[457] | 1 | /* dsa.c
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| 2 | *
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| 3 | * Copyright (C) 2006-2020 wolfSSL Inc.
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| 4 | *
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| 5 | * This file is part of wolfSSL.
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| 6 | *
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| 7 | * wolfSSL is free software; you can redistribute it and/or modify
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| 8 | * it under the terms of the GNU General Public License as published by
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| 9 | * the Free Software Foundation; either version 2 of the License, or
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| 10 | * (at your option) any later version.
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| 11 | *
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| 12 | * wolfSSL is distributed in the hope that it will be useful,
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| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 15 | * GNU General Public License for more details.
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| 16 | *
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| 17 | * You should have received a copy of the GNU General Public License
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| 18 | * along with this program; if not, write to the Free Software
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| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
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| 20 | */
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| 21 |
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| 22 |
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| 23 | #ifdef HAVE_CONFIG_H
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| 24 | #include <config.h>
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| 25 | #endif
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| 26 |
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| 27 | #include <wolfssl/wolfcrypt/settings.h>
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| 28 |
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| 29 | #ifndef NO_DSA
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| 30 |
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| 31 | #include <wolfssl/wolfcrypt/random.h>
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| 32 | #include <wolfssl/wolfcrypt/integer.h>
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| 33 | #include <wolfssl/wolfcrypt/error-crypt.h>
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| 34 | #include <wolfssl/wolfcrypt/logging.h>
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| 35 | #include <wolfssl/wolfcrypt/sha.h>
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| 36 | #include <wolfssl/wolfcrypt/dsa.h>
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| 37 |
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| 38 | #ifdef NO_INLINE
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| 39 | #include <wolfssl/wolfcrypt/misc.h>
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| 40 | #else
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| 41 | #define WOLFSSL_MISC_INCLUDED
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| 42 | #include <wolfcrypt/src/misc.c>
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| 43 | #endif
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| 44 |
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[464] | 45 | #ifdef _MSC_VER
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| 46 | /* disable for while(0) cases (MSVC bug) */
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| 47 | #pragma warning(disable:4127)
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| 48 | #endif
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| 49 |
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[457] | 50 | int wc_InitDsaKey(DsaKey* key)
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| 51 | {
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| 52 | if (key == NULL)
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| 53 | return BAD_FUNC_ARG;
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| 54 |
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| 55 | key->type = -1; /* haven't decided yet */
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| 56 | key->heap = NULL;
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| 57 |
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| 58 | return mp_init_multi(
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| 59 | /* public alloc parts */
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| 60 | &key->p,
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| 61 | &key->q,
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| 62 | &key->g,
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| 63 | &key->y,
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| 64 |
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| 65 | /* private alloc parts */
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| 66 | &key->x,
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| 67 | NULL
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| 68 | );
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| 69 | }
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| 70 |
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| 71 |
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| 72 | int wc_InitDsaKey_h(DsaKey* key, void* h)
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| 73 | {
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| 74 | int ret = wc_InitDsaKey(key);
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| 75 | if (ret == 0)
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| 76 | key->heap = h;
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| 77 |
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| 78 | return ret;
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| 79 | }
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| 80 |
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| 81 |
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| 82 | void wc_FreeDsaKey(DsaKey* key)
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| 83 | {
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| 84 | if (key == NULL)
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| 85 | return;
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| 86 |
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| 87 | if (key->type == DSA_PRIVATE)
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| 88 | mp_forcezero(&key->x);
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| 89 |
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| 90 | mp_clear(&key->x);
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| 91 | mp_clear(&key->y);
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| 92 | mp_clear(&key->g);
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| 93 | mp_clear(&key->q);
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| 94 | mp_clear(&key->p);
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| 95 | }
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| 96 |
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| 97 |
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| 98 | /* validate that (L,N) match allowed sizes from FIPS 186-4, Section 4.2.
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| 99 | * modLen - represents L, the size of p (prime modulus) in bits
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| 100 | * divLen - represents N, the size of q (prime divisor) in bits
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| 101 | * return 0 on success, -1 on error */
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| 102 | static int CheckDsaLN(int modLen, int divLen)
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| 103 | {
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| 104 | int ret = -1;
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| 105 |
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| 106 | switch (modLen) {
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| 107 | case 1024:
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| 108 | if (divLen == 160)
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| 109 | ret = 0;
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| 110 | break;
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| 111 | case 2048:
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| 112 | if (divLen == 224 || divLen == 256)
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| 113 | ret = 0;
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| 114 | break;
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| 115 | case 3072:
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| 116 | if (divLen == 256)
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| 117 | ret = 0;
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| 118 | break;
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| 119 | default:
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| 120 | break;
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| 121 | }
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| 122 |
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| 123 | return ret;
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| 124 | }
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| 125 |
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| 126 |
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| 127 | #ifdef WOLFSSL_KEY_GEN
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| 128 |
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| 129 | /* Create DSA key pair (&dsa->x, &dsa->y)
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| 130 | *
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| 131 | * Based on NIST FIPS 186-4,
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| 132 | * "B.1.1 Key Pair Generation Using Extra Random Bits"
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| 133 | *
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| 134 | * rng - pointer to initialized WC_RNG structure
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| 135 | * dsa - pointer to initialized DsaKey structure, will hold generated key
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| 136 | *
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| 137 | * return 0 on success, negative on error */
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| 138 | int wc_MakeDsaKey(WC_RNG *rng, DsaKey *dsa)
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| 139 | {
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| 140 | byte* cBuf;
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| 141 | int qSz, pSz, cSz, err;
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| 142 | mp_int tmpQ;
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| 143 |
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| 144 | if (rng == NULL || dsa == NULL)
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| 145 | return BAD_FUNC_ARG;
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| 146 |
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| 147 | qSz = mp_unsigned_bin_size(&dsa->q);
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| 148 | pSz = mp_unsigned_bin_size(&dsa->p);
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| 149 |
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| 150 | /* verify (L,N) pair bit lengths */
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| 151 | if (CheckDsaLN(pSz * WOLFSSL_BIT_SIZE, qSz * WOLFSSL_BIT_SIZE) != 0)
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| 152 | return BAD_FUNC_ARG;
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| 153 |
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| 154 | /* generate extra 64 bits so that bias from mod function is negligible */
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| 155 | cSz = qSz + (64 / WOLFSSL_BIT_SIZE);
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| 156 | cBuf = (byte*)XMALLOC(cSz, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 157 | if (cBuf == NULL) {
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| 158 | return MEMORY_E;
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| 159 | }
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| 160 |
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| 161 | if ((err = mp_init_multi(&dsa->x, &dsa->y, &tmpQ, NULL, NULL, NULL))
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| 162 | != MP_OKAY) {
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| 163 | XFREE(cBuf, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 164 | return err;
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| 165 | }
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| 166 |
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| 167 | do {
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| 168 | /* generate N+64 bits (c) from RBG into &dsa->x, making sure positive.
