wolf SSL / wolfSSL

wolfSSL SSL/TLS library, support up to TLS1.3

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wolfcrypt/src/wolfmath.c@17:a5f916481144, 2020-06-05 (annotated)

Committer:
wolfSSL
Date:
Fri Jun 05 00:11:07 2020 +0000
Revision:
17:a5f916481144
Parent:
16:8e0d178b1d1e 
wolfSSL 4.4.0

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wolfSSL 15:117db924cf7c 1 /* wolfmath.c
wolfSSL 15:117db924cf7c 2 *
wolfSSL 16:8e0d178b1d1e 3 * Copyright (C) 2006-2020 wolfSSL Inc.
wolfSSL 15:117db924cf7c 4 *
wolfSSL 15:117db924cf7c 5 * This file is part of wolfSSL.
wolfSSL 15:117db924cf7c 6 *
wolfSSL 15:117db924cf7c 7 * wolfSSL is free software; you can redistribute it and/or modify
wolfSSL 15:117db924cf7c 8 * it under the terms of the GNU General Public License as published by
wolfSSL 15:117db924cf7c 9 * the Free Software Foundation; either version 2 of the License, or
wolfSSL 15:117db924cf7c 10 * (at your option) any later version.
wolfSSL 15:117db924cf7c 11 *
wolfSSL 15:117db924cf7c 12 * wolfSSL is distributed in the hope that it will be useful,
wolfSSL 15:117db924cf7c 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
wolfSSL 15:117db924cf7c 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
wolfSSL 15:117db924cf7c 15 * GNU General Public License for more details.
wolfSSL 15:117db924cf7c 16 *
wolfSSL 15:117db924cf7c 17 * You should have received a copy of the GNU General Public License
wolfSSL 15:117db924cf7c 18 * along with this program; if not, write to the Free Software
wolfSSL 15:117db924cf7c 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
wolfSSL 15:117db924cf7c 20 */
wolfSSL 15:117db924cf7c 21
wolfSSL 15:117db924cf7c 22
wolfSSL 15:117db924cf7c 23 /* common functions for either math library */
wolfSSL 15:117db924cf7c 24
wolfSSL 15:117db924cf7c 25 #ifdef HAVE_CONFIG_H
wolfSSL 15:117db924cf7c 26 #include <config.h>
wolfSSL 15:117db924cf7c 27 #endif
wolfSSL 15:117db924cf7c 28
wolfSSL 15:117db924cf7c 29 /* in case user set USE_FAST_MATH there */
wolfSSL 15:117db924cf7c 30 #include <wolfssl/wolfcrypt/settings.h>
wolfSSL 15:117db924cf7c 31
wolfSSL 16:8e0d178b1d1e 32 #include <wolfssl/wolfcrypt/integer.h>
wolfSSL 15:117db924cf7c 33
wolfSSL 15:117db924cf7c 34 #include <wolfssl/wolfcrypt/error-crypt.h>
wolfSSL 15:117db924cf7c 35 #include <wolfssl/wolfcrypt/logging.h>
wolfSSL 15:117db924cf7c 36
wolfSSL 15:117db924cf7c 37 #if defined(USE_FAST_MATH) || !defined(NO_BIG_INT)
wolfSSL 15:117db924cf7c 38
wolfSSL 15:117db924cf7c 39 #ifdef WOLFSSL_ASYNC_CRYPT
wolfSSL 15:117db924cf7c 40 #include <wolfssl/wolfcrypt/async.h>
wolfSSL 15:117db924cf7c 41 #endif
wolfSSL 15:117db924cf7c 42
