detect/ssh: remove deprecated keywords

Ticket: 2377
pull/11510/head
Philippe Antoine 1 year ago committed by Victor Julien
parent 0a1062fad2
commit bce8f4b853

@ -31,10 +31,6 @@ ssh.software
Match on the software string from the SSH banner. ``ssh.software`` is a sticky
buffer, and can be used as fast pattern.
``ssh.software`` replaces the previous keyword names: ``ssh_software`` &
``ssh.softwareversion``. You may continue to use the previous name, but it's
recommended that rules be converted to use the new name.
Format::
ssh.software;
@ -49,46 +45,6 @@ The example above matches on SSH connections where the software string contains
"openssh".
ssh.protoversion
----------------
Matches on the version of the SSH protocol used. A value of ``2_compat``
includes SSH version 1.99.
Format::
ssh.protoversion:[0-9](\.[0-9])?|2_compat;
Example:
.. container:: example-rule
alert ssh any any -> any any (msg:"SSH v2 compatible"; :example-rule-emphasis:`ssh.protoversion:2_compat;` sid:1;)
The example above matches on SSH connections with SSH version 2 or 1.99.
.. container:: example-rule
alert ssh any any -> any any (msg:"SSH v1.10"; :example-rule-emphasis:`ssh.protoversion:1.10;` sid:1;)
The example above matches on SSH connections with SSH version 1.10 only.
ssh.softwareversion
-------------------
This keyword has been deprecated. Please use ``ssh.software`` instead. Matches
on the software string from the SSH banner.
Example:
.. container:: example-rule
alert ssh any any -> any any (msg:"match SSH software string"; :example-rule-emphasis:`ssh.softwareversion:"OpenSSH";` sid:10000040;)
Suricata comes with a Hassh integration (https://github.com/salesforce/hassh). Hassh is used to fingerprint ssh clients and servers.
Hassh must be enabled in the Suricata config file (set 'app-layer.protocols.ssh.hassh' to 'yes').
ssh.hassh
---------

@ -95,10 +95,10 @@ They drop the traffic and create an 'xbit' 'badssh' for the source ip.
It expires in an hour::
drop ssh any any -> $MYSERVER 22 (msg:"DROP libssh incoming"; \
flow:to_server,established; ssh.softwareversion:"libssh"; \
flow:to_server,established; ssh.software; content:"libssh"; \
xbits:set, badssh, track ip_src, expire 3600; sid:4000000005;)
drop ssh any any -> $MYSERVER 22 (msg:"DROP PUTTY incoming"; \
flow:to_server,established; ssh.softwareversion:"PUTTY"; \
flow:to_server,established; ssh.software; content:"PUTTY"; \
xbits:set, badssh, track ip_src, expire 3600; sid:4000000007;)
Then the following rule simply drops any incoming traffic to that server

@ -71,6 +71,10 @@ Major changes
- PF_RING support has been moved to a plugin. See :doc:`PF_RING plugin
<upgrade/8.0-pfring-plugin>`.
Removals
~~~~~~~~
- The ssh keywords ``ssh.protoversion`` and ``ssh.softwareversion`` have been removed.
Upgrading 6.0 to 7.0
--------------------

@ -20,553 +20,25 @@
*
* \author Pablo Rincon <pablo.rincon.crespo@gmail.com>
*
* Implements the ssh.protoversion keyword
* You can specify a concrete version like ssh.protoversion: 1.66
* or search for protoversion 2 compat (1.99 is considered as 2) like
* ssh.protoversion:2_compat
* or just the beginning of the string like ssh.protoversion:"1."
*/
#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-state.h"
#include "detect-engine-build.h"
#include "flow.h"
#include "flow-var.h"
#include "flow-util.h"
#include "util-debug.h"
#include "util-unittest.h"
#include "util-unittest-helper.h"
#include "app-layer.h"
#include "app-layer-parser.h"
#include "app-layer-ssh.h"
#include "detect-engine-register.h"
#include "detect-ssh-proto-version.h"
#include "rust.h"
#include "stream-tcp.h"
/**
* \brief Regex for parsing the protoversion string
*/
#define PARSE_REGEX "^\\s*\"?\\s*([0-9]+([\\.\\-0-9]+)?|2_compat)\\s*\"?\\s*$"
static DetectParseRegex parse_regex;
static int DetectSshVersionMatch (DetectEngineThreadCtx *,
Flow *, uint8_t, void *, void *,
const Signature *, const SigMatchCtx *);
static int DetectSshVersionSetup (DetectEngineCtx *, Signature *, const char *);
#ifdef UNITTESTS
static void DetectSshVersionRegisterTests(void);
#endif
static void DetectSshVersionFree(DetectEngineCtx *, void *);
static int g_ssh_banner_list_id = 0;
/**
* \brief Registration function for keyword: ssh.protoversion
