1 /* ====================================================================
2 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
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.
8 * The ECC Code is licensed pursuant to the OpenSSL open source
9 * license provided below.
11 * The ECDH software is originally written by Douglas Stebila of
12 * Sun Microsystems Laboratories.
15 /* ====================================================================
16 * Copyright (c) 2000-2002 The OpenSSL Project. All rights reserved.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
22 * 1. Redistributions of source code must retain the above copyright
23 * notice, this list of conditions and the following disclaimer.
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
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/)"
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@OpenSSL.org.
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.
44 * 6. Redistributions of any form whatsoever must retain the following
46 * "This product includes software developed by the OpenSSL Project
47 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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 * ====================================================================
63 * This product includes cryptographic software written by Eric Young
64 * (eay@cryptsoft.com). This product includes software written by Tim
65 * Hudson (tjh@cryptsoft.com). */
67 #include <openssl/ecdh.h>
72 #include <openssl/bn.h>
73 #include <openssl/digest.h>
74 #include <openssl/err.h>
75 #include <openssl/mem.h>
77 #include "../fipsmodule/ec/internal.h"
78 #include "../internal.h"
81 int ECDH_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
82 const EC_KEY *priv_key,
83 void *(*kdf)(const void *in, size_t inlen, void *out,
85 if (priv_key->priv_key == NULL) {
86 OPENSSL_PUT_ERROR(ECDH, ECDH_R_NO_PRIVATE_VALUE);
89 const EC_SCALAR *const priv = &priv_key->priv_key->scalar;
91 BN_CTX *ctx = BN_CTX_new();
101 const EC_GROUP *const group = EC_KEY_get0_group(priv_key);
102 EC_POINT *tmp = EC_POINT_new(group);
104 OPENSSL_PUT_ERROR(ECDH, ERR_R_MALLOC_FAILURE);
108 if (!ec_point_mul_scalar(group, tmp, NULL, pub_key, priv, ctx)) {
109 OPENSSL_PUT_ERROR(ECDH, ECDH_R_POINT_ARITHMETIC_FAILURE);
113 BIGNUM *x = BN_CTX_get(ctx);
115 OPENSSL_PUT_ERROR(ECDH, ERR_R_MALLOC_FAILURE);
119 if (!EC_POINT_get_affine_coordinates_GFp(group, tmp, x, NULL, ctx)) {
120 OPENSSL_PUT_ERROR(ECDH, ECDH_R_POINT_ARITHMETIC_FAILURE);
124 buflen = (EC_GROUP_get_degree(group) + 7) / 8;
125 buf = OPENSSL_malloc(buflen);
127 OPENSSL_PUT_ERROR(ECDH, ERR_R_MALLOC_FAILURE);
131 if (!BN_bn2bin_padded(buf, buflen, x)) {
132 OPENSSL_PUT_ERROR(ECDH, ERR_R_INTERNAL_ERROR);
137 if (kdf(buf, buflen, out, &outlen) == NULL) {
138 OPENSSL_PUT_ERROR(ECDH, ECDH_R_KDF_FAILED);
142 // no KDF, just copy as much as we can
143 if (buflen < outlen) {
146 OPENSSL_memcpy(out, buf, outlen);
149 if (outlen > INT_MAX) {
150 OPENSSL_PUT_ERROR(ECDH, ERR_R_OVERFLOW);