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      1 /* ====================================================================
      2  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
      3  *
      4  * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
      5  * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
      6  * to the OpenSSL project.
      7  *
      8  * The ECC Code is licensed pursuant to the OpenSSL open source
      9  * license provided below.
     10  *
     11  * The ECDH software is originally written by Douglas Stebila of
     12  * Sun Microsystems Laboratories.
     13  *
     14  */
     15 /* ====================================================================
     16  * Copyright (c) 2000-2002 The OpenSSL Project.  All rights reserved.
     17  *
     18  * Redistribution and use in source and binary forms, with or without
     19  * modification, are permitted provided that the following conditions
     20  * are met:
     21  *
     22  * 1. Redistributions of source code must retain the above copyright
     23  *    notice, this list of conditions and the following disclaimer.
     24  *
     25  * 2. Redistributions in binary form must reproduce the above copyright
     26  *    notice, this list of conditions and the following disclaimer in
     27  *    the documentation and/or other materials provided with the
     28  *    distribution.
     29  *
     30  * 3. All advertising materials mentioning features or use of this
     31  *    software must display the following acknowledgment:
     32  *    "This product includes software developed by the OpenSSL Project
     33  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
     34  *
     35  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
     36  *    endorse or promote products derived from this software without
     37  *    prior written permission. For written permission, please contact
     38  *    licensing (at) OpenSSL.org.
     39  *
     40  * 5. Products derived from this software may not be called "OpenSSL"
     41  *    nor may "OpenSSL" appear in their names without prior written
     42  *    permission of the OpenSSL Project.
     43  *
     44  * 6. Redistributions of any form whatsoever must retain the following
     45  *    acknowledgment:
     46  *    "This product includes software developed by the OpenSSL Project
     47  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
     48  *
     49  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
     50  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     52  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
     53  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     54  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     55  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     56  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     58  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     59  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     60  * OF THE POSSIBILITY OF SUCH DAMAGE.
     61  * ====================================================================
     62  *
     63  * This product includes cryptographic software written by Eric Young
     64  * (eay (at) cryptsoft.com).  This product includes software written by Tim
     65  * Hudson (tjh (at) cryptsoft.com). */
     66 
     67 #include <openssl/ecdh.h>
     68 
     69 #include <string.h>
     70 
     71 #include <openssl/ec.h>
     72 #include <openssl/ec_key.h>
     73 #include <openssl/err.h>
     74 #include <openssl/mem.h>
     75 #include <openssl/sha.h>
     76 
     77 #include "../ec/internal.h"
     78 
     79 
     80 int ECDH_compute_key_fips(uint8_t *out, size_t out_len, const EC_POINT *pub_key,
     81                           const EC_KEY *priv_key) {
     82   if (priv_key->priv_key == NULL) {
     83     OPENSSL_PUT_ERROR(ECDH, ECDH_R_NO_PRIVATE_VALUE);
     84     return 0;
     85   }
     86   const EC_SCALAR *const priv = &priv_key->priv_key->scalar;
     87   const EC_GROUP *const group = EC_KEY_get0_group(priv_key);
     88   if (EC_GROUP_cmp(group, pub_key->group, NULL) != 0) {
     89     OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS);
     90     return 0;
     91   }
     92 
     93   EC_RAW_POINT shared_point;
     94   uint8_t buf[EC_MAX_BYTES];
     95   size_t buflen;
     96   if (!ec_point_mul_scalar(group, &shared_point, NULL, &pub_key->raw, priv) ||
     97       !ec_point_get_affine_coordinate_bytes(group, buf, NULL, &buflen,
     98                                             sizeof(buf), &shared_point)) {
     99     OPENSSL_PUT_ERROR(ECDH, ECDH_R_POINT_ARITHMETIC_FAILURE);
    100     return 0;
    101   }
    102 
    103   switch (out_len) {
    104     case SHA224_DIGEST_LENGTH:
    105       SHA224(buf, buflen, out);
    106       break;
    107     case SHA256_DIGEST_LENGTH:
    108       SHA256(buf, buflen, out);
    109       break;
    110     case SHA384_DIGEST_LENGTH:
    111       SHA384(buf, buflen, out);
    112       break;
    113     case SHA512_DIGEST_LENGTH:
    114       SHA512(buf, buflen, out);
    115       break;
    116     default:
    117       OPENSSL_PUT_ERROR(ECDH, ECDH_R_UNKNOWN_DIGEST_LENGTH);
    118       return 0;
    119   }
    120 
    121   return 1;
    122 }
    123