--- /dev/null
+/* Copyright (C) 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.
+ */
+
+#include "suricata-common.h"
+#include "threads.h"
+#include "debug.h"
+#include "detect.h"
+
+#include "detect-parse.h"
+#include "detect-engine.h"
+#include "detect-engine-mpm.h"
+#include "detect-content.h"
+
+#include "flow.h"
+#include "stream-tcp.h"
+
+#include "app-layer.h"
+#include "app-layer-ssl.h"
+#include "detect-engine-prefilter.h"
+#include "detect-tls-random.h"
+
+#define DETECT_TLS_RANDOM_TIME_LEN 4
+#define DETECT_TLS_RANDOM_BYTES_LEN 28
+
+static int DetectTlsRandomTimeSetup(DetectEngineCtx *, Signature *, const char *);
+static int DetectTlsRandomBytesSetup(DetectEngineCtx *, Signature *, const char *);
+static int DetectTlsRandomSetup(DetectEngineCtx *, Signature *, const char *);
+static InspectionBuffer *GetRandomTimeData(DetectEngineThreadCtx *det_ctx,
+ const DetectEngineTransforms *transforms, Flow *f, const uint8_t flow_flags, void *txv,
+ const int list_id);
+static InspectionBuffer *GetRandomBytesData(DetectEngineThreadCtx *det_ctx,
+ const DetectEngineTransforms *transforms, Flow *f, const uint8_t flow_flags, void *txv,
+ const int list_id);
+static InspectionBuffer *GetRandomData(DetectEngineThreadCtx *det_ctx,
+ const DetectEngineTransforms *transforms, Flow *f, const uint8_t flow_flags, void *txv,
+ const int list_id);
+
+static int g_tls_random_time_buffer_id = 0;
+static int g_tls_random_bytes_buffer_id = 0;
+static int g_tls_random_buffer_id = 0;
+
+void DetectTlsRandomTimeRegister(void)
+{
+ sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].name = "tls.random_time";
+ sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].desc = "sticky buffer to match specifically and only "
+ "on the first 4 bytes of a TLS random buffer";
+ sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].url = "/rules/tls-keywords.html#tls-random-time";
+ sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].Setup = DetectTlsRandomTimeSetup;
+ sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
+
+ /* Register engine for Server random */
+ DetectAppLayerInspectEngineRegister2("tls.random_time", ALPROTO_TLS, SIG_FLAG_TOSERVER, 0,
+ DetectEngineInspectBufferGeneric, GetRandomTimeData);
+ DetectAppLayerMpmRegister2("tls.random_time", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
+ GetRandomTimeData, ALPROTO_TLS, 0);
+
+ /* Register engine for Client random */
+ DetectAppLayerInspectEngineRegister2("tls.random_time", ALPROTO_TLS, SIG_FLAG_TOCLIENT, 0,
+ DetectEngineInspectBufferGeneric, GetRandomTimeData);
+ DetectAppLayerMpmRegister2("tls.random_time", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister,
+ GetRandomTimeData, ALPROTO_TLS, 0);
+
+ DetectBufferTypeSetDescriptionByName("tls.random_time", "TLS Random Time");
+
+ g_tls_random_time_buffer_id = DetectBufferTypeGetByName("tls.random_time");
+}
+
+void DetectTlsRandomBytesRegister(void)
+{
+ sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].name = "tls.random_bytes";
+ sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].desc =
+ "sticky buffer to match specifically and only on the last 28 bytes of a TLS random "
+ "buffer";
+ sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].url = "/rules/tls-keywords.html#tls-random-bytes";
+ sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].Setup = DetectTlsRandomBytesSetup;
+ sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].flags |=
+ SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
+
+ /* Register engine for Server random */
+ DetectAppLayerInspectEngineRegister2("tls.random_bytes", ALPROTO_TLS, SIG_FLAG_TOSERVER, 0,
+ DetectEngineInspectBufferGeneric, GetRandomBytesData);
+ DetectAppLayerMpmRegister2("tls.random_bytes", SIG_FLAG_TOSERVER, 2,
+ PrefilterGenericMpmRegister, GetRandomBytesData, ALPROTO_TLS, 0);
+
+ /* Register engine for Client random */
+ DetectAppLayerInspectEngineRegister2("tls.random_bytes", ALPROTO_TLS, SIG_FLAG_TOCLIENT, 0,
+ DetectEngineInspectBufferGeneric, GetRandomBytesData);
+ DetectAppLayerMpmRegister2("tls.random_bytes", SIG_FLAG_TOCLIENT, 2,
+ PrefilterGenericMpmRegister, GetRandomBytesData, ALPROTO_TLS, 0);
+
+ DetectBufferTypeSetDescriptionByName("tls.random_bytes", "TLS Random Bytes");
+
+ g_tls_random_bytes_buffer_id = DetectBufferTypeGetByName("tls.random_bytes");
+}
+
+/**
+ * \brief Registration function for keyword: tls.random
