/* $OpenBSD: hm_ameth.c,v 1.12 2021/12/12 21:30:14 tb Exp $ */

/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL

 * project 2007.

 */

/* ====================================================================

 * Copyright (c) 2007 The OpenSSL Project.  All rights reserved.

 *

 * 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.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED 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 OpenSSL PROJECT OR

 * ITS 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.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include <stdio.h>

#include <string.h>

#include <openssl/evp.h>

#include <openssl/hmac.h>

#include "asn1_locl.h"

#include "evp_locl.h"

#include "hmac_local.h"

#define HMAC_TEST_PRIVATE_KEY_FORMAT

/* HMAC "ASN1" method. This is just here to indicate the

 * maximum HMAC output length and to free up an HMAC

 * key.

 */

static int

hmac_size(const EVP_PKEY *pkey)

{

  return EVP_MAX_MD_SIZE;

}

static void

hmac_key_free(EVP_PKEY *pkey)

{

  ASN1_OCTET_STRING *os = (ASN1_OCTET_STRING *)pkey->pkey.ptr;

  if (os) {

    if (os->data)

      explicit_bzero(os->data, os->length);

    ASN1_OCTET_STRING_free(os);

  }

}

static int

hmac_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)

{

  switch (op) {

  case ASN1_PKEY_CTRL_DEFAULT_MD_NID:

    *(int *)arg2 = NID_sha1;

    return 1;

  default:

    return -2;

  }

}

#ifdef HMAC_TEST_PRIVATE_KEY_FORMAT

/* A bogus private key format for test purposes. This is simply the

 * HMAC key with "HMAC PRIVATE KEY" in the headers. When enabled the

 * genpkey utility can be used to "generate" HMAC keys.

 */

static int

old_hmac_decode(EVP_PKEY *pkey, const unsigned char **pder, int derlen)

{

  ASN1_OCTET_STRING *os;

  os = ASN1_OCTET_STRING_new();

  if (os == NULL)

    goto err;

  if (ASN1_OCTET_STRING_set(os, *pder, derlen) == 0)

    goto err;

  if (EVP_PKEY_assign(pkey, EVP_PKEY_HMAC, os) == 0)

    goto err;

  return 1;

err:

  ASN1_OCTET_STRING_free(os);

  return 0;

}

static int

old_hmac_encode(const EVP_PKEY *pkey, unsigned char **pder)

{

  int inc;

  ASN1_OCTET_STRING *os = (ASN1_OCTET_STRING *)pkey->pkey.ptr;

  if (pder) {

    if (!*pder) {

      *pder = malloc(os->length);

      if (*pder == NULL)

        return -1;

      inc = 0;

    } else

      inc = 1;

    memcpy(*pder, os->data, os->length);

    if (inc)

      *pder += os->length;

  }

  return os->length;

}

#endif

const EVP_PKEY_ASN1_METHOD hmac_asn1_meth = {

  .pkey_id = EVP_PKEY_HMAC,

  .pkey_base_id = EVP_PKEY_HMAC,

  .pem_str = "HMAC",

  .info = "OpenSSL HMAC method",

  .pkey_size = hmac_size,

  .pkey_free = hmac_key_free,

  .pkey_ctrl = hmac_pkey_ctrl,

#ifdef HMAC_TEST_PRIVATE_KEY_FORMAT

  .old_priv_decode = old_hmac_decode,

  .old_priv_encode = old_hmac_encode

#endif

};