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Diffstat (limited to 'src/detect-http-raw-header.c')
| -rw-r--r-- | src/detect-http-raw-header.c | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/src/detect-http-raw-header.c b/src/detect-http-raw-header.c new file mode 100644 index 0000000..946c223 --- /dev/null +++ b/src/detect-http-raw-header.c @@ -0,0 +1,377 @@ +/* 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 Pablo Rincon <pablo.rincon.crespo@gmail.com> + * + * Implements support for http_raw_header 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-content.h" + +#include "flow.h" +#include "flow-var.h" +#include "flow-util.h" + +#include "util-debug.h" +#include "util-profiling.h" + +#include "app-layer.h" +#include "app-layer-parser.h" +#include "app-layer-htp.h" +#include "detect-http-raw-header.h" + +static int DetectHttpRawHeaderSetup(DetectEngineCtx *, Signature *, const char *); +static int DetectHttpRawHeaderSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str); +#ifdef UNITTESTS +static void DetectHttpRawHeaderRegisterTests(void); +#endif +static bool DetectHttpRawHeaderValidateCallback(const Signature *s, const char **sigerror); +static int g_http_raw_header_buffer_id = 0; +static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx, + const DetectEngineTransforms *transforms, Flow *_f, + const uint8_t flow_flags, void *txv, const int list_id); +static InspectionBuffer *GetData2(DetectEngineThreadCtx *det_ctx, + const DetectEngineTransforms *transforms, Flow *_f, const uint8_t flow_flags, void *txv, + const int list_id); + +static int PrefilterMpmHttpHeaderRawRequestRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, + MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id); +static int PrefilterMpmHttpHeaderRawResponseRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, + MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id); + +/** + * \brief Registers the keyword handlers for the "http_raw_header" keyword. + */ +void DetectHttpRawHeaderRegister(void) +{ + /* http_raw_header content modifier */ + sigmatch_table[DETECT_AL_HTTP_RAW_HEADER].name = "http_raw_header"; + sigmatch_table[DETECT_AL_HTTP_RAW_HEADER].desc = "content modifier to match the raw HTTP header buffer"; + sigmatch_table[DETECT_AL_HTTP_RAW_HEADER].url = "/rules/http-keywords.html#http-header-and-http-raw-header"; + sigmatch_table[DETECT_AL_HTTP_RAW_HEADER].Setup = DetectHttpRawHeaderSetup; +#ifdef UNITTESTS + sigmatch_table[DETECT_AL_HTTP_RAW_HEADER].RegisterTests = DetectHttpRawHeaderRegisterTests; +#endif + sigmatch_table[DETECT_AL_HTTP_RAW_HEADER].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_CONTENT_MODIFIER; + sigmatch_table[DETECT_AL_HTTP_RAW_HEADER].alternative = DETECT_HTTP_RAW_HEADER; + + /* http.header.raw sticky buffer */ + sigmatch_table[DETECT_HTTP_RAW_HEADER].name = "http.header.raw"; + sigmatch_table[DETECT_HTTP_RAW_HEADER].desc = "sticky buffer to match the raw HTTP header buffer"; + sigmatch_table[DETECT_HTTP_RAW_HEADER].url = "/rules/http-keywords.html#http-header-and-http-raw-header"; + sigmatch_table[DETECT_HTTP_RAW_HEADER].Setup = DetectHttpRawHeaderSetupSticky; + sigmatch_table[DETECT_HTTP_RAW_HEADER].