*/
void DetectSshVersionRegister(void)
{
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].name = "ssh.protoversion";
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].desc = "match SSH protocol version";
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].url = "/rules/ssh-keywords.html#ssh-protoversion";
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].AppLayerTxMatch = DetectSshVersionMatch;
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].Setup = DetectSshVersionSetup;
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].Free = DetectSshVersionFree;
#ifdef UNITTESTS
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].RegisterTests = DetectSshVersionRegisterTests;
#endif
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].flags = SIGMATCH_QUOTES_OPTIONAL|SIGMATCH_INFO_DEPRECATED;
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].alternative = DETECT_AL_SSH_PROTOCOL;
DetectSetupParseRegexes(PARSE_REGEX, &parse_regex);
g_ssh_banner_list_id = DetectBufferTypeRegister("ssh_banner");
}
/**
* \brief match the specified version on a ssh session
*
* \param t pointer to thread vars
* \param det_ctx pointer to the pattern matcher thread
* \param p pointer to the current packet
* \param m pointer to the sigmatch that we will cast into DetectSshVersionData
*
* \retval 0 no match
* \retval 1 match
*/
static int DetectSshVersionMatch (DetectEngineThreadCtx *det_ctx,
Flow *f, uint8_t flags, void *state, void *txv,
const Signature *s, const SigMatchCtx *m)
{
SCEnter();
SCLogDebug("lets see");
DetectSshVersionData *ssh = (DetectSshVersionData *)m;
if (state == NULL) {
SCLogDebug("no ssh state, no match");
SCReturnInt(0);
}
int ret = 0;
const uint8_t *protocol = NULL;
uint32_t b_len = 0;
if (rs_ssh_tx_get_protocol(txv, &protocol, &b_len, flags) != 1)
SCReturnInt(0);
if (protocol == NULL || b_len == 0)
SCReturnInt(0);
if (ssh->flags & SSH_FLAG_PROTOVERSION_2_COMPAT) {
SCLogDebug("looking for ssh protoversion 2 compat");
if (protocol[0] == '2') {
ret = 1;
} else if (b_len >= 4) {
if (memcmp(protocol, "1.99", 4) == 0) {
ret = 1;
}
}
} else {
SCLogDebug("looking for ssh protoversion %s length %"PRIu16"", ssh->ver, ssh->len);
if (b_len == ssh->len) {
if (memcmp(protocol, ssh->ver, ssh->len) == 0) {
ret = 1;
}
}
}
SCReturnInt(ret);
}
/**
* \brief This function is used to parse IPV4 ip_id passed via keyword: "id"
*
* \param de_ctx Pointer to the detection engine context
* \param idstr Pointer to the user provided id option
*
* \retval id_d pointer to DetectSshVersionData on success
* \retval NULL on failure
*/
static DetectSshVersionData *DetectSshVersionParse (DetectEngineCtx *de_ctx, const char *str)
{
DetectSshVersionData *ssh = NULL;
int res = 0;
size_t pcre2_len;
pcre2_match_data *match = NULL;
int ret = DetectParsePcreExec(&parse_regex, &match, str, 0, 0);
if (ret < 1 || ret > 3) {
SCLogError("invalid ssh.protoversion option");
goto error;
}
if (ret > 1) {
const char *str_ptr;
res = pcre2_substring_get_bynumber(match, 1, (PCRE2_UCHAR8 **)&str_ptr, &pcre2_len);
if (res < 0) {
SCLogError("pcre2_substring_get_bynumber failed");
goto error;
}
/* We have a correct id option */
ssh = SCCalloc(1, sizeof(DetectSshVersionData));
if (unlikely(ssh == NULL)) {
pcre2_substring_free((PCRE2_UCHAR *)str_ptr);
goto error;
}
/* If we expect a protocol version 2 or 1.99 (considered 2, we
* will compare it with both strings) */
if (strcmp("2_compat", str_ptr) == 0) {
ssh->flags |= SSH_FLAG_PROTOVERSION_2_COMPAT;
SCLogDebug("will look for ssh protocol version 2 (2, 2.0, 1.99 that's considered as 2");
pcre2_substring_free((PCRE2_UCHAR *)str_ptr);
return ssh;
}
ssh->ver = (uint8_t *)SCStrdup((char*)str_ptr);
if (ssh->ver == NULL) {
pcre2_substring_free((PCRE2_UCHAR *)str_ptr);
goto error;
}
ssh->len = (uint16_t)strlen((char *)ssh->ver);
pcre2_substring_free((PCRE2_UCHAR *)str_ptr);
SCLogDebug("will look for ssh %s", ssh->ver);
}
pcre2_match_data_free(match);
return ssh;
error:
if (match) {
pcre2_match_data_free(match);
}
if (ssh != NULL)
DetectSshVersionFree(de_ctx, ssh);
return NULL;
}
/**
* \brief this function is used to add the parsed "id" option
* \brief into the current signature
*
