--- /dev/null
+/* 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 */
projects / thirdparty / suricata.git / commitdiff
