suricata
detect-http-cookie.c
Go to the documentation of this file.
1 /* Copyright (C) 2007-2018 Open Information Security Foundation
2  *
3  * You can copy, redistribute or modify this Program under the terms of
4  * the GNU General Public License version 2 as published by the Free
5  * Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * version 2 along with this program; if not, write to the Free Software
14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
15  * 02110-1301, USA.
16  */
17 
18 /**
19  * \ingroup httplayer
20  *
21  * @{
22  */
23 
24 
25 /**
26  * \file
27  *
28  * \author Gurvinder Singh <gurvindersinghdahiya@gmail.com>
29  *
30  * Implements the http_cookie keyword
31  */
32 
33 #include "suricata-common.h"
34 #include "threads.h"
35 #include "decode.h"
36 #include "detect.h"
37 
38 #include "detect-parse.h"
39 #include "detect-engine.h"
40 #include "detect-engine-mpm.h"
41 #include "detect-engine-prefilter.h"
42 #include "detect-content.h"
43 #include "detect-pcre.h"
44 
45 #include "flow.h"
46 #include "flow-var.h"
47 #include "flow-util.h"
48 
49 #include "util-debug.h"
50 #include "util-error.h"
51 #include "util-unittest.h"
52 #include "util-unittest-helper.h"
53 #include "util-spm.h"
54 #include "util-print.h"
55 
56 #include "app-layer.h"
57 #include "app-layer-parser.h"
58 
59 #include "app-layer-htp.h"
60 #include "detect-http-cookie.h"
61 #include "stream-tcp.h"
62 
63 static int DetectHttpCookieSetup (DetectEngineCtx *, Signature *, const char *);
64 static int DetectHttpCookieSetupSticky (DetectEngineCtx *, Signature *, const char *);
65 #ifdef UNITTESTS
66 static void DetectHttpCookieRegisterTests(void);
67 #endif
68 static int g_http_cookie_buffer_id = 0;
69 
70 static InspectionBuffer *GetRequestData(DetectEngineThreadCtx *det_ctx,
71  const DetectEngineTransforms *transforms,
72  Flow *_f, const uint8_t _flow_flags,
73  void *txv, const int list_id);
74 static InspectionBuffer *GetResponseData(DetectEngineThreadCtx *det_ctx,
75  const DetectEngineTransforms *transforms,
76  Flow *_f, const uint8_t _flow_flags,
77  void *txv, const int list_id);
78 static InspectionBuffer *GetRequestData2(DetectEngineThreadCtx *det_ctx,
79  const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,
80  const int list_id);
81 static InspectionBuffer *GetResponseData2(DetectEngineThreadCtx *det_ctx,
82  const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,
83  const int list_id);
84 /**
85  * \brief Registration function for keyword: http_cookie
86  */
87 void DetectHttpCookieRegister(void)
88 {
89  /* http_cookie content modifier */
90  sigmatch_table[DETECT_AL_HTTP_COOKIE].name = "http_cookie";
91  sigmatch_table[DETECT_AL_HTTP_COOKIE].desc = "content modifier to match only on the HTTP cookie-buffer";
92  sigmatch_table[DETECT_AL_HTTP_COOKIE].url = "/rules/http-keywords.html#http-cookie";
93  sigmatch_table[DETECT_AL_HTTP_COOKIE].Setup = DetectHttpCookieSetup;
94 #ifdef UNITTESTS
95  sigmatch_table[DETECT_AL_HTTP_COOKIE].RegisterTests = DetectHttpCookieRegisterTests;
96 #endif
97  sigmatch_table[DETECT_AL_HTTP_COOKIE].flags |= SIGMATCH_NOOPT;
98  sigmatch_table[DETECT_AL_HTTP_COOKIE].flags |= SIGMATCH_INFO_CONTENT_MODIFIER;
99  sigmatch_table[DETECT_AL_HTTP_COOKIE].alternative = DETECT_HTTP_COOKIE;
100 
101  /* http.cookie sticky buffer */
102  sigmatch_table[DETECT_HTTP_COOKIE].name = "http.cookie";
103  sigmatch_table[DETECT_HTTP_COOKIE].desc = "sticky buffer to match on the HTTP Cookie/Set-Cookie buffers";
104  sigmatch_table[DETECT_HTTP_COOKIE].url = "/rules/http-keywords.html#http-cookie";
