for tls %"PRIu8"", tls->ver); } return tls; error: if (tls != NULL) DetectTlsVersionFree(tls); return NULL; } /** * \brief this function is used to add the parsed "id" option * \brief into the current signature * * \param de_ctx pointer to the Detection Engine Context * \param s pointer to the Current Signature * \param idstr pointer to the user provided "id" option * * \retval 0 on Success * \retval -1 on Failure */ static int DetectTlsVersionSetup (DetectEngineCtx *de_ctx, Signature *s, char *str) { DetectTlsVersionData *tls = NULL; SigMatch *sm = NULL; tls = DetectTlsVersionParse(str); if (tls == 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_AL_TLS_VERSION; sm->ctx = (void *)tls; SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_AMATCH); if (s->alproto != ALPROTO_UNKNOWN && s->alproto != ALPROTO_TLS) { SCLogError(SC_ERR_CONFLICTING_RULE_KEYWORDS, "rule contains conflicting keywords."); goto error; } s->alproto = ALPROTO_TLS; return 0; error: if (tls != NULL) DetectTlsVersionFree(tls); if (sm != NULL) SCFree(sm); return -1; } /** * \brief this function will free memory associated with DetectTlsVersionData * * \param id_d pointer to DetectTlsVersionData */ void DetectTlsVersionFree(void *ptr) { DetectTlsVersionData *id_d = (DetectTlsVersionData *)ptr; SCFree(id_d); } #ifdef UNITTESTS /* UNITTESTS */ /** * \test DetectTlsVersionTestParse01 is a test to make sure that we parse the "id" * option correctly when given valid id option */ int DetectTlsVersionTestParse01 (void) { DetectTlsVersionData *tls = NULL; tls = DetectTlsVersionParse("1.0"); if (tls != NULL && tls->ver == TLS_VERSION_10) { DetectTlsVersionFree(tls); return 1; } return 0; } /** * \test DetectTlsVersionTestParse02 is a test to make sure that we parse the "id" * option correctly when given an invalid id option * it should return id_d = NULL */ int DetectTlsVersionTestParse02 (void) { DetectTlsVersionData *tls = NULL; tls = DetectTlsVersionParse("2.5"); if (tls == NULL) { DetectTlsVersionFree(tls); return 1; } return 0; } #include "stream-tcp-reassemble.h" /** \test Send a get request in three chunks + more data. */ static int DetectTlsVersionTestDetect01(void) { int result = 0; Flow f; uint8_t tlsbuf1[] = { 0x16 }; uint32_t tlslen1 = sizeof(tlsbuf1); uint8_t tlsbuf2[] = { 0x03 }; uint32_t tlslen2 = sizeof(tlsbuf2); uint8_t tlsbuf3[] = { 0x01 }; uint32_t tlslen3 = sizeof(tlsbuf3); uint8_t tlsbuf4[] = { 0x01, 0x00, 0x00, 0xad, 0x03, 0x01 }; uint32_t tlslen4 = sizeof(tlsbuf4); TcpSession ssn; Packet *p = NULL; Signature *s = NULL; ThreadVars th_v; DetectEngineThreadCtx *det_ctx = NULL; AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc(); memset(&th_v, 0, sizeof(th_v)); memset(&f, 0, sizeof(f)); memset(&ssn, 0, sizeof(ssn)); p = UTHBuildPacket(NULL, 0, IPPROTO_TCP); FLOW_INITIALIZE(&f); f.protoctx = (void *)&ssn; f.proto = IPPROTO_TCP; p->flow = &f; p->flowflags |= FLOW_PKT_TOSERVER; p->flowflags |= FLOW_PKT_ESTABLISHED; p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST; f.alproto = ALPROTO_TLS; StreamTcpInitConfig(TRUE); DetectEngineCtx *de_ctx = DetectEngineCtxInit(); if (de_ctx == NULL) { goto end; } de_ctx->flags |= DE_QUIET; s = de_ctx->sig_list = SigInit(de_ctx,"alert tls any any -> any any (msg:\"TLS\"; tls.version:1.0; sid:1;)"); if (s == NULL) { goto end; } SigGroupBuild(de_ctx); DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx); SCMutexLock(&f.m); int r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf1, tlslen1); if (r != 0) { printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf2, tlslen2); if (r != 0) { printf("toserver chunk 2 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf3, tlslen3); if (r != 0) { printf("toserver chunk 3 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf4, tlslen4); if (r != 