wolfSSL 15:117db924cf7c 43 #ifdef NO_INLINE
wolfSSL 15:117db924cf7c 44 #include <wolfssl/wolfcrypt/misc.h>
wolfSSL 15:117db924cf7c 45 #else
wolfSSL 15:117db924cf7c 46 #define WOLFSSL_MISC_INCLUDED
wolfSSL 15:117db924cf7c 47 #include <wolfcrypt/src/misc.c>
wolfSSL 15:117db924cf7c 48 #endif
wolfSSL 15:117db924cf7c 49
wolfSSL 15:117db924cf7c 50
wolfSSL 15:117db924cf7c 51 #if !defined(WC_NO_CACHE_RESISTANT) && \
wolfSSL 15:117db924cf7c 52 ((defined(HAVE_ECC) && defined(ECC_TIMING_RESISTANT)) || \
wolfSSL 15:117db924cf7c 53 (defined(USE_FAST_MATH) && defined(TFM_TIMING_RESISTANT)))
wolfSSL 15:117db924cf7c 54
wolfSSL 15:117db924cf7c 55 /* all off / all on pointer addresses for constant calculations */
wolfSSL 15:117db924cf7c 56 /* ecc.c uses same table */
wolfSSL 15:117db924cf7c 57 const wolfssl_word wc_off_on_addr[2] =
wolfSSL 15:117db924cf7c 58 {
wolfSSL 15:117db924cf7c 59 #if defined(WC_64BIT_CPU)
wolfSSL 15:117db924cf7c 60 W64LIT(0x0000000000000000),
wolfSSL 15:117db924cf7c 61 W64LIT(0xffffffffffffffff)
wolfSSL 15:117db924cf7c 62 #elif defined(WC_16BIT_CPU)
wolfSSL 15:117db924cf7c 63 0x0000U,
wolfSSL 15:117db924cf7c 64 0xffffU
wolfSSL 15:117db924cf7c 65 #else
wolfSSL 15:117db924cf7c 66 /* 32 bit */
wolfSSL 15:117db924cf7c 67 0x00000000U,
wolfSSL 15:117db924cf7c 68 0xffffffffU
wolfSSL 15:117db924cf7c 69 #endif
wolfSSL 15:117db924cf7c 70 };
wolfSSL 15:117db924cf7c 71 #endif
wolfSSL 15:117db924cf7c 72
wolfSSL 15:117db924cf7c 73
wolfSSL 16:8e0d178b1d1e 74 #if !defined(WOLFSSL_SP_MATH)
wolfSSL 15:117db924cf7c 75 int get_digit_count(mp_int* a)
wolfSSL 15:117db924cf7c 76 {
wolfSSL 15:117db924cf7c 77 if (a == NULL)
wolfSSL 15:117db924cf7c 78 return 0;
wolfSSL 15:117db924cf7c 79
wolfSSL 15:117db924cf7c 80 return a->used;
wolfSSL 15:117db924cf7c 81 }
wolfSSL 16:8e0d178b1d1e 82 #endif
wolfSSL 15:117db924cf7c 83
wolfSSL 15:117db924cf7c 84 mp_digit get_digit(mp_int* a, int n)
wolfSSL 15:117db924cf7c 85 {
wolfSSL 15:117db924cf7c 86 if (a == NULL)
wolfSSL 15:117db924cf7c 87 return 0;
wolfSSL 15:117db924cf7c 88
wolfSSL 15:117db924cf7c 89 return (n >= a->used || n < 0) ? 0 : a->dp[n];
wolfSSL 15:117db924cf7c 90 }
wolfSSL 15:117db924cf7c 91
wolfSSL 16:8e0d178b1d1e 92 /* Conditionally copy a into b. Performed in constant time.
wolfSSL 16:8e0d178b1d1e 93 *
wolfSSL 16:8e0d178b1d1e 94 * a MP integer to copy.
wolfSSL 16:8e0d178b1d1e 95 * copy On 1, copy a into b. on 0 leave b unchanged.
wolfSSL 16:8e0d178b1d1e 96 * b MP integer to copy into.
wolfSSL 16:8e0d178b1d1e 97 * returns BAD_FUNC_ARG when a or b is NULL, MEMORY_E when growing b fails and
wolfSSL 16:8e0d178b1d1e 98 * MP_OKAY otherwise.
