/* $OpenBSD: hm_pmeth.c,v 1.13 2022/03/30 07:17:48 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 <openssl/x509.h>

#include <openssl/x509v3.h>

#include "evp_locl.h"

#include "hmac_local.h"

/* HMAC pkey context structure */

typedef struct {

  const EVP_MD *md; /* MD for HMAC use */

  ASN1_OCTET_STRING ktmp; /* Temp storage for key */

  HMAC_CTX ctx;

} HMAC_PKEY_CTX;

static int

pkey_hmac_init(EVP_PKEY_CTX *ctx)

{

  HMAC_PKEY_CTX *hctx;

  if ((hctx = calloc(1, sizeof(HMAC_PKEY_CTX))) == NULL)

    return 0;

  hctx->ktmp.type = V_ASN1_OCTET_STRING;

  HMAC_CTX_init(&hctx->ctx);

  ctx->data = hctx;

  ctx->keygen_info_count = 0;

  return 1;

}

static int

pkey_hmac_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)

{

  HMAC_PKEY_CTX *sctx, *dctx;

  if (!pkey_hmac_init(dst))

    return 0;

  sctx = src->data;

  dctx = dst->data;

  dctx->md = sctx->md;

  HMAC_CTX_init(&dctx->ctx);

  if (!HMAC_CTX_copy(&dctx->ctx, &sctx->ctx))

    return 0;

  if (sctx->ktmp.data) {

    if (!ASN1_OCTET_STRING_set(&dctx->ktmp, sctx->ktmp.data,

        sctx->ktmp.length))

      return 0;

  }

  return 1;

}

static void

pkey_hmac_cleanup(EVP_PKEY_CTX *ctx)

{

  HMAC_PKEY_CTX *hctx;

  if ((hctx = ctx->data) == NULL)

    return;

  HMAC_CTX_cleanup(&hctx->ctx);

  freezero(hctx->ktmp.data, hctx->ktmp.length);

  free(hctx);

}

static int

pkey_hmac_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)

{

  ASN1_OCTET_STRING *hkey = NULL;

  HMAC_PKEY_CTX *hctx = ctx->data;

  if (!hctx->ktmp.data)

    return 0;

  hkey = ASN1_OCTET_STRING_dup(&hctx->ktmp);

  if (!hkey)

    return 0;

  EVP_PKEY_assign(pkey, EVP_PKEY_HMAC, hkey);

  return 1;

}

static int

int_update(EVP_MD_CTX *ctx, const void *data, size_t count)

{

  HMAC_PKEY_CTX *hctx = ctx->pctx->data;

  if (!HMAC_Update(&hctx->ctx, data, count))

    return 0;

  return 1;

}

static int

hmac_signctx_init(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)

{

  HMAC_PKEY_CTX *hctx = ctx->data;

  HMAC_CTX_set_flags(&hctx->ctx, mctx->flags & ~EVP_MD_CTX_FLAG_NO_INIT);

  EVP_MD_CTX_set_flags(mctx, EVP_MD_CTX_FLAG_NO_INIT);

  mctx->update = int_update;

  return 1;

}

static int

hmac_signctx(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,

    EVP_MD_CTX *mctx)

{

  unsigned int hlen;

  HMAC_PKEY_CTX *hctx = ctx->data;

  int l = EVP_MD_CTX_size(mctx);

  if (l < 0)

    return 0;

  *siglen = l;

  if (!sig)

    return 1;

  if (!HMAC_Final(&hctx->ctx, sig, &hlen))

    return 0;

  *siglen = (size_t)hlen;

  return 1;

}

static int

pkey_hmac_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)

{

  HMAC_PKEY_CTX *hctx = ctx->data;

  ASN1_OCTET_STRING *key;

  switch (type) {

  case EVP_PKEY_CTRL_SET_MAC_KEY:

    if ((!p2 && p1 > 0) || (p1 < -1))

      return 0;

    if (!ASN1_OCTET_STRING_set(&hctx->ktmp, p2, p1))

      return 0;

    break;

  case EVP_PKEY_CTRL_MD:

    hctx->md = p2;

    break;

  case EVP_PKEY_CTRL_DIGESTINIT:

    key = (ASN1_OCTET_STRING *)ctx->pkey->pkey.ptr;

    if (!HMAC_Init_ex(&hctx->ctx, key->data, key->length, hctx->md,

        ctx->engine))

      return 0;

    break;

  default:

    return -2;

  }

  return 1;

}

static int

pkey_hmac_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value)

{

  if (!value)

    return 0;

  if (!strcmp(type, "key")) {

    void *p = (void *)value;

    return pkey_hmac_ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, -1, p);

  }

  if (!strcmp(type, "hexkey")) {

    unsigned char *key;

    int r;

    long keylen;

    key = string_to_hex(value, &keylen);

    if (!key)

      return 0;

    r = pkey_hmac_ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, keylen, key);

    free(key);

    return r;

  }

  return -2;

}

const EVP_PKEY_METHOD hmac_pkey_meth = {

  .pkey_id = EVP_PKEY_HMAC,

  .init = pkey_hmac_init,

  .copy = pkey_hmac_copy,

  .cleanup = pkey_hmac_cleanup,

  .keygen = pkey_hmac_keygen,

  .signctx_init = hmac_signctx_init,

  .signctx = hmac_signctx,

  .ctrl = pkey_hmac_ctrl,

  .ctrl_str = pkey_hmac_ctrl_str

};