105  sigmatch_table[DETECT_HTTP_COOKIE].Setup = DetectHttpCookieSetupSticky;
106  sigmatch_table[DETECT_HTTP_COOKIE].flags |= SIGMATCH_NOOPT;
107  sigmatch_table[DETECT_HTTP_COOKIE].flags |= SIGMATCH_INFO_STICKY_BUFFER;
108 
109  DetectAppLayerInspectEngineRegister("http_cookie", ALPROTO_HTTP1, SIG_FLAG_TOSERVER,
110  HTP_REQUEST_HEADERS, DetectEngineInspectBufferGeneric, GetRequestData);
111  DetectAppLayerInspectEngineRegister("http_cookie", ALPROTO_HTTP1, SIG_FLAG_TOCLIENT,
112  HTP_REQUEST_HEADERS, DetectEngineInspectBufferGeneric, GetResponseData);
113 
114  DetectAppLayerMpmRegister("http_cookie", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
115  GetRequestData, ALPROTO_HTTP1, HTP_REQUEST_HEADERS);
116  DetectAppLayerMpmRegister("http_cookie", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister,
117  GetResponseData, ALPROTO_HTTP1, HTP_REQUEST_HEADERS);
118 
119  DetectAppLayerInspectEngineRegister("http_cookie", ALPROTO_HTTP2, SIG_FLAG_TOSERVER,
120  HTTP2StateDataClient, DetectEngineInspectBufferGeneric, GetRequestData2);
121  DetectAppLayerInspectEngineRegister("http_cookie", ALPROTO_HTTP2, SIG_FLAG_TOCLIENT,
122  HTTP2StateDataServer, DetectEngineInspectBufferGeneric, GetResponseData2);
123 
124  DetectAppLayerMpmRegister("http_cookie", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
125  GetRequestData2, ALPROTO_HTTP2, HTTP2StateDataClient);
126  DetectAppLayerMpmRegister("http_cookie", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister,
127  GetResponseData2, ALPROTO_HTTP2, HTTP2StateDataServer);
128 
129  DetectBufferTypeSetDescriptionByName("http_cookie",
130  "http cookie header");
131 
132  g_http_cookie_buffer_id = DetectBufferTypeGetByName("http_cookie");
133 }
134 
135 /**
136  * \brief this function setups the http_cookie modifier keyword used in the rule
137  *
138  * \param de_ctx Pointer to the Detection Engine Context
139  * \param s Pointer to the Signature to which the current keyword belongs
140  * \param str Should hold an empty string always
141  *
142  * \retval 0 On success
143  * \retval -1 On failure
144  */
145 
146 static int DetectHttpCookieSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
147 {
148  return DetectEngineContentModifierBufferSetup(
149  de_ctx, s, str, DETECT_AL_HTTP_COOKIE, g_http_cookie_buffer_id, ALPROTO_HTTP1);
150 }
151 
152 /**
153  * \brief this function setup the http.cookie keyword used in the rule
154  *
155  * \param de_ctx Pointer to the Detection Engine Context
156  * \param s Pointer to the Signature to which the current keyword belongs
157  * \param str Should hold an empty string always
158  *
159  * \retval 0 On success
160  */
161 static int DetectHttpCookieSetupSticky(DetectEngineCtx *de_ctx, Signature *s, const char *str)
162 {
163  if (DetectBufferSetActiveList(de_ctx, s, g_http_cookie_buffer_id) < 0)
164  return -1;
165 
166  if (DetectSignatureSetAppProto(s, ALPROTO_HTTP) < 0)
167  return -1;
168 
169  return 0;
170 }
171 
172 static InspectionBuffer *GetRequestData(DetectEngineThreadCtx *det_ctx,
173  const DetectEngineTransforms *transforms, Flow *_f,
174  const uint8_t _flow_flags, void *txv, const int list_id)
175 {
176  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
177  if (buffer->inspect == NULL) {
178  htp_tx_t *tx = (htp_tx_t *)txv;
179 
180  if (tx->request_headers == NULL)
181  return NULL;
182 
183  htp_header_t *h = (htp_header_t *)htp_table_get_c(tx->request_headers,
184  "Cookie");
185  if (h == NULL || h->value == NULL) {
186  SCLogDebug("HTTP cookie header not present in this request");
