/*

 * Copyright (c) 2022 Sippy Software, Inc., http://www.sippysoft.com

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 */

#include <string.h>

#include <openssl/ssl.h>

#include <openssl/err.h>

#include "rtpp_dtls_util.h"

int

rtpp_dtls_fp_gen(const X509 *cert, char *buf, int len)

{

    uint8_t fp[FP_DIGEST_LEN] = {0};

    unsigned int fp_len, i;

    if (len < FP_DIGEST_STRBUF_LEN)

        return (-1);

    fp_len = sizeof(fp);

    if (X509_digest(cert, EVP_sha256(), fp, &fp_len) != 1) {

        ERR_clear_error();

        return (-1);

    }

    memcpy(buf, FP_DIGEST_ALG, sizeof(FP_DIGEST_ALG) - 1);

    buf += sizeof(FP_DIGEST_ALG) - 1;

    buf[0] = ' ';

    buf++;

    for (i = 0; i < FP_DIGEST_LEN; i++) {

        sprintf(buf, "%.2X", fp[i]);

        buf += 2;

        if (i != (FP_DIGEST_LEN - 1)) {

            buf[0] = ':';

            buf++;

        }

    }

    return (0);

}