mirror of https://github.com/OISF/suricata
Add krb5_err_code detection keyword
Pierre Chifflier
7 years ago
parent
d6b9c0294a
commit
1076c7cd47
@ -0,0 +1,275 @@
|
||||
/* Copyright (C) 2018 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 Pierre Chifflier <chifflier@wzdftpd.net>
|
||||
*/
|
||||
|
||||
#include "suricata-common.h"
|
||||
#include "util-unittest.h"
|
||||
|
||||
#include "detect-parse.h"
|
||||
#include "detect-engine.h"
|
||||
|
||||
#include "detect-krb5-errcode.h"
|
||||
|
||||
#ifdef HAVE_RUST
|
||||
|
||||
#include "app-layer-krb5.h"
|
||||
#include "rust-krb-detect-gen.h"
|
||||
|
||||
/**
|
||||
* \brief Regex for parsing our keyword options
|
||||
*/
|
||||
#define PARSE_REGEX "^\\s*([A-z0-9\\.]+|\"[A-z0-9_\\.]+\")\\s*$"
|
||||
static pcre *parse_regex;
|
||||
static pcre_extra *parse_regex_study;
|
||||
|
||||
/* Prototypes of functions registered in DetectKrb5ErrCodeRegister below */
|
||||
static int DetectKrb5ErrCodeMatch (ThreadVars *, DetectEngineThreadCtx *, Flow *,
|
||||
uint8_t, void *, void *, const Signature *,
|
||||
const SigMatchCtx *);
|
||||
static int DetectKrb5ErrCodeSetup (DetectEngineCtx *, Signature *, const char *);
|
||||
static void DetectKrb5ErrCodeFree (void *);
|
||||
static void DetectKrb5ErrCodeRegisterTests (void);
|
||||
|
||||
static int DetectEngineInspectKRB5Generic(ThreadVars *tv,
|
||||
DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx,
|
||||
const Signature *s, const SigMatchData *smd,
|
||||
Flow *f, uint8_t flags, void *alstate,
|
||||
void *txv, uint64_t tx_id);
|
||||
|
||||
static int g_krb5_err_code_list_id = 0;
|
||||
|
||||
/**
|
||||
* \brief Registration function for krb5_err_code: keyword
|
||||
*
|
||||
* This function is called once in the 'lifetime' of the engine.
|
||||
*/
|
||||
void DetectKrb5ErrCodeRegister(void) {
|
||||
sigmatch_table[DETECT_AL_KRB5_ERRCODE].name = "krb5_err_code";
|
||||
sigmatch_table[DETECT_AL_KRB5_ERRCODE].desc = "match Kerberos 5 message type";
|
||||
sigmatch_table[DETECT_AL_KRB5_ERRCODE].url = DOC_URL DOC_VERSION "/rules/kerberos-keywords.html#krb5_err_code";
|
||||
sigmatch_table[DETECT_AL_KRB5_ERRCODE].Match = NULL;
|
||||
sigmatch_table[DETECT_AL_KRB5_ERRCODE].AppLayerTxMatch = DetectKrb5ErrCodeMatch;
|
||||
sigmatch_table[DETECT_AL_KRB5_ERRCODE].Setup = DetectKrb5ErrCodeSetup;
|
||||
sigmatch_table[DETECT_AL_KRB5_ERRCODE].Free = DetectKrb5ErrCodeFree;
|
||||
sigmatch_table[DETECT_AL_KRB5_ERRCODE].RegisterTests = DetectKrb5ErrCodeRegisterTests;
|
||||
|
||||
DetectAppLayerInspectEngineRegister("krb5_err_code",
|
||||
ALPROTO_KRB5, SIG_FLAG_TOSERVER, 0,
|
||||
DetectEngineInspectKRB5Generic);
|
||||
|
||||
DetectAppLayerInspectEngineRegister("krb5_err_code",
|
||||
ALPROTO_KRB5, SIG_FLAG_TOCLIENT, 0,
|
||||
DetectEngineInspectKRB5Generic);
|
||||
|
||||
/* set up the PCRE for keyword parsing */
|
||||
DetectSetupParseRegexes(PARSE_REGEX, &parse_regex, &parse_regex_study);
