d 0773d / CyaSSL

Fork of CyaSSL for my specific settings

Dependents:   CyaSSL_Example

Fork of CyaSSL by wolf SSL

ctaocrypt/src/dh.c@4:28ac50e1d49c, 2015-03-03 (annotated)

Committer:
d0773d
Date:
Tue Mar 03 22:52:52 2015 +0000
Revision:
4:28ac50e1d49c
Parent:
0:1239e9b70ca2 
CyaSSL example

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wolfSSL 0:1239e9b70ca2 1 /* dh.c
wolfSSL 0:1239e9b70ca2 2 *
wolfSSL 0:1239e9b70ca2 3 * Copyright (C) 2006-2014 wolfSSL Inc.
wolfSSL 0:1239e9b70ca2 4 *
wolfSSL 0:1239e9b70ca2 5 * This file is part of CyaSSL.
wolfSSL 0:1239e9b70ca2 6 *
wolfSSL 0:1239e9b70ca2 7 * CyaSSL is free software; you can redistribute it and/or modify
wolfSSL 0:1239e9b70ca2 8 * it under the terms of the GNU General Public License as published by
wolfSSL 0:1239e9b70ca2 9 * the Free Software Foundation; either version 2 of the License, or
wolfSSL 0:1239e9b70ca2 10 * (at your option) any later version.
wolfSSL 0:1239e9b70ca2 11 *
wolfSSL 0:1239e9b70ca2 12 * CyaSSL is distributed in the hope that it will be useful,
wolfSSL 0:1239e9b70ca2 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
wolfSSL 0:1239e9b70ca2 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
wolfSSL 0:1239e9b70ca2 15 * GNU General Public License for more details.
wolfSSL 0:1239e9b70ca2 16 *
wolfSSL 0:1239e9b70ca2 17 * You should have received a copy of the GNU General Public License
wolfSSL 0:1239e9b70ca2 18 * along with this program; if not, write to the Free Software
wolfSSL 0:1239e9b70ca2 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
wolfSSL 0:1239e9b70ca2 20 */
wolfSSL 0:1239e9b70ca2 21
wolfSSL 0:1239e9b70ca2 22 #ifdef HAVE_CONFIG_H
wolfSSL 0:1239e9b70ca2 23 #include <config.h>
wolfSSL 0:1239e9b70ca2 24 #endif
wolfSSL 0:1239e9b70ca2 25
wolfSSL 0:1239e9b70ca2 26 #include <cyassl/ctaocrypt/settings.h>
wolfSSL 0:1239e9b70ca2 27
wolfSSL 0:1239e9b70ca2 28 #ifndef NO_DH
wolfSSL 0:1239e9b70ca2 29
wolfSSL 0:1239e9b70ca2 30 #include <cyassl/ctaocrypt/dh.h>
wolfSSL 0:1239e9b70ca2 31 #include <cyassl/ctaocrypt/error-crypt.h>
wolfSSL 0:1239e9b70ca2 32
wolfSSL 0:1239e9b70ca2 33 #ifndef USER_MATH_LIB
wolfSSL 0:1239e9b70ca2 34 #include <math.h>
wolfSSL 0:1239e9b70ca2 35 #define XPOW(x,y) pow((x),(y))
wolfSSL 0:1239e9b70ca2 36 #define XLOG(x) log((x))
wolfSSL 0:1239e9b70ca2 37 #else
wolfSSL 0:1239e9b70ca2 38 /* user's own math lib */
wolfSSL 0:1239e9b70ca2 39 #endif
wolfSSL 0:1239e9b70ca2 40
wolfSSL 0:1239e9b70ca2 41
wolfSSL 0:1239e9b70ca2 42 #ifndef min
wolfSSL 0:1239e9b70ca2 43
wolfSSL 0:1239e9b70ca2 44 static INLINE word32 min(word32 a, word32 b)
wolfSSL 0:1239e9b70ca2 45 {
wolfSSL 0:1239e9b70ca2 46 return a > b ? b : a;
wolfSSL 0:1239e9b70ca2 47 }
wolfSSL 0:1239e9b70ca2 48
wolfSSL 0:1239e9b70ca2 49 #endif /* min */
wolfSSL 0:1239e9b70ca2 50
wolfSSL 0:1239e9b70ca2 51
wolfSSL 0:1239e9b70ca2 52 void InitDhKey(DhKey* key)
wolfSSL 0:1239e9b70ca2 53 {
