You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
suricata/src/detect-tls-sni.c

336 lines
11 KiB
C

/* Copyright (C) 2007-2016 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_sni keyword.
*/
#include "suricata-common.h"
#include "threads.h"
#include "debug.h"
#include "decode.h"
#include "detect.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.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-unittest.h"
#include "util-spm.h"
#include "util-print.h"
#include "stream-tcp.h"
#include "app-layer.h"
#include "app-layer-ssl.h"
#include "detect-engine-prefilter.h"
#include "detect-tls-sni.h"
#include "util-unittest.h"
#include "util-unittest-helper.h"
static int DetectTlsSniSetup(DetectEngineCtx *, Signature *, const char *);
static void DetectTlsSniRegisterTests(void);
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_sni_buffer_id = 0;
/**
* \brief Registration function for keyword: tls_sni
*/
void DetectTlsSniRegister(void)
{
sigmatch_table[DETECT_AL_TLS_SNI].name = "tls_sni";
sigmatch_table[DETECT_AL_TLS_SNI].desc = "content modifier to match specifically and only on the TLS SNI buffer";
sigmatch_table[DETECT_AL_TLS_SNI].url = DOC_URL DOC_VERSION "/rules/tls-keywords.html#tls-sni";
sigmatch_table[DETECT_AL_TLS_SNI].Match = NULL;
sigmatch_table[DETECT_AL_TLS_SNI].Setup = DetectTlsSniSetup;
sigmatch_table[DETECT_AL_TLS_SNI].Free = NULL;
sigmatch_table[DETECT_AL_TLS_SNI].RegisterTests = DetectTlsSniRegisterTests;
sigmatch_table[DETECT_AL_TLS_SNI].flags |= SIGMATCH_NOOPT;
DetectAppLayerInspectEngineRegister2("tls_sni", ALPROTO_TLS, SIG_FLAG_TOSERVER, 0,
DetectEngineInspectBufferGeneric, GetData);
DetectAppLayerMpmRegister2("tls_sni", SIG_FLAG_TOSERVER, 2,
PrefilterGenericMpmRegister, GetData, ALPROTO_TLS, 0);
DetectBufferTypeSetDescriptionByName("tls_sni",
"TLS Server Name Indication (SNI) extension");
g_tls_sni_buffer_id = DetectBufferTypeGetByName("tls_sni");
}
/**
* \brief this function setup the tls_sni 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
*/
static int DetectTlsSniSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
DetectBufferSetActiveList(s, g_tls_sni_buffer_id);
s->alproto = ALPROTO_TLS;
return 0;
}
static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
const DetectEngineTransforms *transforms, Flow *_f,
const uint8_t _flow_flags, void *txv, const int list_id)
{
BUG_ON(det_ctx->inspect_buffers == NULL);
InspectionBuffer *buffer = &det_ctx->inspect_buffers[list_id];
if (buffer->inspect == NULL) {
SSLState *ssl_state = (SSLState *)_f->alstate;
if (ssl_state->client_connp.sni == NULL) {
return NULL;
}
const uint32_t data_len = strlen(ssl_state->client_connp.sni);
const uint8_t *data = (uint8_t *)ssl_state->client_connp.sni;
InspectionBufferSetup(buffer, data, data_len);