|
||||
|
||||
g_krb5_err_code_list_id = DetectBufferTypeRegister("krb5_err_code");
|
||||
SCLogDebug("g_krb5_err_code_list_id %d", g_krb5_err_code_list_id);
|
||||
}
|
||||
|
||||
static int DetectEngineInspectKRB5Generic(ThreadVars *tv,
|
||||
DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx,
|
||||
const Signature *s, const SigMatchData *smd,
|
||||
Flow *f, uint8_t flags, void *alstate,
|
||||
void *txv, uint64_t tx_id)
|
||||
{
|
||||
return DetectEngineInspectGenericList(tv, de_ctx, det_ctx, s, smd,
|
||||
f, flags, alstate, txv, tx_id);
|
||||
}
|
||||
|
||||
/**
|
||||
* \brief This function is used to match KRB5 rule option on a packet
|
||||
*
|
||||
* \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 with context that we will cast into DetectKrb5Data
|
||||
*
|
||||
* \retval 0 no match
|
||||
* \retval 1 match
|
||||
*/
|
||||
static int DetectKrb5ErrCodeMatch (ThreadVars *t, DetectEngineThreadCtx *det_ctx,
|
||||
Flow *f, uint8_t flags, void *state,
|
||||
void *txv, const Signature *s,
|
||||
const SigMatchCtx *ctx)
|
||||
{
|
||||
int32_t err_code;
|
||||
int ret;
|
||||
const DetectKrb5ErrCodeData *dd = (const DetectKrb5ErrCodeData *)ctx;
|
||||
|
||||
SCEnter();
|
||||
|
||||
ret = rs_krb5_tx_get_errcode(txv, &err_code);
|
||||
if (ret != 0)
|
||||
SCReturnInt(0);
|
||||
|
||||
if (dd->err_code == err_code)
|
||||
SCReturnInt(1);
|
||||
|
||||
SCReturnInt(0);
|
||||
}
|
||||
|
||||
/**
|
||||
* \brief This function is used to parse options passed via krb5_errcode: keyword
|
||||
*
|
||||
* \param krb5str Pointer to the user provided krb5_err_code options
|
||||
*
|
||||
* \retval krb5d pointer to DetectKrb5Data on success
|
||||
* \retval NULL on failure
|
||||
*/
|
||||
static DetectKrb5ErrCodeData *DetectKrb5ErrCodeParse (const char *krb5str)
|
||||
{
|
||||
DetectKrb5ErrCodeData *krb5d = NULL;
|
||||
char arg1[4] = "";
|
||||
#define MAX_SUBSTRINGS 30
|
||||
int ret = 0, res = 0;
|
||||
int ov[MAX_SUBSTRINGS];
|
||||
|
||||
ret = pcre_exec(parse_regex, parse_regex_study,
|
||||
krb5str, strlen(krb5str),
|
||||
0, 0, ov, MAX_SUBSTRINGS);
|
||||
if (ret != 2) {
|
||||
SCLogError(SC_ERR_PCRE_MATCH, "parse error, ret %" PRId32 "", ret);
|
||||
goto error;
|
||||
}
|
||||
|
||||
res = pcre_copy_substring((char *) krb5str, ov, MAX_SUBSTRINGS, 1, arg1, sizeof(arg1));
|
||||
if (res < 0) {
|
||||
SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre_copy_substring failed");
|
||||
goto error;
|
||||
}
|
||||
|
||||
krb5d = SCMalloc(sizeof (DetectKrb5ErrCodeData));
|
||||
if (unlikely(krb5d == NULL))
|
||||
goto error;
|
||||
krb5d->err_code = (int32_t)atoi(arg1);
|
||||
|
||||
return krb5d;
|
||||
|
||||
error:
|
||||
if (krb5d)
|
||||
SCFree(krb5d);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/**
|
||||
* \brief parse the options from the 'krb5_err_code' keyword in the rule into
|
||||
* the Signature data structure.
