1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
|
/* Copyright (C) 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.
*/
#include "suricata-common.h"
#include "threads.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
#include "detect-content.h"
#include "flow.h"
#include "stream-tcp.h"
#include "app-layer.h"
#include "app-layer-ssl.h"
#include "detect-engine-prefilter.h"
#include "detect-tls-random.h"
#define DETECT_TLS_RANDOM_TIME_LEN 4
#define DETECT_TLS_RANDOM_BYTES_LEN 28
static int DetectTlsRandomTimeSetup(DetectEngineCtx *, Signature *, const char *);
static int DetectTlsRandomBytesSetup(DetectEngineCtx *, Signature *, const char *);
static int DetectTlsRandomSetup(DetectEngineCtx *, Signature *, const char *);
static InspectionBuffer *GetRandomTimeData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Flow *f, const uint8_t flow_flags, void *txv,
const int list_id);
static InspectionBuffer *GetRandomBytesData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Flow *f, const uint8_t flow_flags, void *txv,
const int list_id);
static InspectionBuffer *GetRandomData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Flow *f, const uint8_t flow_flags, void *txv,
const int list_id);
static int g_tls_random_time_buffer_id = 0;
static int g_tls_random_bytes_buffer_id = 0;
static int g_tls_random_buffer_id = 0;
void DetectTlsRandomTimeRegister(void)
{
sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].name = "tls.random_time";
sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].desc = "sticky buffer to match specifically and only "
"on the first 4 bytes of a TLS random buffer";
sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].url = "/rules/tls-keywords.html#tls-random-time";
sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].Setup = DetectTlsRandomTimeSetup;
sigmatch_table[DETECT_AL_TLS_RANDOM_TIME].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
/* Register engine for Server random */
DetectAppLayerInspectEngineRegister2("tls.random_time", ALPROTO_TLS, SIG_FLAG_TOSERVER, 0,
DetectEngineInspectBufferGeneric, GetRandomTimeData);
DetectAppLayerMpmRegister2("tls.random_time", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
GetRandomTimeData, ALPROTO_TLS, 0);
/* Register engine for Client random */
DetectAppLayerInspectEngineRegister2("tls.random_time", ALPROTO_TLS, SIG_FLAG_TOCLIENT, 0,
DetectEngineInspectBufferGeneric, GetRandomTimeData);
DetectAppLayerMpmRegister2("tls.random_time", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister,
GetRandomTimeData, ALPROTO_TLS, 0);
DetectBufferTypeSetDescriptionByName("tls.random_time", "TLS Random Time");
g_tls_random_time_buffer_id = DetectBufferTypeGetByName("tls.random_time");
}
void DetectTlsRandomBytesRegister(void)
{
sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].name = "tls.random_bytes";
sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].desc =
"sticky buffer to match specifically and only on the last 28 bytes of a TLS random "
"buffer";
sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].url = "/rules/tls-keywords.html#tls-random-bytes";
sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].Setup = DetectTlsRandomBytesSetup;
sigmatch_table[DETECT_AL_TLS_RANDOM_BYTES].flags |=
SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
/* Register engine for Server random */
DetectAppLayerInspectEngineRegister2("tls.random_bytes", ALPROTO_TLS, SIG_FLAG_TOSERVER, 0,
DetectEngineInspectBufferGeneric, GetRandomBytesData);
DetectAppLayerMpmRegister2("tls.random_bytes", SIG_FLAG_TOSERVER, 2,
PrefilterGenericMpmRegister, GetRandomBytesData, ALPROTO_TLS, 0);
/* Register engine for Client random */
DetectAppLayerInspectEngineRegister2("tls.random_bytes", ALPROTO_TLS, SIG_FLAG_TOCLIENT, 0,
DetectEngineInspectBufferGeneric, GetRandomBytesData);
DetectAppLayerMpmRegister2("tls.random_bytes", SIG_FLAG_TOCLIENT, 2,
PrefilterGenericMpmRegister, GetRandomBytesData, ALPROTO_TLS, 0);
DetectBufferTypeSetDescriptionByName("tls.random_bytes", "TLS Random Bytes");
g_tls_random_bytes_buffer_id = DetectBufferTypeGetByName("tls.random_bytes");
}
/**
* \brief Registration function for keyword: tls.random
*/
void DetectTlsRandomRegister(void)