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| 169 | * Hash_DRBG uses SHA-256 which matches maximum
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| 170 | * requested_security_strength of (L,N) */
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| 171 | err = wc_RNG_GenerateBlock(rng, cBuf, cSz);
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| 172 | if (err != MP_OKAY) {
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| 173 | mp_clear(&dsa->x);
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| 174 | mp_clear(&dsa->y);
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| 175 | mp_clear(&tmpQ);
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| 176 | XFREE(cBuf, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 177 | return err;
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| 178 | }
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| 179 |
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| 180 | err = mp_read_unsigned_bin(&dsa->x, cBuf, cSz);
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| 181 | if (err != MP_OKAY) {
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| 182 | mp_clear(&dsa->x);
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| 183 | mp_clear(&dsa->y);
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| 184 | mp_clear(&tmpQ);
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| 185 | XFREE(cBuf, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 186 | return err;
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| 187 | }
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| 188 | } while (mp_cmp_d(&dsa->x, 1) != MP_GT);
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| 189 |
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| 190 | XFREE(cBuf, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 191 |
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| 192 | /* tmpQ = q - 1 */
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| 193 | if (err == MP_OKAY)
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| 194 | err = mp_copy(&dsa->q, &tmpQ);
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| 195 |
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| 196 | if (err == MP_OKAY)
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| 197 | err = mp_sub_d(&tmpQ, 1, &tmpQ);
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| 198 |
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| 199 | /* x = c mod (q-1), &dsa->x holds c */
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| 200 | if (err == MP_OKAY)
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| 201 | err = mp_mod(&dsa->x, &tmpQ, &dsa->x);
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| 202 |
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| 203 | /* x = c mod (q-1) + 1 */
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| 204 | if (err == MP_OKAY)
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| 205 | err = mp_add_d(&dsa->x, 1, &dsa->x);
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| 206 |
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| 207 | /* public key : y = g^x mod p */
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| 208 | if (err == MP_OKAY)
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| 209 | err = mp_exptmod_ex(&dsa->g, &dsa->x, dsa->q.used, &dsa->p, &dsa->y);
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| 210 |
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| 211 | if (err == MP_OKAY)
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| 212 | dsa->type = DSA_PRIVATE;
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| 213 |
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| 214 | if (err != MP_OKAY) {
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| 215 | mp_clear(&dsa->x);
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| 216 | mp_clear(&dsa->y);
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| 217 | }
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| 218 | mp_clear(&tmpQ);
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| 219 |
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| 220 | return err;
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| 221 | }
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| 222 |
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| 223 |
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| 224 | /* modulus_size in bits */
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| 225 | int wc_MakeDsaParameters(WC_RNG *rng, int modulus_size, DsaKey *dsa)
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| 226 | {
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| 227 | mp_int tmp, tmp2;
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| 228 | int err, msize, qsize,
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| 229 | loop_check_prime = 0,
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| 230 | check_prime = MP_NO;
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| 231 | unsigned char *buf;
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| 232 |
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| 233 | if (rng == NULL || dsa == NULL)
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| 234 | return BAD_FUNC_ARG;
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| 235 |
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| 236 | /* set group size in bytes from modulus size
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| 237 | * FIPS 186-4 defines valid values (1024, 160) (2048, 256) (3072, 256)
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| 238 | */
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| 239 | switch (modulus_size) {
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| 240 | case 1024:
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| 241 | qsize = 20;
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| 242 | break;
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| 243 | case 2048:
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| 244 | case 3072:
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| 245 | qsize = 32;
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| 246 | break;
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| 247 | default:
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| 248 | return BAD_FUNC_ARG;
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| 249 | }
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| 250 |
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| 251 | /* modulus size in bytes */
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| 252 | msize = modulus_size / WOLFSSL_BIT_SIZE;
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| 253 |
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| 254 | /* allocate ram */
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| 255 | buf = (unsigned char *)XMALLOC(msize - qsize,
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| 256 | dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 257 | if (buf == NULL) {
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| 258 | return MEMORY_E;
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| 259 | }
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| 260 |
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| 261 | /* make a random string that will be multiplied against q */
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| 262 | err = wc_RNG_GenerateBlock(rng, buf, msize - qsize);
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| 263 | if (err != MP_OKAY) {
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| 264 | XFREE(buf, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 265 | return err;
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| 266 | }
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| 267 |
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| 268 | /* force magnitude */
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| 269 | buf[0] |= 0xC0;
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| 270 |
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| 271 | /* force even */
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| 272 | buf[msize - qsize - 1] &= ~1;
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| 273 |
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| 274 | if (mp_init_multi(&tmp2, &dsa->p, &dsa->q, 0, 0, 0) != MP_OKAY) {
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| 275 | mp_clear(&dsa->q);