187  return NULL;
188  }
189 
190  const uint32_t data_len = bstr_len(h->value);
191  const uint8_t *data = bstr_ptr(h->value);
192 
193  InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
194  InspectionBufferApplyTransforms(buffer, transforms);
195  }
196 
197  return buffer;
198 }
199 
200 static InspectionBuffer *GetResponseData(DetectEngineThreadCtx *det_ctx,
201  const DetectEngineTransforms *transforms, Flow *_f,
202  const uint8_t _flow_flags, void *txv, const int list_id)
203 {
204  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
205  if (buffer->inspect == NULL) {
206  htp_tx_t *tx = (htp_tx_t *)txv;
207 
208  if (tx->response_headers == NULL)
209  return NULL;
210 
211  htp_header_t *h = (htp_header_t *)htp_table_get_c(tx->response_headers,
212  "Set-Cookie");
213  if (h == NULL || h->value == NULL) {
214  SCLogDebug("HTTP cookie header not present in this request");
215  return NULL;
216  }
217 
218  const uint32_t data_len = bstr_len(h->value);
219  const uint8_t *data = bstr_ptr(h->value);
220 
221  InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
222  InspectionBufferApplyTransforms(buffer, transforms);
223  }
224 
225  return buffer;
226 }
227 
228 static InspectionBuffer *GetRequestData2(DetectEngineThreadCtx *det_ctx,
229  const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,
230  const int list_id)
231 {
232  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
233  if (buffer->inspect == NULL) {
234  uint32_t b_len = 0;
235  const uint8_t *b = NULL;
236 
237  if (rs_http2_tx_get_cookie(txv, STREAM_TOSERVER, &b, &b_len) != 1)
238  return NULL;
239  if (b == NULL || b_len == 0)
240  return NULL;
241 
242  InspectionBufferSetup(det_ctx, list_id, buffer, b, b_len);
243  InspectionBufferApplyTransforms(buffer, transforms);
244  }
245 
246  return buffer;
247 }
248 
249 static InspectionBuffer *GetResponseData2(DetectEngineThreadCtx *det_ctx,
250  const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv,
251  const int list_id)
252 {
253  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
254  if (buffer->inspect == NULL) {
255  uint32_t b_len = 0;
256  const uint8_t *b = NULL;
257 
258  if (rs_http2_tx_get_cookie(txv, STREAM_TOCLIENT, &b, &b_len) != 1)
259  return NULL;
260  if (b == NULL || b_len == 0)
261  return NULL;
262 
263  InspectionBufferSetup(det_ctx, list_id, buffer, b, b_len);
264  InspectionBufferApplyTransforms(buffer, transforms);
265  }
266 
267  return buffer;
268 }
269 
270 /******************************** UNITESTS **********************************/
271 
272 #ifdef UNITTESTS
273 #include "tests/detect-http-cookie.c"
274 #endif /* UNITTESTS */
275 
276 /**
277  * @}
278  */
SigTableElmt_::url
const char * url
Definition: detect.h:1299
DetectSignatureSetAppProto
int DetectSignatureSetAppProto(Signature *s, AppProto alproto)
Definition: detect-parse.c:1753
detect-content.h
detect-engine.h
SIGMATCH_INFO_STICKY_BUFFER
#define SIGMATCH_INFO_STICKY_BUFFER
Definition: detect.h:1500
SigTableElmt_::desc
const char * desc
Definition: detect.h:1298
DetectEngineInspectBufferGeneric
uint8_t DetectEngineInspectBufferGeneric(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)
Do the content inspection & validation for a signature.
Definition: detect-engine.c:2122
flow-util.h
SIGMATCH_INFO_CONTENT_MODIFIER
#define SIGMATCH_INFO_CONTENT_MODIFIER
Definition: detect.h:1498
SigTableElmt_::name
const char * name
Definition: detect.h:1296
stream-tcp.h
DetectEngineTransforms
Definition: detect.h:409
SCLogDebug
#define SCLogDebug(...)