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER; + + DetectAppLayerInspectEngineRegister2("http_raw_header", ALPROTO_HTTP1, SIG_FLAG_TOSERVER, + HTP_REQUEST_HEADERS + 1, DetectEngineInspectBufferGeneric, GetData); + DetectAppLayerInspectEngineRegister2("http_raw_header", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT, + HTP_RESPONSE_HEADERS + 1, DetectEngineInspectBufferGeneric, GetData); + + DetectAppLayerMpmRegister2("http_raw_header", SIG_FLAG_TOSERVER, 2, + PrefilterMpmHttpHeaderRawRequestRegister, NULL, ALPROTO_HTTP1, + 0); /* progress handled in register */ + DetectAppLayerMpmRegister2("http_raw_header", SIG_FLAG_TOCLIENT, 2, + PrefilterMpmHttpHeaderRawResponseRegister, NULL, ALPROTO_HTTP1, + 0); /* progress handled in register */ + + DetectAppLayerInspectEngineRegister2("http_raw_header", ALPROTO_HTTP2, SIG_FLAG_TOSERVER, + HTTP2StateDataClient, DetectEngineInspectBufferGeneric, GetData2); + DetectAppLayerInspectEngineRegister2("http_raw_header", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT, + HTTP2StateDataServer, DetectEngineInspectBufferGeneric, GetData2); + + DetectAppLayerMpmRegister2("http_raw_header", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister, + GetData2, ALPROTO_HTTP2, HTTP2StateDataClient); + DetectAppLayerMpmRegister2("http_raw_header", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister, + GetData2, ALPROTO_HTTP2, HTTP2StateDataServer); + + DetectBufferTypeSetDescriptionByName("http_raw_header", + "raw http headers"); + + DetectBufferTypeRegisterValidateCallback("http_raw_header", + DetectHttpRawHeaderValidateCallback); + + g_http_raw_header_buffer_id = DetectBufferTypeGetByName("http_raw_header"); +} + +/** + * \brief The setup function for the http_raw_header keyword for a signature. + * + * \param de_ctx Pointer to the detection engine context. + * \param s Pointer to signature for the current Signature being parsed + * from the rules. + * \param m Pointer to the head of the SigMatchs for the current rule + * being parsed. + * \param arg Pointer to the string holding the keyword value. + * + * \retval 0 On success. + * \retval -1 On failure. + */ +int DetectHttpRawHeaderSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg) +{ + return DetectEngineContentModifierBufferSetup( + de_ctx, s, arg, DETECT_AL_HTTP_RAW_HEADER, g_http_raw_header_buffer_id, ALPROTO_HTTP1); +} + +/** + * \brief this function setup the http.header.raw 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 + */ +static int DetectHttpRawHeaderSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str) +{ + if (DetectBufferSetActiveList(de_ctx, s, g_http_raw_header_buffer_id) < 0) + return -1; + if (DetectSignatureSetAppProto(s, ALPROTO_HTTP) < 0) + return -1; + return 0; +} + +static bool DetectHttpRawHeaderValidateCallback(const Signature *s, const char **sigerror) +{ + if ((s->flags & (SIG_FLAG_TOCLIENT|SIG_FLAG_TOSERVER)) == (SIG_FLAG_TOCLIENT|SIG_FLAG_TOSERVER)) { + *sigerror = "http_raw_header signature " + "without a flow direction. Use flow:to_server for " + "inspecting request headers or flow:to_client for " + "inspecting response headers."; + + SCLogError("%s", *sigerror); + SCReturnInt(false); + } + return true; +} + +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; + + HtpTxUserData *tx_ud = htp_tx_get_user_data(tx); + if (tx_ud == NULL) + return NULL; + + const bool ts = ((flow_flags & STREAM_TOSERVER) != 0); + const uint8_t *data = ts ? + tx_ud->request_headers_raw : tx_ud->response_headers_raw; + if (data == NULL) + return NULL; + const uint32_t data_len = ts ? + tx_ud->request_headers_raw_len : tx_ud->response_headers_raw_len; + + InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len); + InspectionBufferApplyTransforms(buffer, transforms); + } + + return buffer; +} + +static InspectionBuffer *GetData2(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) { + uint32_t b_len = 0; + const uint8_t *b = NULL; + + if (rs_http2_tx_get_headers_raw(txv, flow_flags, &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; +} + +typedef struct PrefilterMpmHttpHeaderRawCtx { + int