Xuyi Wang / wolfSSL

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wolfcrypt/src/idea.c@3:6f956bdb3073, 2016-04-28 (annotated)

Committer:
wolfSSL
Date:
Thu Apr 28 00:56:55 2016 +0000
Revision:
3:6f956bdb3073
wolfSSL 3.9.0

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wolfSSL 3:6f956bdb3073 1 /* idea.c
wolfSSL 3:6f956bdb3073 2 *
wolfSSL 3:6f956bdb3073 3 * Copyright (C) 2006-2016 wolfSSL Inc.
wolfSSL 3:6f956bdb3073 4 *
wolfSSL 3:6f956bdb3073 5 * This file is part of wolfSSL.
wolfSSL 3:6f956bdb3073 6 *
wolfSSL 3:6f956bdb3073 7 * wolfSSL is free software; you can redistribute it and/or modify
wolfSSL 3:6f956bdb3073 8 * it under the terms of the GNU General Public License as published by
wolfSSL 3:6f956bdb3073 9 * the Free Software Foundation; either version 2 of the License, or
wolfSSL 3:6f956bdb3073 10 * (at your option) any later version.
wolfSSL 3:6f956bdb3073 11 *
wolfSSL 3:6f956bdb3073 12 * wolfSSL is distributed in the hope that it will be useful,
wolfSSL 3:6f956bdb3073 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
wolfSSL 3:6f956bdb3073 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
wolfSSL 3:6f956bdb3073 15 * GNU General Public License for more details.
wolfSSL 3:6f956bdb3073 16 *
wolfSSL 3:6f956bdb3073 17 * You should have received a copy of the GNU General Public License
wolfSSL 3:6f956bdb3073 18 * along with this program; if not, write to the Free Software
wolfSSL 3:6f956bdb3073 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
wolfSSL 3:6f956bdb3073 20 */
wolfSSL 3:6f956bdb3073 21
wolfSSL 3:6f956bdb3073 22
wolfSSL 3:6f956bdb3073 23 #ifdef HAVE_CONFIG_H
wolfSSL 3:6f956bdb3073 24 #include <config.h>
wolfSSL 3:6f956bdb3073 25 #endif
wolfSSL 3:6f956bdb3073 26
wolfSSL 3:6f956bdb3073 27 #include <wolfssl/wolfcrypt/settings.h>
wolfSSL 3:6f956bdb3073 28
wolfSSL 3:6f956bdb3073 29 #ifdef HAVE_IDEA
wolfSSL 3:6f956bdb3073 30
wolfSSL 3:6f956bdb3073 31 #include <wolfssl/wolfcrypt/idea.h>
wolfSSL 3:6f956bdb3073 32
wolfSSL 3:6f956bdb3073 33 #include <wolfssl/wolfcrypt/error-crypt.h>
wolfSSL 3:6f956bdb3073 34 #include <wolfssl/wolfcrypt/logging.h>
wolfSSL 3:6f956bdb3073 35
wolfSSL 3:6f956bdb3073 36 #ifdef NO_INLINE
wolfSSL 3:6f956bdb3073 37 #include <wolfssl/wolfcrypt/misc.h>
wolfSSL 3:6f956bdb3073 38 #else
wolfSSL 3:6f956bdb3073 39 #include <wolfcrypt/src/misc.c>
wolfSSL 3:6f956bdb3073 40 #endif
wolfSSL 3:6f956bdb3073 41
wolfSSL 3:6f956bdb3073 42 /* multiplication of x and y modulo 2^16+1
wolfSSL 3:6f956bdb3073 43 * IDEA specify a special case when an entry value is 0 ( x or y)
wolfSSL 3:6f956bdb3073 44 * then it must be replaced by 2^16
wolfSSL 3:6f956bdb3073 45 */
wolfSSL 3:6f956bdb3073 46 static INLINE word16 idea_mult(word16 x, word16 y)
wolfSSL 3:6f956bdb3073 47 {
wolfSSL 3:6f956bdb3073 48 long mul, res;
wolfSSL 3:6f956bdb3073 49
wolfSSL 3:6f956bdb3073 50 mul = (long)x * (long)y;
