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Diffstat (limited to '')
| -rw-r--r-- | src/detect-http-header.c | 861 |
1 files changed, 861 insertions, 0 deletions
diff --git a/src/detect-http-header.c b/src/detect-http-header.c new file mode 100644 index 0000000..2803d05 --- /dev/null +++ b/src/detect-http-header.c @@ -0,0 +1,861 @@ +/* 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_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-state.h" +#include "detect-engine-prefilter.h" +#include "detect-engine-content-inspection.h" +#include "detect-content.h" +#include "detect-pcre.h" + +#include "util-debug.h" +#include "util-print.h" +#include "util-memcmp.h" +#include "util-profiling.h" +#include "util-validate.h" + +#include "app-layer.h" +#include "app-layer-parser.h" + +#include "app-layer-htp.h" +#include "detect-http-header.h" +#include "detect-http-header-common.h" + +static int DetectHttpHeaderSetup(DetectEngineCtx *, Signature *, const char *); +#ifdef UNITTESTS +static void DetectHttpHeaderRegisterTests(void); +#endif +static int g_http_header_buffer_id = 0; +static int g_keyword_thread_id = 0; + +#define BUFFER_SIZE_STEP 1024 +static HttpHeaderThreadDataConfig g_td_config = { BUFFER_SIZE_STEP }; + +static uint8_t *GetBufferForTX( + htp_tx_t *tx, DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags, uint32_t *buffer_len) +{ + *buffer_len = 0; + + HttpHeaderThreadData *hdr_td = NULL; + HttpHeaderBuffer *buf = + HttpHeaderGetBufferSpace(det_ctx, f, flags, g_keyword_thread_id, &hdr_td); + if (unlikely(buf == NULL)) { + return NULL; + } + + htp_table_t *headers; + if (flags & STREAM_TOSERVER) { + if (AppLayerParserGetStateProgress(IPPROTO_TCP, ALPROTO_HTTP1, tx, flags) <= + HTP_REQUEST_HEADERS) + return NULL; + headers = tx->request_headers; + } else { + if (AppLayerParserGetStateProgress(IPPROTO_TCP, ALPROTO_HTTP1, tx, flags) <= + HTP_RESPONSE_HEADERS) + return NULL; + headers = tx->response_headers; + } + if (headers == NULL) + return NULL; + + size_t i = 0; + size_t no_of_headers = htp_table_size(headers); + for (; i < no_of_headers; i++) { + htp_header_t *h = htp_table_get_index(headers, i, NULL); + size_t size1 = bstr_size(h->name); + size_t size2 = bstr_size(h->value); + + if (flags & STREAM_TOSERVER) { + if (size1 == 6 && + SCMemcmpLowercase("cookie", bstr_ptr(h->name), 6) == 0) { + continue; + } + } else { + if (size1 == 10 && + SCMemcmpLowercase("set-cookie", bstr_ptr(h->name), 10) == 0) { + continue; + } + } + + size_t size = size1 + size2 + 4; +#if 0 + if (i + 1 == no_of_headers) + size += 2; +#endif + if (size + buf->len > buf->size) { + if (HttpHeaderExpandBuffer(hdr_td, buf, size) != 0) { + return NULL; + } + } + + memcpy(buf->buffer + buf->len, bstr_ptr(h->name), bstr_size(h->name)); + buf->len += bstr_size(h->name); + buf->buffer[buf->len++] = ':'; + buf->buffer[buf->len++] = ' '; + memcpy(buf->buffer + buf->len, bstr_ptr(h->value), bstr_size(h->value)); + buf->len += bstr_size(h->value); + buf->buffer[buf->len++] = '\r'; + buf->buffer[buf->len++] = '\n'; +#if 0 // looks like this breaks existing rules + if (i + 1 == no_of_headers) { + buf->buffer[buf->len++] = '\r'; + buf->buffer[buf->len++] = '\n'; + } +#endif + } + + *buffer_len = buf->len; + return buf->buffer; +} + +static InspectionBuffer *GetBuffer2ForTX(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(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; +} + +/** \internal + * \brief custom inspect function to utilize the cached headers + */ +static uint8_t DetectEngineInspectBufferHttpHeader(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) +{ + SCEnter(); + + const int list_id = engine->sm_list; + InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id); + if (buffer->inspect == NULL) { + SCLogDebug("setting up inspect buffer %d", list_id); + + /* if prefilter didn't already run, we need to consider transformations */ + const DetectEngineTransforms *transforms = NULL; + if (!engine->mpm) { + transforms = engine->v2.transforms; + } + + uint32_t rawdata_len = 0; + uint8_t *rawdata = GetBufferForTX(txv, det_ctx, f, flags, &rawdata_len); + if (rawdata_len == 0) { + SCLogDebug("no data"); + goto end; + } + /* setup buffer and apply transforms */ + InspectionBufferSetup(det_ctx, list_id, buffer, rawdata, rawdata_len); + InspectionBufferApplyTransforms(buffer, transforms); + } + + const uint32_t data_len = buffer->inspect_len; + const uint8_t *data = buffer->inspect; + const uint64_t offset = buffer->inspect_offset; + + det_ctx->discontinue_matching = 0; + det_ctx->buffer_offset = 0; + det_ctx->inspection_recursion_counter = 0; + + /* Inspect all the uricontents fetched on each + * transaction at the app layer */ + int r = DetectEngineContentInspection(de_ctx, det_ctx, s, engine->smd, + NULL, f, (uint8_t *)data, data_len, offset, + DETECT_CI_FLAGS_SINGLE, DETECT_ENGINE_CONTENT_INSPECTION_MODE_STATE); + SCLogDebug("r = %d", r); + if (r == 1) { + return DETECT_ENGINE_INSPECT_SIG_MATCH; + } +end: + if (flags & STREAM_TOSERVER) { + if (AppLayerParserGetStateProgress(IPPROTO_TCP, ALPROTO_HTTP1, txv, flags) > + HTP_REQUEST_HEADERS) + return DETECT_ENGINE_INSPECT_SIG_CANT_MATCH; + } else { + if (AppLayerParserGetStateProgress(IPPROTO_TCP, ALPROTO_HTTP1, txv, flags) > + HTP_RESPONSE_HEADERS) + return DETECT_ENGINE_INSPECT_SIG_CANT_MATCH; + } + return DETECT_ENGINE_INSPECT_SIG_NO_MATCH; +} + +typedef struct PrefilterMpmHttpHeaderCtx { + int list_id; + const MpmCtx *mpm_ctx; + const DetectEngineTransforms *transforms; +} PrefilterMpmHttpHeaderCtx; + +/** \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 PrefilterMpmHttpHeader(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 PrefilterMpmHttpHeaderCtx *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 = InspectionBufferGet(det_ctx, list_id); + if (buffer->inspect == NULL) { + uint32_t rawdata_len = 0; + uint8_t *rawdata = GetBufferForTX(txv, det_ctx, f, flags, &rawdata_len); + if (rawdata_len == 0) + return; + + /* setup buffer and apply transforms */ + InspectionBufferSetup(det_ctx, list_id, buffer, rawdata, rawdata_len); + InspectionBufferApplyTransforms(buffer, ctx->transforms); + } + + 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 PrefilterMpmHttpTrailer(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; + } + PrefilterMpmHttpHeader(det_ctx, pectx, p, f, txv, idx, _txd, flags); + SCReturn; +} + +static void PrefilterMpmHttpHeaderFree(void *ptr) +{ + SCFree(ptr); +} + +static int PrefilterMpmHttpHeaderRequestRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, + MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id) +{ + SCEnter(); + + /* header */ + PrefilterMpmHttpHeaderCtx *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, PrefilterMpmHttpHeader, + mpm_reg->app_v2.alproto, HTP_REQUEST_HEADERS, + pectx, PrefilterMpmHttpHeaderFree, 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, PrefilterMpmHttpTrailer, + mpm_reg->app_v2.alproto, HTP_REQUEST_TRAILER, + pectx, PrefilterMpmHttpHeaderFree, mpm_reg->pname); + if (r != 0) { + SCFree(pectx); + } + return r; +} + +static int PrefilterMpmHttpHeaderResponseRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, + MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id) +{ + SCEnter(); + + /* header */ + PrefilterMpmHttpHeaderCtx *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, PrefilterMpmHttpHeader, + mpm_reg->app_v2.alproto, HTP_RESPONSE_HEADERS, + pectx, PrefilterMpmHttpHeaderFree, 