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Jarno Lamsa18987a42019-04-24 15:40:43 +03001/* ec_dh.c - TinyCrypt implementation of EC-DH */
2
Jarno Lamsa187fbb12019-04-25 09:03:19 +03003/*
Simon Butcher92c3d1f2019-09-09 17:25:08 +01004 * Copyright (c) 2019, Arm Limited (or its affiliates), All Rights Reserved.
5 * SPDX-License-Identifier: BSD-3-Clause
6 */
7
8/*
Jarno Lamsa18987a42019-04-24 15:40:43 +03009 * Copyright (c) 2014, Kenneth MacKay
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions are met:
14 * * Redistributions of source code must retain the above copyright notice,
15 * this list of conditions and the following disclaimer.
16 * * Redistributions in binary form must reproduce the above copyright notice,
17 * this list of conditions and the following disclaimer in the documentation
18 * and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33/*
34 * Copyright (C) 2017 by Intel Corporation, All Rights Reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions are met:
38 *
39 * - Redistributions of source code must retain the above copyright notice,
40 * this list of conditions and the following disclaimer.
41 *
42 * - Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 *
46 * - Neither the name of Intel Corporation nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
51 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
54 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
55 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
56 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
57 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
58 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
59 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
60 * POSSIBILITY OF SUCH DAMAGE.
61 */
Hanno Becker36ae7582019-07-23 15:52:35 +010062
63#if !defined(MBEDTLS_CONFIG_FILE)
64#include "mbedtls/config.h"
65#else
66#include MBEDTLS_CONFIG_FILE
67#endif
68
Manuel Pégourié-Gonnardafdc1b52019-05-09 11:24:11 +020069#if defined(MBEDTLS_USE_TINYCRYPT)
Jarno Lamsa18987a42019-04-24 15:40:43 +030070#include <tinycrypt/ecc.h>
71#include <tinycrypt/ecc_dh.h>
72#include <string.h>
Jarno Lamsa187fbb12019-04-25 09:03:19 +030073#include "mbedtls/platform_util.h"
Jarno Lamsa18987a42019-04-24 15:40:43 +030074
Jarno Lamsa18987a42019-04-24 15:40:43 +030075int uECC_make_key_with_d(uint8_t *public_key, uint8_t *private_key,
76 unsigned int *d, uECC_Curve curve)
77{
78
79 uECC_word_t _private[NUM_ECC_WORDS];
80 uECC_word_t _public[NUM_ECC_WORDS * 2];
81
82 /* This function is designed for test purposes-only (such as validating NIST
83 * test vectors) as it uses a provided value for d instead of generating
84 * it uniformly at random. */
Teppo Järvelin91d79382019-10-02 09:09:31 +030085 mbedtls_platform_memcpy (_private, d, NUM_ECC_BYTES);
Jarno Lamsa18987a42019-04-24 15:40:43 +030086
87 /* Computing public-key from private: */
88 if (EccPoint_compute_public_key(_public, _private, curve)) {
89
90 /* Converting buffers to correct bit order: */
91 uECC_vli_nativeToBytes(private_key,
92 BITS_TO_BYTES(curve->num_n_bits),
93 _private);
94 uECC_vli_nativeToBytes(public_key,
95 curve->num_bytes,
96 _public);
97 uECC_vli_nativeToBytes(public_key + curve->num_bytes,
98 curve->num_bytes,
Manuel Pégourié-Gonnard17659332019-11-21 09:27:38 +010099 _public + NUM_ECC_WORDS);