* \param de_ctx pointer to the Detection Engine Context
* \param s pointer to the Current Signature
* \param idstr pointer to the user provided "id" option
*
* \retval 0 on Success
* \retval -1 on Failure
*/
static int DetectSshVersionSetup (DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
DetectSshVersionData *ssh = NULL;
if (DetectSignatureSetAppProto(s, ALPROTO_SSH) != 0)
return -1;
ssh = DetectSshVersionParse(de_ctx, str);
if (ssh == NULL)
goto error;
/* Okay so far so good, lets get this into a SigMatch
* and put it in the Signature. */
if (SigMatchAppendSMToList(de_ctx, s, DETECT_AL_SSH_PROTOVERSION, (SigMatchCtx *)ssh,
g_ssh_banner_list_id) == NULL) {
goto error;
}
return 0;
error:
if (ssh != NULL)
DetectSshVersionFree(de_ctx, ssh);
SCLogError("ssh.protoversion is obsolete, use now ssh.proto");
return -1;
}
/**
* \brief this function will free memory associated with DetectSshVersionData
*
* \param id_d pointer to DetectSshVersionData
*/
void DetectSshVersionFree(DetectEngineCtx *de_ctx, void *ptr)
{
DetectSshVersionData *sshd = (DetectSshVersionData *)ptr;
SCFree(sshd->ver);
SCFree(sshd);
}
#ifdef UNITTESTS /* UNITTESTS */
#include "detect-engine-alert.h"
/**
* \test DetectSshVersionTestParse01 is a test to make sure that we parse
* a proto version correctly
*/
static int DetectSshVersionTestParse01 (void)
{
DetectSshVersionData *ssh = NULL;
ssh = DetectSshVersionParse(NULL, "1.0");
FAIL_IF_NULL(ssh);
FAIL_IF_NOT(strncmp((char *)ssh->ver, "1.0", 3) == 0);
DetectSshVersionFree(NULL, ssh);
PASS;
}
/**
* \test DetectSshVersionTestParse02 is a test to make sure that we parse
* the proto version (compatible with proto version 2) correctly
*/
static int DetectSshVersionTestParse02 (void)
{
DetectSshVersionData *ssh = NULL;
ssh = DetectSshVersionParse(NULL, "2_compat");
FAIL_IF_NOT(ssh->flags & SSH_FLAG_PROTOVERSION_2_COMPAT);
DetectSshVersionFree(NULL, ssh);
PASS;
}
/**
* \test DetectSshVersionTestParse03 is a test to make sure that we
* don't return a ssh_data with an invalid value specified
*/
static int DetectSshVersionTestParse03 (void)
{
DetectSshVersionData *ssh = NULL;
ssh = DetectSshVersionParse(NULL, "2_com");
FAIL_IF_NOT_NULL(ssh);
ssh = DetectSshVersionParse(NULL, "");
FAIL_IF_NOT_NULL(ssh);
ssh = DetectSshVersionParse(NULL, ".1");
FAIL_IF_NOT_NULL(ssh);
ssh = DetectSshVersionParse(NULL, "lalala");
FAIL_IF_NOT_NULL(ssh);
PASS;
}
#include "stream-tcp-reassemble.h"
#include "stream-tcp-util.h"
/** \test Send a get request in three chunks + more data. */
static int DetectSshVersionTestDetect01(void)
{
TcpReassemblyThreadCtx *ra_ctx = NULL;
ThreadVars tv;
TcpSession ssn;
Flow *f = NULL;
Packet *p = NULL;
uint8_t sshbuf1[] = "SSH-1.";
uint8_t sshbuf2[] = "10-PuTTY_2.123" ;
uint8_t sshbuf3[] = "\n";
uint8_t sshbuf4[] = "whatever...";
uint8_t* sshbufs[4] = {sshbuf1, sshbuf2, sshbuf3, sshbuf4};
uint32_t sshlens[4] = {sizeof(sshbuf1) - 1, sizeof(sshbuf2) - 1, sizeof(sshbuf3) - 1, sizeof(sshbuf4) - 1};
memset(&tv, 0x00, sizeof(tv));
StreamTcpUTInit(&ra_ctx);
StreamTcpUTInitInline();
StreamTcpUTSetupSession(&ssn);
StreamTcpUTSetupStream(&ssn.server, 1);
StreamTcpUTSetupStream(&ssn.client, 1);
f = UTHBuildFlow(AF_INET, "1.1.1.1", "2.2.2.2", 1234, 2222);
FAIL_IF_NULL(f);
f->protoctx = &ssn;
f->proto = IPPROTO_TCP;
f->alproto = ALPROTO_SSH;
p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);
FAIL_IF(unlikely(p == NULL));
p->flow = f;
Signature *s = NULL;
ThreadVars th_v;
DetectEngineThreadCtx *det_ctx = NULL;
memset(&th_v, 0, sizeof(th_v));
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->flags |= DE_QUIET;
s = de_ctx->sig_list = SigInit(de_ctx,"alert ssh any any -> any any (msg:\"SSH\"; ssh.protoversion:1.10; sid:1;)");
FAIL_IF_NULL(s);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
uint32_t seq = 2;
for (int i=0; i<4; i++) {
FAIL_IF(StreamTcpUTAddSegmentWithPayload(&tv, ra_ctx, &ssn.server, seq, sshbufs[i], sshlens[i]) == -1);
seq += sshlens[i];
FAIL_IF(StreamTcpReassembleAppLayer(&tv, ra_ctx, &ssn, &ssn.server, p, UPDATE_DIR_PACKET) < 0);
}
void *ssh_state = f->alstate;
FAIL_IF_NULL(ssh_state);
/* do detect */
SigMatchSignatures(&th_v, de_ctx, det_ctx, p);
FAIL_IF(PacketAlertCheck(p, 1));
DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx);
DetectEngineCtxFree(de_ctx);
UTHFreePacket(p);
StreamTcpUTClearSession(&ssn);
StreamTcpUTDeinit(ra_ctx);
UTHFreeFlow(f);
PASS;
}
/** \test Send a get request in three chunks + more data. */
static int DetectSshVersionTestDetect02(void)
{
TcpReassemblyThreadCtx *ra_ctx = NULL;
ThreadVars tv;
TcpSession ssn;
Flow *f = NULL;
Packet *p = NULL;
uint8_t sshbuf1[] = "SSH-1.99-Pu";
uint8_t sshbuf2[] = "TTY_2.123" ;
uint8_t sshbuf3[] = "\n";
uint8_t sshbuf4[] = "whatever...";
uint8_t* sshbufs[4] = {sshbuf1, sshbuf2, sshbuf3, sshbuf4};
uint32_t sshlens[4] = {sizeof(sshbuf1) - 1, sizeof(sshbuf2) - 1, sizeof(sshbuf3) - 1, sizeof(sshbuf4) - 1};
memset(&tv, 0x00, sizeof(tv));
StreamTcpUTInit(&ra_ctx);
StreamTcpUTInitInline();
StreamTcpUTSetupSession(&ssn);
StreamTcpUTSetupStream(&ssn.server, 1);
StreamTcpUTSetupStream(&ssn.client, 1);
f = UTHBuildFlow(AF_INET, "1.1.1.1", "2.2.2.2", 1234, 2222);
FAIL_IF_NULL(f);
f->protoctx = &ssn;
f->proto = IPPROTO_TCP;
f->alproto = ALPROTO_SSH;
p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);
FAIL_IF(unlikely(p == NULL));
p->flow = f;
Signature *s = NULL;
ThreadVars th_v;
DetectEngineThreadCtx *det_ctx = NULL;
memset(&th_v, 0, sizeof(th_v));
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->flags |= DE_QUIET;
s = de_ctx->sig_list = SigInit(de_ctx,"alert ssh any any -> any any (msg:\"SSH\"; ssh.protoversion:2_compat; sid:1;)");
FAIL_IF_NULL(s);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
uint32_t seq = 2;
for (int i=0; i<4; i++) {
FAIL_IF(StreamTcpUTAddSegmentWithPayload(&tv, ra_ctx, &ssn.server, seq, sshbufs[i], sshlens[i]) == -1);
seq += sshlens[i];
FAIL_IF(StreamTcpReassembleAppLayer(&tv, ra_ctx, &ssn, &ssn.server, p, UPDATE_DIR_PACKET) < 0);
}
void *ssh_state = f->alstate;
FAIL_IF_NULL(ssh_state);
/* do detect */
SigMatchSignatures(&th_v, de_ctx, det_ctx, p);
FAIL_IF(PacketAlertCheck(p, 1));
DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx);
DetectEngineCtxFree(de_ctx);
UTHFreePacket(p);
StreamTcpUTClearSession(&ssn);
StreamTcpUTDeinit(ra_ctx);
UTHFreeFlow(f);
PASS;
}
/** \test Send a get request in three chunks + more data. */
static int DetectSshVersionTestDetect03(void)
{
TcpReassemblyThreadCtx *ra_ctx = NULL;
ThreadVars tv;
TcpSession ssn;
Flow *f = NULL;
Packet *p = NULL;
uint8_t sshbuf1[] = "SSH-1.";
uint8_t sshbuf2[] = "7-PuTTY_2.123" ;
uint8_t sshbuf3[] = "\n";
uint8_t sshbuf4[] = "whatever...";
uint8_t* sshbufs[4] = {sshbuf1, sshbuf2, sshbuf3, sshbuf4};
uint32_t sshlens[4] = {sizeof(sshbuf1) - 1, sizeof(sshbuf2) - 1, sizeof(sshbuf3) - 1, sizeof(sshbuf4) - 1};
memset(&tv, 0x00, sizeof(tv));
StreamTcpUTInit(&ra_ctx);
StreamTcpUTInitInline();
StreamTcpUTSetupSession(&ssn);
StreamTcpUTSetupStream(&ssn.server, 1);
StreamTcpUTSetupStream(&ssn.client, 1);
f = UTHBuildFlow(AF_INET, "1.1.1.1", "2.2.2.2", 1234, 2222);
FAIL_IF_NULL(f);
f->protoctx = &ssn;
f->proto = IPPROTO_TCP;
f->alproto = ALPROTO_SSH;
p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);
FAIL_IF(unlikely(p == NULL));
p->flow = f;
Signature *s = NULL;
ThreadVars th_v;
DetectEngineThreadCtx *det_ctx = NULL;
memset(&th_v, 0, sizeof(th_v));
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->flags |= DE_QUIET;
s = de_ctx->sig_list = SigInit(de_ctx,"alert ssh any any -> any any (msg:\"SSH\"; ssh.protoversion:2_compat; sid:1;)");
FAIL_IF_NULL(s);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
uint32_t seq = 2;
for (int i=0; i<4; i++) {
FAIL_IF(StreamTcpUTAddSegmentWithPayload(&tv, ra_ctx, &ssn.server, seq, sshbufs[i], sshlens[i]) == -1);
seq += sshlens[i];
FAIL_IF(StreamTcpReassembleAppLayer(&tv, ra_ctx, &ssn, &ssn.server, p, UPDATE_DIR_PACKET) < 0);
}
void *ssh_state = f->alstate;
FAIL_IF_NULL(ssh_state);
/* do detect */
SigMatchSignatures(&th_v, de_ctx, det_ctx, p);
FAIL_IF(PacketAlertCheck(p, 1));
DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx);
DetectEngineCtxFree(de_ctx);
UTHFreePacket(p);
StreamTcpUTClearSession(&ssn);
StreamTcpUTDeinit(ra_ctx);
UTHFreeFlow(f);
PASS;
}
/**
* \brief this function registers unit tests for DetectSshVersion
* \brief Registration function for keyword: ssh.protoversion
*/
static void DetectSshVersionRegisterTests(void)
