--- /dev/null
+/* Copyright (C) 2019 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 Mats Klepsland <mats.klepsland@gmail.com>
+ *
+ * Implements support for ja3s.hash 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-prefilter.h"
+#include "detect-content.h"
+#include "detect-pcre.h"
+#include "detect-tls-ja3s-hash.h"
+
+#include "flow.h"
+#include "flow-util.h"
+#include "flow-var.h"
+
+#include "conf.h"
+#include "conf-yaml-loader.h"
+
+#include "util-debug.h"
+#include "util-unittest.h"
+#include "util-spm.h"
+#include "util-print.h"
+#include "util-ja3.h"
+
+#include "stream-tcp.h"
+
+#include "app-layer.h"
+#include "app-layer-ssl.h"
+
+#include "util-unittest.h"
+#include "util-unittest-helper.h"
+
+static int DetectTlsJa3SHashSetup(DetectEngineCtx *, Signature *, const char *);
+static void DetectTlsJa3SHashRegisterTests(void);
+static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
+ const DetectEngineTransforms *transforms,
+ Flow *f, const uint8_t flow_flags,
+ void *txv, const int list_id);
+static void DetectTlsJa3SHashSetupCallback(const DetectEngineCtx *de_ctx,
+ Signature *s);
+static _Bool DetectTlsJa3SHashValidateCallback(const Signature *s,
+ const char **sigerror);
+static int g_tls_ja3s_hash_buffer_id = 0;
+
+/**
+ * \brief Registration function for keyword: ja3s.hash
+ */
+void DetectTlsJa3SHashRegister(void)
+{
+ sigmatch_table[DETECT_AL_TLS_JA3S_HASH].name = "ja3s.hash";
+ sigmatch_table[DETECT_AL_TLS_JA3S_HASH].desc = "content modifier to match the JA3S hash sticky buffer";
+ sigmatch_table[DETECT_AL_TLS_JA3S_HASH].url = DOC_URL DOC_VERSION "/rules/ja3-keywords.html#ja3s-hash";
+ sigmatch_table[DETECT_AL_TLS_JA3S_HASH].Setup = DetectTlsJa3SHashSetup;
+ sigmatch_table[DETECT_AL_TLS_JA3S_HASH].RegisterTests = DetectTlsJa3SHashRegisterTests;
+
+ sigmatch_table[DETECT_AL_TLS_JA3S_HASH].flags |= SIGMATCH_NOOPT;
+ sigmatch_table[DETECT_AL_TLS_JA3S_HASH].flags |= SIGMATCH_INFO_STICKY_BUFFER;
+
+ DetectAppLayerInspectEngineRegister2("ja3s.hash", ALPROTO_TLS, SIG_FLAG_TOCLIENT, 0,
+ DetectEngineInspectBufferGeneric, GetData);
+
+ DetectAppLayerMpmRegister2("ja3s.hash", SIG_FLAG_TOCLIENT, 2,
+ PrefilterGenericMpmRegister, GetData, ALPROTO_TLS, 0);
+
+ DetectBufferTypeSetDescriptionByName("ja3s.hash", "TLS JA3S hash");
+
+ DetectBufferTypeRegisterSetupCallback("ja3s.hash",
+ DetectTlsJa3SHashSetupCallback);
+
+ DetectBufferTypeRegisterValidateCallback("ja3s.hash",
+ DetectTlsJa3SHashValidateCallback);
+
+ g_tls_ja3s_hash_buffer_id = DetectBufferTypeGetByName("ja3s.hash");
+}
+
+/**
+ * \brief this function setup the ja3s.hash modifier 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
+ * \retval -1 On failure
+ */
+static int DetectTlsJa3SHashSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
+{
+ if (DetectBufferSetActiveList(s, g_tls_ja3s_hash_buffer_id) < 0)
+ return -1;
+
+ if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
+ return -1;
+
+ /* Check if JA3 is disabled */
+ if (!RunmodeIsUnittests() && Ja3IsDisabled("rule"))
+ return -1;
+
+ return 0;
+}
+
+static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
+ const DetectEngineTransforms *transforms, Flow *f,
+ const uint8_t flow_flags, void *txv, const int list_id)
+{
+ InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
+ if (buffer->inspect == NULL) {
+ const SSLState *ssl_state = (SSLState *)f->alstate;