wolfSSL 3:6f956bdb3073 51 if (mul) {
wolfSSL 3:6f956bdb3073 52 res = (mul & IDEA_MASK) - ((word32)mul >> 16);
wolfSSL 3:6f956bdb3073 53 if (res <= 0)
wolfSSL 3:6f956bdb3073 54 res += IDEA_MODULO;
wolfSSL 3:6f956bdb3073 55
wolfSSL 3:6f956bdb3073 56 return (word16) (res & IDEA_MASK);
wolfSSL 3:6f956bdb3073 57 }
wolfSSL 3:6f956bdb3073 58
wolfSSL 3:6f956bdb3073 59 if (!x)
wolfSSL 3:6f956bdb3073 60 return ((IDEA_MODULO - y) & IDEA_MASK);
wolfSSL 3:6f956bdb3073 61
wolfSSL 3:6f956bdb3073 62 /* !y */
wolfSSL 3:6f956bdb3073 63 return ((IDEA_MODULO - x) & IDEA_MASK);
wolfSSL 3:6f956bdb3073 64 }
wolfSSL 3:6f956bdb3073 65
wolfSSL 3:6f956bdb3073 66 /* compute 1/a modulo 2^16+1 using Extended euclidean algorithm
wolfSSL 3:6f956bdb3073 67 * adapted from fp_invmod */
wolfSSL 3:6f956bdb3073 68 static INLINE word16 idea_invmod(word16 x)
wolfSSL 3:6f956bdb3073 69 {
wolfSSL 3:6f956bdb3073 70 int u, v, b, d;
wolfSSL 3:6f956bdb3073 71
wolfSSL 3:6f956bdb3073 72 if (x <= 1)
wolfSSL 3:6f956bdb3073 73 return x;
wolfSSL 3:6f956bdb3073 74
wolfSSL 3:6f956bdb3073 75 u = IDEA_MODULO;
wolfSSL 3:6f956bdb3073 76 v = x;
wolfSSL 3:6f956bdb3073 77 d = 1;
wolfSSL 3:6f956bdb3073 78 b = 0;
wolfSSL 3:6f956bdb3073 79
wolfSSL 3:6f956bdb3073 80 do {
wolfSSL 3:6f956bdb3073 81 while (!(u & 1)) {
wolfSSL 3:6f956bdb3073 82 u >>= 1;
wolfSSL 3:6f956bdb3073 83 if (b & 1)
wolfSSL 3:6f956bdb3073 84 b -= IDEA_MODULO;
wolfSSL 3:6f956bdb3073 85 b >>= 1;
wolfSSL 3:6f956bdb3073 86 }
wolfSSL 3:6f956bdb3073 87
wolfSSL 3:6f956bdb3073 88 while (!(v & 1)) {
wolfSSL 3:6f956bdb3073 89 v >>= 1;
wolfSSL 3:6f956bdb3073 90 if (d & 1) {
wolfSSL 3:6f956bdb3073 91 d -= IDEA_MODULO;
wolfSSL 3:6f956bdb3073 92 }
wolfSSL 3:6f956bdb3073 93 d >>= 1;
wolfSSL 3:6f956bdb3073 94 }
wolfSSL 3:6f956bdb3073 95
wolfSSL 3:6f956bdb3073 96 if (u >= v) {
wolfSSL 3:6f956bdb3073 97 u -= v;
wolfSSL 3:6f956bdb3073 98 b -= d;
wolfSSL 3:6f956bdb3073 99 } else {
wolfSSL 3:6f956bdb3073 100 v -= u;
wolfSSL 3:6f956bdb3073 101 d -= b;
wolfSSL 3:6f956bdb3073 102 }
wolfSSL 3:6f956bdb3073 103 } while (u != 0);
wolfSSL 3:6f956bdb3073 104
wolfSSL 3:6f956bdb3073 105 /* d is now the inverse, put positive value if required */
wolfSSL 3:6f956bdb3073 106 while (d < 0)
wolfSSL 3:6f956bdb3073 107 d += IDEA_MODULO;
wolfSSL 3:6f956bdb3073 108
wolfSSL 3:6f956bdb3073 109 /* d must be < IDEA_MODULO */
wolfSSL 3:6f956bdb3073 110 while (d >= (int)IDEA_MODULO)
wolfSSL 3:6f956bdb3073 111 d -= IDEA_MODULO;
wolfSSL 3:6f956bdb3073 112
wolfSSL 3:6f956bdb3073 113 return (word16)(d & IDEA_MASK);
wolfSSL 3:6f956bdb3073 114 }
wolfSSL 3:6f956bdb3073 115
wolfSSL 3:6f956bdb3073 116 /* generate the 52 16-bits key sub-blocks from the 128 key */
wolfSSL 3:6f956bdb3073 117 int wc_IdeaSetKey(Idea *idea, const byte* key, word16 keySz,
wolfSSL 3:6f956bdb3073 118 const byte *iv, int dir)
wolfSSL 3:6f956bdb3073 119 {