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| 276 | XFREE(buf, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 277 | return MP_INIT_E;
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| 278 | }
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| 279 |
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| 280 | err = mp_read_unsigned_bin(&tmp2, buf, msize - qsize);
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| 281 | if (err != MP_OKAY) {
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| 282 | mp_clear(&dsa->q);
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| 283 | mp_clear(&dsa->p);
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| 284 | mp_clear(&tmp2);
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| 285 | XFREE(buf, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 286 | return err;
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| 287 | }
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| 288 | XFREE(buf, dsa->heap, DYNAMIC_TYPE_TMP_BUFFER);
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| 289 |
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| 290 | /* make our prime q */
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| 291 | err = mp_rand_prime(&dsa->q, qsize, rng, NULL);
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| 292 | if (err != MP_OKAY) {
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| 293 | mp_clear(&dsa->q);
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| 294 | mp_clear(&dsa->p);
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| 295 | mp_clear(&tmp2);
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| 296 | return err;
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| 297 | }
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| 298 |
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| 299 | /* p = random * q */
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| 300 | err = mp_mul(&dsa->q, &tmp2, &dsa->p);
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| 301 | if (err != MP_OKAY) {
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| 302 | mp_clear(&dsa->q);
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| 303 | mp_clear(&dsa->p);
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| 304 | mp_clear(&tmp2);
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| 305 | return err;
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| 306 | }
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| 307 |
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| 308 | /* p = random * q + 1, so q is a prime divisor of p-1 */
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| 309 | err = mp_add_d(&dsa->p, 1, &dsa->p);
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| 310 | if (err != MP_OKAY) {
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| 311 | mp_clear(&dsa->q);
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| 312 | mp_clear(&dsa->p);
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| 313 | mp_clear(&tmp2);
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| 314 | return err;
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| 315 | }
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| 316 |
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| 317 | if (mp_init(&tmp) != MP_OKAY) {
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| 318 | mp_clear(&dsa->q);
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| 319 | mp_clear(&dsa->p);
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| 320 | mp_clear(&tmp2);
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| 321 | return MP_INIT_E;
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| 322 | }
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| 323 |
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| 324 | /* tmp = 2q */
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| 325 | err = mp_add(&dsa->q, &dsa->q, &tmp);
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| 326 | if (err != MP_OKAY) {
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| 327 | mp_clear(&dsa->q);
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| 328 | mp_clear(&dsa->p);
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| 329 | mp_clear(&tmp);
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| 330 | mp_clear(&tmp2);
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| 331 | return err;
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| 332 | }
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| 333 |
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| 334 | /* loop until p is prime */
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| 335 | while (check_prime == MP_NO) {
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| 336 | err = mp_prime_is_prime_ex(&dsa->p, 8, &check_prime, rng);
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| 337 | if (err != MP_OKAY) {
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| 338 | mp_clear(&dsa->q);
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| 339 | mp_clear(&dsa->p);
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| 340 | mp_clear(&tmp);
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| 341 | mp_clear(&tmp2);
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| 342 | return err;
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| 343 | }
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| 344 |
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| 345 | if (check_prime != MP_YES) {
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| 346 | /* p += 2q */
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| 347 | err = mp_add(&tmp, &dsa->p, &dsa->p);
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| 348 | if (err != MP_OKAY) {
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| 349 | mp_clear(&dsa->q);
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| 350 | mp_clear(&dsa->p);
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| 351 | mp_clear(&tmp);
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| 352 | mp_clear(&tmp2);
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| 353 | return err;
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| 354 | }
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| 355 |
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| 356 | loop_check_prime++;
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| 357 | }
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| 358 | }
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| 359 |
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| 360 | /* tmp2 += (2*loop_check_prime)
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| 361 | * to have p = (q * tmp2) + 1 prime
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| 362 | */
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| 363 | if (loop_check_prime) {
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| 364 | err = mp_add_d(&tmp2, 2*loop_check_prime, &tmp2);
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| 365 | if (err != MP_OKAY) {
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| 366 | mp_clear(&dsa->q);
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| 367 | mp_clear(&dsa->p);
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| 368 | mp_clear(&tmp);
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| 369 | mp_clear(&tmp2);
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| 370 | return err;
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| 371 | }
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| 372 | }
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| 373 |
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| 374 | if (mp_init(&dsa->g) != MP_OKAY) {
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| 375 | mp_clear(&dsa->q);
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| 376 | mp_clear(&dsa->p);
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| 377 | mp_clear(&tmp);
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| 378 | mp_clear(&tmp2);
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| 379 | return MP_INIT_E;
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| 380 | }
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| 381 |
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| 382 | /* find a value g for which g^tmp2 != 1 */
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| 383 | if (mp_set(&dsa->g, 1) != MP_OKAY) {
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| 384 | mp_clear(&dsa->q);
