[453] | 1 | /* wolfmath.c
|
---|
| 2 | *
|
---|
| 3 | * Copyright (C) 2006-2020 wolfSSL Inc.
|
---|
| 4 | *
|
---|
| 5 | * This file is part of wolfSSL.
|
---|
| 6 | *
|
---|
| 7 | * wolfSSL is free software; you can redistribute it and/or modify
|
---|
| 8 | * it under the terms of the GNU General Public License as published by
|
---|
| 9 | * the Free Software Foundation; either version 2 of the License, or
|
---|
| 10 | * (at your option) any later version.
|
---|
| 11 | *
|
---|
| 12 | * wolfSSL is distributed in the hope that it will be useful,
|
---|
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
---|
| 15 | * GNU General Public License for more details.
|
---|
| 16 | *
|
---|
| 17 | * You should have received a copy of the GNU General Public License
|
---|
| 18 | * along with this program; if not, write to the Free Software
|
---|
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
|
---|
| 20 | */
|
---|
| 21 |
|
---|
| 22 |
|
---|
| 23 | /* common functions for either math library */
|
---|
| 24 |
|
---|
| 25 | #ifdef HAVE_CONFIG_H
|
---|
| 26 | #include <config.h>
|
---|
| 27 | #endif
|
---|
| 28 |
|
---|
| 29 | /* in case user set USE_FAST_MATH there */
|
---|
| 30 | #include <wolfssl/wolfcrypt/settings.h>
|
---|
| 31 |
|
---|
| 32 | #include <wolfssl/wolfcrypt/integer.h>
|
---|
| 33 |
|
---|
| 34 | #include <wolfssl/wolfcrypt/error-crypt.h>
|
---|
| 35 | #include <wolfssl/wolfcrypt/logging.h>
|
---|
| 36 |
|
---|
| 37 | #if defined(USE_FAST_MATH) || !defined(NO_BIG_INT)
|
---|
| 38 |
|
---|
| 39 | #ifdef WOLFSSL_ASYNC_CRYPT
|
---|
| 40 | #include <wolfssl/wolfcrypt/async.h>
|
---|
| 41 | #endif
|
---|
| 42 |
|
---|
| 43 | #ifdef NO_INLINE
|
---|
| 44 | #include <wolfssl/wolfcrypt/misc.h>
|
---|
| 45 | #else
|
---|
| 46 | #define WOLFSSL_MISC_INCLUDED
|
---|
| 47 | #include <wolfcrypt/src/misc.c>
|
---|
| 48 | #endif
|
---|
| 49 |
|
---|
| 50 |
|
---|
| 51 | #if !defined(WC_NO_CACHE_RESISTANT) && \
|
---|
| 52 | ((defined(HAVE_ECC) && defined(ECC_TIMING_RESISTANT)) || \
|
---|
| 53 | (defined(USE_FAST_MATH) && defined(TFM_TIMING_RESISTANT)))
|
---|
| 54 |
|
---|
| 55 | /* all off / all on pointer addresses for constant calculations */
|
---|
| 56 | /* ecc.c uses same table */
|
---|
| 57 | const wolfssl_word wc_off_on_addr[2] =
|
---|
| 58 | {
|
---|
| 59 | #if defined(WC_64BIT_CPU)
|
---|
| 60 | W64LIT(0x0000000000000000),
|
---|
| 61 | W64LIT(0xffffffffffffffff)
|
---|
| 62 | #elif defined(WC_16BIT_CPU)
|
---|
| 63 | 0x0000U,
|
---|
| 64 | 0xffffU
|
---|
| 65 | #else
|
---|
| 66 | /* 32 bit */
|
---|
| 67 | 0x00000000U,
|
---|
| 68 | 0xffffffffU
|
---|
| 69 | #endif
|
---|
| 70 | };
|
---|
| 71 | #endif
|
---|
| 72 |
|
---|
| 73 |
|
---|
| 74 | #if !defined(WOLFSSL_SP_MATH)
|
---|
| 75 | int get_digit_count(mp_int* a)
|
---|
| 76 | {
|
---|
| 77 | if (a == NULL)
|
---|
| 78 | return 0;
|
---|
| 79 |
|
---|
| 80 | return a->used;
|
---|
| 81 | }
|
---|
| 82 | #endif
|
---|
| 83 |
|
---|
| 84 | mp_digit get_digit(mp_int* a, int n)
|
---|
| 85 | {
|
---|
| 86 | if (a == NULL)
|
---|
| 87 | return 0;
|
---|
| 88 |
|
---|
| 89 | return (n >= a->used || n < 0) ? 0 : a->dp[n];
|
---|
| 90 | }
|
---|
| 91 |
|
---|
| 92 | /* Conditionally copy a into b. Performed in constant time.