wolfSSL 3:6f956bdb3073 120 word16 idx = 0;
wolfSSL 3:6f956bdb3073 121 word32 t;
wolfSSL 3:6f956bdb3073 122 short i;
wolfSSL 3:6f956bdb3073 123
wolfSSL 3:6f956bdb3073 124 if (idea == NULL || key == NULL || keySz != IDEA_KEY_SIZE ||
wolfSSL 3:6f956bdb3073 125 (dir != IDEA_ENCRYPTION && dir != IDEA_DECRYPTION))
wolfSSL 3:6f956bdb3073 126 return BAD_FUNC_ARG;
wolfSSL 3:6f956bdb3073 127
wolfSSL 3:6f956bdb3073 128 /* initial key schedule for 0 -> 7 */
wolfSSL 3:6f956bdb3073 129 for (i = 0; i < IDEA_ROUNDS; i++) {
wolfSSL 3:6f956bdb3073 130 idea->skey[i] = (word16)key[idx++] << 8;
wolfSSL 3:6f956bdb3073 131 idea->skey[i] |= (word16)key[idx++];
wolfSSL 3:6f956bdb3073 132 }
wolfSSL 3:6f956bdb3073 133
wolfSSL 3:6f956bdb3073 134 /* shift phase key schedule for 8 -> 51 */
wolfSSL 3:6f956bdb3073 135 for (i = IDEA_ROUNDS; i < IDEA_SK_NUM; i++) {
wolfSSL 3:6f956bdb3073 136 t = (word32)idea->skey[((i+1) & 7) ? i-7 : i-15] << 9;
wolfSSL 3:6f956bdb3073 137 t |= (word32)idea->skey[((i+2) & 7) < 2 ? i-14 : i-6] >> 7;
wolfSSL 3:6f956bdb3073 138 idea->skey[i] = (word16)(t & IDEA_MASK);
wolfSSL 3:6f956bdb3073 139 }
wolfSSL 3:6f956bdb3073 140
wolfSSL 3:6f956bdb3073 141 /* compute decryption key from encryption key */
wolfSSL 3:6f956bdb3073 142 if (dir == IDEA_DECRYPTION) {
wolfSSL 3:6f956bdb3073 143 word16 enckey[IDEA_SK_NUM];
wolfSSL 3:6f956bdb3073 144
wolfSSL 3:6f956bdb3073 145 /* put encryption key in tmp buffer */
wolfSSL 3:6f956bdb3073 146 XMEMCPY(enckey, idea->skey, sizeof(idea->skey));
wolfSSL 3:6f956bdb3073 147
wolfSSL 3:6f956bdb3073 148 idx = 0;
wolfSSL 3:6f956bdb3073 149
wolfSSL 3:6f956bdb3073 150 idea->skey[6*IDEA_ROUNDS] = idea_invmod(enckey[idx++]);
wolfSSL 3:6f956bdb3073 151 idea->skey[6*IDEA_ROUNDS+1] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 152 idea->skey[6*IDEA_ROUNDS+2] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 153 idea->skey[6*IDEA_ROUNDS+3] = idea_invmod(enckey[idx++]);
wolfSSL 3:6f956bdb3073 154
wolfSSL 3:6f956bdb3073 155 for (i = 6*(IDEA_ROUNDS-1); i >= 0; i -= 6) {
wolfSSL 3:6f956bdb3073 156 idea->skey[i+4] = enckey[idx++];
wolfSSL 3:6f956bdb3073 157 idea->skey[i+5] = enckey[idx++];
wolfSSL 3:6f956bdb3073 158
wolfSSL 3:6f956bdb3073 159 idea->skey[i] = idea_invmod(enckey[idx++]);
wolfSSL 3:6f956bdb3073 160 if (i) {
wolfSSL 3:6f956bdb3073 161 idea->skey[i+2] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 162 idea->skey[i+1] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 163 }
wolfSSL 3:6f956bdb3073 164 else {
wolfSSL 3:6f956bdb3073 165 idea->skey[1] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 166 idea->skey[2] = (IDEA_2EXP16 - enckey[idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 167 }
wolfSSL 3:6f956bdb3073 168
wolfSSL 3:6f956bdb3073 169 idea->skey[i+3] = idea_invmod(enckey[idx++]);
wolfSSL 3:6f956bdb3073 170 }
wolfSSL 3:6f956bdb3073 171
wolfSSL 3:6f956bdb3073 172 /* erase temporary buffer */