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, PrefilterMpmHttpTrailer, + mpm_reg->app_v2.alproto, HTP_RESPONSE_TRAILER, + pectx, PrefilterMpmHttpHeaderFree, mpm_reg->pname); + if (r != 0) { + SCFree(pectx); + } + return r; +} + +/** + * \brief The setup function for the http_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. + */ +static int DetectHttpHeaderSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg) +{ + return DetectEngineContentModifierBufferSetup( + de_ctx, s, arg, DETECT_AL_HTTP_HEADER, g_http_header_buffer_id, ALPROTO_HTTP1); +} + +/** + * \brief this function setup the http.header 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 DetectHttpHeaderSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str) +{ + if (DetectBufferSetActiveList(de_ctx, s, g_http_header_buffer_id) < 0) + return -1; + if (DetectSignatureSetAppProto(s, ALPROTO_HTTP) < 0) + return -1; + return 0; +} + +/** + * \brief Registers the keyword handlers for the "http_header" keyword. + */ +void DetectHttpHeaderRegister(void) +{ + /* http_header content modifier */ + sigmatch_table[DETECT_AL_HTTP_HEADER].name = "http_header"; + sigmatch_table[DETECT_AL_HTTP_HEADER].desc = "content modifier to match only on the HTTP header-buffer"; + sigmatch_table[DETECT_AL_HTTP_HEADER].url = "/rules/http-keywords.html#http-header-and-http-raw-header"; + sigmatch_table[DETECT_AL_HTTP_HEADER].Setup = DetectHttpHeaderSetup; +#ifdef UNITTESTS + sigmatch_table[DETECT_AL_HTTP_HEADER].RegisterTests = DetectHttpHeaderRegisterTests; +#endif + sigmatch_table[DETECT_AL_HTTP_HEADER].flags |= SIGMATCH_NOOPT ; + sigmatch_table[DETECT_AL_HTTP_HEADER].flags |= SIGMATCH_INFO_CONTENT_MODIFIER; + sigmatch_table[DETECT_AL_HTTP_HEADER].alternative = DETECT_HTTP_HEADER; + + /* http.header sticky buffer */ + sigmatch_table[DETECT_HTTP_HEADER].name = "http.header"; + sigmatch_table[DETECT_HTTP_HEADER].desc = "sticky buffer to match on the normalized HTTP header-buffer"; + sigmatch_table[DETECT_HTTP_HEADER].url = "/rules/http-keywords.html#http-header-and-http-raw-header"; + sigmatch_table[DETECT_HTTP_HEADER].Setup = DetectHttpHeaderSetupSticky; + sigmatch_table[DETECT_HTTP_HEADER].flags |= SIGMATCH_NOOPT; + sigmatch_table[DETECT_HTTP_HEADER].flags |= SIGMATCH_INFO_STICKY_BUFFER; + + DetectAppLayerInspectEngineRegister2("http_header", ALPROTO_HTTP1, SIG_FLAG_TOSERVER, + HTP_REQUEST_HEADERS, DetectEngineInspectBufferHttpHeader, NULL); + DetectAppLayerMpmRegister2("http_header", SIG_FLAG_TOSERVER, 2, + PrefilterMpmHttpHeaderRequestRegister, NULL, ALPROTO_HTTP1, + 0); /* not used, registered twice: HEADERS/TRAILER */ + + DetectAppLayerInspectEngineRegister2("http_header", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT, + HTP_RESPONSE_HEADERS, DetectEngineInspectBufferHttpHeader, NULL); + DetectAppLayerMpmRegister2("http_header", SIG_FLAG_TOCLIENT, 2, + PrefilterMpmHttpHeaderResponseRegister, NULL, ALPROTO_HTTP1, + 0); /* not used, registered twice: HEADERS/TRAILER */ + + DetectAppLayerInspectEngineRegister2("http_header", ALPROTO_HTTP2, SIG_FLAG_TOSERVER, + HTTP2StateDataClient, DetectEngineInspectBufferGeneric, GetBuffer2ForTX); + DetectAppLayerMpmRegister2("http_header", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister, + GetBuffer2ForTX, ALPROTO_HTTP2, HTTP2StateDataClient); + + DetectAppLayerInspectEngineRegister2("http_header", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT, + HTTP2StateDataServer, DetectEngineInspectBufferGeneric, GetBuffer2ForTX); + DetectAppLayerMpmRegister2("http_header", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister, + GetBuffer2ForTX, ALPROTO_HTTP2, HTTP2StateDataServer); + + DetectBufferTypeSetDescriptionByName("http_header", + "http headers"); + + g_http_header_buffer_id = DetectBufferTypeGetByName("http_header"); + + g_keyword_thread_id = DetectRegisterThreadCtxGlobalFuncs("http_header", + HttpHeaderThreadDataInit, &g_td_config, HttpHeaderThreadDataFree); +} + +static int g_http_request_header_buffer_id = 0; +static int g_http_response_header_buffer_id = 0; +static int g_request_header_thread_id = 0; +static int g_response_header_thread_id = 0; + +static InspectionBuffer *GetHttp2HeaderData(DetectEngineThreadCtx *det_ctx, const uint8_t flags, + const DetectEngineTransforms *transforms, Flow *_f, const struct MpmListIdDataArgs *cbdata, + int list_id) +{ + SCEnter(); + + InspectionBuffer *buffer = + InspectionBufferMultipleForListGet(det_ctx, list_id, cbdata->local_id); + if (buffer == NULL) + return NULL; + if (buffer->initialized) + return buffer; + + uint32_t b_len = 0; + const uint8_t *b = NULL; + + if (rs_http2_tx_get_header(cbdata->txv, flags, cbdata->local_id, &b, &b_len) != 1) { + InspectionBufferSetupMultiEmpty(buffer); + return NULL; + } + if (b == NULL || b_len == 0) { + InspectionBufferSetupMultiEmpty(buffer); + return NULL; + } + + InspectionBufferSetupMulti(buffer, transforms, b, b_len); + + SCReturnPtr(buffer, "InspectionBuffer"); +} + +static void PrefilterTxHttp2Header(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 PrefilterMpmListId *ctx = (const PrefilterMpmListId *)pectx; + const MpmCtx *mpm_ctx = ctx->mpm_ctx; + const int list_id = ctx->list_id; + + uint32_t local_id = 0; + + while (1) { + // loop until we get a NULL + + struct MpmListIdDataArgs cbdata = { local_id, txv }; + InspectionBuffer *buffer = + GetHttp2HeaderData(det_ctx, flags, 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); + } + + local_id++; + } +} + +static uint8_t DetectEngineInspectHttp2Header(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) +{ + uint32_t local_id = 0; + + const DetectEngineTransforms *transforms = NULL; + if (!engine->mpm) { + transforms = engine->v2.transforms; + } + + while (1) { + struct MpmListIdDataArgs cbdata = { + local_id, + txv, + }; + InspectionBuffer *buffer = + GetHttp2HeaderData(det_ctx, flags, 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; + } + local_id++; + } + + return DETECT_ENGINE_INSPECT_SIG_NO_MATCH; +} + +static int PrefilterMpmHttp2HeaderRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, + MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id) +{ + PrefilterMpmListId *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, PrefilterTxHttp2Header, mpm_reg->app_v2.alproto, + mpm_reg->app_v2.tx_min_progress, pectx, PrefilterMpmHttpHeaderFree, mpm_reg->name); +} + +typedef struct HttpMultiBufItem { + uint8_t *buffer; + size_t len; +} HttpMultiBufItem; + +typedef struct HttpMultiBufHeaderThreadData { + // array of items, being defined as a buffer with its length just above + HttpMultiBufItem *items; + // capacity of items (size of allocation) + size_t cap; + // length of items (number in use) + size_t len; +} HttpMultiBufHeaderThreadData; + +static void *HttpMultiBufHeaderThreadDataInit(void *data) +{ + HttpMultiBufHeaderThreadData *td = SCCalloc(1, sizeof(*td)); + return td; +} + +static void HttpMultiBufHeaderThreadDataFree(void *data) +{ + HttpMultiBufHeaderThreadData *td = data; + for (size_t i = 0; i < td->cap; i++) { + SCFree(td->items[i].buffer); + } + SCFree(td->items); + SCFree(td); +} + +static InspectionBuffer *GetHttp1HeaderData(DetectEngineThreadCtx *det_ctx, const uint8_t flags, + const DetectEngineTransforms *transforms, Flow *f, const struct MpmListIdDataArgs *cbdata, + int list_id) +{ + SCEnter(); + + InspectionBuffer *buffer = + InspectionBufferMultipleForListGet(det_ctx, list_id, cbdata->local_id); + if (buffer == NULL) + return NULL; + if (buffer->initialized) + return buffer; + + int kw_thread_id; + if (flags & STREAM_TOSERVER) { + kw_thread_id = g_request_header_thread_id; + } else { + kw_thread_id = g_response_header_thread_id; + } + HttpMultiBufHeaderThreadData *hdr_td = + DetectThreadCtxGetGlobalKeywordThreadCtx(det_ctx, kw_thread_id); + if (unlikely(hdr_td == NULL)) { + return NULL; + } + + htp_tx_t *tx = (htp_tx_t *)cbdata->txv; + htp_table_t *headers; + if (flags & STREAM_TOSERVER) { + headers = tx->request_headers; + } else { + headers = tx->response_headers; + } + size_t no_of_headers = htp_table_size(headers); + if (cbdata->local_id == 0) { + // We initialize a big buffer on first item + // Then, we will just use parts of it + hdr_td->len = 0; + if (hdr_td->cap < no_of_headers) { + void *new_buffer = SCRealloc(hdr_td->items, no_of_headers * sizeof(HttpMultiBufItem)); + if (unlikely(new_buffer == NULL)) { + return NULL; + } + hdr_td->items = new_buffer; + // zeroes the new part of the items + memset(hdr_td->items + hdr_td->cap, 0, + (no_of_headers - hdr_td->cap) * sizeof(HttpMultiBufItem)); + hdr_td->cap = no_of_headers; + } + for (size_t i = 0; i < no_of_headers; i++) { + htp_header_t *h = htp_table_get_index(headers, i, NULL); + size_t size1 = bstr_size(h->name); + size_t size2 = bstr_size(h->value); + size_t size = size1 + size2 + 2; + if (hdr_td->items[i].len < size) { + // Use realloc, as this pointer is not freed until HttpMultiBufHeaderThreadDataFree + hdr_td->items[i].buffer = SCRealloc(hdr_td->items[i].buffer, size); + if (unlikely(hdr_td->items[i].buffer == NULL)) { + return NULL; + } + } + memcpy(hdr_td->items[i].buffer, bstr_ptr(h->name), size1); + hdr_td->items[i].buffer[size1] = ':'; + hdr_td->items[i].buffer[size1 + 1] = ' '; + memcpy(hdr_td->items[i].buffer + size1 + 2, bstr_ptr(h->value), size2); + hdr_td->items[i].len = size; + } + hdr_td->len = no_of_headers; + } + + // cbdata->local_id is the index of the requested header buffer + // hdr_td->len is the number of header buffers + if (cbdata->local_id < hdr_td->len) { + // we have one valid header buffer + InspectionBufferSetupMulti(buffer, transforms, hdr_td->items[cbdata->local_id].buffer, + hdr_td->items[cbdata->local_id].len); + SCReturnPtr(buffer, "InspectionBuffer"); + } // else there are no more header buffer to get + InspectionBufferSetupMultiEmpty(buffer); + return NULL; +} + +static void PrefilterTxHttp1Header(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 PrefilterMpmListId *ctx = (const PrefilterMpmListId *)pectx; + const MpmCtx *mpm_ctx = ctx->mpm_ctx; + const int list_id = ctx->list_id; + + uint32_t local_id = 0; + + while (1) { + // loop until we get a NULL + + struct MpmListIdDataArgs cbdata = { local_id, txv }; + InspectionBuffer *buffer = + GetHttp1HeaderData(det_ctx, flags, 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); + } + + local_id++; + } +} + +static int PrefilterMpmHttp1HeaderRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, + MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id) +{ + PrefilterMpmListId *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, PrefilterTxHttp1Header, mpm_reg->app_v2.alproto, + mpm_reg->app_v2.tx_min_progress, pectx, PrefilterMpmHttpHeaderFree, mpm_reg->name); +} + +static uint8_t DetectEngineInspectHttp1Header(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) +{ + uint32_t local_id = 0; + + const DetectEngineTransforms *transforms = NULL; + if (!engine->mpm) { + transforms = engine->v2.transforms; + } + + while (1) { + struct MpmListIdDataArgs cbdata = { + local_id, + txv, + }; + InspectionBuffer *buffer = + GetHttp1HeaderData(det_ctx, flags, 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; + } + local_id++; + } + + return DETECT_ENGINE_INSPECT_SIG_NO_MATCH; +} + +static int DetectHTTPRequestHeaderSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg) +{ + if (DetectBufferSetActiveList(de_ctx, s, g_http_request_header_buffer_id) < 0) + return -1; + + if (DetectSignatureSetAppProto(s, ALPROTO_HTTP) != 0) + return -1; + + return 0; +} + +void DetectHttpRequestHeaderRegister(void) +{ + sigmatch_table[DETECT_HTTP_REQUEST_HEADER].name = "http.request_header"; + sigmatch_table[DETECT_HTTP_REQUEST_HEADER].desc = + "sticky buffer to match on only one HTTP header name and value"; + sigmatch_table[DETECT_HTTP_REQUEST_HEADER].url = "/rules/http-keywords.html#request_header"; + sigmatch_table[DETECT_HTTP_REQUEST_HEADER].Setup = DetectHTTPRequestHeaderSetup; + sigmatch_table[DETECT_HTTP_REQUEST_HEADER].flags |= + SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER; + + DetectAppLayerMpmRegister2("http_request_header", SIG_FLAG_TOSERVER, 2, + PrefilterMpmHttp2HeaderRegister, NULL, ALPROTO_HTTP2, HTTP2StateOpen); + DetectAppLayerInspectEngineRegister2("http_request_header", ALPROTO_HTTP2, SIG_FLAG_TOSERVER, + HTTP2StateOpen, DetectEngineInspectHttp2Header, NULL); + DetectAppLayerMpmRegister2("http_request_header", SIG_FLAG_TOSERVER, 2, + PrefilterMpmHttp1HeaderRegister, NULL, ALPROTO_HTTP1, 0); + DetectAppLayerInspectEngineRegister2("http_request_header", ALPROTO_HTTP1, SIG_FLAG_TOSERVER, + HTP_REQUEST_HEADERS, DetectEngineInspectHttp1Header, NULL); + + DetectBufferTypeSetDescriptionByName("http_request_header", "HTTP header name and value"); + g_http_request_header_buffer_id = DetectBufferTypeGetByName("http_request_header"); + DetectBufferTypeSupportsMultiInstance("http_request_header"); + g_request_header_thread_id = DetectRegisterThreadCtxGlobalFuncs("http_request_header", + HttpMultiBufHeaderThreadDataInit, NULL, HttpMultiBufHeaderThreadDataFree); +} + +static int DetectHTTPResponseHeaderSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg) +{ + if (DetectBufferSetActiveList(de_ctx, s, g_http_response_header_buffer_id) < 0) + return -1; + + if (DetectSignatureSetAppProto(s, ALPROTO_HTTP) != 0) + return -1; + + return 0; +} + +void DetectHttpResponseHeaderRegister(void) +{ + sigmatch_table[DETECT_HTTP_RESPONSE_HEADER].name = "http.response_header"; + sigmatch_table[DETECT_HTTP_RESPONSE_HEADER].desc = + "sticky buffer to match on only one HTTP header name and value"; + sigmatch_table[DETECT_HTTP_RESPONSE_HEADER].url = "/rules/http2-keywords.html#response_header"; + sigmatch_table[DETECT_HTTP_RESPONSE_HEADER].Setup = DetectHTTPResponseHeaderSetup; + sigmatch_table[DETECT_HTTP_RESPONSE_HEADER].flags |= + SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER; + + DetectAppLayerMpmRegister2("http_response_header", SIG_FLAG_TOCLIENT, 2, + PrefilterMpmHttp2HeaderRegister, NULL, ALPROTO_HTTP2, HTTP2StateOpen); + DetectAppLayerInspectEngineRegister2("http_response_header", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT, + HTTP2StateOpen, DetectEngineInspectHttp2Header, NULL); + DetectAppLayerMpmRegister2("http_response_header", SIG_FLAG_TOCLIENT, 2, + PrefilterMpmHttp1HeaderRegister, NULL, ALPROTO_HTTP1, 0); + DetectAppLayerInspectEngineRegister2("http_response_header", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT, + HTP_RESPONSE_HEADERS, DetectEngineInspectHttp1Header, NULL); + + DetectBufferTypeSetDescriptionByName("http_response_header", "HTTP header name and value"); + g_http_response_header_buffer_id = DetectBufferTypeGetByName("http_response_header"); + DetectBufferTypeSupportsMultiInstance("http_response_header"); + g_response_header_thread_id = DetectRegisterThreadCtxGlobalFuncs("http_response_header", + HttpMultiBufHeaderThreadDataInit, NULL, HttpMultiBufHeaderThreadDataFree); +} + +/************************************Unittests*********************************/ + +#ifdef UNITTESTS +#include "tests/detect-http-header.c" +#endif + +/** + * @} + */ |