|
---|
| 93 | *
|
---|
| 94 | * a MP integer to copy.
|
---|
| 95 | * copy On 1, copy a into b. on 0 leave b unchanged.
|
---|
| 96 | * b MP integer to copy into.
|
---|
| 97 | * returns BAD_FUNC_ARG when a or b is NULL, MEMORY_E when growing b fails and
|
---|
| 98 | * MP_OKAY otherwise.
|
---|
| 99 | */
|
---|
| 100 | int mp_cond_copy(mp_int* a, int copy, mp_int* b)
|
---|
| 101 | {
|
---|
| 102 | int err = MP_OKAY;
|
---|
| 103 | int i;
|
---|
| 104 | mp_digit mask = (mp_digit)0 - copy;
|
---|
| 105 |
|
---|
| 106 | if (a == NULL || b == NULL)
|
---|
| 107 | err = BAD_FUNC_ARG;
|
---|
| 108 |
|
---|
| 109 | /* Ensure b has enough space to copy a into */
|
---|
| 110 | if (err == MP_OKAY)
|
---|
| 111 | err = mp_grow(b, a->used + 1);
|
---|
| 112 | if (err == MP_OKAY) {
|
---|
| 113 | /* When mask 0, b is unchanged2
|
---|
| 114 | * When mask all set, b ^ b ^ a = a
|
---|
| 115 | */
|
---|
| 116 | /* Conditionaly copy all digits and then number of used diigits.
|
---|
| 117 | * get_digit() returns 0 when index greater than available digit.
|
---|
| 118 | */
|
---|
| 119 | for (i = 0; i < a->used; i++) {
|
---|
| 120 | b->dp[i] ^= (get_digit(a, i) ^ get_digit(b, i)) & mask;
|
---|
| 121 | }
|
---|
| 122 | for (; i < b->used; i++) {
|
---|
| 123 | b->dp[i] ^= (get_digit(a, i) ^ get_digit(b, i)) & mask;
|
---|
| 124 | }
|
---|
| 125 | b->used ^= (a->used ^ b->used) & (int)mask;
|
---|
| 126 | }
|
---|
| 127 |
|
---|
| 128 | return err;
|
---|
| 129 | }
|
---|
| 130 |
|
---|
| 131 | #ifndef WC_NO_RNG
|
---|
| 132 | int get_rand_digit(WC_RNG* rng, mp_digit* d)
|
---|
| 133 | {
|
---|
| 134 | return wc_RNG_GenerateBlock(rng, (byte*)d, sizeof(mp_digit));
|
---|
| 135 | }
|
---|
| 136 |
|
---|
| 137 | #ifdef WC_RSA_BLINDING
|
---|
| 138 | int mp_rand(mp_int* a, int digits, WC_RNG* rng)
|
---|
| 139 | {
|
---|
| 140 | int ret = 0;
|
---|
| 141 | int cnt = digits * sizeof(mp_digit);
|
---|
| 142 | #if !defined(USE_FAST_MATH) && !defined(WOLFSSL_SP_MATH)
|
---|
| 143 | int i;
|
---|
| 144 | #endif
|
---|
| 145 |
|
---|
| 146 | if (rng == NULL) {
|
---|
| 147 | ret = MISSING_RNG_E;
|
---|
| 148 | }
|
---|
| 149 | else if (a == NULL) {
|
---|
| 150 | ret = BAD_FUNC_ARG;
|
---|
| 151 | }
|
---|
| 152 |
|
---|
| 153 | #if !defined(USE_FAST_MATH) && !defined(WOLFSSL_SP_MATH)
|
---|
| 154 | /* allocate space for digits */
|
---|
| 155 | if (ret == MP_OKAY) {
|
---|
| 156 | ret = mp_set_bit(a, digits * DIGIT_BIT - 1);
|
---|
| 157 | }
|
---|
| 158 | #else
|
---|
| 159 | #if defined(WOLFSSL_SP_MATH)
|
---|
| 160 | if ((ret == MP_OKAY) && (digits > SP_INT_DIGITS))
|
---|
