suricata
detect-tls-ja3-hash.c
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1 /* Copyright (C) 2017 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 Mats Klepsland <mats.klepsland@gmail.com>
22  *
23  * Implements support for ja3.hash keyword.
24  */
25 
26 #include "suricata-common.h"
27 #include "threads.h"
28 #include "decode.h"
29 #include "detect.h"
30 
31 #include "detect-parse.h"
32 #include "detect-engine.h"
33 #include "detect-engine-buffer.h"
34 #include "detect-engine-mpm.h"
36 #include "detect-content.h"
37 #include "detect-pcre.h"
38 #include "detect-tls-ja3-hash.h"
39 
40 #include "flow.h"
41 #include "flow-util.h"
42 #include "flow-var.h"
43 
44 #include "conf.h"
45 #include "conf-yaml-loader.h"
46 
47 #include "util-debug.h"
48 #include "util-spm.h"
49 #include "util-print.h"
50 #include "util-ja3.h"
51 
52 #include "stream-tcp.h"
53 
54 #include "app-layer.h"
55 #include "app-layer-ssl.h"
56 
57 #include "util-unittest.h"
58 #include "util-unittest-helper.h"
59 
60 #ifndef HAVE_JA3
61 static int DetectJA3SetupNoSupport(DetectEngineCtx *a, Signature *b, const char *c)
62 {
63  SCLogError("no JA3 support built in");
64  return -1;
65 }
66 #endif
67 
68 #ifdef HAVE_JA3
69 static int DetectTlsJa3HashSetup(DetectEngineCtx *, Signature *, const char *);
70 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
71  const DetectEngineTransforms *transforms,
72  Flow *f, const uint8_t flow_flags,
73  void *txv, const int list_id);
74 static void DetectTlsJa3HashSetupCallback(const DetectEngineCtx *de_ctx, Signature *s);
75 static int g_tls_ja3_hash_buffer_id = 0;
76 #endif
77 
78 /**
79  * \brief Registration function for keyword: ja3_hash
80  */
82 {
85  sigmatch_table[DETECT_TLS_JA3_HASH].desc = "sticky buffer to match the JA3 hash buffer";
86  sigmatch_table[DETECT_TLS_JA3_HASH].url = "/rules/ja3-keywords.html#ja3-hash";
87 #ifdef HAVE_JA3
88  sigmatch_table[DETECT_TLS_JA3_HASH].Setup = DetectTlsJa3HashSetup;
89 #else /* HAVE_JA3 */
90  sigmatch_table[DETECT_TLS_JA3_HASH].Setup = DetectJA3SetupNoSupport;
91 #endif /* HAVE_JA3 */
94 
95 #ifdef HAVE_JA3
98 
101 
103  Ja3DetectGetHash, ALPROTO_QUIC, 1);
104 
106  DetectEngineInspectBufferGeneric, Ja3DetectGetHash);
107 
108  DetectBufferTypeSetDescriptionByName("ja3.hash", "TLS JA3 hash");
109 
111  DetectTlsJa3HashSetupCallback);
112 
114 
115  g_tls_ja3_hash_buffer_id = DetectBufferTypeGetByName("ja3.hash");
116 #endif /* HAVE_JA3 */
117 }
118 
119 #ifdef HAVE_JA3
120 /**
121  * \brief this function setup the ja3.hash modifier keyword used in the rule
122  *
123  * \param de_ctx Pointer to the Detection Engine Context
124  * \param s Pointer to the Signature to which the current keyword belongs
125  * \param str Should hold an empty string always
126  *
127  * \retval 0 On success
128  * \retval -1 On failure
129  * \retval -2 on failure that should be silent after the first
130  */
131 static int DetectTlsJa3HashSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
132 {
133  if (SCDetectBufferSetActiveList(de_ctx, s, g_tls_ja3_hash_buffer_id) < 0)
134  return -1;
135 
137  if (DetectSignatureSetMultiAppProto(s, alprotos) < 0) {
138  SCLogError("rule contains conflicting protocols.");
139  return -1;
140  }
141 
142  /* try to enable JA3 */
143  SSLEnableJA3();
144 
145  /* Check if JA3 is disabled */
146  if (!RunmodeIsUnittests() && Ja3IsDisabled("rule")) {
