/* Copyright (C) 2007-2020 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 to_md5 transformation keyword

 */

#include "suricata-common.h"

#include "detect.h"

#include "detect-engine.h"

#include "detect-engine-prefilter.h"

#include "detect-parse.h"

#include "detect-transform-md5.h"

#include "util-unittest.h"

#include "util-print.h"

#include "rust.h"

static int DetectTransformToMd5Setup (DetectEngineCtx *, Signature *, const char *);

#ifdef UNITTESTS

static void DetectTransformToMd5RegisterTests(void);

#endif

static void TransformToMd5(InspectionBuffer *buffer, void *options);

void DetectTransformMd5Register(void)

{

    sigmatch_table[DETECT_TRANSFORM_MD5].name = "to_md5";

    sigmatch_table[DETECT_TRANSFORM_MD5].desc =

        "convert to md5 hash of the buffer";

    sigmatch_table[DETECT_TRANSFORM_MD5].url =

        "/rules/transforms.html#to-md5";

    sigmatch_table[DETECT_TRANSFORM_MD5].Setup =

        DetectTransformToMd5Setup;

    sigmatch_table[DETECT_TRANSFORM_MD5].Transform =

        TransformToMd5;

#ifdef UNITTESTS

    sigmatch_table[DETECT_TRANSFORM_MD5].RegisterTests =

        DetectTransformToMd5RegisterTests;

#endif

    sigmatch_table[DETECT_TRANSFORM_MD5].flags |= SIGMATCH_NOOPT;

}

/**

 *  \internal

 *  \brief Apply the nocase keyword to the last pattern match, either content or uricontent

 *  \param det_ctx detection engine ctx

 *  \param s signature

 *  \param nullstr should be null

 *  \retval 0 ok

 *  \retval -1 failure

 */

static int DetectTransformToMd5Setup (DetectEngineCtx *de_ctx, Signature *s, const char *nullstr)

{

    SCEnter();

    if (g_disable_hashing) {

        SCLogError("MD5 hashing has been disabled, "

                   "needed for to_md5 keyword");

        SCReturnInt(-1);

    }

    int r = DetectSignatureAddTransform(s, DETECT_TRANSFORM_MD5, NULL);

    SCReturnInt(r);

}

static void TransformToMd5(InspectionBuffer *buffer, void *options)

{

    const uint8_t *input = buffer->inspect;

    const uint32_t input_len = buffer->inspect_len;

    uint8_t output[SC_MD5_LEN];

    //PrintRawDataFp(stdout, input, input_len);

    SCMd5HashBuffer(input, input_len, output, sizeof(output));

    InspectionBufferCopy(buffer, output, sizeof(output));

}

#ifdef UNITTESTS

static int DetectTransformToMd5Test01(void)

{

    const uint8_t *input = (const uint8_t *)" A B C D ";

    uint32_t input_len = strlen((char *)input);

    InspectionBuffer buffer;

    InspectionBufferInit(&buffer, 8);

    InspectionBufferSetup(NULL, -1, &buffer, input, input_len);

    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);

    TransformToMd5(&buffer, NULL);

    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);

    InspectionBufferFree(&buffer);

    PASS;

}

static void DetectTransformToMd5RegisterTests(void)

{

    UtRegisterTest("DetectTransformToMd5Test01",

            DetectTransformToMd5Test01);

}

#endif