| 161 | #else
|
---|
| 162 | if ((ret == MP_OKAY) && (digits > FP_SIZE))
|
---|
| 163 | #endif
|
---|
| 164 | {
|
---|
| 165 | ret = BAD_FUNC_ARG;
|
---|
| 166 | }
|
---|
| 167 | if (ret == MP_OKAY) {
|
---|
| 168 | a->used = digits;
|
---|
| 169 | }
|
---|
| 170 | #endif
|
---|
| 171 | /* fill the data with random bytes */
|
---|
| 172 | if (ret == MP_OKAY) {
|
---|
| 173 | ret = wc_RNG_GenerateBlock(rng, (byte*)a->dp, cnt);
|
---|
| 174 | }
|
---|
| 175 | if (ret == MP_OKAY) {
|
---|
| 176 | #if !defined(USE_FAST_MATH) && !defined(WOLFSSL_SP_MATH)
|
---|
| 177 | /* Mask down each digit to only bits used */
|
---|
| 178 | for (i = 0; i < a->used; i++) {
|
---|
| 179 | a->dp[i] &= MP_MASK;
|
---|
| 180 | }
|
---|
| 181 | #endif
|
---|
| 182 | /* ensure top digit is not zero */
|
---|
| 183 | while ((ret == MP_OKAY) && (a->dp[a->used - 1] == 0)) {
|
---|
| 184 | ret = get_rand_digit(rng, &a->dp[a->used - 1]);
|
---|
| 185 | #if !defined(USE_FAST_MATH) && !defined(WOLFSSL_SP_MATH)
|
---|
| 186 | a->dp[a->used - 1] &= MP_MASK;
|
---|
| 187 | #endif
|
---|
| 188 | }
|
---|
| 189 | }
|
---|
| 190 |
|
---|
| 191 | return ret;
|
---|
| 192 | }
|
---|
| 193 | #endif /* WC_RSA_BLINDING */
|
---|
| 194 | #endif
|
---|
| 195 |
|
---|
| 196 | /* export an mp_int as unsigned char or hex string
|
---|
| 197 | * encType is WC_TYPE_UNSIGNED_BIN or WC_TYPE_HEX_STR
|
---|
| 198 | * return MP_OKAY on success */
|
---|
| 199 | int wc_export_int(mp_int* mp, byte* buf, word32* len, word32 keySz,
|
---|
| 200 | int encType)
|
---|
| 201 | {
|
---|
| 202 | int err;
|
---|
| 203 |
|
---|
| 204 | if (mp == NULL)
|
---|
| 205 | return BAD_FUNC_ARG;
|
---|
| 206 |
|
---|
| 207 | /* check buffer size */
|
---|
| 208 | if (*len < keySz) {
|
---|
| 209 | *len = keySz;
|
---|
| 210 | return BUFFER_E;
|
---|
| 211 | }
|
---|
| 212 |
|
---|
| 213 | *len = keySz;
|
---|
| 214 | XMEMSET(buf, 0, *len);
|
---|
| 215 |
|
---|
| 216 | if (encType == WC_TYPE_HEX_STR) {
|
---|
| 217 | #ifdef WC_MP_TO_RADIX
|
---|
| 218 | err = mp_tohex(mp, (char*)buf);
|
---|
| 219 | #else
|
---|
| 220 | err = NOT_COMPILED_IN;
|
---|
| 221 | #endif
|
---|
| 222 | }
|
---|
| 223 | else {
|
---|
| 224 | err = mp_to_unsigned_bin(mp, buf + (keySz - mp_unsigned_bin_size(mp)));
|
---|
| 225 | }
|
---|
| 226 |
|
---|
| 227 | return err;
|
---|
| 228 | }
|
---|
| 229 |
|
---|
| 230 |
|
---|
| 231 | #ifdef HAVE_WOLF_BIGINT
|
---|
| 232 | void wc_bigint_init(WC_BIGINT* a)
|
---|
| 233 | {
|
---|
| 234 | if (a != NULL) {
|
---|
| 235 | a->buf = NULL;
|
---|
| 236 | a->len = 0;
|
---|
| 237 | a->heap = NULL;
|
---|
| 238 | }
|
---|