InspectionBufferApplyTransforms(buffer, transforms);
}
return buffer;
}
#ifdef UNITTESTS
/**
* \test Test matching on a simple google.com SNI
*/
static int DetectTlsSniTest01(void)
{
/* client hello */
uint8_t buf[] = { 0x16, 0x03, 0x03, 0x00, 0x82, 0x01, 0x00, 0x00, 0x7E,
0x03, 0x03, 0x57, 0x04, 0x9F, 0x5D, 0xC9, 0x5C, 0x87,
0xAE, 0xF2, 0xA7, 0x4A, 0xFC, 0x59, 0x78, 0x23, 0x31,
0x61, 0x2D, 0x29, 0x92, 0xB6, 0x70, 0xA5, 0xA1, 0xFC,
0x0E, 0x79, 0xFE, 0xC3, 0x97, 0x37, 0xC0, 0x00, 0x00,
0x44, 0x00, 0x04, 0x00, 0x05, 0x00, 0x0A, 0x00, 0x0D,
0x00, 0x10, 0x00, 0x13, 0x00, 0x16, 0x00, 0x2F, 0x00,
0x30, 0x00, 0x31, 0x00, 0x32, 0x00, 0x33, 0x00, 0x35,
0x00, 0x36, 0x00, 0x37, 0x00, 0x38, 0x00, 0x39, 0x00,
0x3C, 0x00, 0x3D, 0x00, 0x3E, 0x00, 0x3F, 0x00, 0x40,
0x00, 0x41, 0x00, 0x44, 0x00, 0x45, 0x00, 0x66, 0x00,
0x67, 0x00, 0x68, 0x00, 0x69, 0x00, 0x6A, 0x00, 0x6B,
0x00, 0x84, 0x00, 0x87, 0x00, 0xFF, 0x01, 0x00, 0x00,
0x13, 0x00, 0x00, 0x00, 0x0F, 0x00, 0x0D, 0x00, 0x00,
0x0A, 0x67, 0x6F, 0x6F, 0x67, 0x6C, 0x65, 0x2E, 0x63,
0x6F, 0x6D, };
Flow f;
SSLState *ssl_state = NULL;
Packet *p = NULL;
Signature *s = NULL;
ThreadVars tv;
DetectEngineThreadCtx *det_ctx = NULL;
TcpSession ssn;
AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();
memset(&tv, 0, sizeof(ThreadVars));
memset(&f, 0, sizeof(Flow));
memset(&ssn, 0, sizeof(TcpSession));
p = UTHBuildPacketReal(buf, sizeof(buf), IPPROTO_TCP,
"192.168.1.5", "192.168.1.1",
41424, 443);
FLOW_INITIALIZE(&f);
f.protoctx = (void *)&ssn;
f.flags |= FLOW_IPV4;
f.proto = IPPROTO_TCP;
f.protomap = FlowGetProtoMapping(f.proto);
p->flow = &f;
p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
p->flowflags |= FLOW_PKT_TOSERVER|FLOW_PKT_ESTABLISHED;
f.alproto = ALPROTO_TLS;
StreamTcpInitConfig(TRUE);
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->mpm_matcher = mpm_default_matcher;
de_ctx->flags |= DE_QUIET;
s = DetectEngineAppendSig(de_ctx, "alert tls any any -> any any "
"(msg:\"Test tls_sni option\"; "
"tls_sni; content:\"google.com\"; sid:1;)");
FAIL_IF_NULL(s);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
FLOWLOCK_WRLOCK(&f);
int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_TLS,
STREAM_TOSERVER, buf, sizeof(buf));
FLOWLOCK_UNLOCK(&f);
FAIL_IF(r != 0);
ssl_state = f.alstate;
FAIL_IF_NULL(ssl_state);
/* do detect */
SigMatchSignatures(&tv, de_ctx, det_ctx, p);
FAIL_IF_NOT(PacketAlertCheck(p, 1));
AppLayerParserThreadCtxFree(alp_tctx);
DetectEngineThreadCtxDeinit(&tv, det_ctx);
DetectEngineCtxFree(de_ctx);
StreamTcpFreeConfig(TRUE);
FLOW_DESTROY(&f);
UTHFreePacket(p);
PASS;
}
/**
* \test Test matching on a simple google.com SNI with pcre
*/
static int DetectTlsSniTest02(void)
{
/* client hello */
uint8_t buf[] = { 0x16, 0x03, 0x03, 0x00, 0x82, 0x01, 0x00, 0x00, 0x7E,