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| 385 | mp_clear(&dsa->p);
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| 386 | mp_clear(&tmp);
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| 387 | mp_clear(&tmp2);
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| 388 | return MP_INIT_E;
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| 389 | }
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| 390 |
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| 391 | do {
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| 392 | err = mp_add_d(&dsa->g, 1, &dsa->g);
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| 393 | if (err != MP_OKAY) {
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| 394 | mp_clear(&dsa->q);
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| 395 | mp_clear(&dsa->p);
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| 396 | mp_clear(&dsa->g);
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| 397 | mp_clear(&tmp);
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| 398 | mp_clear(&tmp2);
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| 399 | return err;
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| 400 | }
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| 401 |
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| 402 | err = mp_exptmod(&dsa->g, &tmp2, &dsa->p, &tmp);
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| 403 | if (err != MP_OKAY) {
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| 404 | mp_clear(&dsa->q);
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| 405 | mp_clear(&dsa->p);
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| 406 | mp_clear(&dsa->g);
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| 407 | mp_clear(&tmp);
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| 408 | mp_clear(&tmp2);
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| 409 | return err;
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| 410 | }
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| 411 |
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| 412 | } while (mp_cmp_d(&tmp, 1) == MP_EQ);
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| 413 |
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| 414 | /* at this point tmp generates a group of order q mod p */
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[464] | 415 | #ifndef USE_FAST_MATH
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| 416 | /* Exchanging is quick when the data pointer can be copied. */
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[457] | 417 | mp_exch(&tmp, &dsa->g);
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[464] | 418 | #else
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| 419 | mp_copy(&tmp, &dsa->g);
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| 420 | #endif
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[457] | 421 |
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| 422 | mp_clear(&tmp);
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| 423 | mp_clear(&tmp2);
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| 424 |
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| 425 | return MP_OKAY;
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| 426 | }
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| 427 | #endif /* WOLFSSL_KEY_GEN */
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| 428 |
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| 429 |
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| 430 | static int _DsaImportParamsRaw(DsaKey* dsa, const char* p, const char* q,
|
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| 431 | const char* g, int trusted, WC_RNG* rng)
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| 432 | {
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| 433 | int err;
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| 434 | word32 pSz, qSz;
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| 435 |
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| 436 | if (dsa == NULL || p == NULL || q == NULL || g == NULL)
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| 437 | return BAD_FUNC_ARG;
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| 438 |
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| 439 | /* read p */
|
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| 440 | err = mp_read_radix(&dsa->p, p, MP_RADIX_HEX);
|
---|
| 441 | if (err == MP_OKAY && !trusted) {
|
---|
| 442 | int isPrime = 1;
|
---|
| 443 | if (rng == NULL)
|
---|
| 444 | err = mp_prime_is_prime(&dsa->p, 8, &isPrime);
|
---|
| 445 | else
|
---|
| 446 | err = mp_prime_is_prime_ex(&dsa->p, 8, &isPrime, rng);
|
---|
| 447 |
|
---|
| 448 | if (err == MP_OKAY) {
|
---|
| 449 | if (!isPrime)
|
---|
| 450 | err = DH_CHECK_PUB_E;
|
---|
| 451 | }
|
---|
| 452 | }
|
---|
| 453 |
|
---|
| 454 | /* read q */
|
---|
| 455 | if (err == MP_OKAY)
|
---|
| 456 | err = mp_read_radix(&dsa->q, q, MP_RADIX_HEX);
|
---|
| 457 |
|
---|
| 458 | /* read g */
|
---|
| 459 | if (err == MP_OKAY)
|
---|
| 460 | err = mp_read_radix(&dsa->g, g, MP_RADIX_HEX);
|
---|
| 461 |
|
---|
| 462 | /* verify (L,N) pair bit lengths */
|
---|
| 463 | pSz = mp_unsigned_bin_size(&dsa->p);
|
---|
| 464 | qSz = mp_unsigned_bin_size(&dsa->q);
|
---|
| 465 |
|
---|
| 466 | if (CheckDsaLN(pSz * WOLFSSL_BIT_SIZE, qSz * WOLFSSL_BIT_SIZE) != 0) {
|
---|
| 467 | WOLFSSL_MSG("Invalid DSA p or q parameter size");
|
---|
| 468 | err = BAD_FUNC_ARG;
|
---|
| 469 | }
|
---|
| 470 |
|
---|
| 471 | if (err != MP_OKAY) {
|
---|
| 472 | mp_clear(&dsa->p);
|
---|
| 473 | mp_clear(&dsa->q);
|
---|
| 474 | mp_clear(&dsa->g);
|
---|
| 475 | }
|
---|
| 476 |
|
---|
| 477 | return err;
|
---|
| 478 | }
|
---|
| 479 |
|
---|
| 480 |
|
---|
| 481 | /* Import raw DSA parameters into DsaKey structure for use with wc_MakeDsaKey(),
|
---|
| 482 | * input parameters (p,q,g) should be represented as ASCII hex values.
|
---|
| 483 | *
|
---|
| 484 | * dsa - pointer to initialized DsaKey structure
|
---|
| 485 | * p - DSA (p) parameter, ASCII hex string
|
---|
| 486 | * pSz - length of p
|
---|
| 487 | * q - DSA (q) parameter, ASCII hex string
|
---|
| 488 | * qSz - length of q
|
---|
| 489 | * g - DSA (g) parameter, ASCII hex string
|
---|
| 490 | * gSz - length of g
|
---|
| 491 | *
|
---|
| 492 | * returns 0 on success, negative upon failure
|
---|
| 493 | */
|
---|
| 494 | int wc_DsaImportParamsRaw(DsaKey* dsa, const char* p, const char* q,
|
---|
| 495 | const char* g)
|
---|
| 496 | {
|
---|
| 497 | return _DsaImportParamsRaw(dsa, p, q, g, 1, NULL);
|
---|
| 498 | }
|
---|
| 499 |
|
---|
| 500 |
|
---|
| 501 | /* Import raw DSA parameters into DsaKey structure for use with wc_MakeDsaKey(),
|
---|
| 502 | * input parameters (p,q,g) should be represented as ASCII hex values. Check
|
---|
| 503 | * that the p value is probably prime.
|
---|
| 504 | *
|
---|
| 505 | * dsa - pointer to initialized DsaKey structure
|
---|
| 506 | * p - DSA (p) parameter, ASCII hex string
|
---|
| 507 | * pSz - length of p
|
---|
| 508 | * q - DSA (q) parameter, ASCII hex string
|
---|
| 509 | * qSz - length of q
|
---|
| 510 | * g - DSA (g) parameter, ASCII hex string
|
---|
| 511 | * gSz - length of g
|
---|
| 512 | * trusted - trust that p is OK
|
---|
| 513 | * rng - random number generator for the prime test
|
---|
| 514 | *
|
---|
| 515 | * returns 0 on success, negative upon failure
|
---|
| 516 | */
|
---|
| 517 | int wc_DsaImportParamsRawCheck(DsaKey* dsa, const char* p, const char* q,
|
---|
| 518 | const char* g, int trusted, WC_RNG* rng)
|
---|
| 519 | {
|
---|
| 520 | return _DsaImportParamsRaw(dsa, p, q, g, trusted, rng);
|
---|
| 521 | }
|
---|
| 522 |
|
---|
| 523 |
|
---|
| 524 | /* Export raw DSA parameters from DsaKey structure
|
---|
| 525 | *
|
---|
| 526 | * dsa - pointer to initialized DsaKey structure
|
---|
| 527 | * p - output location for DSA (p) parameter
|
---|
| 528 | * pSz - [IN/OUT] size of output buffer for p, size of p
|
---|
| 529 | * q - output location for DSA (q) parameter
|
---|
| 530 | * qSz - [IN/OUT] size of output buffer for q, size of q
|
---|
| 531 | * g - output location for DSA (g) parameter
|
---|
| 532 | * gSz - [IN/OUT] size of output buffer for g, size of g
|
---|
| 533 | *
|
---|
| 534 | * If p, q, and g pointers are all passed in as NULL, the function
|
---|
| 535 | * will set pSz, qSz, and gSz to the required output buffer sizes for p,
|
---|
| 536 | * q, and g. In this case, the function will return LENGTH_ONLY_E.