0) { printf("toserver chunk 4 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } SCMutexUnlock(&f.m); SSLState *ssl_state = f.alstate; if (ssl_state == NULL) { printf("no tls state: "); goto end; } if (ssl_state->client_connp.content_type != 0x16) { printf("expected content_type %" PRIu8 ", got %" PRIu8 ": ", 0x16, ssl_state->client_connp.content_type); goto end; } if (ssl_state->client_connp.version != TLS_VERSION_10) { printf("expected version %04" PRIu16 ", got %04" PRIu16 ": ", TLS_VERSION_10, ssl_state->client_connp.version); goto end; } SCLogDebug("ssl_state is at %p, ssl_state->server_version 0x%02X " "ssl_state->client_version 0x%02X", ssl_state, ssl_state->server_connp.version, ssl_state->client_connp.version); /* do detect */ SigMatchSignatures(&th_v, de_ctx, det_ctx, p); if (!(PacketAlertCheck(p, 1))) { goto end; } result = 1; end: if (alp_tctx != NULL) AppLayerParserThreadCtxFree(alp_tctx); SigGroupCleanup(de_ctx); SigCleanSignatures(de_ctx); DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx); DetectEngineCtxFree(de_ctx); StreamTcpFreeConfig(TRUE); FLOW_DESTROY(&f); UTHFreePackets(&p, 1); return result; } static int DetectTlsVersionTestDetect02(void) { int result = 0; Flow f; uint8_t tlsbuf1[] = { 0x16 }; uint32_t tlslen1 = sizeof(tlsbuf1); uint8_t tlsbuf2[] = { 0x03 }; uint32_t tlslen2 = sizeof(tlsbuf2); uint8_t tlsbuf3[] = { 0x01 }; uint32_t tlslen3 = sizeof(tlsbuf3); uint8_t tlsbuf4[] = { 0x01, 0x00, 0x00, 0xad, 0x03, 0x02 }; uint32_t tlslen4 = sizeof(tlsbuf4); TcpSession ssn; Packet *p = NULL; Signature *s = NULL; ThreadVars th_v; DetectEngineThreadCtx *det_ctx = NULL; AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc(); memset(&th_v, 0, sizeof(th_v)); memset(&f, 0, sizeof(f)); memset(&ssn, 0, sizeof(ssn)); p = UTHBuildPacket(NULL, 0, IPPROTO_TCP); FLOW_INITIALIZE(&f); f.protoctx = (void *)&ssn; f.proto = IPPROTO_TCP; p->flow = &f; p->flowflags |= FLOW_PKT_TOSERVER; p->flowflags |= FLOW_PKT_ESTABLISHED; p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST; f.alproto = ALPROTO_TLS; StreamTcpInitConfig(TRUE); DetectEngineCtx *de_ctx = DetectEngineCtxInit(); if (de_ctx == NULL) { goto end; } de_ctx->flags |= DE_QUIET; s = de_ctx->sig_list = SigInit(de_ctx,"alert tls any any -> any any (msg:\"TLS\"; tls.version:1.0; sid:1;)"); if (s == NULL) { goto end; } SigGroupBuild(de_ctx); DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx); SCMutexLock(&f.m); int r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf1, tlslen1); if (r != 0) { printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf2, tlslen2); if (r != 0) { printf("toserver chunk 2 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf3, tlslen3); if (r != 0) { printf("toserver chunk 3 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf4, tlslen4); if (r != 0) { printf("toserver chunk 4 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } SCMutexUnlock(&f.m); SSLState *ssl_state = f.alstate; if (ssl_state == NULL) { printf("no tls state: "); goto end; } if (ssl_state->client_connp.content_type != 0x16) { printf("expected content_type %" PRIu8 ", got %" PRIu8 ": ", 0x16, ssl_state->client_connp.content_type); goto end; } if (ssl_state->client_connp.version != TLS_VERSION_10) { printf("expected version %04" PRIu16 ", got %04" PRIu16 ": ", TLS_VERSION_10, ssl_state->client_connp.version); goto end; } /* do detect */ SigMatchSignatures(&th_v, de_ctx, det_ctx, p); if (!