148  SCLogError("ja3 support is not enabled");
149  }
150  return -2;
151  }
152 
153  return 0;
154 }
155 
156 static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
157  const DetectEngineTransforms *transforms, Flow *f,
158  const uint8_t flow_flags, void *txv, const int list_id)
159 {
160  InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
161  if (buffer->inspect == NULL) {
162  const SSLState *ssl_state = (SSLState *)f->alstate;
163 
164  if (ssl_state->client_connp.ja3_hash == NULL) {
165  return NULL;
166  }
167 
168  const uint32_t data_len = (uint32_t)strlen(ssl_state->client_connp.ja3_hash);
169  const uint8_t *data = (uint8_t *)ssl_state->client_connp.ja3_hash;
170 
172  det_ctx, list_id, buffer, data, data_len, transforms);
173  }
174 
175  return buffer;
176 }
177 
178 static void DetectTlsJa3HashSetupCallback(const DetectEngineCtx *de_ctx,
179  Signature *s)
180 {
181  for (uint32_t x = 0; x < s->init_data->buffer_index; x++) {
182  if (s->init_data->buffers[x].id != (uint32_t)g_tls_ja3_hash_buffer_id)
183  continue;
184  SigMatch *sm = s->init_data->buffers[x].head;
185  for (; sm != NULL; sm = sm->next) {
186  if (sm->type != DETECT_CONTENT)
187  continue;
188 
190 
191  bool changed = false;
192  uint32_t u;
193  for (u = 0; u < cd->content_len; u++) {
194  if (isupper(cd->content[u])) {
195  cd->content[u] = u8_tolower(cd->content[u]);
196  changed = true;
197  }
198  }
199 
200  /* recreate the context if changes were made */
201  if (changed) {
202  SpmDestroyCtx(cd->spm_ctx);
203  cd->spm_ctx =
205  }
206  }
207  }
208 }
209 #endif
SigTableElmt_::url
const char * url
Definition: detect.h:1431
SignatureInitDataBuffer_::head
SigMatch * head
Definition: detect.h:548
SSLState_
SSLv[2.0|3.[0|1|2|3]] state structure.
Definition: app-layer-ssl.h:301
detect-content.h
DetectTlsJa3HashRegister
void DetectTlsJa3HashRegister(void)
Registration function for keyword: ja3_hash.
Definition: detect-tls-ja3-hash.c:81
detect-engine.h
SIGMATCH_INFO_STICKY_BUFFER
#define SIGMATCH_INFO_STICKY_BUFFER
Definition: detect.h:1645
SigTableElmt_::desc
const char * desc
Definition: detect.h:1430
sigmatch_table
SigTableElmt * sigmatch_table
Definition: detect-parse.c:155
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:2103
flow-util.h
SigTableElmt_::name
const char * name
Definition: detect.h:1428
InspectionBufferSetupAndApplyTransforms
void InspectionBufferSetupAndApplyTransforms(DetectEngineThreadCtx *det_ctx, const int list_id, InspectionBuffer *buffer, const uint8_t *data, const uint32_t data_len, const DetectEngineTransforms *transforms)
setup the buffer with our initial data
Definition: detect-engine.c:1570
stream-tcp.h
DetectEngineTransforms
Definition: detect.h:415
SSLState_::client_connp
SSLStateConnp client_connp
Definition: app-layer-ssl.h:322
DETECT_CONTENT
@ DETECT_CONTENT
Definition: detect-engine-register.h:69
DetectSignatureSetMultiAppProto
int DetectSignatureSetMultiAppProto(Signature *s, const AppProto *alprotos)
this function is used to set multiple possible app-layer protos
Definition: detect-parse.c:2235
ALPROTO_TLS
@ ALPROTO_TLS
Definition: app-layer-protos.h:39
AppProto
uint16_t AppProto
Definition: app-layer-protos.h:85
ALPROTO_QUIC
@ ALPROTO_QUIC
Definition: app-layer-protos.h:57
SSLStateConnp_::ja3_hash
char * ja3_hash
Definition: app-layer-ssl.h:283
InspectionBuffer
Definition: detect.h:380
threads.h
Flow_
Flow data structure.