|
---|
| 537 | *
|
---|
| 538 | * returns 0 on success, negative upon failure
|
---|
| 539 | */
|
---|
| 540 | int wc_DsaExportParamsRaw(DsaKey* dsa, byte* p, word32* pSz,
|
---|
| 541 | byte* q, word32* qSz, byte* g, word32* gSz)
|
---|
| 542 | {
|
---|
| 543 | int err;
|
---|
| 544 | word32 pLen, qLen, gLen;
|
---|
| 545 |
|
---|
| 546 | if (dsa == NULL || pSz == NULL || qSz == NULL || gSz == NULL)
|
---|
| 547 | return BAD_FUNC_ARG;
|
---|
| 548 |
|
---|
| 549 | /* get required output buffer sizes */
|
---|
| 550 | pLen = mp_unsigned_bin_size(&dsa->p);
|
---|
| 551 | qLen = mp_unsigned_bin_size(&dsa->q);
|
---|
| 552 | gLen = mp_unsigned_bin_size(&dsa->g);
|
---|
| 553 |
|
---|
| 554 | /* return buffer sizes and LENGTH_ONLY_E if buffers are NULL */
|
---|
| 555 | if (p == NULL && q == NULL && g == NULL) {
|
---|
| 556 | *pSz = pLen;
|
---|
| 557 | *qSz = qLen;
|
---|
| 558 | *gSz = gLen;
|
---|
| 559 | return LENGTH_ONLY_E;
|
---|
| 560 | }
|
---|
| 561 |
|
---|
| 562 | if (p == NULL || q == NULL || g == NULL)
|
---|
| 563 | return BAD_FUNC_ARG;
|
---|
| 564 |
|
---|
| 565 | /* export p */
|
---|
| 566 | if (*pSz < pLen) {
|
---|
| 567 | WOLFSSL_MSG("Output buffer for DSA p parameter too small, "
|
---|
| 568 | "required size placed into pSz");
|
---|
| 569 | *pSz = pLen;
|
---|
| 570 | return BUFFER_E;
|
---|
| 571 | }
|
---|
| 572 | *pSz = pLen;
|
---|
| 573 | err = mp_to_unsigned_bin(&dsa->p, p);
|
---|
| 574 |
|
---|
| 575 | /* export q */
|
---|
| 576 | if (err == MP_OKAY) {
|
---|
| 577 | if (*qSz < qLen) {
|
---|
| 578 | WOLFSSL_MSG("Output buffer for DSA q parameter too small, "
|
---|
| 579 | "required size placed into qSz");
|
---|
| 580 | *qSz = qLen;
|
---|
| 581 | return BUFFER_E;
|
---|
| 582 | }
|
---|
| 583 | *qSz = qLen;
|
---|
| 584 | err = mp_to_unsigned_bin(&dsa->q, q);
|
---|
| 585 | }
|
---|
| 586 |
|
---|
| 587 | /* export g */
|
---|
| 588 | if (err == MP_OKAY) {
|
---|
| 589 | if (*gSz < gLen) {
|
---|
| 590 | WOLFSSL_MSG("Output buffer for DSA g parameter too small, "
|
---|
| 591 | "required size placed into gSz");
|
---|
| 592 | *gSz = gLen;
|
---|
| 593 | return BUFFER_E;
|
---|
| 594 | }
|
---|
| 595 | *gSz = gLen;
|
---|
| 596 | err = mp_to_unsigned_bin(&dsa->g, g);
|
---|
| 597 | }
|
---|
| 598 |
|
---|
| 599 | return err;
|
---|
| 600 | }
|
---|
| 601 |
|
---|
| 602 |
|
---|
| 603 | /* Export raw DSA key (x, y) from DsaKey structure
|
---|
| 604 | *
|
---|
| 605 | * dsa - pointer to initialized DsaKey structure
|
---|
| 606 | * x - output location for private key
|
---|
| 607 | * xSz - [IN/OUT] size of output buffer for x, size of x
|
---|
| 608 | * y - output location for public key
|
---|
| 609 | * ySz - [IN/OUT] size of output buffer for y, size of y
|
---|
| 610 | *
|
---|
| 611 | * If x and y pointers are all passed in as NULL, the function
|
---|
| 612 | * will set xSz and ySz to the required output buffer sizes for x
|
---|
| 613 | * and y. In this case, the function will return LENGTH_ONLY_E.
