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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.h"
#include "detect-engine-content-inspection.h"
#include "detect-parse.h"
#include "detect-base64-data.h"
#include "detect-engine-build.h"
#include "util-unittest.h"
static int DetectBase64DataSetup(DetectEngineCtx *, Signature *, const char *);
#ifdef UNITTESTS
static void DetectBase64DataRegisterTests(void);
#endif
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 =
"/rules/base64-keywords.html#base64-data";
sigmatch_table[DETECT_BASE64_DATA].Setup = DetectBase64DataSetup;
#ifdef UNITTESTS
sigmatch_table[DETECT_BASE64_DATA].RegisterTests =
DetectBase64DataRegisterTests;
#endif
sigmatch_table[DETECT_BASE64_DATA].flags |= SIGMATCH_NOOPT;
}
static int DetectBase64DataSetup(DetectEngineCtx *de_ctx, Signature *s,
const char *str)
{
SigMatch *pm = NULL;
/* Check for a preceding base64_decode. */
pm = DetectGetLastSMFromLists(s, DETECT_BASE64_DECODE, -1);
if (pm == NULL) {
SCLogError("\"base64_data\" keyword seen without preceding base64_decode.");
return -1;
}
s->init_data->list = DETECT_SM_LIST_BASE64_DATA;
return 0;
}
int DetectBase64DataDoMatch(DetectEngineCtx *de_ctx,
DetectEngineThreadCtx *det_ctx, const Signature *s, Flow *f)
{
if (det_ctx->base64_decoded_len) {
return DetectEngineContentInspection(de_ctx, det_ctx, s,
s->sm_arrays[DETECT_SM_LIST_BASE64_DATA], NULL, f, det_ctx->base64_decoded,
det_ctx->base64_decoded_len, 0, DETECT_CI_FLAGS_SINGLE,
DETECT_ENGINE_CONTENT_INSPECTION_MODE_STATE);
}
return 0;
}
#ifdef UNITTESTS
static int g_file_data_buffer_id = 0;
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->init_data->smlists[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->init_data->smlists[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;
}
/**
* \test Test that the list can be changed to post-detection lists
* after the base64 keyword.
*/
static int DetectBase64DataSetupTest04(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 tcp any any -> any any (msg:\"some b64thing\"; flow:established,from_server; file_data; content:\"sometext\"; fast_pattern; base64_decode:relative; base64_data; content:\"foobar\"; nocase; tag:session,120,seconds; sid:1111111; rev:1;)");
if (de_ctx->sig_list == NULL) {
printf("SigInit failed: ");
goto end;
}
retval = 1;
end:
if (de_ctx != NULL) {
SigGroupCleanup(de_ctx);
SigCleanSignatures(de_ctx);
DetectEngineCtxFree(de_ctx);
}
return retval;
}
static void DetectBase64DataRegisterTests(void)
{
g_file_data_buffer_id = DetectBufferTypeGetByName("file_data");
UtRegisterTest("DetectBase64DataSetupTest01", DetectBase64DataSetupTest01);
UtRegisterTest("DetectBase64DataSetupTest04", DetectBase64DataSetupTest04);
}
#endif /* UNITTESTS */
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