wolfSSL 16:8e0d178b1d1e 99 */
wolfSSL 16:8e0d178b1d1e 100 int mp_cond_copy(mp_int* a, int copy, mp_int* b)
wolfSSL 16:8e0d178b1d1e 101 {
wolfSSL 16:8e0d178b1d1e 102 int err = MP_OKAY;
wolfSSL 16:8e0d178b1d1e 103 int i;
wolfSSL 16:8e0d178b1d1e 104 mp_digit mask = (mp_digit)0 - copy;
wolfSSL 16:8e0d178b1d1e 105
wolfSSL 16:8e0d178b1d1e 106 if (a == NULL || b == NULL)
wolfSSL 16:8e0d178b1d1e 107 err = BAD_FUNC_ARG;
wolfSSL 16:8e0d178b1d1e 108
wolfSSL 16:8e0d178b1d1e 109 /* Ensure b has enough space to copy a into */
wolfSSL 16:8e0d178b1d1e 110 if (err == MP_OKAY)
wolfSSL 16:8e0d178b1d1e 111 err = mp_grow(b, a->used + 1);
wolfSSL 16:8e0d178b1d1e 112 if (err == MP_OKAY) {
wolfSSL 16:8e0d178b1d1e 113 /* When mask 0, b is unchanged2
wolfSSL 16:8e0d178b1d1e 114 * When mask all set, b ^ b ^ a = a
wolfSSL 16:8e0d178b1d1e 115 */
wolfSSL 16:8e0d178b1d1e 116 /* Conditionaly copy all digits and then number of used diigits.
wolfSSL 16:8e0d178b1d1e 117 * get_digit() returns 0 when index greater than available digit.
wolfSSL 16:8e0d178b1d1e 118 */
wolfSSL 16:8e0d178b1d1e 119 for (i = 0; i < a->used; i++) {
wolfSSL 16:8e0d178b1d1e 120 b->dp[i] ^= (get_digit(a, i) ^ get_digit(b, i)) & mask;
wolfSSL 16:8e0d178b1d1e 121 }
wolfSSL 16:8e0d178b1d1e 122 for (; i < b->used; i++) {
wolfSSL 16:8e0d178b1d1e 123 b->dp[i] ^= (get_digit(a, i) ^ get_digit(b, i)) & mask;
wolfSSL 16:8e0d178b1d1e 124 }
wolfSSL 16:8e0d178b1d1e 125 b->used ^= (a->used ^ b->used) & (int)mask;
wolfSSL 16:8e0d178b1d1e 126 }
wolfSSL 16:8e0d178b1d1e 127
wolfSSL 16:8e0d178b1d1e 128 return err;
wolfSSL 16:8e0d178b1d1e 129 }
wolfSSL 16:8e0d178b1d1e 130
wolfSSL 16:8e0d178b1d1e 131 #ifndef WC_NO_RNG
wolfSSL 15:117db924cf7c 132 int get_rand_digit(WC_RNG* rng, mp_digit* d)
wolfSSL 15:117db924cf7c 133 {
wolfSSL 15:117db924cf7c 134 return wc_RNG_GenerateBlock(rng, (byte*)d, sizeof(mp_digit));
wolfSSL 15:117db924cf7c 135 }
wolfSSL 15:117db924cf7c 136
wolfSSL 15:117db924cf7c 137 #ifdef WC_RSA_BLINDING
wolfSSL 15:117db924cf7c 138 int mp_rand(mp_int* a, int digits, WC_RNG* rng)
wolfSSL 15:117db924cf7c 139 {
wolfSSL 15:117db924cf7c 140 int ret = 0;
wolfSSL 16:8e0d178b1d1e 141 int cnt = digits * sizeof(mp_digit);
wolfSSL 16:8e0d178b1d1e 142 #if !defined(USE_FAST_MATH) && !defined(WOLFSSL_SP_MATH)
wolfSSL 16:8e0d178b1d1e 143 int i;
wolfSSL 16:8e0d178b1d1e 144 #endif
wolfSSL 15:117db924cf7c 145
wolfSSL 15:117db924cf7c 146 if (rng == NULL) {
wolfSSL 16:8e0d178b1d1e 147 ret = MISSING_RNG_E;
wolfSSL 15:117db924cf7c 148 }
wolfSSL 16:8e0d178b1d1e 149 else if (a == NULL) {
wolfSSL 16:8e0d178b1d1e 150 ret = BAD_FUNC_ARG;
wolfSSL 15:117db924cf7c 151 }
