1 /* crypto/ecdh/ech_ossl.c */
2 /* ====================================================================
3 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
5 * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
6 * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
7 * to the OpenSSL project.
9 * The ECC Code is licensed pursuant to the OpenSSL open source
10 * license provided below.
12 * In addition, Sun covenants to all licensees who provide a reciprocal
13 * covenant with respect to their own patents if any, not to sue under
14 * current and future patent claims necessarily infringed by the making,
15 * using, practicing, selling, offering for sale and/or otherwise
16 * disposing of the ECC Code as delivered hereunder (or portions thereof),
17 * provided that such covenant shall not apply:
18 * 1) for code that a licensee deletes from the ECC Code;
19 * 2) separates from the ECC Code; or
20 * 3) for infringements caused by:
21 * i) the modification of the ECC Code or
22 * ii) the combination of the ECC Code with other software or
23 * devices where such combination causes the infringement.
25 * The ECDH software is originally written by Douglas Stebila of
26 * Sun Microsystems Laboratories.
29 /* ====================================================================
30 * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright
40 * notice, this list of conditions and the following disclaimer in
41 * the documentation and/or other materials provided with the
44 * 3. All advertising materials mentioning features or use of this
45 * software must display the following acknowledgment:
46 * "This product includes software developed by the OpenSSL Project
47 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
49 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
50 * endorse or promote products derived from this software without
51 * prior written permission. For written permission, please contact
52 * openssl-core@OpenSSL.org.
54 * 5. Products derived from this software may not be called "OpenSSL"
55 * nor may "OpenSSL" appear in their names without prior written
56 * permission of the OpenSSL Project.
58 * 6. Redistributions of any form whatsoever must retain the following
60 * "This product includes software developed by the OpenSSL Project
61 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
63 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
64 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
65 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
66 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
67 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
68 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
69 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
70 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
71 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
72 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
73 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
74 * OF THE POSSIBILITY OF SUCH DAMAGE.
75 * ====================================================================
77 * This product includes cryptographic software written by Eric Young
78 * (eay@cryptsoft.com). This product includes software written by Tim
79 * Hudson (tjh@cryptsoft.com).
85 #include <openssl/err.h>
86 #include <openssl/sha.h>
87 #include <openssl/obj_mac.h>
89 static int ecdh_compute_key(unsigned char *key, const EC_POINT *pub_key, EC_KEY *ecdh);
91 static ECDH_METHOD openssl_ecdh_meth = {
92 "OpenSSL ECDH method",
102 const ECDH_METHOD *ECDH_OpenSSL(void)
104 return &openssl_ecdh_meth;
108 /* This implementation is based on the following primitives in the IEEE 1363 standard:
113 static int ecdh_compute_key(unsigned char *key, const EC_POINT *pub_key, EC_KEY *ecdh)
117 BIGNUM *x=NULL, *y=NULL;
119 unsigned char *buf=NULL;
121 if ((ctx = BN_CTX_new()) == NULL) goto err;
126 if (ecdh->priv_key == NULL)
128 ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_NO_PRIVATE_VALUE);
132 if ((tmp=EC_POINT_new(ecdh->group)) == NULL)
134 ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE);
138 if (!EC_POINT_mul(ecdh->group, tmp, NULL, pub_key, ecdh->priv_key, ctx))
140 ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
144 if (EC_METHOD_get_field_type(EC_GROUP_method_of(ecdh->group)) == NID_X9_62_prime_field)
146 if (!EC_POINT_get_affine_coordinates_GFp(ecdh->group, tmp, x, y, ctx))
148 ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
154 if (!EC_POINT_get_affine_coordinates_GF2m(ecdh->group, tmp, x, y, ctx))
156 ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
161 if ((buf = (unsigned char *)OPENSSL_malloc(sizeof(unsigned char) * BN_num_bytes(x))) == NULL)
163 ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE);
167 if ((len = BN_bn2bin(x,buf)) <= 0)
169 ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_BN_LIB);
173 if ((SHA1(buf, len, key) == NULL))
175 ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_SHA1_DIGEST_FAILED);
182 if (tmp) EC_POINT_free(tmp);
183 if (ctx) BN_CTX_end(ctx);
184 if (ctx) BN_CTX_free(ctx);
185 if (buf) OPENSSL_free(buf);