0x03, 0x03, 0x57, 0x04, 0x9F, 0x5D, 0xC9, 0x5C, 0x87,
0xAE, 0xF2, 0xA7, 0x4A, 0xFC, 0x59, 0x78, 0x23, 0x31,
0x61, 0x2D, 0x29, 0x92, 0xB6, 0x70, 0xA5, 0xA1, 0xFC,
0x0E, 0x79, 0xFE, 0xC3, 0x97, 0x37, 0xC0, 0x00, 0x00,
0x44, 0x00, 0x04, 0x00, 0x05, 0x00, 0x0A, 0x00, 0x0D,
0x00, 0x10, 0x00, 0x13, 0x00, 0x16, 0x00, 0x2F, 0x00,
0x30, 0x00, 0x31, 0x00, 0x32, 0x00, 0x33, 0x00, 0x35,
0x00, 0x36, 0x00, 0x37, 0x00, 0x38, 0x00, 0x39, 0x00,
0x3C, 0x00, 0x3D, 0x00, 0x3E, 0x00, 0x3F, 0x00, 0x40,
0x00, 0x41, 0x00, 0x44, 0x00, 0x45, 0x00, 0x66, 0x00,
0x67, 0x00, 0x68, 0x00, 0x69, 0x00, 0x6A, 0x00, 0x6B,
0x00, 0x84, 0x00, 0x87, 0x00, 0xFF, 0x01, 0x00, 0x00,
0x13, 0x00, 0x00, 0x00, 0x0F, 0x00, 0x0D, 0x00, 0x00,
0x0A, 0x67, 0x6F, 0x6F, 0x67, 0x6C, 0x65, 0x2E, 0x63,
0x6F, 0x6D, };
Flow f;
SSLState *ssl_state = NULL;
Packet *p = NULL;
Signature *s = NULL;
ThreadVars tv;
DetectEngineThreadCtx *det_ctx = NULL;
TcpSession ssn;
AppLayerParserThreadCtx *alp_tctx = AppLayerParserThreadCtxAlloc();
memset(&tv, 0, sizeof(ThreadVars));
memset(&f, 0, sizeof(Flow));
memset(&ssn, 0, sizeof(TcpSession));
p = UTHBuildPacketReal(buf, sizeof(buf), IPPROTO_TCP,
"192.168.1.5", "192.168.1.1",
41424, 443);
FLOW_INITIALIZE(&f);
f.protoctx = (void *)&ssn;
f.flags |= FLOW_IPV4;
f.proto = IPPROTO_TCP;
f.protomap = FlowGetProtoMapping(f.proto);
p->flow = &f;
p->flags |= PKT_HAS_FLOW|PKT_STREAM_EST;
p->flowflags |= FLOW_PKT_TOSERVER|FLOW_PKT_ESTABLISHED;
f.alproto = ALPROTO_TLS;
StreamTcpInitConfig(TRUE);
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->mpm_matcher = mpm_default_matcher;
de_ctx->flags |= DE_QUIET;
s = DetectEngineAppendSig(de_ctx, "alert tls any any -> any any "
"(msg:\"Test tls_sni option\"; "
"tls_sni; content:\"google\"; nocase; "
"pcre:\"/google\\.com$/i\"; sid:1;)");
FAIL_IF_NULL(s);
s = DetectEngineAppendSig(de_ctx, "alert tls any any -> any any "
"(msg:\"Test tls_sni option\"; "
"tls_sni; content:\"google\"; nocase; "
"pcre:\"/^\\.[a-z]{2,3}$/iR\"; sid:2;)");
FAIL_IF_NULL(s);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&tv, (void *)de_ctx, (void *)&det_ctx);
FLOWLOCK_WRLOCK(&f);
int r = AppLayerParserParse(NULL, alp_tctx, &f, ALPROTO_TLS,
STREAM_TOSERVER, buf, sizeof(buf));
FLOWLOCK_UNLOCK(&f);
FAIL_IF(r != 0);
ssl_state = f.alstate;
FAIL_IF_NULL(ssl_state);
/* do detect */
SigMatchSignatures(&tv, de_ctx, det_ctx, p);
FAIL_IF_NOT(PacketAlertCheck(p, 1));
FAIL_IF_NOT(PacketAlertCheck(p, 2));
AppLayerParserThreadCtxFree(alp_tctx);
DetectEngineThreadCtxDeinit(&tv, det_ctx);
DetectEngineCtxFree(de_ctx);
StreamTcpFreeConfig(TRUE);
FLOW_DESTROY(&f);
UTHFreePacket(p);
PASS;
}
#endif
static void DetectTlsSniRegisterTests(void)
{
#ifdef UNITTESTS
UtRegisterTest("DetectTlsSniTest01", DetectTlsSniTest01);
UtRegisterTest("DetectTlsSniTest02", DetectTlsSniTest02);
#endif
}