wolfSSL 15:117db924cf7c 152
wolfSSL 16:8e0d178b1d1e 153 #if !defined(USE_FAST_MATH) && !defined(WOLFSSL_SP_MATH)
wolfSSL 16:8e0d178b1d1e 154 /* allocate space for digits */
wolfSSL 16:8e0d178b1d1e 155 if (ret == MP_OKAY) {
wolfSSL 16:8e0d178b1d1e 156 ret = mp_set_bit(a, digits * DIGIT_BIT - 1);
wolfSSL 16:8e0d178b1d1e 157 }
wolfSSL 16:8e0d178b1d1e 158 #else
wolfSSL 16:8e0d178b1d1e 159 #if defined(WOLFSSL_SP_MATH)
wolfSSL 16:8e0d178b1d1e 160 if ((ret == MP_OKAY) && (digits > SP_INT_DIGITS))
wolfSSL 16:8e0d178b1d1e 161 #else
wolfSSL 16:8e0d178b1d1e 162 if ((ret == MP_OKAY) && (digits > FP_SIZE))
wolfSSL 16:8e0d178b1d1e 163 #endif
wolfSSL 16:8e0d178b1d1e 164 {
wolfSSL 16:8e0d178b1d1e 165 ret = BAD_FUNC_ARG;
wolfSSL 16:8e0d178b1d1e 166 }
wolfSSL 16:8e0d178b1d1e 167 if (ret == MP_OKAY) {
wolfSSL 16:8e0d178b1d1e 168 a->used = digits;
wolfSSL 15:117db924cf7c 169 }
wolfSSL 16:8e0d178b1d1e 170 #endif
wolfSSL 16:8e0d178b1d1e 171 /* fill the data with random bytes */
wolfSSL 16:8e0d178b1d1e 172 if (ret == MP_OKAY) {
wolfSSL 16:8e0d178b1d1e 173 ret = wc_RNG_GenerateBlock(rng, (byte*)a->dp, cnt);
wolfSSL 16:8e0d178b1d1e 174 }
wolfSSL 16:8e0d178b1d1e 175 if (ret == MP_OKAY) {
wolfSSL 16:8e0d178b1d1e 176 #if !defined(USE_FAST_MATH) && !defined(WOLFSSL_SP_MATH)
wolfSSL 16:8e0d178b1d1e 177 /* Mask down each digit to only bits used */
wolfSSL 16:8e0d178b1d1e 178 for (i = 0; i < a->used; i++) {
wolfSSL 16:8e0d178b1d1e 179 a->dp[i] &= MP_MASK;
wolfSSL 15:117db924cf7c 180 }
wolfSSL 16:8e0d178b1d1e 181 #endif
wolfSSL 16:8e0d178b1d1e 182 /* ensure top digit is not zero */
wolfSSL 16:8e0d178b1d1e 183 while ((ret == MP_OKAY) && (a->dp[a->used - 1] == 0)) {
wolfSSL 16:8e0d178b1d1e 184 ret = get_rand_digit(rng, &a->dp[a->used - 1]);
wolfSSL 16:8e0d178b1d1e 185 #if !defined(USE_FAST_MATH) && !defined(WOLFSSL_SP_MATH)
wolfSSL 16:8e0d178b1d1e 186 a->dp[a->used - 1] &= MP_MASK;
wolfSSL 16:8e0d178b1d1e 187 #endif
wolfSSL 15:117db924cf7c 188 }
wolfSSL 15:117db924cf7c 189 }
wolfSSL 15:117db924cf7c 190
wolfSSL 15:117db924cf7c 191 return ret;
wolfSSL 15:117db924cf7c 192 }
wolfSSL 15:117db924cf7c 193 #endif /* WC_RSA_BLINDING */
wolfSSL 16:8e0d178b1d1e 194 #endif
wolfSSL 16:8e0d178b1d1e 195
wolfSSL 16:8e0d178b1d1e 196 /* export an mp_int as unsigned char or hex string
wolfSSL 16:8e0d178b1d1e 197 * encType is WC_TYPE_UNSIGNED_BIN or WC_TYPE_HEX_STR
wolfSSL 16:8e0d178b1d1e 198 * return MP_OKAY on success */
wolfSSL 16:8e0d178b1d1e 199 int wc_export_int(mp_int* mp, byte* buf, word32* len, word32 keySz,
wolfSSL 16:8e0d178b1d1e 200 int encType)
wolfSSL 16:8e0d178b1d1e 201 {
wolfSSL 16:8e0d178b1d1e 202 int err;