| 239 | }
|
---|
| 240 |
|
---|
| 241 | int wc_bigint_alloc(WC_BIGINT* a, word32 sz)
|
---|
| 242 | {
|
---|
| 243 | int err = MP_OKAY;
|
---|
| 244 |
|
---|
| 245 | if (a == NULL)
|
---|
| 246 | return BAD_FUNC_ARG;
|
---|
| 247 |
|
---|
| 248 | if (sz > 0) {
|
---|
| 249 | if (a->buf && sz > a->len) {
|
---|
| 250 | wc_bigint_free(a);
|
---|
| 251 | }
|
---|
| 252 | if (a->buf == NULL) {
|
---|
| 253 | a->buf = (byte*)XMALLOC(sz, a->heap, DYNAMIC_TYPE_WOLF_BIGINT);
|
---|
| 254 | if (a->buf == NULL) {
|
---|
| 255 | err = MP_MEM;
|
---|
| 256 | }
|
---|
| 257 | }
|
---|
| 258 | else {
|
---|
| 259 | XMEMSET(a->buf, 0, sz);
|
---|
| 260 | }
|
---|
| 261 | }
|
---|
| 262 | a->len = sz;
|
---|
| 263 |
|
---|
| 264 | return err;
|
---|
| 265 | }
|
---|
| 266 |
|
---|
| 267 | /* assumes input is big endian format */
|
---|
| 268 | int wc_bigint_from_unsigned_bin(WC_BIGINT* a, const byte* in, word32 inlen)
|
---|
| 269 | {
|
---|
| 270 | int err;
|
---|
| 271 |
|
---|
| 272 | if (a == NULL || in == NULL || inlen == 0)
|
---|
| 273 | return BAD_FUNC_ARG;
|
---|
| 274 |
|
---|
| 275 | err = wc_bigint_alloc(a, inlen);
|
---|
| 276 | if (err == 0) {
|
---|
| 277 | XMEMCPY(a->buf, in, inlen);
|
---|
| 278 | }
|
---|
| 279 |
|
---|
| 280 | return err;
|
---|
| 281 | }
|
---|
| 282 |
|
---|
| 283 | int wc_bigint_to_unsigned_bin(WC_BIGINT* a, byte* out, word32* outlen)
|
---|
| 284 | {
|
---|
| 285 | word32 sz;
|
---|
| 286 |
|
---|
| 287 | if (a == NULL || out == NULL || outlen == NULL || *outlen == 0)
|
---|
| 288 | return BAD_FUNC_ARG;
|
---|
| 289 |
|
---|
| 290 | /* trim to fit into output buffer */
|
---|
| 291 | sz = a->len;
|
---|
| 292 | if (a->len > *outlen) {
|
---|
| 293 | WOLFSSL_MSG("wc_bigint_export: Truncating output");
|
---|
| 294 | sz = *outlen;
|
---|
| 295 | }
|
---|
| 296 |
|
---|
| 297 | if (a->buf) {
|
---|
| 298 | XMEMCPY(out, a->buf, sz);
|
---|
| 299 | }
|
---|
| 300 |
|
---|
| 301 | *outlen = sz;
|
---|
| 302 |
|
---|
| 303 | return MP_OKAY;
|
---|
| 304 | }
|
---|
| 305 |
|
---|
| 306 | void wc_bigint_zero(WC_BIGINT* a)
|
---|
| 307 | {
|
---|
| 308 | if (a && a->buf) {
|
---|
| 309 | ForceZero(a->buf, a->len);
|
---|
| 310 | }
|
---|
| 311 | }
|
---|
| 312 |
|
---|
| 313 | void wc_bigint_free(WC_BIGINT* a)
|
---|
| 314 | {
|
---|
| 315 | if (a) {
|
---|
| 316 | if (a->buf) {
|
---|
| 317 | XFREE(a->buf, a->heap, DYNAMIC_TYPE_WOLF_BIGINT);
|
---|
| 318 | }
|
---|
| 319 | a->buf = NULL;
|
---|
| 320 | a->len = 0;
|
---|
| 321 | }
|
---|
| 322 | }
|
---|
| 323 |
|
---|
| 324 | /* sz: make sure the buffer is at least that size and zero padded.