(PacketAlertCheck(p, 1))) { printf("signature 1 didn't match while it should have: "); goto end; } result = 1; end: if (alp_tctx != NULL) AppLayerParserThreadCtxFree(alp_tctx); SigGroupCleanup(de_ctx); SigCleanSignatures(de_ctx); DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx); DetectEngineCtxFree(de_ctx); StreamTcpFreeConfig(TRUE); FLOW_DESTROY(&f); UTHFreePackets(&p, 1); return result; } static int DetectTlsVersionTestDetect03(void) { DetectEngineCtx *de_ctx = NULL; int result = 0; Flow f; uint8_t tlsbuf1[] = { 0x16 }; uint32_t tlslen1 = sizeof(tlsbuf1); uint8_t tlsbuf2[] = { 0x03 }; uint32_t tlslen2 = sizeof(tlsbuf2); uint8_t tlsbuf3[] = { 0x01 }; uint32_t tlslen3 = sizeof(tlsbuf3); uint8_t tlsbuf4[] = { 0x01, 0x00, 0x00, 0xad, 0x03, 0x02 }; uint32_t tlslen4 = sizeof(tlsbuf4); TcpSession ssn; Packet *p = NULL; Signature *s = NULL; ThreadVars th_v; DetectEngineThreadCtx *det_ctx = NULL; AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc(); memset(&th_v, 0, sizeof(th_v)); memset(&f, 0, sizeof(f)); memset(&ssn, 0, sizeof(ssn)); p = UTHBuildPacket(NULL, 0, IPPROTO_TCP); p->tcph->th_seq = htonl(1000); FLOW_INITIALIZE(&f); f.protoctx = (void *)&ssn; p->flow = &f; p->flowflags |= FLOW_PKT_TOSERVER; p->flowflags |= FLOW_PKT_ESTABLISHED; p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST; f.alproto = ALPROTO_TLS; f.proto = p->proto; StreamTcpInitConfig(TRUE); StreamMsg *stream_msg = StreamMsgGetFromPool(); if (stream_msg == NULL) { printf("no stream_msg: "); goto end; } memcpy(stream_msg->data, tlsbuf4, tlslen4); stream_msg->data_len = tlslen4; ssn.toserver_smsg_head = stream_msg; ssn.toserver_smsg_tail = stream_msg; de_ctx = DetectEngineCtxInit(); if (de_ctx == NULL) { goto end; } de_ctx->flags |= DE_QUIET; s = de_ctx->sig_list = SigInit(de_ctx,"alert tcp any any -> any any (msg:\"TLS\"; tls.version:1.0; content:\"|01 00 00 AD|\"; sid:1;)"); if (s == NULL) { goto end; } SigGroupBuild(de_ctx); DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx); SCMutexLock(&f.m); int r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf1, tlslen1); if (r != 0) { printf("toserver chunk 1 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf2, tlslen2); if (r != 0) { printf("toserver chunk 2 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf3, tlslen3); if (r != 0) { printf("toserver chunk 3 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } r = AppLayerParserParse(alp_tctx, &f, ALPROTO_TLS, STREAM_TOSERVER, tlsbuf4, tlslen4); if (r != 0) { printf("toserver chunk 4 returned %" PRId32 ", expected 0: ", r); SCMutexUnlock(&f.m); goto end; } SCMutexUnlock(&f.m); SSLState *ssl_state = f.alstate; if (ssl_state == NULL) { printf("no tls state: "); goto end; } if (ssl_state->client_connp.content_type != 0x16) { printf("expected content_type %" PRIu8 ", got %" PRIu8 ": ", 0x16, ssl_state->client_connp.content_type); goto end; } if (ssl_state->client_connp.version != TLS_VERSION_10) { printf("expected version %04" PRIu16 ", got %04" PRIu16 ": ", TLS_VERSION_10, ssl_state->client_connp.version); goto end; } /* do detect */ SigMatchSignatures(&th_v, de_ctx, det_ctx, p); if (!(PacketAlertCheck(p, 1))) { printf("signature 1 didn't match while it should have: "); goto end; } result = 1; end: if (alp_tctx != NULL) AppLayerParserThreadCtxFree(alp_tctx); if (de_ctx != NULL) { SigGroupCleanup(de_ctx); SigCleanSignatures(de_ctx); DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx); DetectEngineCtxFree(de_ctx); } StreamTcpFreeConfig(TRUE); FLOW_DESTROY(&f); UTHFreePackets(&p, 1); return result; } #endif /* UNITTESTS */ /** * \brief this function registers unit tests for DetectTlsVersion */ void DetectTlsVersionRegisterTests(void) { #ifdef UNITTESTS /* UNITTESTS */ UtRegisterTest("DetectTlsVersionTestParse01", DetectTlsVersionTestParse01, 1); UtRegisterTest("DetectTlsVersionTestParse02", DetectTlsVersionTestParse02, 1); UtRegisterTest("DetectTlsVersionTestDetect01", DetectTlsVersionTestDetect01, 1); UtRegisterTest("DetectTlsVersionTestDetect02", DetectTlsVersionTestDetect02, 1); UtRegisterTest("DetectTlsVersionTestDetect03", DetectTlsVersionTestDetect03, 1); #endif /* UNITTESTS */ }