suricata
detect-tls-alpn.c
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1 /* Copyright (C) 2024 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 Victor Julien <vjulien@oisf.net>
22  *
23  * Implements support for tls.alpn 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"
37 #include "detect-content.h"
38 #include "detect-tls-alpn.h"
39 #include "detect-engine-uint.h"
40 
41 #include "flow.h"
42 #include "flow-util.h"
43 #include "flow-var.h"
44 
45 #include "util-debug.h"
46 #include "util-spm.h"
47 #include "util-print.h"
48 
49 #include "stream-tcp.h"
50 
51 #include "app-layer.h"
52 #include "app-layer-ssl.h"
53 #include "util-profiling.h"
54 
55 static int DetectTlsAlpnSetup(DetectEngineCtx *, Signature *, const char *);
56 static int g_tls_alpn_buffer_id = 0;
57 
58 static bool TlsAlpnGetData(DetectEngineThreadCtx *det_ctx, const void *txv, const uint8_t flags,
59  uint32_t idx, const uint8_t **buf, uint32_t *buf_len)
60 {
61  SCEnter();
62 
63  const SSLState *ssl_state = (SSLState *)txv;
64  const SSLStateConnp *connp;
65  CStringData d;
66 
67  if (flags & STREAM_TOSERVER) {
68  connp = &ssl_state->client_connp;
69  } else {
70  connp = &ssl_state->server_connp;
71  }
72 
73  if (SCTLSHandshakeGetALPN(connp->hs, idx, &d)) {
74  *buf = d.data;
75  *buf_len = (uint32_t)d.len;
76  return true;
77  } else {
78  return false;
79  }
80 }
81 
82 /**
83  * \brief Registration function for keyword: tls.alpn
84  */
86 {
87  sigmatch_table[DETECT_TLS_ALPN].name = "tls.alpn";
88  sigmatch_table[DETECT_TLS_ALPN].desc = "sticky buffer to match the TLS ALPN buffer";
89  sigmatch_table[DETECT_TLS_ALPN].url = "/rules/tls-keywords.html#tls-alpn";
90  sigmatch_table[DETECT_TLS_ALPN].Setup = DetectTlsAlpnSetup;
93 
95  TLS_STATE_CLIENT_HELLO_DONE, TlsAlpnGetData, 2);
97  "tls.alpn", ALPROTO_TLS, SIG_FLAG_TOCLIENT, TLS_STATE_SERVER_HELLO, TlsAlpnGetData, 2);
98 
99  DetectBufferTypeSetDescriptionByName("tls.alpn", "TLS APLN");
100 
102 
103  g_tls_alpn_buffer_id = DetectBufferTypeGetByName("tls.alpn");
104 }
105 
106 /**
107  * \brief This function setup the tls.alpn sticky buffer keyword
108  *
109  * \param de_ctx Pointer to the Detect Engine Context
110  * \param s Pointer to the Signature to which the keyword belongs
111  * \param str Should hold an empty string always
112  *
113  * \retval 0 On success
114  * \retval -1 On failure
115  */
116 static int DetectTlsAlpnSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
117 {
118  if (SCDetectBufferSetActiveList(de_ctx, s, g_tls_alpn_buffer_id) < 0)
119  return -1;
120 
122  return -1;
123 
124  return 0;
125 }
detect-engine-uint.h
SigTableElmt_::url
const char * url
Definition: detect.h:1422
SSLState_
SSLv[2.0|3.[0|1|2|3]] state structure.
Definition: app-layer-ssl.h:227
detect-content.h
detect-engine.h
SIGMATCH_INFO_STICKY_BUFFER
#define SIGMATCH_INFO_STICKY_BUFFER
Definition: detect.h:1636
SigTableElmt_::desc
const char * desc
Definition: detect.h:1421
sigmatch_table
SigTableElmt * sigmatch_table
Definition: detect-parse.c:79
flow-util.h
SigTableElmt_::name
const char * name
Definition: detect.h:1419
stream-tcp.h
SSLState_::client_connp
SSLStateConnp client_connp
Definition: app-layer-ssl.h:248
ALPROTO_TLS
@ ALPROTO_TLS
Definition: app-layer-protos.h:39
SSLState_::server_connp
SSLStateConnp server_connp
Definition: app-layer-ssl.h:249
SSLStateConnp_
Definition: app-layer-ssl.h:167
threads.h
SigTableElmt_::flags
uint16_t flags
Definition: detect.h:1413
DetectEngineCtx_
main detection engine ctx
Definition: detect.h:919
DetectBufferTypeSupportsMultiInstance
void DetectBufferTypeSupportsMultiInstance(const char *name)
Definition: detect-engine.c:1206
SCDetectBufferSetActiveList
int SCDetectBufferSetActiveList(DetectEngineCtx *de_ctx, Signature *s, const int list)
Definition: detect-engine-buffer.c:29
SCDetectSignatureSetAppProto
int SCDetectSignatureSetAppProto(Signature *s, AppProto alproto)
Definition: detect-parse.c:2212
SIG_FLAG_TOCLIENT
#define SIG_FLAG_TOCLIENT
Definition: detect.h:272
SigTableElmt_::Setup
int(* Setup)(DetectEngineCtx *, Signature *, const char *)
Definition: detect.h:1404
detect-engine-prefilter.h
DetectBufferTypeGetByName
int DetectBufferTypeGetByName(const char *name)
Definition: detect-engine.c:1256
SIG_FLAG_TOSERVER
#define SIG_FLAG_TOSERVER
Definition: detect.h:271
decode.h
util-debug.h
de_ctx
DetectEngineCtx * de_ctx
Definition: fuzz_siginit.c:18
DetectEngineThreadCtx_
Definition: detect.h:1211
TLS_STATE_CLIENT_HELLO_DONE
@ TLS_STATE_CLIENT_HELLO_DONE
Definition: app-layer-ssl.h:79
util-print.h
SCEnter
#define SCEnter(...)
Definition: util-debug.h:272
detect-engine-mpm.h
detect.h
util-profiling.h
detect-engine-content-inspection.h
DETECT_TLS_ALPN
@ DETECT_TLS_ALPN
Definition: detect-engine-register.h:148
flags
uint8_t flags
Definition: decode-gre.h:0
suricata-common.h
DetectTlsAlpnRegister
void DetectTlsAlpnRegister(void)
Registration function for keyword: tls.alpn.
Definition: detect-tls-alpn.c:85
util-spm.h
detect-engine-buffer.h
detect-tls-alpn.h
str
#define str(s)
Definition: suricata-common.h:308
detect-parse.h
Signature_
Signature container.
Definition: detect.h:657
SSLStateConnp_::hs
HandshakeParams * hs
Definition: app-layer-ssl.h:211
SIGMATCH_NOOPT
#define SIGMATCH_NOOPT
Definition: detect.h:1611
TLS_STATE_SERVER_HELLO
@ TLS_STATE_SERVER_HELLO
Definition: app-layer-ssl.h:87
DetectBufferTypeSetDescriptionByName
void DetectBufferTypeSetDescriptionByName(const char *name, const char *desc)
Definition: detect-engine.c:1353
DetectAppLayerMultiRegister
void DetectAppLayerMultiRegister(const char *name, AppProto alproto, uint32_t dir, int progress, InspectionMultiBufferGetDataPtr GetData, int priority)
Definition: detect-engine.c:2086
flow.h
flow-var.h
app-layer-ssl.h
app-layer.h