Definition: flow.h:356
DetectBufferTypeRegisterSetupCallback
void DetectBufferTypeRegisterSetupCallback(const char *name, void(*SetupCallback)(const DetectEngineCtx *, Signature *))
Definition: detect-engine.c:1351
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1422
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:931
DetectBufferTypeRegisterValidateCallback
void DetectBufferTypeRegisterValidateCallback(const char *name, bool(*ValidateCallback)(const Signature *, const char **sigerror, const DetectBufferType *))
Definition: detect-engine.c:1369
u8_tolower
#define u8_tolower(c)
Definition: suricata-common.h:453
util-ja3.h
SCDetectBufferSetActiveList
int SCDetectBufferSetActiveList(DetectEngineCtx *de_ctx, Signature *s, const int list)
Definition: detect-engine-buffer.c:29
DetectContentData_
Definition: detect-content.h:93
DetectMd5ValidateCallback
bool DetectMd5ValidateCallback(const Signature *s, const char **sigerror, const DetectBufferType *map)
Definition: detect-engine.c:5035
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1413
detect-pcre.h
detect-engine-prefilter.h
util-unittest.h
InspectionBufferGet
InspectionBuffer * InspectionBufferGet(DetectEngineThreadCtx *det_ctx, const int list_id)
Definition: detect-engine.c:1429
util-unittest-helper.h
DetectBufferTypeGetByName
int DetectBufferTypeGetByName(const char *name)
Definition: detect-engine.c:1157
Ja3IsDisabled
int Ja3IsDisabled(const char *type)
Definition: util-ja3.c:324
SIG_FLAG_TOSERVER
#define SIG_FLAG_TOSERVER
Definition: detect.h:270
decode.h
util-debug.h
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:18
DetectEngineThreadCtx_
Definition: detect.h:1223
TLS_STATE_CLIENT_HELLO_DONE
@ TLS_STATE_CLIENT_HELLO_DONE
Definition: app-layer-ssl.h:79
util-print.h
detect-engine-mpm.h
detect.h
SigMatch_::next
struct SigMatch_ * next
Definition: detect.h:360
PrefilterGenericMpmRegister
int PrefilterGenericMpmRegister(DetectEngineCtx *de_ctx, SigGroupHead *sgh, MpmCtx *mpm_ctx, const DetectBufferMpmRegistry *mpm_reg, int list_id)
Definition: detect-engine-prefilter.c:1547
DetectAppLayerMpmRegister
void DetectAppLayerMpmRegister(const char *name, int direction, int priority, PrefilterRegisterFunc PrefilterRegister, InspectionBufferGetDataPtr GetData, AppProto alproto, int tx_min_progress)
register an app layer keyword for mpm
Definition: detect-engine-mpm.c:151
SigMatch_::ctx
SigMatchCtx * ctx
Definition: detect.h:359
conf-yaml-loader.h
conf.h
SSLEnableJA3
void SSLEnableJA3(void)
if not explicitly disabled in config, enable ja3 support
Definition: app-layer-ssl.c:3489
Signature_::init_data
SignatureInitData * init_data
Definition: detect.h:749
RunmodeIsUnittests
int RunmodeIsUnittests(void)
Definition: suricata.c:257
DETECT_TLS_JA3_HASH
@ DETECT_TLS_JA3_HASH
Definition: detect-engine-register.h:258
SigMatchSilentErrorEnabled
bool SigMatchSilentErrorEnabled(const DetectEngineCtx *de_ctx, const enum DetectKeywordId id)
Definition: detect-parse.c:406
SigTableElmt_::alias
const char * alias
Definition: detect.h:1429
suricata-common.h
SigMatch_::type
uint16_t type
Definition: detect.h:357
util-spm.h
DetectContentData_::content
uint8_t * content
Definition: detect-content.h:94
detect-engine-buffer.h
DetectContentData_::spm_ctx
SpmCtx * spm_ctx
Definition: detect-content.h:111
SignatureInitData_::buffers
SignatureInitDataBuffer * buffers
Definition: detect.h:649
InspectionBuffer::inspect
const uint8_t * inspect
Definition: detect.h:381
str
#define str(s)
Definition: suricata-common.h:308
SCLogError
#define SCLogError(...)
Macro used to log ERROR messages.
Definition: util-debug.h:261
Flow_::alstate
void * alstate
Definition: flow.h:479
detect-parse.h
SignatureInitDataBuffer_::id
uint32_t id
Definition: detect.h:539
Signature_
Signature container.
Definition: detect.h:670
SigMatch_
a single match condition for a signature
Definition: detect.h:356
ALPROTO_UNKNOWN
@ ALPROTO_UNKNOWN
Definition: app-layer-protos.h:29
detect-tls-ja3-hash.h
DetectContentData_::content_len
uint16_t content_len
Definition: detect-content.h:95
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1620
DetectAppLayerInspectEngineRegister
void DetectAppLayerInspectEngineRegister(const char *name, AppProto alproto, uint32_t dir, int progress, InspectEngineFuncPtr Callback, InspectionBufferGetDataPtr GetData)
Registers an app inspection engine.
Definition: detect-engine.c:245
DetectEngineCtx_::spm_global_thread_ctx
SpmGlobalThreadCtx * spm_global_thread_ctx
Definition: detect.h:985
DetectBufferTypeSetDescriptionByName
void DetectBufferTypeSetDescriptionByName(const char *name, const char *desc)
Definition: detect-engine.c:1254
flow.h
SpmDestroyCtx
void SpmDestroyCtx(SpmCtx *ctx)
Definition: util-spm.c:183
SignatureInitData_::buffer_index
uint32_t buffer_index
Definition: detect.h:650
flow-var.h
SpmInitCtx
SpmCtx * SpmInitCtx(const uint8_t *needle, uint16_t needle_len, int nocase, SpmGlobalThreadCtx *global_thread_ctx)
Definition: util-spm.c:173
app-layer-ssl.h
app-layer.h