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suricata/src/detect-http-raw-header.c

375 lines
13 KiB
C

/* 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, const DetectBufferType *dbt);
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_HTTP_RAW_HEADER_CM].name = "http_raw_header";
sigmatch_table[DETECT_HTTP_RAW_HEADER_CM].desc =
"content modifier to match the raw HTTP header buffer";
sigmatch_table[DETECT_HTTP_RAW_HEADER_CM].url =
"/rules/http-keywords.html#http-header-and-http-raw-header";
sigmatch_table[DETECT_HTTP_RAW_HEADER_CM].Setup = DetectHttpRawHeaderSetup;
#ifdef UNITTESTS
sigmatch_table[DETECT_HTTP_RAW_HEADER_CM].RegisterTests = DetectHttpRawHeaderRegisterTests;
#endif
sigmatch_table[DETECT_HTTP_RAW_HEADER_CM].flags |=
SIGMATCH_NOOPT | SIGMATCH_INFO_CONTENT_MODIFIER;
sigmatch_table[DETECT_HTTP_RAW_HEADER_CM].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;
DetectAppLayerInspectEngineRegister("http_raw_header", ALPROTO_HTTP1, SIG_FLAG_TOSERVER,
HTP_REQUEST_PROGRESS_HEADERS + 1, DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerInspectEngineRegister("http_raw_header", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT,
HTP_RESPONSE_PROGRESS_HEADERS + 1, DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerMpmRegister("http_raw_header", SIG_FLAG_TOSERVER, 2,
PrefilterMpmHttpHeaderRawRequestRegister, NULL, ALPROTO_HTTP1,
0); /* progress handled in register */
DetectAppLayerMpmRegister("http_raw_header", SIG_FLAG_TOCLIENT, 2,
PrefilterMpmHttpHeaderRawResponseRegister, NULL, ALPROTO_HTTP1,
0); /* progress handled in register */
DetectAppLayerInspectEngineRegister("http_raw_header", ALPROTO_HTTP2, SIG_FLAG_TOSERVER,
HTTP2StateDataClient, DetectEngineInspectBufferGeneric, GetData2);
DetectAppLayerInspectEngineRegister("http_raw_header", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT,
HTTP2StateDataServer, DetectEngineInspectBufferGeneric, GetData2);
DetectAppLayerMpmRegister("http_raw_header", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
GetData2, ALPROTO_HTTP2, HTTP2StateDataClient);
DetectAppLayerMpmRegister("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_HTTP_RAW_HEADER_CM, 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, const DetectBufferType *dbt)
{
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);
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;
InspectionBufferSetupAndApplyTransforms(
det_ctx, list_id, buffer, data, data_len, 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;
InspectionBufferSetupAndApplyTransforms(det_ctx, list_id, buffer, b, b_len, 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->mtc, &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 (((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_PROGRESS_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_PROGRESS_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_PROGRESS_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_PROGRESS_TRAILER, pectx, PrefilterMpmHttpHeaderRawFree, mpm_reg->pname);
if (r != 0) {
SCFree(pectx);
}
return r;
}
/************************************Unittests*********************************/
#ifdef UNITTESTS
#include "tests/detect-http-raw-header.c"
#endif
/**
* @}
*/