suricata
detect-krb5-cname.c
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1 /* Copyright (C) 2018-2022 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  * \file
20  *
21  * \author Pierre Chifflier <chifflier@wzdftpd.net>
22  */
23 
24 #include "suricata-common.h"
25 #include "util-unittest.h"
26 
27 #include "detect-parse.h"
28 #include "detect-engine.h"
29 #include "detect-engine-mpm.h"
30 #include "detect-engine-state.h"
33 
34 #include "detect-krb5-cname.h"
35 
36 #include "rust.h"
37 #include "app-layer-krb5.h"
38 #include "util-profiling.h"
39 
40 static int g_krb5_cname_buffer_id = 0;
41 
43  uint32_t local_id; /**< used as index into thread inspect array */
44  void *txv;
45 };
46 
47 static int DetectKrb5CNameSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)
48 {
49  if (DetectBufferSetActiveList(s, g_krb5_cname_buffer_id) < 0)
50  return -1;
51 
53  return -1;
54 
55  return 0;
56 }
57 
58 static InspectionBuffer *GetKrb5CNameData(DetectEngineThreadCtx *det_ctx,
59  const DetectEngineTransforms *transforms,
60  Flow *_f, const struct Krb5PrincipalNameDataArgs *cbdata,
61  int list_id, bool first)
62 {
63  SCEnter();
64 
65  InspectionBuffer *buffer =
66  InspectionBufferMultipleForListGet(det_ctx, list_id, cbdata->local_id);
67  if (buffer == NULL)
68  return NULL;
69  if (!first && buffer->inspect != NULL)
70  return buffer;
71 
72  uint32_t b_len = 0;
73  const uint8_t *b = NULL;
74 
75  if (rs_krb5_tx_get_cname(cbdata->txv, cbdata->local_id, &b, &b_len) != 1)
76  return NULL;
77  if (b == NULL || b_len == 0)
78  return NULL;
79 
80  InspectionBufferSetupMulti(buffer, transforms, b, b_len);
81 
82  SCReturnPtr(buffer, "InspectionBuffer");
83 }
84 
85 static uint8_t DetectEngineInspectKrb5CName(DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx,
86  const DetectEngineAppInspectionEngine *engine, const Signature *s, Flow *f, uint8_t flags,
87  void *alstate, void *txv, uint64_t tx_id)
88 {
89  uint32_t local_id = 0;
90 
91  const DetectEngineTransforms *transforms = NULL;
92  if (!engine->mpm) {
93  transforms = engine->v2.transforms;
94  }
95 
96  while (1) {
97  struct Krb5PrincipalNameDataArgs cbdata = { local_id, txv, };
98  InspectionBuffer *buffer = GetKrb5CNameData(det_ctx,
99  transforms, f, &cbdata, engine->sm_list, false);
100 
101  if (buffer == NULL || buffer->inspect == NULL)
102  break;
103 
104  det_ctx->buffer_offset = 0;
105  det_ctx->discontinue_matching = 0;
106  det_ctx->inspection_recursion_counter = 0;
107 
108  const int match = DetectEngineContentInspection(de_ctx, det_ctx, s, engine->smd,
109  NULL, f,
110  (uint8_t *)buffer->inspect,
111  buffer->inspect_len,
114  if (match == 1) {
116  }
117  local_id++;
118  }
119 
121 }
122 
123 typedef struct PrefilterMpmKrb5Name {
124  int list_id;
125  const MpmCtx *mpm_ctx;
128 
129 /** \brief Krb5CName Krb5CName Mpm prefilter callback
130  *
131  * \param det_ctx detection engine thread ctx
132  * \param p packet to inspect
133  * \param f flow to inspect
134  * \param txv tx to inspect
135  * \param pectx inspection context
136  */
137 static void PrefilterTxKrb5CName(DetectEngineThreadCtx *det_ctx, const void *pectx, Packet *p,