void DetectSshVersionRegister(void)
{
UtRegisterTest("DetectSshVersionTestParse01", DetectSshVersionTestParse01);
UtRegisterTest("DetectSshVersionTestParse02", DetectSshVersionTestParse02);
UtRegisterTest("DetectSshVersionTestParse03", DetectSshVersionTestParse03);
UtRegisterTest("DetectSshVersionTestDetect01",
DetectSshVersionTestDetect01);
UtRegisterTest("DetectSshVersionTestDetect02",
DetectSshVersionTestDetect02);
UtRegisterTest("DetectSshVersionTestDetect03",
DetectSshVersionTestDetect03);
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].name = "ssh.protoversion";
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].desc = "obsolete keyword, use now ssh.proto";
sigmatch_table[DETECT_AL_SSH_PROTOVERSION].Setup = DetectSshVersionSetup;
}
#endif /* UNITTESTS */

@ -24,15 +24,6 @@
#ifndef SURICATA_DETECT_SSH_VERSION_H
#define SURICATA_DETECT_SSH_VERSION_H
/** proto version 1.99 is considered proto version 2 */
#define SSH_FLAG_PROTOVERSION_2_COMPAT 0x01
typedef struct DetectSshVersionData_ {
uint8_t *ver; /** ssh version to match */
uint16_t len; /** ssh version length to match */
uint8_t flags;
} DetectSshVersionData;
/* prototypes */
void DetectSshVersionRegister (void);

@ -20,548 +20,25 @@
*
* \author Pablo Rincon <pablo.rincon.crespo@gmail.com>
*
* Implements the ssh.softwareversion keyword
* You can match over the software version string of ssh, and it will
* be compared from the beginning of the string so you can say for
* example ssh.softwareversion:"PuTTY" and it can match, or you can
* also specify the version, something like
* ssh.softwareversion:"PuTTY-Release-0.55"
* I find this useful to match over a known vulnerable server/client
* software version in combination to other checks, so you can know
* that the risk is higher
*/
#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-state.h"
#include "detect-engine-build.h"
#include "flow.h"
#include "flow-var.h"
#include "flow-util.h"
#include "util-debug.h"
#include "util-unittest.h"
#include "util-unittest-helper.h"
#include "app-layer.h"
#include "app-layer-parser.h"
#include "app-layer-ssh.h"
#include "detect-engine-register.h"
#include "detect-ssh-software-version.h"
#include "rust.h"
#include "stream-tcp.h"
/**
* \brief Regex for parsing the softwareversion string
*/
#define PARSE_REGEX "^\\s*\"?\\s*?([0-9a-zA-Z\\:\\.\\-\\_\\+\\s+]+)\\s*\"?\\s*$"
static DetectParseRegex parse_regex;
static int DetectSshSoftwareVersionMatch (DetectEngineThreadCtx *,
Flow *, uint8_t, void *, void *,
const Signature *, const SigMatchCtx *);
static int DetectSshSoftwareVersionSetup (DetectEngineCtx *, Signature *, const char *);
#ifdef UNITTESTS
static void DetectSshSoftwareVersionRegisterTests(void);
#endif
static void DetectSshSoftwareVersionFree(DetectEngineCtx *de_ctx, void *);
static int g_ssh_banner_list_id = 0;
/**
* \brief Registration function for keyword: ssh.softwareversion
*/
void DetectSshSoftwareVersionRegister(void)
{
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].name = "ssh.softwareversion";
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].desc = "match SSH software string";
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].url = "/rules/ssh-keywords.html#ssh-softwareversion";
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].AppLayerTxMatch = DetectSshSoftwareVersionMatch;
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].Setup = DetectSshSoftwareVersionSetup;
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].Free = DetectSshSoftwareVersionFree;
#ifdef UNITTESTS
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].RegisterTests = DetectSshSoftwareVersionRegisterTests;
#endif
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].flags = SIGMATCH_QUOTES_OPTIONAL|SIGMATCH_INFO_DEPRECATED;
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].alternative = DETECT_AL_SSH_SOFTWARE;
DetectSetupParseRegexes(PARSE_REGEX, &parse_regex);
g_ssh_banner_list_id = DetectBufferTypeRegister("ssh_banner");
DetectAppLayerInspectEngineRegister("ssh_banner", ALPROTO_SSH, SIG_FLAG_TOSERVER,
SshStateBannerDone, DetectEngineInspectGenericList, NULL);
DetectAppLayerInspectEngineRegister("ssh_banner", ALPROTO_SSH, SIG_FLAG_TOCLIENT,