+
+ if (ssl_state->server_connp.ja3_hash == NULL) {
+ return NULL;
+ }
+
+ const uint32_t data_len = strlen(ssl_state->server_connp.ja3_hash);
+ const uint8_t *data = (uint8_t *)ssl_state->server_connp.ja3_hash;
+
+ InspectionBufferSetup(buffer, data, data_len);
+ InspectionBufferApplyTransforms(buffer, transforms);
+ }
+
+ return buffer;
+}
+
+static _Bool DetectTlsJa3SHashValidateCallback(const Signature *s,
+ const char **sigerror)
+{
+ const SigMatch *sm = s->init_data->smlists[g_tls_ja3s_hash_buffer_id];
+ for ( ; sm != NULL; sm = sm->next)
+ {
+ if (sm->type != DETECT_CONTENT)
+ continue;
+
+ const DetectContentData *cd = (DetectContentData *)sm->ctx;
+
+ if (cd->flags & DETECT_CONTENT_NOCASE) {
+ *sigerror = "ja3s.hash should not be used together with "
+ "nocase, since the rule is automatically "
+ "lowercased anyway which makes nocase redundant.";
+ SCLogWarning(SC_WARN_POOR_RULE, "rule %u: %s", s->id, *sigerror);
+ }
+
+ if (cd->content_len == 32)
+ return TRUE;
+
+ *sigerror = "Invalid length of the specified JA3S hash (should "
+ "be 32 characters long). This rule will therefore "
+ "never match.";
+ SCLogError(SC_ERR_INVALID_RULE_ARGUMENT, "rule %u: %s", s->id, *sigerror);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static void DetectTlsJa3SHashSetupCallback(const DetectEngineCtx *de_ctx,
+ Signature *s)
+{
+ SigMatch *sm = s->init_data->smlists[g_tls_ja3s_hash_buffer_id];
+ for ( ; sm != NULL; sm = sm->next)
+ {
+ if (sm->type != DETECT_CONTENT)
+ continue;
+
+ DetectContentData *cd = (DetectContentData *)sm->ctx;
+
+ _Bool changed = FALSE;
+ uint32_t u;
+ for (u = 0; u < cd->content_len; u++)
+ {
+ if (isupper(cd->content[u])) {
+ cd->content[u] = tolower(cd->content[u]);
+ changed = TRUE;
+ }
+ }
+
+ /* recreate the context if changes were made */
+ if (changed) {
+ SpmDestroyCtx(cd->spm_ctx);
+ cd->spm_ctx = SpmInitCtx(cd->content, cd->content_len, 1,
+ de_ctx->spm_global_thread_ctx);
+ }
+ }
+}
+
+#ifndef HAVE_NSS
+
+static void DetectTlsJa3SHashRegisterTests(void)
+{
+ /* Don't register any tests */
+}
+
+#else /* HAVE_NSS */
+
+#ifdef UNITTESTS
+
+/**
+ * \test Test matching on a JA3S hash from a ServerHello record
+ */
+static int DetectTlsJa3SHashTest01(void)
+{
+ /* client hello */
+ uint8_t client_hello[] = {
+ 0x16, 0x03, 0x01, 0x00, 0xc8, 0x01, 0x00, 0x00,
+ 0xc4, 0x03, 0x03, 0xd6, 0x08, 0x5a, 0xa2, 0x86,
+ 0x5b, 0x85, 0xd4, 0x40, 0xab, 0xbe, 0xc0, 0xbc,
+ 0x41, 0xf2, 0x26, 0xf0, 0xfe, 0x21, 0xee, 0x8b,
+ 0x4c, 0x7e, 0x07, 0xc8, 0xec, 0xd2, 0x00, 0x46,
+ 0x4c, 0xeb, 0xb7, 0x00, 0x00, 0x16, 0xc0, 0x2b,
+ 0xc0, 0x2f, 0xc0, 0x0a, 0xc0, 0x09, 0xc0, 0x13,
+ 0xc0, 0x14, 0x00, 0x33, 0x00, 0x39, 0x00, 0x2f,
+ 0x00, 0x35, 0x00, 0x0a, 0x01, 0x00, 0x00, 0x85,
+ 0x00, 0x00, 0x00, 0x12, 0x00, 0x10, 0x00, 0x00,
+ 0x0d, 0x77, 0x77, 0x77, 0x2e, 0x67, 0x6f, 0x6f,
+ 0x67, 0x6c, 0x65, 0x2e, 0x6e, 0x6f, 0xff, 0x01,
+ 0x00, 0x01, 0x00, 0x00, 0x0a, 0x00, 0x08, 0x00,
+ 0x06, 0x00, 0x17, 0x00, 0x18, 0x00, 0x19, 0x00,
+ 0x0b, 0x00, 0x02, 0x01, 0x00, 0x00, 0x23, 0x00,
+ 0x00, 0x33, 0x74, 0x00, 0x00, 0x00, 0x10, 0x00,
+ 0x29, 0x00, 0x27, 0x05, 0x68, 0x32, 0x2d, 0x31,
+ 0x36, 0x05, 0x68, 0x32, 0x2d, 0x31, 0x35, 0x05,
+ 0x68, 0x32, 0x2d, 0x31, 0x34, 0x02, 0x68, 0x32,
+ 0x08, 0x73, 0x70, 0x64, 0x79, 0x2f, 0x33, 0x2e,
+ 0x31, 0x08, 0x68, 0x74, 0x74, 0x70, 0x2f, 0x31,