{
DetectTlsRandomTimeRegister();
DetectTlsRandomBytesRegister();
sigmatch_table[DETECT_AL_TLS_RANDOM].name = "tls.random";
sigmatch_table[DETECT_AL_TLS_RANDOM].desc =
"sticky buffer to match specifically and only on a TLS random buffer";
sigmatch_table[DETECT_AL_TLS_RANDOM].url = "/rules/tls-keywords.html#tls-random";
sigmatch_table[DETECT_AL_TLS_RANDOM].Setup = DetectTlsRandomSetup;
sigmatch_table[DETECT_AL_TLS_RANDOM].flags |= SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER;
/* Register engine for Server random */
DetectAppLayerInspectEngineRegister2("tls.random", ALPROTO_TLS, SIG_FLAG_TOSERVER, 0,
DetectEngineInspectBufferGeneric, GetRandomData);
DetectAppLayerMpmRegister2("tls.random", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
GetRandomData, ALPROTO_TLS, 0);
/* Register engine for Client random */
DetectAppLayerInspectEngineRegister2("tls.random", ALPROTO_TLS, SIG_FLAG_TOCLIENT, 0,
DetectEngineInspectBufferGeneric, GetRandomData);
DetectAppLayerMpmRegister2("tls.random", SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister,
GetRandomData, ALPROTO_TLS, 0);
DetectBufferTypeSetDescriptionByName("tls.random", "TLS Random");
g_tls_random_buffer_id = DetectBufferTypeGetByName("tls.random");
}
/**
* \brief this function setup the tls.random_time sticky buffer 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
* \retval -1 On failure
*/
static int DetectTlsRandomTimeSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
if (DetectBufferSetActiveList(de_ctx, s, g_tls_random_time_buffer_id) < 0)
return -1;
if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
return -1;
return 0;
}
/**
* \brief this function setup the tls.random_bytes sticky buffer 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
* \retval -1 On failure
*/
static int DetectTlsRandomBytesSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
if (DetectBufferSetActiveList(de_ctx, s, g_tls_random_bytes_buffer_id) < 0)
return -1;
if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
return -1;
return 0;
}
/**
* \brief this function setup the tls.random sticky buffer 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
* \retval -1 On failure
*/
static int DetectTlsRandomSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
if (DetectBufferSetActiveList(de_ctx, s, g_tls_random_buffer_id) < 0)
return -1;
if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
return -1;
return 0;
}
static InspectionBuffer *GetRandomTimeData(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) {
const SSLState *ssl_state = (SSLState *)f->alstate;
if (flow_flags & STREAM_TOSERVER) {
if (!(ssl_state->flags & TLS_TS_RANDOM_SET))
return NULL;
} else {
if (!(ssl_state->flags & TLS_TC_RANDOM_SET))
return NULL;
}
const uint32_t data_len = DETECT_TLS_RANDOM_TIME_LEN;
const uint8_t *data;
if (flow_flags & STREAM_TOSERVER) {
data = ssl_state->server_connp.random;
} else {
data = ssl_state->client_connp.random;
}
InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
static InspectionBuffer *GetRandomBytesData(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) {
const SSLState *ssl_state = (SSLState *)f->alstate;
if (flow_flags & STREAM_TOSERVER) {
if (!(ssl_state->flags & TLS_TS_RANDOM_SET))
return NULL;
} else {
if (!(ssl_state->flags & TLS_TC_RANDOM_SET))
return NULL;
}
const uint32_t data_len = DETECT_TLS_RANDOM_BYTES_LEN;
const uint8_t *data;
if (flow_flags & STREAM_TOSERVER) {
data = ssl_state->server_connp.random + DETECT_TLS_RANDOM_TIME_LEN;
} else {
data = ssl_state->client_connp.random + DETECT_TLS_RANDOM_TIME_LEN;
}
InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
static InspectionBuffer *GetRandomData(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) {
const SSLState *ssl_state = (SSLState *)f->alstate;
if (flow_flags & STREAM_TOSERVER) {
if (!(ssl_state->flags & TLS_TS_RANDOM_SET))
return NULL;
} else {
if (!(ssl_state->flags & TLS_TC_RANDOM_SET))
return NULL;
}
const uint32_t data_len = TLS_RANDOM_LEN;
const uint8_t *data;
if (flow_flags & STREAM_TOSERVER) {
data = ssl_state->server_connp.random;
} else {
data = ssl_state->client_connp.random;
}
InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
|
