add RFB parser
This commit adds support for the Remote Framebuffer Protocol (RFB) as
used, for example, by various VNC implementations. It targets the
official versions 3.3, 3.7 and 3.8 of the protocol and provides logging
for the RFB handshake communication for now. Logged events include
endpoint versions, details of the security (i.e. authentication)
exchange as well as metadata about the image transfer parameters.
Detection is enabled using keywords for:
- rfb.name: Session name as sticky buffer
- rfb.sectype: Security type, e.g. VNC-style challenge-response
- rfb.secresult: Result of the security exchange, e.g. OK, FAIL, ...
The latter could be used, for example, to detect brute-force attempts
on open VNC servers, while the name could be used to map unwanted VNC
sessions to the desktop owners or machines.
We also ship example EVE-JSON output and keyword docs as part of the
Sphinx source for Suricata's RTD documentation.
5 years ago
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/* Copyright (C) 2020 Open Information Security Foundation
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*
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* You can copy, redistribute or modify this Program under the terms of
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* the GNU General Public License version 2 as published by the Free
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* Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* version 2 along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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/**
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*
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* \author Sascha Steinbiss <sascha.steinbiss@dcso.de>
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*/
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#include "suricata-common.h"
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#include "threads.h"
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#include "debug.h"
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#include "decode.h"
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#include "detect.h"
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#include "detect-parse.h"
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#include "detect-engine.h"
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#include "detect-engine-mpm.h"
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#include "detect-engine-prefilter.h"
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#include "detect-urilen.h"
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#include "flow.h"
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#include "flow-var.h"
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#include "flow-util.h"
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#include "util-debug.h"
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#include "util-unittest.h"
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#include "util-unittest-helper.h"
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#include "util-spm.h"
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#include "app-layer.h"
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#include "app-layer-parser.h"
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#include "detect-rfb-name.h"
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#include "stream-tcp.h"
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#include "rust.h"
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#include "app-layer-rfb.h"
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#include "rust-bindings.h"
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#define KEYWORD_NAME "rfb.name"
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#define KEYWORD_DOC "rfb-keywords.html#rfb-name";
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#define BUFFER_NAME "rfb.name"
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#define BUFFER_DESC "rfb name"
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static int g_buffer_id = 0;
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static int DetectRfbNameSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str)
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{
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if (DetectBufferSetActiveList(s, g_buffer_id) < 0)
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return -1;
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if (DetectSignatureSetAppProto(s, ALPROTO_RFB) < 0)
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return -1;
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return 0;
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}
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static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
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const DetectEngineTransforms *transforms, Flow *_f,
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const uint8_t _flow_flags, void *txv, const int list_id)
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{
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InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id);
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if (buffer->inspect == NULL) {
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const uint8_t *b = NULL;
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uint32_t b_len = 0;
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if (rs_rfb_tx_get_name(txv, &b, &b_len) != 1)
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return NULL;
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if (b == NULL || b_len == 0)
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return NULL;
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InspectionBufferSetup(buffer, b, b_len);
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InspectionBufferApplyTransforms(buffer, transforms);
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}
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return buffer;
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}
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void DetectRfbNameRegister(void)
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{
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sigmatch_table[DETECT_AL_RFB_NAME].name = KEYWORD_NAME;
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sigmatch_table[DETECT_AL_RFB_NAME].url = "/rules/" KEYWORD_DOC
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add RFB parser
This commit adds support for the Remote Framebuffer Protocol (RFB) as
used, for example, by various VNC implementations. It targets the
official versions 3.3, 3.7 and 3.8 of the protocol and provides logging
for the RFB handshake communication for now. Logged events include
endpoint versions, details of the security (i.e. authentication)
exchange as well as metadata about the image transfer parameters.
Detection is enabled using keywords for:
- rfb.name: Session name as sticky buffer
- rfb.sectype: Security type, e.g. VNC-style challenge-response
- rfb.secresult: Result of the security exchange, e.g. OK, FAIL, ...
The latter could be used, for example, to detect brute-force attempts
on open VNC servers, while the name could be used to map unwanted VNC
sessions to the desktop owners or machines.
We also ship example EVE-JSON output and keyword docs as part of the
Sphinx source for Suricata's RTD documentation.
5 years ago
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sigmatch_table[DETECT_AL_RFB_NAME].desc = "sticky buffer to match on the RFB desktop name";
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sigmatch_table[DETECT_AL_RFB_NAME].Setup = DetectRfbNameSetup;
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sigmatch_table[DETECT_AL_RFB_NAME].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER;
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DetectAppLayerInspectEngineRegister2(BUFFER_NAME, ALPROTO_RFB,
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SIG_FLAG_TOCLIENT, 1,
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DetectEngineInspectBufferGeneric, GetData);
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DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOCLIENT, 1,
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PrefilterGenericMpmRegister, GetData, ALPROTO_RFB,
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1);
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DetectBufferTypeSetDescriptionByName(BUFFER_NAME, BUFFER_DESC);
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g_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
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SCLogDebug("registering " BUFFER_NAME " rule option");
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}
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