wolfSSL 16:8e0d178b1d1e 203
wolfSSL 16:8e0d178b1d1e 204 if (mp == NULL)
wolfSSL 16:8e0d178b1d1e 205 return BAD_FUNC_ARG;
wolfSSL 16:8e0d178b1d1e 206
wolfSSL 16:8e0d178b1d1e 207 /* check buffer size */
wolfSSL 16:8e0d178b1d1e 208 if (*len < keySz) {
wolfSSL 16:8e0d178b1d1e 209 *len = keySz;
wolfSSL 16:8e0d178b1d1e 210 return BUFFER_E;
wolfSSL 16:8e0d178b1d1e 211 }
wolfSSL 16:8e0d178b1d1e 212
wolfSSL 16:8e0d178b1d1e 213 *len = keySz;
wolfSSL 16:8e0d178b1d1e 214 XMEMSET(buf, 0, *len);
wolfSSL 16:8e0d178b1d1e 215
wolfSSL 16:8e0d178b1d1e 216 if (encType == WC_TYPE_HEX_STR) {
wolfSSL 16:8e0d178b1d1e 217 #ifdef WC_MP_TO_RADIX
wolfSSL 16:8e0d178b1d1e 218 err = mp_tohex(mp, (char*)buf);
wolfSSL 16:8e0d178b1d1e 219 #else
wolfSSL 16:8e0d178b1d1e 220 err = NOT_COMPILED_IN;
wolfSSL 16:8e0d178b1d1e 221 #endif
wolfSSL 16:8e0d178b1d1e 222 }
wolfSSL 16:8e0d178b1d1e 223 else {
wolfSSL 16:8e0d178b1d1e 224 err = mp_to_unsigned_bin(mp, buf + (keySz - mp_unsigned_bin_size(mp)));
wolfSSL 16:8e0d178b1d1e 225 }
wolfSSL 16:8e0d178b1d1e 226
wolfSSL 16:8e0d178b1d1e 227 return err;
wolfSSL 16:8e0d178b1d1e 228 }
wolfSSL 15:117db924cf7c 229
wolfSSL 15:117db924cf7c 230
wolfSSL 15:117db924cf7c 231 #ifdef HAVE_WOLF_BIGINT
wolfSSL 15:117db924cf7c 232 void wc_bigint_init(WC_BIGINT* a)
wolfSSL 15:117db924cf7c 233 {
wolfSSL 15:117db924cf7c 234 if (a != NULL) {
wolfSSL 15:117db924cf7c 235 a->buf = NULL;
wolfSSL 15:117db924cf7c 236 a->len = 0;
wolfSSL 15:117db924cf7c 237 a->heap = NULL;
wolfSSL 15:117db924cf7c 238 }
wolfSSL 15:117db924cf7c 239 }
wolfSSL 15:117db924cf7c 240
wolfSSL 15:117db924cf7c 241 int wc_bigint_alloc(WC_BIGINT* a, word32 sz)
wolfSSL 15:117db924cf7c 242 {
wolfSSL 15:117db924cf7c 243 int err = MP_OKAY;
wolfSSL 15:117db924cf7c 244
wolfSSL 15:117db924cf7c 245 if (a == NULL)
wolfSSL 15:117db924cf7c 246 return BAD_FUNC_ARG;
wolfSSL 15:117db924cf7c 247
wolfSSL 15:117db924cf7c 248 if (sz > 0) {
wolfSSL 15:117db924cf7c 249 if (a->buf && sz > a->len) {
wolfSSL 15:117db924cf7c 250 wc_bigint_free(a);
wolfSSL 15:117db924cf7c 251 }
wolfSSL 15:117db924cf7c 252 if (a->buf == NULL) {
wolfSSL 15:117db924cf7c 253 a->buf = (byte*)XMALLOC(sz, a->heap, DYNAMIC_TYPE_WOLF_BIGINT);
wolfSSL 16:8e0d178b1d1e 254 if (a->buf == NULL) {
wolfSSL 16:8e0d178b1d1e 255 err = MP_MEM;
wolfSSL 16:8e0d178b1d1e 256 }
wolfSSL 15:117db924cf7c 257 }
wolfSSL 15:117db924cf7c 258 else {
wolfSSL 15:117db924cf7c 259 XMEMSET(a->buf, 0, sz);
wolfSSL 15:117db924cf7c 260 }
wolfSSL 15:117db924cf7c 261 }
wolfSSL 15:117db924cf7c 262 a->len = sz;
wolfSSL 15:117db924cf7c 263
wolfSSL 15:117db924cf7c 264 return err;
wolfSSL 15:117db924cf7c 265 }