Definition: util-debug.h:269
DetectBufferSetActiveList
int DetectBufferSetActiveList(DetectEngineCtx *de_ctx, Signature *s, const int list)
Definition: detect-engine.c:1335
InspectionBuffer
Definition: detect.h:374
threads.h
Flow_
Flow data structure.
Definition: flow.h:351
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1290
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:839
SIG_FLAG_TOCLIENT
#define SIG_FLAG_TOCLIENT
Definition: detect.h:267
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1281
detect-pcre.h
detect-engine-prefilter.h
util-unittest.h
InspectionBufferGet
InspectionBuffer * InspectionBufferGet(DetectEngineThreadCtx *det_ctx, const int list_id)
Definition: detect-engine.c:1479
util-unittest-helper.h
DetectBufferTypeGetByName
int DetectBufferTypeGetByName(const char *name)
Definition: detect-engine.c:1072
SIG_FLAG_TOSERVER
#define SIG_FLAG_TOSERVER
Definition: detect.h:266
app-layer-htp.h
decode.h
util-debug.h
util-error.h
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:17
DetectEngineThreadCtx_
Definition: detect.h:1095
util-print.h
detect-engine-mpm.h
detect.h
PrefilterGenericMpmRegister
int PrefilterGenericMpmRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id)
Definition: detect-engine-prefilter.c:745
SigTableElmt_::alternative
uint16_t alternative
Definition: detect.h:1294
DetectAppLayerMpmRegister
void DetectAppLayerMpmRegister(const char *name, int direction, int priority, PrefilterRegisterFunc PrefilterRegister, InspectionBufferGetDataPtr GetData, AppProto alproto, int tx_min_progress)
register a MPM engine
Definition: detect-engine-mpm.c:89
app-layer-parser.h
DetectEngineContentModifierBufferSetup
int DetectEngineContentModifierBufferSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg, int sm_type, int sm_list, AppProto alproto)
Definition: detect-parse.c:205
ALPROTO_HTTP2
@ ALPROTO_HTTP2
Definition: app-layer-protos.h:62
DETECT_AL_HTTP_COOKIE
@ DETECT_AL_HTTP_COOKIE
Definition: detect-engine-register.h:131
suricata-common.h
InspectionBufferApplyTransforms
void InspectionBufferApplyTransforms(InspectionBuffer *buffer, const DetectEngineTransforms *transforms)
Definition: detect-engine.c:1678
ALPROTO_HTTP1
@ ALPROTO_HTTP1
Definition: app-layer-protos.h:30
sigmatch_table
SigTableElmt sigmatch_table[DETECT_TBLSIZE]
Definition: detect-parse.c:127
util-spm.h
InspectionBuffer::inspect
const uint8_t * inspect
Definition: detect.h:375
str
#define str(s)
Definition: suricata-common.h:291
InspectionBufferSetup
void InspectionBufferSetup(DetectEngineThreadCtx *det_ctx, const int list_id, InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len)
setup the buffer with our initial data
Definition: detect-engine.c:1574
detect-parse.h
Signature_
Signature container.
Definition: detect.h:596
ALPROTO_HTTP
@ ALPROTO_HTTP
Definition: app-layer-protos.h:67
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1476
DetectAppLayerInspectEngineRegister
void DetectAppLayerInspectEngineRegister(const char *name, AppProto alproto, uint32_t dir, int progress, InspectEngineFuncPtr Callback, InspectionBufferGetDataPtr GetData)
register inspect engine at start up time
Definition: detect-engine.c:169
DETECT_HTTP_COOKIE
@ DETECT_HTTP_COOKIE
Definition: detect-engine-register.h:132
DetectBufferTypeSetDescriptionByName
void DetectBufferTypeSetDescriptionByName(const char *name, const char *desc)
Definition: detect-engine.c:1169
flow.h
flow-var.h
SigTableElmt_::RegisterTests
void(* RegisterTests)(void)
Definition: detect.h:1288
app-layer.h