Adding upstream version 1:7.0.3.upstream/1%7.0.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 374 insertions, 0 deletions

diff --git a/src/detect-tls-certs.c b/src/detect-tls-certs.c
new file mode 100644
index 0000000..a020437
--- /dev/null
+++ b/src/detect-tls-certs.c
@@ -0,0 +1,374 @@
+/* Copyright (C) 2019-2022 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 Mats Klepsland <mats.klepsland@gmail.com>
+ *
+ * Implements support for tls.certs keyword.
+ */
+
+#include "suricata-common.h"
+#include "threads.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-engine-content-inspection.h"
+#include "detect-content.h"
+#include "detect-pcre.h"
+#include "detect-tls-certs.h"
+#include "detect-engine-uint.h"
+
+#include "flow.h"
+#include "flow-util.h"
+#include "flow-var.h"
+
+#include "util-debug.h"
+#include "util-spm.h"
+#include "util-print.h"
+
+#include "stream-tcp.h"
+
+#include "app-layer.h"
+#include "app-layer-ssl.h"
+
+#include "util-profiling.h"
+#include "util-unittest.h"
+#include "util-unittest-helper.h"
+
+static int DetectTlsCertsSetup(DetectEngineCtx *, Signature *, const char *);
+#ifdef UNITTESTS
+static void DetectTlsCertsRegisterTests(void);
+#endif
+static uint8_t DetectEngineInspectTlsCerts(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);
+static int PrefilterMpmTlsCertsRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx,
+        const DetectBufferMpmRegistry *mpm_reg, int list_id);
+
+static int g_tls_certs_buffer_id = 0;
+
+struct TlsCertsGetDataArgs {
+    uint32_t local_id; /**< used as index into thread inspect array */
+    SSLCertsChain *cert;
+};
+
+typedef struct PrefilterMpmTlsCerts {
+    int list_id;
+    const MpmCtx *mpm_ctx;
+    const DetectEngineTransforms *transforms;
+} PrefilterMpmTlsCerts;
+
+/**
+ * \brief Registration function for keyword: tls.certs
+ */
+void DetectTlsCertsRegister(void)
+{
+    sigmatch_table[DETECT_AL_TLS_CERTS].name = "tls.certs";
+    sigmatch_table[DETECT_AL_TLS_CERTS].desc = "sticky buffer to match the TLS certificate buffer";
+    sigmatch_table[DETECT_AL_TLS_CERTS].url = "/rules/tls-keywords.html#tls-certs";
+    sigmatch_table[DETECT_AL_TLS_CERTS].Setup = DetectTlsCertsSetup;
+#ifdef UNITTESTS
+    sigmatch_table[DETECT_AL_TLS_CERTS].RegisterTests = DetectTlsCertsRegisterTests;
+#endif
+    sigmatch_table[DETECT_AL_TLS_CERTS].flags |= SIGMATCH_NOOPT;
+    sigmatch_table[DETECT_AL_TLS_CERTS].flags |= SIGMATCH_INFO_STICKY_BUFFER;
+
+    DetectAppLayerInspectEngineRegister2("tls.certs", ALPROTO_TLS,
+            SIG_FLAG_TOCLIENT, TLS_STATE_CERT_READY,
+            DetectEngineInspectTlsCerts, NULL);
+
+    DetectAppLayerMpmRegister2("tls.certs", SIG_FLAG_TOCLIENT, 2,
+            PrefilterMpmTlsCertsRegister, NULL, ALPROTO_TLS,
+            TLS_STATE_CERT_READY);
+
+    DetectAppLayerInspectEngineRegister2("tls.certs", ALPROTO_TLS, SIG_FLAG_TOSERVER,
+            TLS_STATE_CERT_READY, DetectEngineInspectTlsCerts, NULL);
+
+    DetectAppLayerMpmRegister2("tls.certs", SIG_FLAG_TOSERVER, 2, PrefilterMpmTlsCertsRegister,
+            NULL, ALPROTO_TLS, TLS_STATE_CERT_READY);
+
+    DetectBufferTypeSetDescriptionByName("tls.certs", "TLS certificate");
+
+    DetectBufferTypeSupportsMultiInstance("tls.certs");
+
+    g_tls_certs_buffer_id = DetectBufferTypeGetByName("tls.certs");
+}
+
+/**
+ * \brief This function setup the tls.certs modifier keyword
+ *
+ * \param de_ctx Pointer to the Detect Engine Context
+ * \param s      Pointer to the Signature to which the keyword belongs
+ * \param str    Should hold an empty string always
+ *
+ * \retval  0 On success
+ * \retval -1 On failure
+ */
+static int DetectTlsCertsSetup(DetectEngineCtx *de_ctx, Signature *s,
+                               const char *str)