|
||||
*
|
||||
* \param de_ctx pointer to the Detection Engine Context
|
||||
* \param s pointer to the Current Signature
|
||||
* \param krb5str pointer to the user provided options
|
||||
*
|
||||
* \retval 0 on Success
|
||||
* \retval -1 on Failure
|
||||
*/
|
||||
static int DetectKrb5ErrCodeSetup (DetectEngineCtx *de_ctx, Signature *s, const char *krb5str)
|
||||
{
|
||||
DetectKrb5ErrCodeData *krb5d = NULL;
|
||||
SigMatch *sm = NULL;
|
||||
|
||||
if (DetectSignatureSetAppProto(s, ALPROTO_KRB5) != 0)
|
||||
return -1;
|
||||
|
||||
krb5d = DetectKrb5ErrCodeParse(krb5str);
|
||||
if (krb5d == NULL)
|
||||
goto error;
|
||||
|
||||
sm = SigMatchAlloc();
|
||||
if (sm == NULL)
|
||||
goto error;
|
||||
|
||||
sm->type = DETECT_AL_KRB5_ERRCODE;
|
||||
sm->ctx = (void *)krb5d;
|
||||
|
||||
s->flags |= SIG_FLAG_STATE_MATCH;
|
||||
SigMatchAppendSMToList(s, sm, g_krb5_err_code_list_id);
|
||||
|
||||
return 0;
|
||||
|
||||
error:
|
||||
if (krb5d != NULL)
|
||||
DetectKrb5ErrCodeFree(krb5d);
|
||||
if (sm != NULL)
|
||||
SCFree(sm);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/**
|
||||
* \brief this function will free memory associated with DetectKrb5Data
|
||||
*
|
||||
* \param ptr pointer to DetectKrb5Data
|
||||
*/
|
||||
static void DetectKrb5ErrCodeFree(void *ptr) {
|
||||
DetectKrb5ErrCodeData *krb5d = (DetectKrb5ErrCodeData *)ptr;
|
||||
|
||||
SCFree(krb5d);
|
||||
}
|
||||
|
||||
#ifdef UNITTESTS
|
||||
|
||||
/**
|
||||
* \test description of the test
|
||||
*/
|
||||
|
||||
static int DetectKrb5ErrCodeParseTest01 (void)
|
||||
{
|
||||
DetectKrb5ErrCodeData *krb5d = DetectKrb5ErrCodeParse("10");
|
||||
FAIL_IF_NULL(krb5d);
|
||||
FAIL_IF(!(krb5d->err_code == 10));
|
||||
DetectKrb5ErrCodeFree(krb5d);
|
||||
PASS;
|
||||
}
|
||||
|
||||
static int DetectKrb5ErrCodeSignatureTest01 (void)
|
||||
{
|
||||
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
|
||||
FAIL_IF_NULL(de_ctx);
|
||||
|
||||
Signature *sig = DetectEngineAppendSig(de_ctx, "alert krb5 any any -> any any (krb5_err_code:10; sid:1; rev:1;)");
|
||||
FAIL_IF_NULL(sig);
|
||||
|
||||
DetectEngineCtxFree(de_ctx);
|
||||
PASS;
|
||||
}
|
||||
|
||||
#endif /* UNITTESTS */
|
||||
|
||||
/**
|
||||
* \brief this function registers unit tests for DetectKrb5ErrCode
|
||||
*/
|
||||
static void DetectKrb5ErrCodeRegisterTests(void) {
|
||||
#ifdef UNITTESTS
|
||||
UtRegisterTest("DetectKrb5ErrCodeParseTest01", DetectKrb5ErrCodeParseTest01);
|
||||
UtRegisterTest("DetectKrb5ErrCodeSignatureTest01",
|
||||
DetectKrb5ErrCodeSignatureTest01);
|
||||
#endif /* UNITTESTS */
|
||||
}
|
||||
|
||||
#else /* HAVE_RUST */
|
||||
|
||||
void DetectKrb5ErrCodeRegister(void)
|
||||
{
|
||||
}
|
||||
|
||||
#endif /* HAVE_RUST */
|
||||
@ -0,0 +1,33 @@
|
||||
/* Copyright (C) 2015-2017 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 Pierre Chifflier <chifflier@wzdftpd.net>
|
||||
*/
|
||||
|
||||
#ifndef __DETECT_KRB5_ERRCODE_H__
|
||||
#define __DETECT_KRB5_ERRCODE_H__
|
||||
|
||||
typedef struct DetectKrb5ErrCodeData_ {
|
||||
int32_t err_code;
|
||||
} DetectKrb5ErrCodeData;
|
||||
|
||||
void DetectKrb5ErrCodeRegister(void);
|
||||
|
||||
#endif /* __DETECT_KRB5_ERRCODE_H__ */
|
||||
Loading…
Reference in New Issue