wolfSSL 0:1239e9b70ca2 54 (void)key;
wolfSSL 0:1239e9b70ca2 55 /* TomsFastMath doesn't use memory allocation */
wolfSSL 0:1239e9b70ca2 56 #ifndef USE_FAST_MATH
wolfSSL 0:1239e9b70ca2 57 key->p.dp = 0;
wolfSSL 0:1239e9b70ca2 58 key->g.dp = 0;
wolfSSL 0:1239e9b70ca2 59 #endif
wolfSSL 0:1239e9b70ca2 60 }
wolfSSL 0:1239e9b70ca2 61
wolfSSL 0:1239e9b70ca2 62
wolfSSL 0:1239e9b70ca2 63 void FreeDhKey(DhKey* key)
wolfSSL 0:1239e9b70ca2 64 {
wolfSSL 0:1239e9b70ca2 65 (void)key;
wolfSSL 0:1239e9b70ca2 66 /* TomsFastMath doesn't use memory allocation */
wolfSSL 0:1239e9b70ca2 67 #ifndef USE_FAST_MATH
wolfSSL 0:1239e9b70ca2 68 mp_clear(&key->p);
wolfSSL 0:1239e9b70ca2 69 mp_clear(&key->g);
wolfSSL 0:1239e9b70ca2 70 #endif
wolfSSL 0:1239e9b70ca2 71 }
wolfSSL 0:1239e9b70ca2 72
wolfSSL 0:1239e9b70ca2 73
wolfSSL 0:1239e9b70ca2 74 static word32 DiscreteLogWorkFactor(word32 n)
wolfSSL 0:1239e9b70ca2 75 {
wolfSSL 0:1239e9b70ca2 76 /* assuming discrete log takes about the same time as factoring */
wolfSSL 0:1239e9b70ca2 77 if (n<5)
wolfSSL 0:1239e9b70ca2 78 return 0;
wolfSSL 0:1239e9b70ca2 79 else
wolfSSL 0:1239e9b70ca2 80 return (word32)(2.4 * XPOW((double)n, 1.0/3.0) *
wolfSSL 0:1239e9b70ca2 81 XPOW(XLOG((double)n), 2.0/3.0) - 5);
wolfSSL 0:1239e9b70ca2 82 }
wolfSSL 0:1239e9b70ca2 83
wolfSSL 0:1239e9b70ca2 84
wolfSSL 0:1239e9b70ca2 85 static int GeneratePrivate(DhKey* key, RNG* rng, byte* priv, word32* privSz)
wolfSSL 0:1239e9b70ca2 86 {
wolfSSL 0:1239e9b70ca2 87 int ret;
wolfSSL 0:1239e9b70ca2 88 word32 sz = mp_unsigned_bin_size(&key->p);
wolfSSL 0:1239e9b70ca2 89 sz = min(sz, 2 * DiscreteLogWorkFactor(sz * CYASSL_BIT_SIZE) /
wolfSSL 0:1239e9b70ca2 90 CYASSL_BIT_SIZE + 1);
wolfSSL 0:1239e9b70ca2 91
wolfSSL 0:1239e9b70ca2 92 ret = RNG_GenerateBlock(rng, priv, sz);
wolfSSL 0:1239e9b70ca2 93 if (ret != 0)
wolfSSL 0:1239e9b70ca2 94 return ret;
wolfSSL 0:1239e9b70ca2 95
wolfSSL 0:1239e9b70ca2 96 priv[0] |= 0x0C;
wolfSSL 0:1239e9b70ca2 97
wolfSSL 0:1239e9b70ca2 98 *privSz = sz;
wolfSSL 0:1239e9b70ca2 99
wolfSSL 0:1239e9b70ca2 100 return 0;
wolfSSL 0:1239e9b70ca2 101 }
wolfSSL 0:1239e9b70ca2 102
wolfSSL 0:1239e9b70ca2 103
wolfSSL 0:1239e9b70ca2 104 static int GeneratePublic(DhKey* key, const byte* priv, word32 privSz,
wolfSSL 0:1239e9b70ca2 105 byte* pub, word32* pubSz)
wolfSSL 0:1239e9b70ca2 106 {
wolfSSL 0:1239e9b70ca2 107 int ret = 0;
wolfSSL 0:1239e9b70ca2 108
wolfSSL 0:1239e9b70ca2 109 mp_int x;
wolfSSL 0:1239e9b70ca2 110 mp_int y;
wolfSSL 0:1239e9b70ca2 111
wolfSSL 0:1239e9b70ca2 112 if (mp_init_multi(&x, &y, 0, 0, 0, 0) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 113 return MP_INIT_E;
wolfSSL 0:1239e9b70ca2 114
wolfSSL 0:1239e9b70ca2 115 if (mp_read_unsigned_bin(&x, priv, privSz) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 116 ret = MP_READ_E;
wolfSSL 0:1239e9b70ca2 117