+ */
+void DetectTlsRandomRegister(void)
+{
+ DetectTlsRandomTimeRegister();
+ DetectTlsRandomBytesRegister();
+
+ sigmatch_table[DETECT_AL_TLS_RANDOM].name = "tls.random";
+ sigmatch_table[DETECT_AL_TLS_RANDOM].desc =
+ "sticky buffer to match specifically and only on a TLS random buffer";
+ sigmatch_table[DETECT_AL_TLS_RANDOM].url = "/rules/tls-keywords.html#tls-random";
+ sigmatch_table[DETECT_AL_TLS_RANDOM].Setup = DetectTlsRandomSetup;
+ sigmatch_table[DETECT_AL_TLS_RANDOM].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
+
+ /* Register engine for Server random */
+ DetectAppLayerInspectEngineRegister2("tls.random", ALPROTO_TLS, SIG_FLAG_TOSERVER, 0,
+ DetectEngineInspectBufferGeneric, GetRandomData);
+ DetectAppLayerMpmRegister2("tls.random", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
+ GetRandomData, ALPROTO_TLS, 0);
+
+ /* Register engine for Client random */
+ DetectAppLayerInspectEngineRegister2("tls.random", ALPROTO_TLS, SIG_FLAG_TOCLIENT, 0,
+ DetectEngineInspectBufferGeneric, GetRandomData);
+ DetectAppLayerMpmRegister2("tls.random", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister,
+ GetRandomData, ALPROTO_TLS, 0);
+
+ DetectBufferTypeSetDescriptionByName("tls.random", "TLS Random");
+
+ g_tls_random_buffer_id = DetectBufferTypeGetByName("tls.random");
+}
+
+/**
+ * \brief this function setup the tls.random_time sticky buffer 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 DetectTlsRandomTimeSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
+{
+ if (DetectBufferSetActiveList(s, g_tls_random_time_buffer_id) < 0)
+ return -1;
+
+ if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
+ return -1;
+
+ return 0;
+}
+
+/**
+ * \brief this function setup the tls.random_bytes sticky buffer 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 DetectTlsRandomBytesSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
+{
+ if (DetectBufferSetActiveList(s, g_tls_random_bytes_buffer_id) < 0)
+ return -1;
+
+ if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
+ return -1;
+
+ return 0;
+}
+
+/**
+ * \brief this function setup the tls.random sticky buffer 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 DetectTlsRandomSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
+{
+ if (DetectBufferSetActiveList(s, g_tls_random_buffer_id) < 0)
+ return -1;
+
+ if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
+ return -1;
+
+ return 0;
+}
+
+static InspectionBuffer *GetRandomTimeData(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 (flow_flags & STREAM_TOSERVER) {
+ if (!(ssl_state->flags & TLS_TS_RANDOM_SET))
+ return NULL;
+ } else {
+ if (!(ssl_state->flags & TLS_TC_RANDOM_SET))
+ return NULL;
+ }
+ const uint32_t data_len = DETECT_TLS_RANDOM_TIME_LEN;
+ const uint8_t *data;
+ if (flow_flags & STREAM_TOSERVER) {
+ data = ssl_state->server_connp.random;
+ } else {
+ data = ssl_state->client_connp.random;
+ }
+ InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
+ InspectionBufferApplyTransforms(buffer, transforms);
+ }
+ return buffer;
+}
+
+static InspectionBuffer *GetRandomBytesData(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 (flow_flags & STREAM_TOSERVER) {
+ if (!(ssl_state->flags & TLS_TS_RANDOM_SET))
+ return NULL;
+ } else {
+ if (!(ssl_state->flags & TLS_TC_RANDOM_SET))
+ return NULL;
+ }
+ const uint32_t data_len = DETECT_TLS_RANDOM_BYTES_LEN;
+ const uint8_t *data;
+ if (flow_flags & STREAM_TOSERVER) {
+ data = ssl_state->server_connp.random + DETECT_TLS_RANDOM_TIME_LEN;
+ } else {
+ data = ssl_state->client_connp.random + DETECT_TLS_RANDOM_TIME_LEN;
+ }
+ InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
+ InspectionBufferApplyTransforms(buffer, transforms);
+ }
+ return buffer;
+}
+
+static InspectionBuffer *GetRandomData(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 (flow_flags & STREAM_TOSERVER) {
+ if (!(ssl_state->flags & TLS_TS_RANDOM_SET))
+ return NULL;
+ } else {
+ if (!(ssl_state->flags & TLS_TC_RANDOM_SET))
+ return NULL;
+ }
+ const uint32_t data_len = TLS_RANDOM_LEN;
+ const uint8_t *data;
+ if (flow_flags & STREAM_TOSERVER) {
+ data = ssl_state->server_connp.random;
+ } else {
+ data = ssl_state->client_connp.random;
+ }
+ InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
+ InspectionBufferApplyTransforms(buffer, transforms);
+ }
+ return buffer;
+}
projects / thirdparty / suricata.git / commitdiff