+{
+    if (DetectBufferSetActiveList(de_ctx, s, g_tls_certs_buffer_id) < 0)
+        return -1;
+
+    if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
+        return -1;
+
+    return 0;
+}
+
+static InspectionBuffer *TlsCertsGetData(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms, Flow *f,
+	struct TlsCertsGetDataArgs *cbdata, int list_id)
+{
+    SCEnter();
+
+    InspectionBuffer *buffer =
+            InspectionBufferMultipleForListGet(det_ctx, list_id, cbdata->local_id);
+    if (buffer == NULL || buffer->initialized)
+        return buffer;
+
+    const SSLState *ssl_state = (SSLState *)f->alstate;
+    const SSLStateConnp *connp;
+
+    if (f->flags & STREAM_TOSERVER) {
+        connp = &ssl_state->client_connp;
+    } else {
+        connp = &ssl_state->server_connp;
+    }
+
+    if (TAILQ_EMPTY(&connp->certs)) {
+        InspectionBufferSetupMultiEmpty(buffer);
+        return NULL;
+    }
+
+    if (cbdata->cert == NULL) {
+        cbdata->cert = TAILQ_FIRST(&connp->certs);
+    } else {
+        cbdata->cert = TAILQ_NEXT(cbdata->cert, next);
+    }
+    if (cbdata->cert == NULL) {
+        InspectionBufferSetupMultiEmpty(buffer);
+        return NULL;
+    }
+
+    InspectionBufferSetupMulti(buffer, transforms, cbdata->cert->cert_data, cbdata->cert->cert_len);
+
+    SCReturnPtr(buffer, "InspectionBuffer");
+}
+
+static uint8_t DetectEngineInspectTlsCerts(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;
+    }
+
+    struct TlsCertsGetDataArgs cbdata = { 0, NULL };
+
+    while (1)
+    {
+        InspectionBuffer *buffer = TlsCertsGetData(det_ctx, transforms, f,
+			                           &cbdata, engine->sm_list);
+        if (buffer == NULL || buffer->inspect == NULL)
+            break;
+
+        det_ctx->buffer_offset = 0;
+        det_ctx->discontinue_matching = 0;
+        det_ctx->inspection_recursion_counter = 0;
+
+        const 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;
+        }
+
+        cbdata.local_id++;
+    }
+
+    return DETECT_ENGINE_INSPECT_SIG_NO_MATCH;
+}
+
+static void PrefilterTxTlsCerts(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p,
+        Flow *f, void *txv, const uint64_t idx, const AppLayerTxData *_txd, const uint8_t flags)
+{
+    SCEnter();
+
+    const PrefilterMpmTlsCerts *ctx = (const PrefilterMpmTlsCerts *)pectx;
+    const MpmCtx *mpm_ctx = ctx->mpm_ctx;
+    const int list_id = ctx->list_id;
+
+    struct TlsCertsGetDataArgs cbdata = { 0, NULL };
+
+    while (1)
+    {
+        InspectionBuffer *buffer = TlsCertsGetData(det_ctx, ctx->transforms,
+                                                   f, &cbdata, list_id);
+        if (buffer == NULL)
+            break;
+
+        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);
+        }
+
+        cbdata.local_id++;
+    }
+}
+
+static void PrefilterMpmTlsCertsFree(void *ptr)
+{
+    SCFree(ptr);
+}
+
+static int PrefilterMpmTlsCertsRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx,
+        const DetectBufferMpmRegistry *mpm_reg, int list_id)
+{
+    PrefilterMpmTlsCerts *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, PrefilterTxTlsCerts,
+            mpm_reg->app_v2.alproto, mpm_reg->app_v2.tx_min_progress,
+            pectx, PrefilterMpmTlsCertsFree, mpm_reg->name);
+}
+
+static int g_tls_cert_buffer_id = 0;
+#define BUFFER_NAME  "tls_validity"
+#define KEYWORD_ID   DETECT_AL_TLS_CHAIN_LEN
+#define KEYWORD_NAME "tls.cert_chain_len"
+#define KEYWORD_DESC "match TLS certificate chain length"
+#define KEYWORD_URL  "/rules/tls-keywords.html#tls-cert-chain-len"
+
+/**
+ * \internal
+ * \brief Function to match cert chain length in TLS
+ *
+ * \param t       Pointer to thread vars.
