/* $OpenBSD: hm_ameth.c,v 1.20 2024/01/04 17:01:26 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 <limits.h>

#include <stdio.h>

#include <string.h>

#include <openssl/evp.h>

#include <openssl/hmac.h>

#include "asn1_local.h"

#include "bytestring.h"

#include "evp_local.h"

#include "hmac_local.h"

static int

hmac_pkey_public_cmp(const EVP_PKEY *a, const EVP_PKEY *b)

{

  /* The ameth pub_cmp must return 1 on match, 0 on mismatch. */

  return ASN1_OCTET_STRING_cmp(a->pkey.ptr, b->pkey.ptr) == 0;

}

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;

  if ((os = pkey->pkey.ptr) == NULL)

    return;

  if (os->data != NULL)

    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;

  }

}

static int

hmac_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv, size_t len)

{

  ASN1_OCTET_STRING *os = NULL;

  if (pkey->pkey.ptr != NULL)

    goto err;

  if (len > INT_MAX)

    goto err;

  if ((os = ASN1_OCTET_STRING_new()) == NULL)

    goto err;

  if (!ASN1_OCTET_STRING_set(os, priv, len))

    goto err;

  pkey->pkey.ptr = os;

  return 1;

 err:

  ASN1_OCTET_STRING_free(os);

  return 0;

}

static int

hmac_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv, size_t *len)

{

  ASN1_OCTET_STRING *os;

  CBS cbs;

  if ((os = pkey->pkey.ptr) == NULL)

    return 0;

  if (priv == NULL) {

    *len = os->length;

    return 1;

  }

  CBS_init(&cbs, os->data, os->length);

  return CBS_write_bytes(&cbs, priv, *len, len);

}

const EVP_PKEY_ASN1_METHOD hmac_asn1_meth = {

  .base_method = &hmac_asn1_meth,

  .pkey_id = EVP_PKEY_HMAC,

  .pem_str = "HMAC",

  .info = "OpenSSL HMAC method",

  .pub_cmp = hmac_pkey_public_cmp,

  .pkey_size = hmac_size,

  .pkey_free = hmac_key_free,

  .pkey_ctrl = hmac_pkey_ctrl,

  .set_priv_key = hmac_set_priv_key,

  .get_priv_key = hmac_get_priv_key,

};