Jarno Lamsa18987a42019-04-24 15:40:43 +0300100
101 /* erasing temporary buffer used to store secret: */
Manuel Pégourié-Gonnard7a346b82019-10-02 14:47:01 +0200102 mbedtls_platform_memset(_private, 0, NUM_ECC_BYTES);
Jarno Lamsa18987a42019-04-24 15:40:43 +0300103
104 return 1;
105 }
106 return 0;
107}
108
109int uECC_make_key(uint8_t *public_key, uint8_t *private_key, uECC_Curve curve)
110{
111
112 uECC_word_t _random[NUM_ECC_WORDS * 2];
113 uECC_word_t _private[NUM_ECC_WORDS];
114 uECC_word_t _public[NUM_ECC_WORDS * 2];
115 uECC_word_t tries;
116
117 for (tries = 0; tries < uECC_RNG_MAX_TRIES; ++tries) {
118 /* Generating _private uniformly at random: */
119 uECC_RNG_Function rng_function = uECC_get_rng();
120 if (!rng_function ||
121 !rng_function((uint8_t *)_random, 2 * NUM_ECC_WORDS*uECC_WORD_SIZE)) {
122 return 0;
123 }
124
125 /* computing modular reduction of _random (see FIPS 186.4 B.4.1): */
Manuel Pégourié-Gonnard10349e42019-11-04 14:57:53 +0100126 uECC_vli_mmod(_private, _random, curve->n);
Jarno Lamsa18987a42019-04-24 15:40:43 +0300127
128 /* Computing public-key from private: */
129 if (EccPoint_compute_public_key(_public, _private, curve)) {
130
131 /* Converting buffers to correct bit order: */
132 uECC_vli_nativeToBytes(private_key,
133 BITS_TO_BYTES(curve->num_n_bits),
134 _private);
135 uECC_vli_nativeToBytes(public_key,
136 curve->num_bytes,
137 _public);
138 uECC_vli_nativeToBytes(public_key + curve->num_bytes,
139 curve->num_bytes,
Manuel Pégourié-Gonnard17659332019-11-21 09:27:38 +0100140 _public + NUM_ECC_WORDS);
Jarno Lamsa18987a42019-04-24 15:40:43 +0300141
142 /* erasing temporary buffer that stored secret: */
Manuel Pégourié-Gonnard7a346b82019-10-02 14:47:01 +0200143 mbedtls_platform_memset(_private, 0, NUM_ECC_BYTES);
Jarno Lamsa18987a42019-04-24 15:40:43 +0300144
145 return 1;
146 }
147 }
148 return 0;
149}
150
151int uECC_shared_secret(const uint8_t *public_key, const uint8_t *private_key,
152 uint8_t *secret, uECC_Curve curve)
153{
154
155 uECC_word_t _public[NUM_ECC_WORDS * 2];
156 uECC_word_t _private[NUM_ECC_WORDS];
Manuel Pégourié-Gonnard17659332019-11-21 09:27:38 +0100157 wordcount_t num_words = NUM_ECC_WORDS;
Jarno Lamsa18987a42019-04-24 15:40:43 +0300158 wordcount_t num_bytes = curve->num_bytes;
159 int r;
160
161 /* Converting buffers to correct bit order: */
162 uECC_vli_bytesToNative(_private,
163 private_key,
164 BITS_TO_BYTES(curve->num_n_bits));
165 uECC_vli_bytesToNative(_public,
166 public_key,
167 num_bytes);
168 uECC_vli_bytesToNative(_public + num_words,
169 public_key + num_bytes,
170 num_bytes);
171
Manuel Pégourié-Gonnardef238282019-11-04 11:19:30 +0100172 r = EccPoint_mult_safer(_public, _public, _private, curve);
Jarno Lamsa18987a42019-04-24 15:40:43 +0300173 uECC_vli_nativeToBytes(secret, num_bytes, _public);
Jarno Lamsa18987a42019-04-24 15:40:43 +0300174
Jarno Lamsa18987a42019-04-24 15:40:43 +0300175 /* erasing temporary buffer used to store secret: */
Jarno Lamsa187fbb12019-04-25 09:03:19 +0300176 mbedtls_platform_zeroize(_private, sizeof(_private));
Jarno Lamsa18987a42019-04-24 15:40:43 +0300177
178 return r;
179}
Jarno Lamsa46132202019-04-29 14:29:52 +0300180#else
Manuel Pégourié-Gonnardafdc1b52019-05-09 11:24:11 +0200181typedef int mbedtls_dummy_tinycrypt_def;
182#endif /* MBEDTLS_USE_TINYCRYPT */