wolfSSL 15:117db924cf7c 266
wolfSSL 15:117db924cf7c 267 /* assumes input is big endian format */
wolfSSL 15:117db924cf7c 268 int wc_bigint_from_unsigned_bin(WC_BIGINT* a, const byte* in, word32 inlen)
wolfSSL 15:117db924cf7c 269 {
wolfSSL 15:117db924cf7c 270 int err;
wolfSSL 15:117db924cf7c 271
wolfSSL 15:117db924cf7c 272 if (a == NULL || in == NULL || inlen == 0)
wolfSSL 15:117db924cf7c 273 return BAD_FUNC_ARG;
wolfSSL 15:117db924cf7c 274
wolfSSL 15:117db924cf7c 275 err = wc_bigint_alloc(a, inlen);
wolfSSL 15:117db924cf7c 276 if (err == 0) {
wolfSSL 15:117db924cf7c 277 XMEMCPY(a->buf, in, inlen);
wolfSSL 15:117db924cf7c 278 }
wolfSSL 15:117db924cf7c 279
wolfSSL 15:117db924cf7c 280 return err;
wolfSSL 15:117db924cf7c 281 }
wolfSSL 15:117db924cf7c 282
wolfSSL 15:117db924cf7c 283 int wc_bigint_to_unsigned_bin(WC_BIGINT* a, byte* out, word32* outlen)
wolfSSL 15:117db924cf7c 284 {
wolfSSL 15:117db924cf7c 285 word32 sz;
wolfSSL 15:117db924cf7c 286
wolfSSL 15:117db924cf7c 287 if (a == NULL || out == NULL || outlen == NULL || *outlen == 0)
wolfSSL 15:117db924cf7c 288 return BAD_FUNC_ARG;
wolfSSL 15:117db924cf7c 289
wolfSSL 15:117db924cf7c 290 /* trim to fit into output buffer */
wolfSSL 15:117db924cf7c 291 sz = a->len;
wolfSSL 15:117db924cf7c 292 if (a->len > *outlen) {
wolfSSL 15:117db924cf7c 293 WOLFSSL_MSG("wc_bigint_export: Truncating output");
wolfSSL 15:117db924cf7c 294 sz = *outlen;
wolfSSL 15:117db924cf7c 295 }
wolfSSL 15:117db924cf7c 296
wolfSSL 15:117db924cf7c 297 if (a->buf) {
wolfSSL 15:117db924cf7c 298 XMEMCPY(out, a->buf, sz);
wolfSSL 15:117db924cf7c 299 }
wolfSSL 15:117db924cf7c 300
wolfSSL 15:117db924cf7c 301 *outlen = sz;
wolfSSL 15:117db924cf7c 302
wolfSSL 15:117db924cf7c 303 return MP_OKAY;
wolfSSL 15:117db924cf7c 304 }
wolfSSL 15:117db924cf7c 305
wolfSSL 15:117db924cf7c 306 void wc_bigint_zero(WC_BIGINT* a)
wolfSSL 15:117db924cf7c 307 {
wolfSSL 15:117db924cf7c 308 if (a && a->buf) {
wolfSSL 15:117db924cf7c 309 ForceZero(a->buf, a->len);
wolfSSL 15:117db924cf7c 310 }
wolfSSL 15:117db924cf7c 311 }
wolfSSL 15:117db924cf7c 312
wolfSSL 15:117db924cf7c 313 void wc_bigint_free(WC_BIGINT* a)
wolfSSL 15:117db924cf7c 314 {
wolfSSL 15:117db924cf7c 315 if (a) {
wolfSSL 15:117db924cf7c 316 if (a->buf) {
wolfSSL 15:117db924cf7c 317 XFREE(a->buf, a->heap, DYNAMIC_TYPE_WOLF_BIGINT);
wolfSSL 15:117db924cf7c 318 }
wolfSSL 15:117db924cf7c 319 a->buf = NULL;
wolfSSL 15:117db924cf7c 320 a->len = 0;
wolfSSL 15:117db924cf7c 321 }
wolfSSL 15:117db924cf7c 322 }
wolfSSL 15:117db924cf7c 323
wolfSSL 15:117db924cf7c 324 /* sz: make sure the buffer is at least that size and zero padded.