+ 0x2e, 0x31, 0x00, 0x05, 0x00, 0x05, 0x01, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x0d, 0x00, 0x16, 0x00,
+ 0x14, 0x04, 0x01, 0x05, 0x01, 0x06, 0x01, 0x02,
+ 0x01, 0x04, 0x03, 0x05, 0x03, 0x06, 0x03, 0x02,
+ 0x03, 0x04, 0x02, 0x02, 0x02
+ };
+
+ /* server hello */
+ uint8_t server_hello[] = {
+ 0x16, 0x03, 0x03, 0x00, 0x48, 0x02, 0x00, 0x00,
+ 0x44, 0x03, 0x03, 0x57, 0x91, 0xb8, 0x63, 0xdd,
+ 0xdb, 0xbb, 0x23, 0xcf, 0x0b, 0x43, 0x02, 0x1d,
+ 0x46, 0x11, 0x27, 0x5c, 0x98, 0xcf, 0x67, 0xe1,
+ 0x94, 0x3d, 0x62, 0x7d, 0x38, 0x48, 0x21, 0x23,
+ 0xa5, 0x62, 0x31, 0x00, 0xc0, 0x2f, 0x00, 0x00,
+ 0x1c, 0xff, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x23, 0x00, 0x00, 0x00, 0x10,
+ 0x00, 0x05, 0x00, 0x03, 0x02, 0x68, 0x32, 0x00,
+ 0x0b, 0x00, 0x02, 0x01, 0x00
+ };
+
+ Flow f;
+ SSLState *ssl_state = NULL;
+ TcpSession ssn;
+ Packet *p1 = NULL;
+ Packet *p2 = NULL;
+ ThreadVars tv;
+ DetectEngineThreadCtx *det_ctx = NULL;
+ AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();
+
+ memset(&tv, 0, sizeof(ThreadVars));
+ memset(&f, 0, sizeof(Flow));
+ memset(&ssn, 0, sizeof(TcpSession));
+
+ p1 = UTHBuildPacketReal(client_hello, sizeof(client_hello), IPPROTO_TCP,
+ "192.168.1.5", "192.168.1.1", 51251, 443);
+ p2 = UTHBuildPacketReal(server_hello, sizeof(server_hello), IPPROTO_TCP,
+ "192.168.1.1", "192.168.1.5", 443, 51251);
+
+ FLOW_INITIALIZE(&f);
+ f.flags |= FLOW_IPV4;
+ f.proto = IPPROTO_TCP;
+ f.protomap = FlowGetProtoMapping(f.proto);
+ f.alproto = ALPROTO_TLS;
+
+ p1->flow = &f;
+ p1->flags |= PKT_HAS_FLOW | PKT_STREAM_EST;
+ p1->flowflags |= FLOW_PKT_TOSERVER;
+ p1->flowflags |= FLOW_PKT_ESTABLISHED;
+ p1->pcap_cnt = 1;
+
+ p2->flow = &f;
+ p2->flags |= PKT_HAS_FLOW | PKT_STREAM_EST;
+ p2->flowflags |= FLOW_PKT_TOCLIENT;
+ p2->flowflags |= FLOW_PKT_ESTABLISHED;
+ p2->pcap_cnt = 2;
+
+ StreamTcpInitConfig(TRUE);
+
+ DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+ FAIL_IF_NULL(de_ctx);
+
+ de_ctx->mpm_matcher = mpm_default_matcher;
+ de_ctx->flags |= DE_QUIET;
+
+ Signature *s = DetectEngineAppendSig(de_ctx, "alert tls any any -> any any "
+ "(msg:\"Test ja3s.hash\"; "
+ "ja3s.hash; "
+ "content:\"8217013c502e3461d19c75bb02a12aaf\"; "
+ "sid:1;)");
+ FAIL_IF_NULL(s);
+
+ SigGroupBuild(de_ctx);
+ DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
+
+ int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_TLS,
+ STREAM_TOSERVER, client_hello,
+ sizeof(client_hello));
+
+ FAIL_IF(r != 0);
+
+ ssl_state = f.alstate;
+ FAIL_IF_NULL(ssl_state);
+
+ SigMatchSignatures(&tv, de_ctx, det_ctx, p1);
+
+ FAIL_IF(PacketAlertCheck(p1, 1));
+
+ r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_TLS, STREAM_TOCLIENT,
+ server_hello, sizeof(server_hello));
+
+ FAIL_IF(r != 0);
+
+ FAIL_IF_NULL(ssl_state->server_connp.ja3_hash);
+
+ SigMatchSignatures(&tv, de_ctx, det_ctx, p2);
+
+ FAIL_IF_NOT(PacketAlertCheck(p2, 1));
+
+ AppLayerParserThreadCtxFree(alp_tctx);
+ DetectEngineThreadCtxDeinit(&tv, det_ctx);
+ DetectEngineCtxFree(de_ctx);
+ StreamTcpFreeConfig(TRUE);
+ FLOW_DESTROY(&f);
+ UTHFreePacket(p1);
+ UTHFreePacket(p2);
+
+ PASS;
+}
+
+#endif /* UNITTESTS */
+
+static void DetectTlsJa3SHashRegisterTests(void)
+{
+#ifdef UNITTESTS
+ UtRegisterTest("DetectTlsJa3SHashTest01", DetectTlsJa3SHashTest01);
+#endif /* UNITTESTS */
+}
+
+#endif /* HAVE_NSS */
projects / thirdparty / suricata.git / commitdiff