SshStateBannerDone, DetectEngineInspectGenericList, NULL);
}
/**
* \brief match the specified version on a ssh session
*
* \param t pointer to thread vars
* \param det_ctx pointer to the pattern matcher thread
* \param p pointer to the current packet
* \param m pointer to the sigmatch that we will cast into DetectSshSoftwareVersionData
*
* \retval 0 no match
* \retval 1 match
*/
static int DetectSshSoftwareVersionMatch (DetectEngineThreadCtx *det_ctx,
Flow *f, uint8_t flags, void *state, void *txv,
const Signature *s, const SigMatchCtx *m)
{
SCEnter();
DetectSshSoftwareVersionData *ssh = (DetectSshSoftwareVersionData *)m;
if (state == NULL) {
SCLogDebug("no ssh state, no match");
SCReturnInt(0);
}
int ret = 0;
const uint8_t *software = NULL;
uint32_t b_len = 0;
if (rs_ssh_tx_get_software(txv, &software, &b_len, flags) != 1)
SCReturnInt(0);
if (software == NULL || b_len == 0)
SCReturnInt(0);
if (b_len == ssh->len) {
if (memcmp(software, ssh->software_ver, ssh->len) == 0) {
ret = 1;
}
}
SCReturnInt(ret);
}
/**
* \brief This function is used to parse IPV4 ip_id passed via keyword: "id"
*
* \param de_ctx Pointer to the detection engine context
* \param idstr Pointer to the user provided id option
*
* \retval id_d pointer to DetectSshSoftwareVersionData on success
* \retval NULL on failure
*/
static DetectSshSoftwareVersionData *DetectSshSoftwareVersionParse (DetectEngineCtx *de_ctx, const char *str)
{
DetectSshSoftwareVersionData *ssh = NULL;
int res = 0;
size_t pcre2_len;
pcre2_match_data *match = NULL;
int ret = DetectParsePcreExec(&parse_regex, &match, str, 0, 0);
if (ret < 1 || ret > 3) {
SCLogError("invalid ssh.softwareversion option");
goto error;
}
if (ret > 1) {
const char *str_ptr = NULL;
res = pcre2_substring_get_bynumber(match, 1, (PCRE2_UCHAR8 **)&str_ptr, &pcre2_len);
if (res < 0) {
SCLogError("pcre2_substring_get_bynumber failed");
goto error;
}
/* We have a correct id option */
ssh = SCMalloc(sizeof(DetectSshSoftwareVersionData));
if (unlikely(ssh == NULL)) {
pcre2_substring_free((PCRE2_UCHAR *)str_ptr);
goto error;
}
ssh->software_ver = (uint8_t *)SCStrdup((char *)str_ptr);
if (ssh->software_ver == NULL) {
pcre2_substring_free((PCRE2_UCHAR *)str_ptr);
goto error;
}
pcre2_substring_free((PCRE2_UCHAR *)str_ptr);
ssh->len = (uint16_t)strlen((char *)ssh->software_ver);
SCLogDebug("will look for ssh %s", ssh->software_ver);
}
pcre2_match_data_free(match);
return ssh;
error:
if (match) {
pcre2_match_data_free(match);
}
if (ssh != NULL)
DetectSshSoftwareVersionFree(de_ctx, ssh);
return NULL;
}
/**
* \brief this function is used to add the parsed "id" option
* \brief into the current signature
*
* \param de_ctx pointer to the Detection Engine Context
* \param s pointer to the Current Signature
* \param idstr pointer to the user provided "id" option
*
* \retval 0 on Success
* \retval -1 on Failure
*/
static int DetectSshSoftwareVersionSetup (DetectEngineCtx *de_ctx, Signature *s, const char *str)
{
DetectSshSoftwareVersionData *ssh = NULL;
if (DetectSignatureSetAppProto(s, ALPROTO_SSH) != 0)
return -1;
ssh = DetectSshSoftwareVersionParse(NULL, str);
if (ssh == NULL)
goto error;
/* Okay so far so good, lets get this into a SigMatch
* and put it in the Signature. */
if (SigMatchAppendSMToList(de_ctx, s, DETECT_AL_SSH_SOFTWAREVERSION, (SigMatchCtx *)ssh,
g_ssh_banner_list_id) == NULL) {
goto error;
}
return 0;
error:
if (ssh != NULL)
DetectSshSoftwareVersionFree(de_ctx, ssh);
SCLogError("ssh.softwareversion is obsolete, use now ssh.software");
return -1;
}
/**
* \brief this function will free memory associated with DetectSshSoftwareVersionData
*
* \param id_d pointer to DetectSshSoftwareVersionData
*/
static void DetectSshSoftwareVersionFree(DetectEngineCtx *de_ctx, void *ptr)
{
if (ptr == NULL)
return;
DetectSshSoftwareVersionData *ssh = (DetectSshSoftwareVersionData *)ptr;
if (ssh->software_ver != NULL)
SCFree(ssh->software_ver);
SCFree(ssh);
}
#ifdef UNITTESTS /* UNITTESTS */
#include "detect-engine-alert.h"
/**
* \test DetectSshSoftwareVersionTestParse01 is a test to make sure that we parse
* a software version correctly
*/
static int DetectSshSoftwareVersionTestParse01 (void)
{
DetectSshSoftwareVersionData *ssh = NULL;