+ * \param det_ctx Pointer to the pattern matcher thread.
+ * \param f       Pointer to the current flow.
+ * \param flags   Flags.
+ * \param state   App layer state.
+ * \param s       Pointer to the Signature.
+ * \param m       Pointer to the sigmatch that we will cast into
+ *                DetectU64Data.
+ *
+ * \retval 0 no match.
+ * \retval 1 match.
+ */
+static int DetectTLSCertChainLenMatch(DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags,
+        void *state, void *txv, const Signature *s, const SigMatchCtx *ctx)
+{
+    SCEnter();
+
+    SSLState *ssl_state = state;
+    if (flags & STREAM_TOCLIENT) {
+        SSLStateConnp *connp = &ssl_state->server_connp;
+        uint32_t cnt = 0;
+        SSLCertsChain *cert;
+        TAILQ_FOREACH (cert, &connp->certs, next) {
+            cnt++;
+        }
+        SCLogDebug("%u certs in chain", cnt);
+
+        const DetectU32Data *dd = (const DetectU32Data *)ctx;
+        if (DetectU32Match(cnt, dd)) {
+            SCReturnInt(1);
+        }
+    }
+    SCReturnInt(0);
+}
+
+/**
+ * \internal
+ * \brief Function to free memory associated with DetectU64Data.
+ *
+ * \param de_ptr Pointer to DetectU64Data.
+ */
+static void DetectTLSCertChainLenFree(DetectEngineCtx *de_ctx, void *ptr)
+{
+    rs_detect_u32_free(ptr);
+}
+
+/**
+ * \brief Function to add the parsed tls cert chain len field into the current signature.
+ *
+ * \param de_ctx Pointer to the Detection Engine Context.
+ * \param s      Pointer to the Current Signature.
+ * \param rawstr Pointer to the user provided flags options.
+ * \param type   Defines if this is notBefore or notAfter.
+ *
+ * \retval 0 on Success.
+ * \retval -1 on Failure.
+ */
+static int DetectTLSCertChainLenSetup(DetectEngineCtx *de_ctx, Signature *s, const char *rawstr)
+{
+    if (DetectSignatureSetAppProto(s, ALPROTO_TLS) != 0)
+        return -1;
+
+    DetectU32Data *dd = DetectU32Parse(rawstr);
+    if (dd == NULL) {
+        SCLogError("Parsing \'%s\' failed for %s", rawstr, sigmatch_table[KEYWORD_ID].name);
+        return -1;
+    }
+
+    SigMatch *sm = SigMatchAlloc();
+    if (sm == NULL) {
+        rs_detect_u32_free(dd);
+        return -1;
+    }
+    sm->type = KEYWORD_ID;
+    sm->ctx = (void *)dd;
+
+    SigMatchAppendSMToList(s, sm, g_tls_cert_buffer_id);
+    return 0;
+}
+
+void DetectTlsCertChainLenRegister(void)
+{
+    sigmatch_table[KEYWORD_ID].name = KEYWORD_NAME;
+    sigmatch_table[KEYWORD_ID].desc = KEYWORD_DESC;
+    sigmatch_table[KEYWORD_ID].url = KEYWORD_URL;
+    sigmatch_table[KEYWORD_ID].AppLayerTxMatch = DetectTLSCertChainLenMatch;
+    sigmatch_table[KEYWORD_ID].Setup = DetectTLSCertChainLenSetup;
+    sigmatch_table[KEYWORD_ID].Free = DetectTLSCertChainLenFree;
+
+    DetectAppLayerInspectEngineRegister2(BUFFER_NAME, ALPROTO_TLS, SIG_FLAG_TOCLIENT,
+            TLS_STATE_CERT_READY, DetectEngineInspectGenericList, NULL);
+
+    g_tls_cert_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
+}
+
+#ifdef UNITTESTS
+#include "tests/detect-tls-certs.c"
+#endif