138  Flow *f, void *txv, const uint64_t idx, const AppLayerTxData *_txd, const uint8_t flags)
139 {
140  SCEnter();
141 
142  const PrefilterMpmKrb5Name *ctx = (const PrefilterMpmKrb5Name *)pectx;
143  const MpmCtx *mpm_ctx = ctx->mpm_ctx;
144  const int list_id = ctx->list_id;
145 
146  uint32_t local_id = 0;
147 
148  while(1) {
149  // loop until we get a NULL
150 
151  struct Krb5PrincipalNameDataArgs cbdata = { local_id, txv };
152  InspectionBuffer *buffer = GetKrb5CNameData(det_ctx, ctx->transforms,
153  f, &cbdata, list_id, true);
154  if (buffer == NULL)
155  break;
156 
157  if (buffer->inspect_len >= mpm_ctx->minlen) {
158  (void)mpm_table[mpm_ctx->mpm_type].Search(mpm_ctx,
159  &det_ctx->mtcu, &det_ctx->pmq,
160  buffer->inspect, buffer->inspect_len);
161  PREFILTER_PROFILING_ADD_BYTES(det_ctx, buffer->inspect_len);
162  }
163 
164  local_id++;
165  }
166 }
167 
168 static void PrefilterMpmKrb5NameFree(void *ptr)
169 {
170  SCFree(ptr);
171 }
172 
173 static int PrefilterMpmKrb5CNameRegister(DetectEngineCtx *de_ctx,
174  SigGroupHead *sgh, MpmCtx *mpm_ctx,
175  const DetectBufferMpmRegistery *mpm_reg, int list_id)
176 {
177  PrefilterMpmKrb5Name *pectx = SCCalloc(1, sizeof(*pectx));
178  if (pectx == NULL)
179  return -1;
180  pectx->list_id = list_id;
181  pectx->mpm_ctx = mpm_ctx;
182  pectx->transforms = &mpm_reg->transforms;
183 
184  return PrefilterAppendTxEngine(de_ctx, sgh, PrefilterTxKrb5CName,
185  mpm_reg->app_v2.alproto, mpm_reg->app_v2.tx_min_progress,
186  pectx, PrefilterMpmKrb5NameFree, mpm_reg->name);
187 }
188 
190 {
191  sigmatch_table[DETECT_AL_KRB5_CNAME].name = "krb5.cname";
192  sigmatch_table[DETECT_AL_KRB5_CNAME].alias = "krb5_cname";
193  sigmatch_table[DETECT_AL_KRB5_CNAME].url = "/rules/kerberos-keywords.html#krb5-cname";
194  sigmatch_table[DETECT_AL_KRB5_CNAME].Setup = DetectKrb5CNameSetup;
196  sigmatch_table[DETECT_AL_KRB5_CNAME].desc = "sticky buffer to match on Kerberos 5 client name";
197 
199  PrefilterMpmKrb5CNameRegister, NULL,
200  ALPROTO_KRB5, 1);
201 
204  DetectEngineInspectKrb5CName, NULL);
205 
207  "Kerberos 5 ticket client name");
208 
209  g_krb5_cname_buffer_id = DetectBufferTypeGetByName("krb5_cname");
210 }
PrefilterMpmKrb5Name
Definition: detect-krb5-cname.c:123
DetectEngineAppInspectionEngine_
Definition: detect.h:389
SigTableElmt_::url
const char * url
Definition: detect.h:1238
DetectSignatureSetAppProto
int DetectSignatureSetAppProto(Signature *s, AppProto alproto)
Definition: detect-parse.c:1493
DetectEngineAppInspectionEngine_::mpm
bool mpm
Definition: detect.h:393
MpmCtx_::mpm_type
uint8_t mpm_type
Definition: util-mpm.h:90
DetectEngineThreadCtx_::buffer_offset
uint32_t buffer_offset
Definition: detect.h:1052
detect-engine.h
SIGMATCH_INFO_STICKY_BUFFER
#define SIGMATCH_INFO_STICKY_BUFFER
Definition: detect.h:1444
SigTableElmt_::desc
const char * desc
Definition: detect.h:1237
DETECT_ENGINE_CONTENT_INSPECTION_MODE_STATE
@ DETECT_ENGINE_CONTENT_INSPECTION_MODE_STATE
Definition: detect-engine-content-inspection.h:36
SigTableElmt_::name
const char * name
Definition: detect.h:1235
SigGroupHead_
Container for matching data for a signature group.