ssh = DetectSshSoftwareVersionParse(NULL, "PuTTY_1.0");
if (ssh != NULL && strncmp((char *) ssh->software_ver, "PuTTY_1.0", 9) == 0) {
DetectSshSoftwareVersionFree(NULL, ssh);
return 1;
}
return 0;
}
/**
* \test DetectSshSoftwareVersionTestParse02 is a test to make sure that we parse
* the software version correctly
*/
static int DetectSshSoftwareVersionTestParse02 (void)
{
DetectSshSoftwareVersionData *ssh = NULL;
ssh = DetectSshSoftwareVersionParse(NULL, "\"SecureCRT-4.0\"");
if (ssh != NULL && strncmp((char *) ssh->software_ver, "SecureCRT-4.0", 13) == 0) {
DetectSshSoftwareVersionFree(NULL, ssh);
return 1;
}
return 0;
}
/**
* \test DetectSshSoftwareVersionTestParse03 is a test to make sure that we
* don't return a ssh_data with an empty value specified
*/
static int DetectSshSoftwareVersionTestParse03 (void)
{
DetectSshSoftwareVersionData *ssh = NULL;
ssh = DetectSshSoftwareVersionParse(NULL, "");
if (ssh != NULL) {
DetectSshSoftwareVersionFree(NULL, ssh);
return 0;
}
return 1;
}
#include "stream-tcp-reassemble.h"
#include "stream-tcp-util.h"
/** \test Send a get request in three chunks + more data. */
static int DetectSshSoftwareVersionTestDetect01(void)
{
TcpReassemblyThreadCtx *ra_ctx = NULL;
ThreadVars tv;
TcpSession ssn;
Flow *f = NULL;
Packet *p = NULL;
uint8_t sshbuf1[] = "SSH-1.";
uint8_t sshbuf2[] = "10-PuTTY_2.123" ;
uint8_t sshbuf3[] = "\n";
uint8_t sshbuf4[] = "whatever...";
uint8_t* sshbufs[4] = {sshbuf1, sshbuf2, sshbuf3, sshbuf4};
uint32_t sshlens[4] = {sizeof(sshbuf1) - 1, sizeof(sshbuf2) - 1, sizeof(sshbuf3) - 1, sizeof(sshbuf4) - 1};
memset(&tv, 0x00, sizeof(tv));
StreamTcpUTInit(&ra_ctx);
StreamTcpUTInitInline();
StreamTcpUTSetupSession(&ssn);
StreamTcpUTSetupStream(&ssn.server, 1);
StreamTcpUTSetupStream(&ssn.client, 1);
f = UTHBuildFlow(AF_INET, "1.1.1.1", "2.2.2.2", 1234, 2222);
FAIL_IF_NULL(f);
f->protoctx = &ssn;
f->proto = IPPROTO_TCP;
f->alproto = ALPROTO_SSH;
p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);
FAIL_IF(unlikely(p == NULL));
p->flow = f;
Signature *s = NULL;
ThreadVars th_v;
DetectEngineThreadCtx *det_ctx = NULL;
memset(&th_v, 0, sizeof(th_v));
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->flags |= DE_QUIET;
s = de_ctx->sig_list = SigInit(de_ctx,"alert ssh any any -> any any (msg:\"SSH\"; ssh.softwareversion:PuTTY_2.123; sid:1;)");
FAIL_IF_NULL(s);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
uint32_t seq = 2;
for (int i=0; i<4; i++) {
FAIL_IF(StreamTcpUTAddSegmentWithPayload(&tv, ra_ctx, &ssn.server, seq, sshbufs[i], sshlens[i]) == -1);
seq += sshlens[i];
FAIL_IF(StreamTcpReassembleAppLayer(&tv, ra_ctx, &ssn, &ssn.server, p, UPDATE_DIR_PACKET) < 0);
}
void *ssh_state = f->alstate;
FAIL_IF_NULL(ssh_state);
/* do detect */
SigMatchSignatures(&th_v, de_ctx, det_ctx, p);
FAIL_IF(PacketAlertCheck(p, 1));
DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx);
DetectEngineCtxFree(de_ctx);
UTHFreePacket(p);
StreamTcpUTClearSession(&ssn);
StreamTcpUTDeinit(ra_ctx);
UTHFreeFlow(f);
PASS;
}
/** \test Send a get request in three chunks + more data. */
static int DetectSshSoftwareVersionTestDetect02(void)
{
TcpReassemblyThreadCtx *ra_ctx = NULL;
ThreadVars tv;
TcpSession ssn;
Flow *f = NULL;
Packet *p = NULL;
uint8_t sshbuf1[] = "SSH-1.99-Pu";
uint8_t sshbuf2[] = "TTY_2.123" ;
uint8_t sshbuf3[] = "\n";
uint8_t sshbuf4[] = "whatever...";
uint8_t* sshbufs[4] = {sshbuf1, sshbuf2, sshbuf3, sshbuf4};
uint32_t sshlens[4] = {sizeof(sshbuf1) - 1, sizeof(sshbuf2) - 1, sizeof(sshbuf3) - 1, sizeof(sshbuf4) - 1};
memset(&tv, 0x00, sizeof(tv));
StreamTcpUTInit(&ra_ctx);
StreamTcpUTInitInline();
StreamTcpUTSetupSession(&ssn);
StreamTcpUTSetupStream(&ssn.server, 1);
StreamTcpUTSetupStream(&ssn.client, 1);
f = UTHBuildFlow(AF_INET, "1.1.1.1", "2.2.2.2", 1234, 2222);
FAIL_IF_NULL(f);
f->protoctx = &ssn;
f->proto = IPPROTO_TCP;
f->alproto = ALPROTO_SSH;
p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);
FAIL_IF(unlikely(p == NULL));
p->flow = f;
Signature *s = NULL;
ThreadVars th_v;
DetectEngineThreadCtx *det_ctx = NULL;
memset(&th_v, 0, sizeof(th_v));
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->flags |= DE_QUIET;
s = de_ctx->sig_list = SigInit(de_ctx,"alert ssh any any -> any any (msg:\"SSH\"; ssh.softwareversion:PuTTY_2.123; sid:1;)");
