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/* Copyright (C) 2007-2010 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 Victor Julien <victor@inliniac.net>
*
* Implements the msg keyword
*/
#include "suricata-common.h"
#include "detect.h"
#include "util-classification-config.h"
#include "util-debug.h"
#include "util-unittest.h"
#include "detect-parse.h"
#include "detect-engine.h"
#include "detect-engine-mpm.h"
static int DetectMsgSetup (DetectEngineCtx *, Signature *, char *);
void DetectMsgRegisterTests(void);
void DetectMsgRegister (void)
{
sigmatch_table[DETECT_MSG].name = "msg";
sigmatch_table[DETECT_MSG].desc = "information about the rule and the possible alert";
sigmatch_table[DETECT_MSG].url = "https://redmine.openinfosecfoundation.org/projects/suricata/wiki/Meta-settings#msg-message";
sigmatch_table[DETECT_MSG].Match = NULL;
sigmatch_table[DETECT_MSG].Setup = DetectMsgSetup;
sigmatch_table[DETECT_MSG].Free = NULL;
sigmatch_table[DETECT_MSG].RegisterTests = DetectMsgRegisterTests;
}
static int DetectMsgSetup (DetectEngineCtx *de_ctx, Signature *s, char *msgstr)
{
char *str = NULL;
uint16_t len;
if (strlen(msgstr) == 0)
goto error;
/* strip "'s */
if (msgstr[0] == '\"' && msgstr[strlen(msgstr)-1] == '\"') {
str = SCStrdup(msgstr+1);
if (unlikely(str == NULL))
goto error;
str[strlen(msgstr)-2] = '\0';
} else if (msgstr[1] == '\"' && msgstr[strlen(msgstr)-1] == '\"') {
/* XXX do this parsing in a better way */
str = SCStrdup(msgstr+2);
if (unlikely(str == NULL))
goto error;
str[strlen(msgstr)-3] = '\0';
//printf("DetectMsgSetup: format hack applied: \'%s\'\n", str);
} else {
SCLogError(SC_ERR_INVALID_VALUE, "format error \'%s\'", msgstr);
goto error;
}
len = strlen(str);
if (len == 0)
goto error;
char converted = 0;
{
uint16_t i, x;
uint8_t escape = 0;
/* it doesn't matter if we need to escape or not we remove the extra "\" to mimic snort */
for (i = 0, x = 0; i < len; i++) {
//printf("str[%02u]: %c\n", i, str[i]);
if(!escape && str[i] == '\\') {
escape = 1;
} else if (escape) {
if (str[i] != ':' &&
str[i] != ';' &&
str[i] != '\\' &&
str[i] != '\"')
{
SCLogDebug("character \"%c\" does not need to be escaped but is" ,str[i]);
}
escape = 0;
converted = 1;
str[x] = str[i];
x++;
}else{
str[x] = str[i];
x++;
}
}
#if 0 //def DEBUG
if (SCLogDebugEnabled()) {
for (i = 0; i < x; i++) {
printf("%c", str[i]);
}
printf("\n");
}
#endif
if (converted) {
len = x;
str[len] = '\0';
}
}
s->msg = SCMalloc(len + 1);
if (s->msg == NULL)
goto error;
strlcpy(s->msg, str, len + 1);
SCFree(str);
return 0;
error:
SCFree(str);
return -1;
}
/* -------------------------------------Unittests-----------------------------*/
#ifdef UNITTESTS
static int DetectMsgParseTest01(void)
{
int result = 0;
Signature *sig = NULL;
char *teststringparsed = "flow stateless to_server";
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
if (de_ctx == NULL)
goto end;
FILE *fd = SCClassConfGenerateValidDummyClassConfigFD01();
SCClassConfLoadClassficationConfigFile(de_ctx, fd);
sig = SigInit(de_ctx, "alert tcp any any -> any any (msg:\"flow stateless to_server\"; flow:stateless,to_server; content:\"flowstatelesscheck\"; classtype:bad-unknown; sid: 40000002; rev: 1;)");
if(sig == NULL)
goto end;
if (strcmp(sig->msg, teststringparsed) != 0) {
printf("got \"%s\", expected: \"%s\": ", sig->msg, teststringparsed);
goto end;
}
result = 1;
end:
if (sig != NULL)
SigFree(sig);
if (de_ctx != NULL)
DetectEngineCtxFree(de_ctx);
return result;
}
static int DetectMsgParseTest02(void)
{
int result = 0;
Signature *sig = NULL;
char *teststringparsed = "msg escape tests wxy'\"\\;:";
DetectEngineCtx *de_ctx = DetectEngineCtxInit();
if (de_ctx == NULL)
goto end;
sig = SigInit(de_ctx, "alert tcp any any -> any any (msg:\"msg escape tests \\w\\x\\y\\'\\\"\\\\;\\:\"; flow:to_server,established; content:\"blah\"; uricontent:\"/blah/\"; sid: 100;)");
if(sig == NULL)
goto end;
if (strcmp(sig->msg, teststringparsed) != 0) {
printf("got \"%s\", expected: \"%s\": ",sig->msg, teststringparsed);
goto end;
}
result = 1;
end:
if (sig != NULL)
SigFree(sig);
if (de_ctx != NULL)
DetectEngineCtxFree(de_ctx);
return result;
}
#endif /* UNITTESTS */
/**
* \brief this function registers unit tests for DetectMsg
*/
void DetectMsgRegisterTests(void)
{
#ifdef UNITTESTS /* UNITTESTS */
UtRegisterTest("DetectMsgParseTest01", DetectMsgParseTest01, 1);
UtRegisterTest("DetectMsgParseTest02", DetectMsgParseTest02, 1);
#endif /* UNITTESTS */
}
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