|
---|
| 614 | *
|
---|
| 615 | * returns 0 on success, negative upon failure
|
---|
| 616 | */
|
---|
| 617 | int wc_DsaExportKeyRaw(DsaKey* dsa, byte* x, word32* xSz, byte* y, word32* ySz)
|
---|
| 618 | {
|
---|
| 619 | int err;
|
---|
| 620 | word32 xLen, yLen;
|
---|
| 621 |
|
---|
| 622 | if (dsa == NULL || xSz == NULL || ySz == NULL)
|
---|
| 623 | return BAD_FUNC_ARG;
|
---|
| 624 |
|
---|
| 625 | /* get required output buffer sizes */
|
---|
| 626 | xLen = mp_unsigned_bin_size(&dsa->x);
|
---|
| 627 | yLen = mp_unsigned_bin_size(&dsa->y);
|
---|
| 628 |
|
---|
| 629 | /* return buffer sizes and LENGTH_ONLY_E if buffers are NULL */
|
---|
| 630 | if (x == NULL && y == NULL) {
|
---|
| 631 | *xSz = xLen;
|
---|
| 632 | *ySz = yLen;
|
---|
| 633 | return LENGTH_ONLY_E;
|
---|
| 634 | }
|
---|
| 635 |
|
---|
| 636 | if (x == NULL || y == NULL)
|
---|
| 637 | return BAD_FUNC_ARG;
|
---|
| 638 |
|
---|
| 639 | /* export x */
|
---|
| 640 | if (*xSz < xLen) {
|
---|
| 641 | WOLFSSL_MSG("Output buffer for DSA private key (x) too small, "
|
---|
| 642 | "required size placed into xSz");
|
---|
| 643 | *xSz = xLen;
|
---|
| 644 | return BUFFER_E;
|
---|
| 645 | }
|
---|
| 646 | *xSz = xLen;
|
---|
| 647 | err = mp_to_unsigned_bin(&dsa->x, x);
|
---|
| 648 |
|
---|
| 649 | /* export y */
|
---|
| 650 | if (err == MP_OKAY) {
|
---|
| 651 | if (*ySz < yLen) {
|
---|
| 652 | WOLFSSL_MSG("Output buffer to DSA public key (y) too small, "
|
---|
| 653 | "required size placed into ySz");
|
---|
| 654 | *ySz = yLen;
|
---|
| 655 | return BUFFER_E;
|
---|
| 656 | }
|
---|
| 657 | *ySz = yLen;
|
---|
| 658 | err = mp_to_unsigned_bin(&dsa->y, y);
|
---|
| 659 | }
|
---|
| 660 |
|
---|
| 661 | return err;
|
---|
| 662 | }
|
---|
| 663 |
|
---|
| 664 |
|
---|
| 665 | int wc_DsaSign(const byte* digest, byte* out, DsaKey* key, WC_RNG* rng)
|
---|
| 666 | {
|
---|
[464] | 667 | #ifdef WOLFSSL_SMALL_STACK
|
---|
| 668 | mp_int *k = (mp_int *)XMALLOC(sizeof *k,
|
---|
| 669 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 670 | mp_int *kInv = (mp_int *)XMALLOC(sizeof *kInv,
|
---|
| 671 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 672 | mp_int *r = (mp_int *)XMALLOC(sizeof *r,
|
---|
| 673 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 674 | mp_int *s = (mp_int *)XMALLOC(sizeof *s,
|
---|
| 675 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 676 | mp_int *H = (mp_int *)XMALLOC(sizeof *H,
|
---|
| 677 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
[457] | 678 | #ifndef WOLFSSL_MP_INVMOD_CONSTANT_TIME
|
---|
[464] | 679 | mp_int *b = (mp_int *)XMALLOC(sizeof *b,
|
---|
| 680 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
[457] | 681 | #endif
|
---|
[464] | 682 | byte *buffer = (byte *)XMALLOC(DSA_HALF_SIZE, key->heap,
|
---|
| 683 | DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 684 | #else
|
---|
| 685 | mp_int k[1], kInv[1], r[1], s[1], H[1];
|
---|
| 686 | #ifndef WOLFSSL_MP_INVMOD_CONSTANT_TIME
|
---|
| 687 | mp_int b[1];
|
---|
| 688 | #endif
|
---|
| 689 | byte buffer[DSA_HALF_SIZE];
|
---|
| 690 | #endif
|
---|
[457] | 691 | mp_int* qMinus1;
|
---|
[464] | 692 | int ret = 0, sz = 0;
|
---|
[457] | 693 | byte* tmp; /* initial output pointer */
|
---|
| 694 |
|
---|
[464] | 695 | do {
|
---|
[457] | 696 | #ifdef WOLFSSL_MP_INVMOD_CONSTANT_TIME
|
---|
[464] | 697 | if (mp_init_multi(k, kInv, r, s, H, 0) != MP_OKAY)
|
---|
[457] | 698 | #else
|
---|
[464] | 699 | if (mp_init_multi(k, kInv, r, s, H, b) != MP_OKAY)
|
---|
[457] | 700 | #endif
|
---|
[464] | 701 | {
|
---|
| 702 | ret = MP_INIT_E;
|
---|
| 703 | break;
|
---|
| 704 | }
|
---|
[457] | 705 |
|
---|
[464] | 706 | #ifdef WOLFSSL_SMALL_STACK
|
---|
| 707 | if ((k == NULL) ||
|
---|
| 708 | (kInv == NULL) ||
|
---|
| 709 | (r == NULL) ||
|
---|
| 710 | (s == NULL) ||
|
---|
| 711 | (H == NULL)
|
---|
| 712 | #ifndef WOLFSSL_MP_INVMOD_CONSTANT_TIME
|
---|
| 713 | || (b == NULL)
|
---|
| 714 | #endif
|
---|
| 715 | || (buffer == NULL)) {
|
---|
| 716 | ret = MEMORY_E;
|
---|
| 717 | break;
|
---|
| 718 | }
|
---|
| 719 | #endif
|
---|
[457] | 720 |
|
---|
[464] | 721 | if (digest == NULL || out == NULL || key == NULL || rng == NULL) {
|
---|
| 722 | ret = BAD_FUNC_ARG;
|
---|
| 723 | break;
|
---|
| 724 | }
|
---|
| 725 |
|
---|
| 726 | sz = min(DSA_HALF_SIZE, mp_unsigned_bin_size(&key->q));
|
---|
| 727 | tmp = out;
|
---|
| 728 | qMinus1 = kInv;
|
---|
| 729 |
|
---|
| 730 | /* NIST FIPS 186-4: B.2.2
|
---|
| 731 | * Per-Message Secret Number Generation by Testing Candidates
|
---|
| 732 | * Generate k in range [1, q-1].
|
---|
| 733 | * Check that k is less than q-1: range [0, q-2].
|
---|
| 734 | * Add 1 to k: range [1, q-1].