wolfSSL 0:1239e9b70ca2 118 if (ret == 0 && mp_exptmod(&key->g, &x, &key->p, &y) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 119 ret = MP_EXPTMOD_E;
wolfSSL 0:1239e9b70ca2 120
wolfSSL 0:1239e9b70ca2 121 if (ret == 0 && mp_to_unsigned_bin(&y, pub) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 122 ret = MP_TO_E;
wolfSSL 0:1239e9b70ca2 123
wolfSSL 0:1239e9b70ca2 124 if (ret == 0)
wolfSSL 0:1239e9b70ca2 125 *pubSz = mp_unsigned_bin_size(&y);
wolfSSL 0:1239e9b70ca2 126
wolfSSL 0:1239e9b70ca2 127 mp_clear(&y);
wolfSSL 0:1239e9b70ca2 128 mp_clear(&x);
wolfSSL 0:1239e9b70ca2 129
wolfSSL 0:1239e9b70ca2 130 return ret;
wolfSSL 0:1239e9b70ca2 131 }
wolfSSL 0:1239e9b70ca2 132
wolfSSL 0:1239e9b70ca2 133
wolfSSL 0:1239e9b70ca2 134 int DhGenerateKeyPair(DhKey* key, RNG* rng, byte* priv, word32* privSz,
wolfSSL 0:1239e9b70ca2 135 byte* pub, word32* pubSz)
wolfSSL 0:1239e9b70ca2 136 {
wolfSSL 0:1239e9b70ca2 137 int ret = GeneratePrivate(key, rng, priv, privSz);
wolfSSL 0:1239e9b70ca2 138
wolfSSL 0:1239e9b70ca2 139 return (ret != 0) ? ret : GeneratePublic(key, priv, *privSz, pub, pubSz);
wolfSSL 0:1239e9b70ca2 140 }
wolfSSL 0:1239e9b70ca2 141
wolfSSL 0:1239e9b70ca2 142 int DhAgree(DhKey* key, byte* agree, word32* agreeSz, const byte* priv,
wolfSSL 0:1239e9b70ca2 143 word32 privSz, const byte* otherPub, word32 pubSz)
wolfSSL 0:1239e9b70ca2 144 {
wolfSSL 0:1239e9b70ca2 145 int ret = 0;
wolfSSL 0:1239e9b70ca2 146
wolfSSL 0:1239e9b70ca2 147 mp_int x;
wolfSSL 0:1239e9b70ca2 148 mp_int y;
wolfSSL 0:1239e9b70ca2 149 mp_int z;
wolfSSL 0:1239e9b70ca2 150
wolfSSL 0:1239e9b70ca2 151 if (mp_init_multi(&x, &y, &z, 0, 0, 0) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 152 return MP_INIT_E;
wolfSSL 0:1239e9b70ca2 153
wolfSSL 0:1239e9b70ca2 154 if (mp_read_unsigned_bin(&x, priv, privSz) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 155 ret = MP_READ_E;
wolfSSL 0:1239e9b70ca2 156
wolfSSL 0:1239e9b70ca2 157 if (ret == 0 && mp_read_unsigned_bin(&y, otherPub, pubSz) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 158 ret = MP_READ_E;
wolfSSL 0:1239e9b70ca2 159
wolfSSL 0:1239e9b70ca2 160 if (ret == 0 && mp_exptmod(&y, &x, &key->p, &z) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 161 ret = MP_EXPTMOD_E;
wolfSSL 0:1239e9b70ca2 162
wolfSSL 0:1239e9b70ca2 163 if (ret == 0 && mp_to_unsigned_bin(&z, agree) != MP_OKAY)
wolfSSL 0:1239e9b70ca2 164 ret = MP_TO_E;
wolfSSL 0:1239e9b70ca2 165
wolfSSL 0:1239e9b70ca2 166 if (ret == 0)
wolfSSL 0:1239e9b70ca2 167 *agreeSz = mp_unsigned_bin_size(&z);
wolfSSL 0:1239e9b70ca2 168
wolfSSL 0:1239e9b70ca2 169 mp_clear(&z);
wolfSSL 0:1239e9b70ca2 170 mp_clear(&y);
wolfSSL 0:1239e9b70ca2 171 mp_clear(&x);
wolfSSL 0:1239e9b70ca2 172
wolfSSL 0:1239e9b70ca2 173 return ret;
wolfSSL 0:1239e9b70ca2 174 }
wolfSSL 0:1239e9b70ca2 175
wolfSSL 0:1239e9b70ca2 176
wolfSSL 0:1239e9b70ca2 177 #endif /* NO_DH */
wolfSSL 0:1239e9b70ca2 178
wolfSSL 0:1239e9b70ca2 179