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/* Copyright (C) 2015 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.
*/
#include "suricata-common.h"
#include "detect.h"
#include "detect-engine-content-inspection.h"
#include "detect-parse.h"
#include "util-unittest.h"
static int DetectBase64DataSetup(DetectEngineCtx *, Signature *, char *);
static void DetectBase64DataRegisterTests(void);
void DetectBase64DataRegister(void)
{
sigmatch_table[DETECT_BASE64_DATA].name = "base64_data";
sigmatch_table[DETECT_BASE64_DATA].desc =
"Content match base64 decoded data.";
sigmatch_table[DETECT_BASE64_DATA].url =
"https://redmine.openinfosecfoundation.org/projects/suricata/wiki/Payload_keywords#base64_data";
sigmatch_table[DETECT_BASE64_DATA].Setup = DetectBase64DataSetup;
sigmatch_table[DETECT_BASE64_DATA].RegisterTests =
DetectBase64DataRegisterTests;
sigmatch_table[DETECT_BASE64_DATA].flags |= SIGMATCH_NOOPT;
}
static int DetectBase64DataSetup(DetectEngineCtx *de_ctx, Signature *s,
char *str)
{
SigMatch *pm = NULL;
/* Check for a preceding base64_decode. */
pm = SigMatchGetLastSMFromLists(s, 28,
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_PMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_UMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HCBDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_FILEDATA],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HHDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HRHDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HMDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HCDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HRUDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HSMDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HSCDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HUADMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HHHDMATCH],
DETECT_BASE64_DECODE, s->sm_lists_tail[DETECT_SM_LIST_HRHHDMATCH]);
if (pm == NULL) {
SCLogError(SC_ERR_INVALID_SIGNATURE,
"\"base64_data\" keyword seen without preceding base64_decode.");
return -1;
}
s->list = DETECT_SM_LIST_BASE64_DATA;
return 0;
}
int DetectBase64DataDoMatch(DetectEngineCtx *de_ctx,
DetectEngineThreadCtx *det_ctx, Signature *s, Flow *f)
{
if (det_ctx->base64_decoded_len) {
return DetectEngineContentInspection(de_ctx, det_ctx, s,
s->sm_lists[DETECT_SM_LIST_BASE64_DATA], f, det_ctx->base64_decoded,
det_ctx->base64_decoded_len, 0,
DETECT_ENGINE_CONTENT_INSPECTION_MODE_BASE64, NULL);
}
return 0;
}
#ifdef UNITTESTS
#include "detect-engine.h"
static int DetectBase64DataSetupTest01(void)
{
DetectEngineCtx *de_ctx = NULL;
SigMatch *sm;
int retval = 0;
de_ctx = DetectEngineCtxInit();
if (de_ctx == NULL) {
goto end;
}
de_ctx->flags |= DE_QUIET;
de_ctx->sig_list = SigInit(de_ctx,
"alert smtp any any -> any any (msg:\"DetectBase64DataSetupTest\"; "
"base64_decode; base64_data; content:\"content\"; sid:1; rev:1;)");
if (de_ctx->sig_list == NULL) {
printf("SigInit failed: ");
goto end;
}
sm = de_ctx->sig_list->sm_lists[DETECT_SM_LIST_PMATCH];
if (sm == NULL) {
printf("DETECT_SM_LIST_PMATCH should not be NULL: ");
goto end;
}
if (sm->type != DETECT_BASE64_DECODE) {
printf("sm->type should be DETECT_BASE64_DECODE: ");
goto end;
}
if (de_ctx->sig_list->sm_lists[DETECT_SM_LIST_BASE64_DATA] == NULL) {
printf("DETECT_SM_LIST_BASE64_DATA should not be NULL: ");
goto end;
}
retval = 1;
end:
if (de_ctx != NULL) {
SigGroupCleanup(de_ctx);
SigCleanSignatures(de_ctx);
DetectEngineCtxFree(de_ctx);
}
return retval;
}
static int DetectBase64DataSetupTest02(void)
{
DetectEngineCtx *de_ctx = NULL;
SigMatch *sm;
int retval = 0;
de_ctx = DetectEngineCtxInit();
if (de_ctx == NULL) {
goto end;
}
de_ctx->flags |= DE_QUIET;
de_ctx->sig_list = SigInit(de_ctx,
"alert smtp any any -> any any ( "
"msg:\"DetectBase64DataSetupTest\"; "
"file_data; "
"content:\"SGV\"; "
"base64_decode: bytes 16; "
"base64_data; "
"content:\"content\"; "
"sid:1; rev:1;)");
if (de_ctx->sig_list == NULL) {
printf("SigInit failed: ");
goto end;
}
sm = de_ctx->sig_list->sm_lists[DETECT_SM_LIST_PMATCH];
if (sm != NULL) {
printf("DETECT_SM_LIST_PMATCH is not NULL: ");
goto end;
}
sm = de_ctx->sig_list->sm_lists[DETECT_SM_LIST_FILEDATA];
if (sm == NULL) {
printf("DETECT_SM_LIST_FILEDATA is NULL: ");
goto end;
}
sm = de_ctx->sig_list->sm_lists[DETECT_SM_LIST_BASE64_DATA];
if (sm == NULL) {
printf("DETECT_SM_LIST_BASE64_DATA is NULL: ");
goto end;
}
retval = 1;
end:
if (de_ctx != NULL) {
SigGroupCleanup(de_ctx);
SigCleanSignatures(de_ctx);
DetectEngineCtxFree(de_ctx);
}
return retval;
}
static int DetectBase64DataSetupTest03(void)
{
DetectEngineCtx *de_ctx = NULL;
int retval = 0;
de_ctx = DetectEngineCtxInit();
if (de_ctx == NULL) {
goto end;
}
de_ctx->flags |= DE_QUIET;
de_ctx->sig_list = SigInit(de_ctx,
"alert smtp any any -> any any ( "
"msg:\"DetectBase64DataSetupTest\"; "
"base64_decode: bytes 16; "
"base64_data; "
"content:\"content\"; "
"file_data; "
"content:\"SGV\"; "
"sid:1; rev:1;)");
if (de_ctx->sig_list != NULL) {
printf("SigInit should have failed: ");
goto end;
}
retval = 1;
end:
if (de_ctx != NULL) {
SigGroupCleanup(de_ctx);
SigCleanSignatures(de_ctx);
DetectEngineCtxFree(de_ctx);
}
return retval;
}
#endif
static void DetectBase64DataRegisterTests(void)
{
#ifdef UNITTESTS
UtRegisterTest("DetectBase64DataSetupTest01", DetectBase64DataSetupTest01,
1);
UtRegisterTest("DetectBase64DataSetupTest02", DetectBase64DataSetupTest02,
1);
UtRegisterTest("DetectBase64DataSetupTest03", DetectBase64DataSetupTest03,
1);
#endif /* UNITTESTS */
}
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