Definition: detect.h:1392
DetectEngineTransforms
Definition: detect.h:371
DetectBufferMpmRegistery_::transforms
DetectEngineTransforms transforms
Definition: detect.h:639
InspectionBuffer
Definition: detect.h:337
Flow_
Flow data structure.
Definition: flow.h:356
DetectEngineThreadCtx_::pmq
PrefilterRuleStore pmq
Definition: detect.h:1131
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1229
DetectBufferMpmRegistery_::app_v2
struct DetectBufferMpmRegistery_::@87::@89 app_v2
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:784
Krb5PrincipalNameDataArgs::txv
void * txv
Definition: detect-krb5-cname.c:44
rust.h
DetectBufferMpmRegistery_
one time registration of keywords at start up
Definition: detect.h:625
SIG_FLAG_TOCLIENT
#define SIG_FLAG_TOCLIENT
Definition: detect.h:229
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1220
DetectEngineAppInspectionEngine_::v2
struct DetectEngineAppInspectionEngine_::@84 v2
detect-engine-prefilter.h
DetectEngineThreadCtx_::mtcu
MpmThreadCtx mtcu
Definition: detect.h:1129
util-unittest.h
DetectBufferTypeGetByName
int DetectBufferTypeGetByName(const char *name)
Definition: detect-engine.c:1085
ALPROTO_KRB5
@ ALPROTO_KRB5
Definition: app-layer-protos.h:50
PrefilterMpmKrb5Name::list_id
int list_id
Definition: detect-krb5-cname.c:124
DetectEngineAppInspectionEngine_::sm_list
uint16_t sm_list
Definition: detect.h:395
app-layer-krb5.h
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:17
DetectEngineThreadCtx_
Definition: detect.h:1024
SCEnter
#define SCEnter(...)
Definition: util-debug.h:298
detect-engine-mpm.h
DETECT_ENGINE_INSPECT_SIG_MATCH
#define DETECT_ENGINE_INSPECT_SIG_MATCH
Definition: detect-engine-state.h:39
InspectionBuffer::inspect_offset
uint64_t inspect_offset
Definition: detect.h:339
MpmCtx_::minlen
uint16_t minlen
Definition: util-mpm.h:99
util-profiling.h
DetectBufferMpmRegistery_::name
const char * name
Definition: detect.h:626
Packet_
Definition: decode.h:428
DetectAppLayerInspectEngineRegister2
void DetectAppLayerInspectEngineRegister2(const char *name, AppProto alproto, uint32_t dir, int progress, InspectEngineFuncPtr2 Callback2, InspectionBufferGetDataPtr GetData)
register inspect engine at start up time
Definition: detect-engine.c:227
SCReturnPtr
#define SCReturnPtr(x, type)
Definition: util-debug.h:314
detect-engine-state.h
Data structures and function prototypes for keeping state for the detection engine.
detect-krb5-cname.h
MpmTableElmt_::Search
uint32_t(* Search)(const struct MpmCtx_ *, struct MpmThreadCtx_ *, PrefilterRuleStore *, const uint8_t *, uint32_t)
Definition: util-mpm.h:165
detect-engine-content-inspection.h
DetectEngineThreadCtx_::discontinue_matching
uint16_t discontinue_matching
Definition: detect.h:1091
DetectEngineAppInspectionEngine_::smd
SigMatchData * smd
Definition: detect.h:406
PrefilterMpmKrb5Name::transforms
const DetectEngineTransforms * transforms
Definition: detect-krb5-cname.c:126
DetectEngineContentInspection
uint8_t DetectEngineContentInspection(DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, const Signature *s, const SigMatchData *smd, Packet *p, Flow *f, const uint8_t *buffer, uint32_t buffer_len, uint32_t stream_start_offset, uint8_t flags, uint8_t inspection_mode)
Run the actual payload match functions.