|
---|
| 325 | * A `sz == 0` will use the size of `src`.
|
---|
| 326 | * The calulcates sz is stored into dst->len in `wc_bigint_alloc`.
|
---|
| 327 | */
|
---|
| 328 | int wc_mp_to_bigint_sz(mp_int* src, WC_BIGINT* dst, word32 sz)
|
---|
| 329 | {
|
---|
| 330 | int err;
|
---|
| 331 | word32 x, y;
|
---|
| 332 |
|
---|
| 333 | if (src == NULL || dst == NULL)
|
---|
| 334 | return BAD_FUNC_ARG;
|
---|
| 335 |
|
---|
| 336 | /* get size of source */
|
---|
| 337 | x = mp_unsigned_bin_size(src);
|
---|
| 338 | if (sz < x)
|
---|
| 339 | sz = x;
|
---|
| 340 |
|
---|
| 341 | /* make sure destination is allocated and large enough */
|
---|
| 342 | err = wc_bigint_alloc(dst, sz);
|
---|
| 343 | if (err == MP_OKAY) {
|
---|
| 344 |
|
---|
| 345 | /* leading zero pad */
|
---|
| 346 | y = sz - x;
|
---|
| 347 | XMEMSET(dst->buf, 0, y);
|
---|
| 348 |
|
---|
| 349 | /* export src as unsigned bin to destination buf */
|
---|
| 350 | err = mp_to_unsigned_bin(src, dst->buf + y);
|
---|
| 351 | }
|
---|
| 352 |
|
---|
| 353 | return err;
|
---|
| 354 | }
|
---|
| 355 |
|
---|
| 356 | int wc_mp_to_bigint(mp_int* src, WC_BIGINT* dst)
|
---|
| 357 | {
|
---|
| 358 | if (src == NULL || dst == NULL)
|
---|
| 359 | return BAD_FUNC_ARG;
|
---|
| 360 |
|
---|
| 361 | return wc_mp_to_bigint_sz(src, dst, 0);
|
---|
| 362 | }
|
---|
| 363 |
|
---|
| 364 | int wc_bigint_to_mp(WC_BIGINT* src, mp_int* dst)
|
---|
| 365 | {
|
---|
| 366 | int err;
|
---|
| 367 |
|
---|
| 368 | if (src == NULL || dst == NULL)
|
---|
| 369 | return BAD_FUNC_ARG;
|
---|
| 370 |
|
---|
| 371 | if (src->buf == NULL)
|
---|
| 372 | return BAD_FUNC_ARG;
|
---|
| 373 |
|
---|
| 374 | err = mp_read_unsigned_bin(dst, src->buf, src->len);
|
---|
| 375 | wc_bigint_free(src);
|
---|
| 376 |
|
---|
| 377 | return err;
|
---|
| 378 | }
|
---|
| 379 | #endif /* HAVE_WOLF_BIGINT */
|
---|
| 380 |
|
---|
| 381 | #endif /* USE_FAST_MATH || !NO_BIG_INT */
|
---|