list_id; + const MpmCtx *mpm_ctx; + const DetectEngineTransforms *transforms; +} PrefilterMpmHttpHeaderRawCtx; + +/** \brief Generic Mpm prefilter callback + * + * \param det_ctx detection engine thread ctx + * \param p packet to inspect + * \param f flow to inspect + * \param txv tx to inspect + * \param pectx inspection context + */ +static void PrefilterMpmHttpHeaderRaw(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 PrefilterMpmHttpHeaderRawCtx *ctx = pectx; + const MpmCtx *mpm_ctx = ctx->mpm_ctx; + SCLogDebug("running on list %d", ctx->list_id); + + const int list_id = ctx->list_id; + + InspectionBuffer *buffer = GetData(det_ctx, ctx->transforms, f, + flags, txv, list_id); + if (buffer == NULL) + return; + + const uint32_t data_len = buffer->inspect_len; + const uint8_t *data = buffer->inspect; + + SCLogDebug("mpm'ing buffer:"); + //PrintRawDataFp(stdout, data, data_len); + + if (data != NULL && data_len >= mpm_ctx->minlen) { + (void)mpm_table[mpm_ctx->mpm_type].Search(mpm_ctx, + &det_ctx->mtcu, &det_ctx->pmq, data, data_len); + PREFILTER_PROFILING_ADD_BYTES(det_ctx, data_len); + } +} + +static void PrefilterMpmHttpTrailerRaw(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p, + Flow *f, void *txv, const uint64_t idx, const AppLayerTxData *_txd, const uint8_t flags) +{ + SCEnter(); + + htp_tx_t *tx = txv; + const HtpTxUserData *htud = (const HtpTxUserData *)htp_tx_get_user_data(tx); + /* if the request wasn't flagged as having a trailer, we skip */ + if (htud && ( + ((flags & STREAM_TOSERVER) && !htud->request_has_trailers) || + ((flags & STREAM_TOCLIENT) && !htud->response_has_trailers))) { + SCReturn; + } + PrefilterMpmHttpHeaderRaw(det_ctx, pectx, p, f, txv, idx, _txd, flags); + SCReturn; +} + +static void PrefilterMpmHttpHeaderRawFree(void *ptr) +{ + SCFree(ptr); +} + +static int PrefilterMpmHttpHeaderRawRequestRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, + MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id) +{ + SCEnter(); + + /* header */ + PrefilterMpmHttpHeaderRawCtx *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; + + int r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterMpmHttpHeaderRaw, + mpm_reg->app_v2.alproto, HTP_REQUEST_HEADERS+1, + pectx, PrefilterMpmHttpHeaderRawFree, mpm_reg->pname); + if (r != 0) { + SCFree(pectx); + return r; + } + + /* trailer */ + 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; + + r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterMpmHttpTrailerRaw, + mpm_reg->app_v2.alproto, HTP_REQUEST_TRAILER+1, + pectx, PrefilterMpmHttpHeaderRawFree, mpm_reg->pname); + if (r != 0) { + SCFree(pectx); + } + return r; +} + +static int PrefilterMpmHttpHeaderRawResponseRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, + MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id) +{ + SCEnter(); + + /* header */ + PrefilterMpmHttpHeaderRawCtx *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; + + int r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterMpmHttpHeaderRaw, + mpm_reg->app_v2.alproto, HTP_RESPONSE_HEADERS, + pectx, PrefilterMpmHttpHeaderRawFree, mpm_reg->pname); + if (r != 0) { + SCFree(pectx); + return r; + } + + /* trailer */ + 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; + + r = PrefilterAppendTxEngine(de_ctx, sgh, PrefilterMpmHttpTrailerRaw, + mpm_reg->app_v2.alproto, HTP_RESPONSE_TRAILER, + pectx, PrefilterMpmHttpHeaderRawFree, mpm_reg->pname); + if (r != 0) { + SCFree(pectx); + } + return r; +} + +/************************************Unittests*********************************/ + +#ifdef UNITTESTS +#include "tests/detect-http-raw-header.c" +#endif + +/** + * @} + */ |