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
|
/* 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.
*/
/**
* \file
*
* \author Mats Klepsland <mats.klepsland@gmail.com>
*
* Implements support for tls.cert_issuer 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 "detect-pcre.h"
#include "flow.h"
#include "flow-util.h"
#include "flow-var.h"
#include "util-debug.h"
#include "util-spm.h"
#include "util-print.h"
#include "stream-tcp.h"
#include "app-layer.h"
#include "app-layer-ssl.h"
#include "detect-tls-cert-issuer.h"
#include "util-unittest.h"
#include "util-unittest-helper.h"
static int DetectTlsIssuerSetup(DetectEngineCtx *, Signature *, const char *);
#ifdef UNITTESTS
static void DetectTlsIssuerRegisterTests(void);
#endif
static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms,
Flow *f, const uint8_t flow_flags,
void *txv, const int list_id);
static int g_tls_cert_issuer_buffer_id = 0;
/**
* \brief Registration function for keyword: tls.cert_issuer
*/
void DetectTlsIssuerRegister(void)
{
sigmatch_table[DETECT_AL_TLS_CERT_ISSUER].name = "tls.cert_issuer";
sigmatch_table[DETECT_AL_TLS_CERT_ISSUER].alias = "tls_cert_issuer";
sigmatch_table[DETECT_AL_TLS_CERT_ISSUER].desc =
"sticky buffer to match specifically and only on the TLS cert issuer buffer";
sigmatch_table[DETECT_AL_TLS_CERT_ISSUER].url = "/rules/tls-keywords.html#tls-cert-issuer";
sigmatch_table[DETECT_AL_TLS_CERT_ISSUER].Setup = DetectTlsIssuerSetup;
#ifdef UNITTESTS
sigmatch_table[DETECT_AL_TLS_CERT_ISSUER].RegisterTests = DetectTlsIssuerRegisterTests;
#endif
sigmatch_table[DETECT_AL_TLS_CERT_ISSUER].flags |= SIGMATCH_NOOPT;
sigmatch_table[DETECT_AL_TLS_CERT_ISSUER].flags |= SIGMATCH_INFO_STICKY_BUFFER;
DetectAppLayerInspectEngineRegister2("tls.cert_issuer", ALPROTO_TLS, SIG_FLAG_TOSERVER,
TLS_STATE_CERT_READY, DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerMpmRegister2("tls.cert_issuer", SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister,
GetData, ALPROTO_TLS, TLS_STATE_CERT_READY);
DetectAppLayerInspectEngineRegister2("tls.cert_issuer", ALPROTO_TLS,
SIG_FLAG_TOCLIENT, TLS_STATE_CERT_READY,
DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerMpmRegister2("tls.cert_issuer", SIG_FLAG_TOCLIENT, 2,
PrefilterGenericMpmRegister, GetData, ALPROTO_TLS,
TLS_STATE_CERT_READY);
DetectBufferTypeSetDescriptionByName("tls.cert_issuer",
"TLS certificate issuer");
g_tls_cert_issuer_buffer_id = DetectBufferTypeGetByName("tls.cert_issuer");
}
/**
* \brief this function setup the tls_cert_issuer modifier 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 DetectTlsIssuerSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
if (DetectBufferSetActiveList(de_ctx, s, g_tls_cert_issuer_buffer_id) < 0)
return -1;
if (DetectSignatureSetAppProto(s, ALPROTO_TLS) < 0)
return -1;
return 0;
}
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) {
const SSLState *ssl_state = (SSLState *)f->alstate;
const SSLStateConnp *connp;
if (flow_flags & STREAM_TOSERVER) {
connp = &ssl_state->client_connp;
} else {
connp = &ssl_state->server_connp;
}
if (connp->cert0_issuerdn == NULL) {
return NULL;
}
const uint32_t data_len = strlen(connp->cert0_issuerdn);
const uint8_t *data = (uint8_t *)connp->cert0_issuerdn;
InspectionBufferSetup(det_ctx, list_id, buffer, data, data_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
#ifdef UNITTESTS
#include "tests/detect-tls-cert-issuer.c"
#endif
|