|
---|
| 735 | */
|
---|
| 736 | if (mp_sub_d(&key->q, 1, qMinus1)) {
|
---|
| 737 | ret = MP_SUB_E;
|
---|
| 738 | break;
|
---|
| 739 | }
|
---|
| 740 |
|
---|
[457] | 741 | do {
|
---|
| 742 | /* Step 4: generate k */
|
---|
[464] | 743 | if ((ret = wc_RNG_GenerateBlock(rng, buffer, sz))) {
|
---|
| 744 | break;
|
---|
| 745 | }
|
---|
[457] | 746 |
|
---|
| 747 | /* Step 5 */
|
---|
[464] | 748 | if (mp_read_unsigned_bin(k, buffer, sz) != MP_OKAY) {
|
---|
[457] | 749 | ret = MP_READ_E;
|
---|
[464] | 750 | break;
|
---|
| 751 | }
|
---|
[457] | 752 |
|
---|
| 753 | /* k is a random numnber and it should be less than q-1
|
---|
| 754 | * if k greater than repeat
|
---|
| 755 | */
|
---|
[464] | 756 | /* Step 6 */
|
---|
| 757 | } while (mp_cmp(k, qMinus1) != MP_LT);
|
---|
[457] | 758 |
|
---|
[464] | 759 | if (ret != 0)
|
---|
| 760 | break;
|
---|
| 761 |
|
---|
| 762 | /* Step 7 */
|
---|
| 763 | if (mp_add_d(k, 1, k) != MP_OKAY) {
|
---|
| 764 | ret = MP_MOD_E;
|
---|
| 765 | break;
|
---|
| 766 | }
|
---|
| 767 |
|
---|
[457] | 768 | #ifdef WOLFSSL_MP_INVMOD_CONSTANT_TIME
|
---|
[464] | 769 | /* inverse k mod q */
|
---|
| 770 | if (mp_invmod(k, &key->q, kInv) != MP_OKAY) {
|
---|
| 771 | ret = MP_INVMOD_E;
|
---|
| 772 | break;
|
---|
| 773 | }
|
---|
[457] | 774 |
|
---|
[464] | 775 | /* generate r, r = (g exp k mod p) mod q */
|
---|
| 776 | if (mp_exptmod_ex(&key->g, k, key->q.used, &key->p, r) != MP_OKAY) {
|
---|
| 777 | ret = MP_EXPTMOD_E;
|
---|
| 778 | break;
|
---|
| 779 | }
|
---|
[457] | 780 |
|
---|
[464] | 781 | if (mp_mod(r, &key->q, r) != MP_OKAY) {
|
---|
| 782 | ret = MP_MOD_E;
|
---|
| 783 | break;
|
---|
| 784 | }
|
---|
[457] | 785 |
|
---|
[464] | 786 | /* generate H from sha digest */
|
---|
| 787 | if (mp_read_unsigned_bin(H, digest,WC_SHA_DIGEST_SIZE) != MP_OKAY) {
|
---|
| 788 | ret = MP_READ_E;
|
---|
| 789 | break;
|
---|
| 790 | }
|
---|
[457] | 791 |
|
---|
[464] | 792 | /* generate s, s = (kInv * (H + x*r)) % q */
|
---|
| 793 | if (mp_mul(&key->x, r, s) != MP_OKAY) {
|
---|
| 794 | ret = MP_MUL_E;
|
---|
| 795 | break;
|
---|
| 796 | }
|
---|
[457] | 797 |
|
---|
[464] | 798 | if (mp_add(s, H, s) != MP_OKAY) {
|
---|
| 799 | ret = MP_ADD_E;
|
---|
| 800 | break;
|
---|
| 801 | }
|
---|
[457] | 802 |
|
---|
[464] | 803 | if (mp_mulmod(s, kInv, &key->q, s) != MP_OKAY) {
|
---|
| 804 | ret = MP_MULMOD_E;
|
---|
| 805 | break;
|
---|
| 806 | }
|
---|
[457] | 807 | #else
|
---|
[464] | 808 | /* Blinding value
|
---|
| 809 | * Generate b in range [1, q-1].
|
---|
| 810 | */
|
---|
[457] | 811 | do {
|
---|
[464] | 812 | if ((ret = wc_RNG_GenerateBlock(rng, buffer, sz))) {
|
---|
| 813 | break;
|
---|
| 814 | }
|
---|
| 815 | if (mp_read_unsigned_bin(b, buffer, sz) != MP_OKAY) {
|
---|
[457] | 816 | ret = MP_READ_E;
|
---|
[464] | 817 | break;
|
---|
| 818 | }
|
---|
| 819 | } while (mp_cmp(b, qMinus1) != MP_LT);
|
---|
[457] | 820 |
|
---|
[464] | 821 | if (ret != 0)
|
---|
| 822 | break;
|
---|
[457] | 823 |
|
---|
[464] | 824 | if (mp_add_d(b, 1, b) != MP_OKAY) {
|
---|
| 825 | ret = MP_MOD_E;
|
---|
| 826 | break;
|
---|
| 827 | }
|
---|
[457] | 828 |
|
---|
[464] | 829 | /* set H from sha digest */
|
---|
| 830 | if (mp_read_unsigned_bin(H, digest, WC_SHA_DIGEST_SIZE) != MP_OKAY) {
|
---|
| 831 | ret = MP_READ_E;
|
---|
| 832 | break;
|
---|
| 833 | }
|
---|
[457] | 834 |
|
---|
[464] | 835 | /* generate r, r = (g exp k mod p) mod q */
|
---|
| 836 | if (mp_exptmod_ex(&key->g, k, key->q.used, &key->p, r) != MP_OKAY) {
|
---|
| 837 | ret = MP_EXPTMOD_E;
|
---|
| 838 | break;
|
---|
| 839 | }
|
---|
[457] | 840 |
|
---|
[464] | 841 | /* calculate s = (H + xr)/k = b.(H/k.b + x.r/k.b) */
|
---|
[457] | 842 |
|
---|
[464] | 843 | /* k = k.b */
|
---|
| 844 | if (mp_mulmod(k, b, &key->q, k) != MP_OKAY) {
|
---|
| 845 | ret = MP_MULMOD_E;
|
---|
| 846 | break;
|
---|
| 847 | }
|
---|
[457] | 848 |
|
---|
[464] | 849 | /* kInv = 1/k.b mod q */
|
---|
