1 files changed, 203 insertions, 0 deletions
diff --git a/src/detect-http-response-line.c b/src/detect-http-response-line.c
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+/* 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.
+ */
+
+/**
+ * \ingroup httplayer
+ *
+ * @{
+ */
+
+
+/**
+ * \file
+ *
+ * \author Victor Julien <victor@inliniac.net>
+ *
+ * Implements support for the http_response_line 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-state.h"
+#include "detect-engine-prefilter.h"
+#include "detect-engine-content-inspection.h"
+#include "detect-content.h"
+#include "detect-pcre.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 "util-spm.h"
+
+#include "app-layer.h"
+#include "app-layer-parser.h"
+
+#include "app-layer-htp.h"
+#include "stream-tcp.h"
+#include "detect-http-response-line.h"
+
+static int DetectHttpResponseLineSetup(DetectEngineCtx *, Signature *, const char *);
+#ifdef UNITTESTS
+static void DetectHttpResponseLineRegisterTests(void);
+#endif
+static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms,
+        Flow *_f, const uint8_t _flow_flags,
+        void *txv, const int list_id);
+static int g_http_response_line_id = 0;
+
+static InspectionBuffer *GetData2(DetectEngineThreadCtx *det_ctx,
+        const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,
+        const int list_id)
+{
+    SCEnter();
+
+    InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
+    if (buffer->inspect == NULL) {
+        uint32_t b_len = 0;
+        const uint8_t *b = NULL;
+
+        if (rs_http2_tx_get_response_line(txv, &b, &b_len) != 1)
+            return NULL;
+        if (b == NULL || b_len == 0)
+            return NULL;
+
+        InspectionBufferSetup(det_ctx, list_id, buffer, b, b_len);
+        InspectionBufferApplyTransforms(buffer, transforms);
+    }
+
+    return buffer;
+}
+
+/**
+ * \brief Registers the keyword handlers for the "http_response_line" keyword.
+ */
+void DetectHttpResponseLineRegister(void)
+{
+    sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].name = "http.response_line";
+    sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].alias = "http_response_line";
+    sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].desc = "content modifier to match only on the HTTP response line";
+    sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].url = "/rules/http-keywords.html#http-response-line";
+    sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].Setup = DetectHttpResponseLineSetup;
+#ifdef UNITTESTS
+    sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].RegisterTests = DetectHttpResponseLineRegisterTests;
+#endif
+    sigmatch_table[DETECT_AL_HTTP_RESPONSE_LINE].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER;
+
+    DetectAppLayerInspectEngineRegister2("http_response_line", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT,
+            HTP_RESPONSE_LINE, DetectEngineInspectBufferGeneric, GetData);
+
+    DetectAppLayerMpmRegister2("http_response_line", SIG_FLAG_TOCLIENT, 2,
+            PrefilterGenericMpmRegister, GetData, ALPROTO_HTTP1, HTP_RESPONSE_LINE);
+
+    DetectAppLayerInspectEngineRegister2("http_response_line", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT,
+            HTTP2StateDataServer, DetectEngineInspectBufferGeneric, GetData2);
+    DetectAppLayerMpmRegister2("http_response_line", SIG_FLAG_TOCLIENT, 2,
+            PrefilterGenericMpmRegister, GetData2, ALPROTO_HTTP2, HTTP2StateDataServer);
+
+    DetectBufferTypeSetDescriptionByName("http_response_line",
+            "http response line");
+
+    g_http_response_line_id = DetectBufferTypeGetByName("http_response_line");
+}
+
+/**
+ * \brief The setup function for the http_response_line keyword for a signature.
+ *
+ * \param de_ctx Pointer to the detection engine context.
+ * \param s      Pointer to the signature for the current Signature being
+ *               parsed from the rules.
+ * \param m      Pointer to the head of the SigMatch for the current rule
+ *               being parsed.
+ * \param arg    Pointer to the string holding the keyword value.
+ *
+ * \retval  0 On success
+ * \retval -1 On failure
+ */
+static int DetectHttpResponseLineSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)
+{
+    if (DetectBufferSetActiveList(de_ctx, s, g_http_response_line_id) < 0)
+        return -1;
+
+    if (DetectSignatureSetAppProto(s, ALPROTO_HTTP) < 0)
+        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) {
+        htp_tx_t *tx = (htp_tx_t *)txv;
+        if (unlikely(tx->response_line == NULL)) {
+            return NULL;
+        }
+        const uint32_t data_len = bstr_len(tx->response_line);
+        const uint8_t *data = bstr_ptr(tx->response_line);
+
+        InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
+        InspectionBufferApplyTransforms(buffer, transforms);
+    }
+    return buffer;
+}
+
+/************************************Unittests*********************************/
+
+#ifdef UNITTESTS
+
+#include "stream-tcp-reassemble.h"
+
+/**
+ * \test Test that a signature containing a http_response_line is correctly parsed
+ *       and the keyword is registered.
+ */
+static int DetectHttpResponseLineTest01(void)
+{
+    DetectEngineCtx *de_ctx = DetectEngineCtxInit();
+    FAIL_IF_NULL(de_ctx);
+
+    de_ctx->flags |= DE_QUIET;
+    de_ctx->sig_list = SigInit(de_ctx, "alert tcp any any -> any any "
+                               "(http_response_line; content:\"200 OK\"; sid:1;)");
+    FAIL_IF_NULL(de_ctx->sig_list);
+
+    DetectEngineCtxFree(de_ctx);
+    PASS;
+}
+
+void DetectHttpResponseLineRegisterTests(void)
+{
+    UtRegisterTest("DetectHttpResponseLineTest01", DetectHttpResponseLineTest01);
+}
+#endif /* UNITTESTS */
+/**
+ * @}
+ */