wolfSSL 15:117db924cf7c 325 * A `sz == 0` will use the size of `src`.
wolfSSL 15:117db924cf7c 326 * The calulcates sz is stored into dst->len in `wc_bigint_alloc`.
wolfSSL 15:117db924cf7c 327 */
wolfSSL 15:117db924cf7c 328 int wc_mp_to_bigint_sz(mp_int* src, WC_BIGINT* dst, word32 sz)
wolfSSL 15:117db924cf7c 329 {
wolfSSL 15:117db924cf7c 330 int err;
wolfSSL 15:117db924cf7c 331 word32 x, y;
wolfSSL 15:117db924cf7c 332
wolfSSL 15:117db924cf7c 333 if (src == NULL || dst == NULL)
wolfSSL 15:117db924cf7c 334 return BAD_FUNC_ARG;
wolfSSL 15:117db924cf7c 335
wolfSSL 15:117db924cf7c 336 /* get size of source */
wolfSSL 15:117db924cf7c 337 x = mp_unsigned_bin_size(src);
wolfSSL 15:117db924cf7c 338 if (sz < x)
wolfSSL 15:117db924cf7c 339 sz = x;
wolfSSL 15:117db924cf7c 340
wolfSSL 15:117db924cf7c 341 /* make sure destination is allocated and large enough */
wolfSSL 15:117db924cf7c 342 err = wc_bigint_alloc(dst, sz);
wolfSSL 15:117db924cf7c 343 if (err == MP_OKAY) {
wolfSSL 15:117db924cf7c 344
wolfSSL 15:117db924cf7c 345 /* leading zero pad */
wolfSSL 15:117db924cf7c 346 y = sz - x;
wolfSSL 15:117db924cf7c 347 XMEMSET(dst->buf, 0, y);
wolfSSL 15:117db924cf7c 348
wolfSSL 15:117db924cf7c 349 /* export src as unsigned bin to destination buf */
wolfSSL 15:117db924cf7c 350 err = mp_to_unsigned_bin(src, dst->buf + y);
wolfSSL 15:117db924cf7c 351 }
wolfSSL 15:117db924cf7c 352
wolfSSL 15:117db924cf7c 353 return err;
wolfSSL 15:117db924cf7c 354 }
wolfSSL 15:117db924cf7c 355
wolfSSL 15:117db924cf7c 356 int wc_mp_to_bigint(mp_int* src, WC_BIGINT* dst)
wolfSSL 15:117db924cf7c 357 {
wolfSSL 15:117db924cf7c 358 if (src == NULL || dst == NULL)
wolfSSL 15:117db924cf7c 359 return BAD_FUNC_ARG;
wolfSSL 15:117db924cf7c 360
wolfSSL 15:117db924cf7c 361 return wc_mp_to_bigint_sz(src, dst, 0);
wolfSSL 15:117db924cf7c 362 }
wolfSSL 15:117db924cf7c 363
wolfSSL 15:117db924cf7c 364 int wc_bigint_to_mp(WC_BIGINT* src, mp_int* dst)
wolfSSL 15:117db924cf7c 365 {
wolfSSL 15:117db924cf7c 366 int err;
wolfSSL 15:117db924cf7c 367
wolfSSL 15:117db924cf7c 368 if (src == NULL || dst == NULL)
wolfSSL 15:117db924cf7c 369 return BAD_FUNC_ARG;
wolfSSL 15:117db924cf7c 370
wolfSSL 15:117db924cf7c 371 if (src->buf == NULL)
wolfSSL 15:117db924cf7c 372 return BAD_FUNC_ARG;
wolfSSL 15:117db924cf7c 373
wolfSSL 15:117db924cf7c 374 err = mp_read_unsigned_bin(dst, src->buf, src->len);
wolfSSL 15:117db924cf7c 375 wc_bigint_free(src);
wolfSSL 15:117db924cf7c 376
wolfSSL 15:117db924cf7c 377 return err;
wolfSSL 15:117db924cf7c 378 }
wolfSSL 15:117db924cf7c 379 #endif /* HAVE_WOLF_BIGINT */
wolfSSL 15:117db924cf7c 380
wolfSSL 15:117db924cf7c 381 #endif /* USE_FAST_MATH || !NO_BIG_INT */
wolfSSL 15:117db924cf7c 382