wolfSSL 3:6f956bdb3073 173 ForceZero(enckey, sizeof(enckey));
wolfSSL 3:6f956bdb3073 174 }
wolfSSL 3:6f956bdb3073 175
wolfSSL 3:6f956bdb3073 176 /* set the iv */
wolfSSL 3:6f956bdb3073 177 return wc_IdeaSetIV(idea, iv);
wolfSSL 3:6f956bdb3073 178 }
wolfSSL 3:6f956bdb3073 179
wolfSSL 3:6f956bdb3073 180 /* set the IV in the Idea key structure */
wolfSSL 3:6f956bdb3073 181 int wc_IdeaSetIV(Idea *idea, const byte* iv)
wolfSSL 3:6f956bdb3073 182 {
wolfSSL 3:6f956bdb3073 183 if (idea == NULL)
wolfSSL 3:6f956bdb3073 184 return BAD_FUNC_ARG;
wolfSSL 3:6f956bdb3073 185
wolfSSL 3:6f956bdb3073 186 if (iv != NULL)
wolfSSL 3:6f956bdb3073 187 XMEMCPY(idea->reg, iv, IDEA_BLOCK_SIZE);
wolfSSL 3:6f956bdb3073 188 else
wolfSSL 3:6f956bdb3073 189 XMEMSET(idea->reg, 0, IDEA_BLOCK_SIZE);
wolfSSL 3:6f956bdb3073 190
wolfSSL 3:6f956bdb3073 191 return 0;
wolfSSL 3:6f956bdb3073 192 }
wolfSSL 3:6f956bdb3073 193
wolfSSL 3:6f956bdb3073 194 /* encryption/decryption for a block (64 bits)
wolfSSL 3:6f956bdb3073 195 */
wolfSSL 3:6f956bdb3073 196 void wc_IdeaCipher(Idea *idea, byte* out, const byte* in)
wolfSSL 3:6f956bdb3073 197 {
wolfSSL 3:6f956bdb3073 198 word32 t1, t2;
wolfSSL 3:6f956bdb3073 199 word16 i, skey_idx = 0, idx = 0;
wolfSSL 3:6f956bdb3073 200 word16 x[4];
wolfSSL 3:6f956bdb3073 201
wolfSSL 3:6f956bdb3073 202 /* put input byte block in word16 */
wolfSSL 3:6f956bdb3073 203 for (i = 0; i < IDEA_BLOCK_SIZE/2; i++) {
wolfSSL 3:6f956bdb3073 204 x[i] = (word16)in[idx++] << 8;
wolfSSL 3:6f956bdb3073 205 x[i] |= (word16)in[idx++];
wolfSSL 3:6f956bdb3073 206 }
wolfSSL 3:6f956bdb3073 207
wolfSSL 3:6f956bdb3073 208 for (i = 0; i < IDEA_ROUNDS; i++) {
wolfSSL 3:6f956bdb3073 209 x[0] = idea_mult(x[0], idea->skey[skey_idx++]);
wolfSSL 3:6f956bdb3073 210 x[1] = ((word32)x[1] + (word32)idea->skey[skey_idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 211 x[2] = ((word32)x[2] + (word32)idea->skey[skey_idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 212 x[3] = idea_mult(x[3], idea->skey[skey_idx++]);
wolfSSL 3:6f956bdb3073 213
wolfSSL 3:6f956bdb3073 214 t2 = x[0] ^ x[2];
wolfSSL 3:6f956bdb3073 215 t2 = idea_mult((word16)t2, idea->skey[skey_idx++]);
wolfSSL 3:6f956bdb3073 216 t1 = (t2 + (x[1] ^ x[3])) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 217 t1 = idea_mult((word16)t1, idea->skey[skey_idx++]);
wolfSSL 3:6f956bdb3073 218 t2 = (t1 + t2) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 219
wolfSSL 3:6f956bdb3073 220 x[0] ^= t1;
wolfSSL 3:6f956bdb3073 221 x[3] ^= t2;
wolfSSL 3:6f956bdb3073 222
wolfSSL 3:6f956bdb3073 223 t2 ^= x[1];
wolfSSL 3:6f956bdb3073 224 x[1] = x[2] ^ (word16)t1;
wolfSSL 3:6f956bdb3073 225 x[2] = (word16)t2;
wolfSSL 3:6f956bdb3073 226 }
wolfSSL 3:6f956bdb3073 227
wolfSSL 3:6f956bdb3073 228 x[0] = idea_mult(x[0], idea->skey[skey_idx++]);
wolfSSL 3:6f956bdb3073 229 out[0] = (x[0] >> 8) & 0xFF;