FAIL_IF_NULL(s);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
uint32_t seq = 2;
for (int i=0; i<4; i++) {
FAIL_IF(StreamTcpUTAddSegmentWithPayload(&tv, ra_ctx, &ssn.server, seq, sshbufs[i], sshlens[i]) == -1);
seq += sshlens[i];
FAIL_IF(StreamTcpReassembleAppLayer(&tv, ra_ctx, &ssn, &ssn.server, p, UPDATE_DIR_PACKET) < 0);
}
void *ssh_state = f->alstate;
FAIL_IF_NULL(ssh_state);
/* do detect */
SigMatchSignatures(&th_v, de_ctx, det_ctx, p);
FAIL_IF(PacketAlertCheck(p, 1));
DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx);
DetectEngineCtxFree(de_ctx);
UTHFreePacket(p);
StreamTcpUTClearSession(&ssn);
StreamTcpUTDeinit(ra_ctx);
UTHFreeFlow(f);
PASS;
}
/** \test Send a get request in three chunks + more data. */
static int DetectSshSoftwareVersionTestDetect03(void)
{
TcpReassemblyThreadCtx *ra_ctx = NULL;
ThreadVars tv;
TcpSession ssn;
Flow *f = NULL;
Packet *p = NULL;
uint8_t sshbuf1[] = "SSH-1.";
uint8_t sshbuf2[] = "7-PuTTY_2.123" ;
uint8_t sshbuf3[] = "\n";
uint8_t sshbuf4[] = "whatever...";
uint8_t* sshbufs[4] = {sshbuf1, sshbuf2, sshbuf3, sshbuf4};
uint32_t sshlens[4] = {sizeof(sshbuf1) - 1, sizeof(sshbuf2) - 1, sizeof(sshbuf3) - 1, sizeof(sshbuf4) - 1};
memset(&tv, 0x00, sizeof(tv));
StreamTcpUTInit(&ra_ctx);
StreamTcpUTInitInline();
StreamTcpUTSetupSession(&ssn);
StreamTcpUTSetupStream(&ssn.server, 1);
StreamTcpUTSetupStream(&ssn.client, 1);
f = UTHBuildFlow(AF_INET, "1.1.1.1", "2.2.2.2", 1234, 2222);
FAIL_IF_NULL(f);
f->protoctx = &ssn;
f->proto = IPPROTO_TCP;
f->alproto = ALPROTO_SSH;
p = UTHBuildPacket(NULL, 0, IPPROTO_TCP);
FAIL_IF(unlikely(p == NULL));
p->flow = f;
Signature *s = NULL;
ThreadVars th_v;
DetectEngineThreadCtx *det_ctx = NULL;
memset(&th_v, 0, sizeof(th_v));
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
FAIL_IF_NULL(de_ctx);
de_ctx->flags |= DE_QUIET;
s = de_ctx->sig_list = SigInit(de_ctx,"alert ssh any any -> any any (msg:\"SSH\"; ssh.softwareversion:lalala-3.1.4; sid:1;)");
FAIL_IF_NULL(s);
SigGroupBuild(de_ctx);
DetectEngineThreadCtxInit(&th_v, (void *)de_ctx, (void *)&det_ctx);
uint32_t seq = 2;
for (int i=0; i<4; i++) {
FAIL_IF(StreamTcpUTAddSegmentWithPayload(&tv, ra_ctx, &ssn.server, seq, sshbufs[i], sshlens[i]) == -1);
seq += sshlens[i];
FAIL_IF(StreamTcpReassembleAppLayer(&tv, ra_ctx, &ssn, &ssn.server, p, UPDATE_DIR_PACKET) < 0);
}
void *ssh_state = f->alstate;
FAIL_IF_NULL(ssh_state);
/* do detect */
SigMatchSignatures(&th_v, de_ctx, det_ctx, p);
FAIL_IF(PacketAlertCheck(p, 1));
DetectEngineThreadCtxDeinit(&th_v, (void *)det_ctx);
DetectEngineCtxFree(de_ctx);
UTHFreePacket(p);
StreamTcpUTClearSession(&ssn);
StreamTcpUTDeinit(ra_ctx);
UTHFreeFlow(f);
PASS;
}
/**
* \brief this function registers unit tests for DetectSshSoftwareVersion
* \brief Registration function for keyword: ssh.softwareversion
*/
static void DetectSshSoftwareVersionRegisterTests(void)
void DetectSshSoftwareVersionRegister(void)
{
UtRegisterTest("DetectSshSoftwareVersionTestParse01",
DetectSshSoftwareVersionTestParse01);
UtRegisterTest("DetectSshSoftwareVersionTestParse02",
DetectSshSoftwareVersionTestParse02);
UtRegisterTest("DetectSshSoftwareVersionTestParse03",
DetectSshSoftwareVersionTestParse03);
UtRegisterTest("DetectSshSoftwareVersionTestDetect01",
DetectSshSoftwareVersionTestDetect01);
UtRegisterTest("DetectSshSoftwareVersionTestDetect02",
DetectSshSoftwareVersionTestDetect02);
UtRegisterTest("DetectSshSoftwareVersionTestDetect03",
DetectSshSoftwareVersionTestDetect03);
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].name = "ssh.softwareversion";
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].desc = "obsolete keyword, use now ssh.software";
sigmatch_table[DETECT_AL_SSH_SOFTWAREVERSION].Setup = DetectSshSoftwareVersionSetup;
}
#endif /* UNITTESTS */

@ -24,11 +24,6 @@
#ifndef SURICATA_DETECT_SSH_SOFTWARE_VERSION_H
#define SURICATA_DETECT_SSH_SOFTWARE_VERSION_H
typedef struct DetectSshSoftwareVersionData_ {
uint8_t *software_ver; /** ssh version to match */
uint16_t len; /** ssh version length to match */
} DetectSshSoftwareVersionData;
/* prototypes */
void DetectSshSoftwareVersionRegister(void);

Loading…
Cancel
Save