Definition: detect-engine-content-inspection.c:106
DetectAppLayerMpmRegister2
void DetectAppLayerMpmRegister2(const char *name, int direction, int priority, int(*PrefilterRegister)(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistery *mpm_reg, int list_id), InspectionBufferGetDataPtr GetData, AppProto alproto, int tx_min_progress)
register a MPM engine
Definition: detect-engine-mpm.c:89
AppLayerTxData
struct AppLayerTxData AppLayerTxData
Definition: detect.h:1300
PREFILTER_PROFILING_ADD_BYTES
#define PREFILTER_PROFILING_ADD_BYTES(det_ctx, bytes)
Definition: util-profiling.h:307
DETECT_CI_FLAGS_SINGLE
#define DETECT_CI_FLAGS_SINGLE
Definition: detect-engine-content-inspection.h:47
flags
uint8_t flags
Definition: decode-gre.h:0
SigTableElmt_::alias
const char * alias
Definition: detect.h:1236
DetectKrb5CNameRegister
void DetectKrb5CNameRegister(void)
Definition: detect-krb5-cname.c:189
suricata-common.h
sigmatch_table
SigTableElmt sigmatch_table[DETECT_TBLSIZE]
Definition: detect-parse.c:76
DetectEngineThreadCtx_::inspection_recursion_counter
int inspection_recursion_counter
Definition: detect.h:1108
InspectionBufferSetupMulti
void InspectionBufferSetupMulti(InspectionBuffer *buffer, const DetectEngineTransforms *transforms, const uint8_t *data, const uint32_t data_len)
setup the buffer with our initial data
Definition: detect-engine.c:1435
PrefilterAppendTxEngine
int PrefilterAppendTxEngine(DetectEngineCtx *de_ctx, SigGroupHead *sgh, PrefilterTxFn PrefilterTxFunc, AppProto alproto, int tx_min_progress, void *pectx, void(*FreeFunc)(void *pectx), const char *name)
Definition: detect-engine-prefilter.c:270
DETECT_ENGINE_INSPECT_SIG_NO_MATCH
#define DETECT_ENGINE_INSPECT_SIG_NO_MATCH
Definition: detect-engine-state.h:38
InspectionBuffer::inspect_len
uint32_t inspect_len
Definition: detect.h:340
InspectionBuffer::inspect
const uint8_t * inspect
Definition: detect.h:338
Krb5PrincipalNameDataArgs::local_id
uint32_t local_id
Definition: detect-krb5-cname.c:43
SCFree
#define SCFree(p)
Definition: util-mem.h:61
Krb5PrincipalNameDataArgs
Definition: detect-krb5-cname.c:42
detect-parse.h
Signature_
Signature container.
Definition: detect.h:539
DetectEngineAppInspectionEngine_::transforms
const DetectEngineTransforms * transforms
Definition: detect.h:403
PrefilterMpmKrb5Name
struct PrefilterMpmKrb5Name PrefilterMpmKrb5Name
mpm_table
MpmTableElmt mpm_table[MPM_TABLE_SIZE]
Definition: util-mpm.c:48
InspectionBufferMultipleForListGet
InspectionBuffer * InspectionBufferMultipleForListGet(DetectEngineThreadCtx *det_ctx, const int list_id, const uint32_t local_id)
for a InspectionBufferMultipleForList get a InspectionBuffer
Definition: detect-engine.c:1388
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1420
DetectBufferSetActiveList
int DetectBufferSetActiveList(Signature *s, const int list)
Definition: detect-engine.c:1299
DETECT_AL_KRB5_CNAME
@ DETECT_AL_KRB5_CNAME
Definition: detect-engine-register.h:255
DetectBufferTypeSetDescriptionByName
void DetectBufferTypeSetDescriptionByName(const char *name, const char *desc)
Definition: detect-engine.c:1182
MpmCtx_
Definition: util-mpm.h:88
SCCalloc
#define SCCalloc(nm, sz)
Definition: util-mem.h:53
PrefilterMpmKrb5Name::mpm_ctx
const MpmCtx * mpm_ctx
Definition: detect-krb5-cname.c:125