wolfSSL 3:6f956bdb3073 230 out[1] = x[0] & 0xFF;
wolfSSL 3:6f956bdb3073 231
wolfSSL 3:6f956bdb3073 232 x[2] = ((word32)x[2] + (word32)idea->skey[skey_idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 233 out[2] = (x[2] >> 8) & 0xFF;
wolfSSL 3:6f956bdb3073 234 out[3] = x[2] & 0xFF;
wolfSSL 3:6f956bdb3073 235
wolfSSL 3:6f956bdb3073 236 x[1] = ((word32)x[1] + (word32)idea->skey[skey_idx++]) & IDEA_MASK;
wolfSSL 3:6f956bdb3073 237 out[4] = (x[1] >> 8) & 0xFF;
wolfSSL 3:6f956bdb3073 238 out[5] = x[1] & 0xFF;
wolfSSL 3:6f956bdb3073 239
wolfSSL 3:6f956bdb3073 240 x[3] = idea_mult(x[3], idea->skey[skey_idx++]);
wolfSSL 3:6f956bdb3073 241 out[6] = (x[3] >> 8) & 0xFF;
wolfSSL 3:6f956bdb3073 242 out[7] = x[3] & 0xFF;
wolfSSL 3:6f956bdb3073 243 }
wolfSSL 3:6f956bdb3073 244
wolfSSL 3:6f956bdb3073 245 int wc_IdeaCbcEncrypt(Idea *idea, byte* out, const byte* in, word32 len)
wolfSSL 3:6f956bdb3073 246 {
wolfSSL 3:6f956bdb3073 247 int blocks;
wolfSSL 3:6f956bdb3073 248
wolfSSL 3:6f956bdb3073 249 if (idea == NULL || out == NULL || in == NULL)
wolfSSL 3:6f956bdb3073 250 return BAD_FUNC_ARG;
wolfSSL 3:6f956bdb3073 251
wolfSSL 3:6f956bdb3073 252 blocks = len / IDEA_BLOCK_SIZE;
wolfSSL 3:6f956bdb3073 253 while (blocks--) {
wolfSSL 3:6f956bdb3073 254 xorbuf((byte*)idea->reg, in, IDEA_BLOCK_SIZE);
wolfSSL 3:6f956bdb3073 255 wc_IdeaCipher(idea, (byte*)idea->reg, (byte*)idea->reg);
wolfSSL 3:6f956bdb3073 256 XMEMCPY(out, idea->reg, IDEA_BLOCK_SIZE);
wolfSSL 3:6f956bdb3073 257
wolfSSL 3:6f956bdb3073 258 out += IDEA_BLOCK_SIZE;
wolfSSL 3:6f956bdb3073 259 in += IDEA_BLOCK_SIZE;
wolfSSL 3:6f956bdb3073 260 }
wolfSSL 3:6f956bdb3073 261
wolfSSL 3:6f956bdb3073 262 return 0;
wolfSSL 3:6f956bdb3073 263 }
wolfSSL 3:6f956bdb3073 264
wolfSSL 3:6f956bdb3073 265 int wc_IdeaCbcDecrypt(Idea *idea, byte* out, const byte* in, word32 len)
wolfSSL 3:6f956bdb3073 266 {
wolfSSL 3:6f956bdb3073 267 int blocks;
wolfSSL 3:6f956bdb3073 268
wolfSSL 3:6f956bdb3073 269 if (idea == NULL || out == NULL || in == NULL)
wolfSSL 3:6f956bdb3073 270 return BAD_FUNC_ARG;
wolfSSL 3:6f956bdb3073 271
wolfSSL 3:6f956bdb3073 272 blocks = len / IDEA_BLOCK_SIZE;
wolfSSL 3:6f956bdb3073 273 while (blocks--) {
wolfSSL 3:6f956bdb3073 274 XMEMCPY((byte*)idea->tmp, in, IDEA_BLOCK_SIZE);
wolfSSL 3:6f956bdb3073 275 wc_IdeaCipher(idea, out, (byte*)idea->tmp);
wolfSSL 3:6f956bdb3073 276 xorbuf(out, (byte*)idea->reg, IDEA_BLOCK_SIZE);
wolfSSL 3:6f956bdb3073 277 XMEMCPY(idea->reg, idea->tmp, IDEA_BLOCK_SIZE);
wolfSSL 3:6f956bdb3073 278
wolfSSL 3:6f956bdb3073 279 out += IDEA_BLOCK_SIZE;
wolfSSL 3:6f956bdb3073 280 in += IDEA_BLOCK_SIZE;
wolfSSL 3:6f956bdb3073 281 }
wolfSSL 3:6f956bdb3073 282
wolfSSL 3:6f956bdb3073 283 return 0;
wolfSSL 3:6f956bdb3073 284 }
wolfSSL 3:6f956bdb3073 285
wolfSSL 3:6f956bdb3073 286 #endif /* HAVE_IDEA */
wolfSSL 3:6f956bdb3073 287