| 850 | if (mp_invmod(k, &key->q, kInv) != MP_OKAY) {
|
---|
| 851 | ret = MP_INVMOD_E;
|
---|
| 852 | break;
|
---|
| 853 | }
|
---|
[457] | 854 |
|
---|
[464] | 855 | if (mp_mod(r, &key->q, r) != MP_OKAY) {
|
---|
| 856 | ret = MP_MOD_E;
|
---|
| 857 | break;
|
---|
| 858 | }
|
---|
[457] | 859 |
|
---|
[464] | 860 | /* s = x.r */
|
---|
| 861 | if (mp_mul(&key->x, r, s) != MP_OKAY) {
|
---|
| 862 | ret = MP_MUL_E;
|
---|
| 863 | break;
|
---|
| 864 | }
|
---|
[457] | 865 |
|
---|
[464] | 866 | /* s = x.r/k.b */
|
---|
| 867 | if (mp_mulmod(s, kInv, &key->q, s) != MP_OKAY) {
|
---|
| 868 | ret = MP_MULMOD_E;
|
---|
| 869 | break;
|
---|
| 870 | }
|
---|
[457] | 871 |
|
---|
[464] | 872 | /* H = H/k.b */
|
---|
| 873 | if (mp_mulmod(H, kInv, &key->q, H) != MP_OKAY) {
|
---|
| 874 | ret = MP_MULMOD_E;
|
---|
| 875 | break;
|
---|
| 876 | }
|
---|
[457] | 877 |
|
---|
[464] | 878 | /* s = H/k.b + x.r/k.b = (H + x.r)/k.b */
|
---|
| 879 | if (mp_add(s, H, s) != MP_OKAY) {
|
---|
| 880 | ret = MP_ADD_E;
|
---|
| 881 | break;
|
---|
| 882 | }
|
---|
[457] | 883 |
|
---|
[464] | 884 | /* s = b.(e + x.r)/k.b = (e + x.r)/k */
|
---|
| 885 | if (mp_mulmod(s, b, &key->q, s) != MP_OKAY) {
|
---|
| 886 | ret = MP_MULMOD_E;
|
---|
| 887 | break;
|
---|
| 888 | }
|
---|
[457] | 889 |
|
---|
[464] | 890 | /* s = (e + x.r)/k */
|
---|
| 891 | if (mp_mod(s, &key->q, s) != MP_OKAY) {
|
---|
| 892 | ret = MP_MOD_E;
|
---|
| 893 | break;
|
---|
| 894 | }
|
---|
| 895 | #endif
|
---|
[457] | 896 |
|
---|
[464] | 897 | /* detect zero r or s */
|
---|
| 898 | if ((mp_iszero(r) == MP_YES) || (mp_iszero(s) == MP_YES)) {
|
---|
| 899 | ret = MP_ZERO_E;
|
---|
| 900 | break;
|
---|
[457] | 901 | }
|
---|
| 902 |
|
---|
[464] | 903 | /* write out */
|
---|
| 904 | {
|
---|
| 905 | int rSz = mp_unsigned_bin_size(r);
|
---|
| 906 | int sSz = mp_unsigned_bin_size(s);
|
---|
| 907 |
|
---|
| 908 | while (rSz++ < DSA_HALF_SIZE) {
|
---|
[457] | 909 | *out++ = 0x00; /* pad front with zeros */
|
---|
| 910 | }
|
---|
[464] | 911 |
|
---|
| 912 | if (mp_to_unsigned_bin(r, out) != MP_OKAY)
|
---|
| 913 | ret = MP_TO_E;
|
---|
| 914 | else {
|
---|
| 915 | out = tmp + DSA_HALF_SIZE; /* advance to s in output */
|
---|
| 916 | while (sSz++ < DSA_HALF_SIZE) {
|
---|
| 917 | *out++ = 0x00; /* pad front with zeros */
|
---|
| 918 | }
|
---|
| 919 | ret = mp_to_unsigned_bin(s, out);
|
---|
| 920 | }
|
---|
[457] | 921 | }
|
---|
[464] | 922 | } while (0);
|
---|
| 923 |
|
---|
| 924 | #ifdef WOLFSSL_SMALL_STACK
|
---|
| 925 | if (k) {
|
---|
| 926 | if (ret != MP_INIT_E)
|
---|
| 927 | mp_forcezero(k);
|
---|
| 928 | XFREE(k, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
[457] | 929 | }
|
---|
[464] | 930 | if (kInv) {
|
---|
| 931 | if (ret != MP_INIT_E)
|
---|
| 932 | mp_forcezero(kInv);
|
---|
| 933 | XFREE(kInv, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 934 | }
|
---|
| 935 | if (r) {
|
---|
| 936 | if (ret != MP_INIT_E)
|
---|
| 937 | mp_clear(r);
|
---|
| 938 | XFREE(r, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 939 | }
|
---|
| 940 | if (s) {
|
---|
| 941 | if (ret != MP_INIT_E)
|
---|
| 942 | mp_clear(s);
|
---|
| 943 | XFREE(s, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 944 | }
|
---|
| 945 | if (H) {
|
---|
| 946 | if (ret != MP_INIT_E)
|
---|
| 947 | mp_clear(H);
|
---|
| 948 | XFREE(H, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 949 | }
|
---|
[457] | 950 | #ifndef WOLFSSL_MP_INVMOD_CONSTANT_TIME
|
---|
[464] | 951 | if (b) {
|
---|
| 952 | if (ret != MP_INIT_E)
|
---|
| 953 | mp_forcezero(b);
|
---|
| 954 | XFREE(b, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 955 | }
|
---|
[457] | 956 | #endif
|
---|
[464] | 957 | if (buffer) {
|
---|
| 958 | ForceZero(buffer, sz);
|
---|
| 959 | XFREE(buffer, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 960 | }
|
---|
| 961 | #else /* !WOLFSSL_SMALL_STACK */
|
---|
| 962 | if (ret != MP_INIT_E) {
|
---|
| 963 | ForceZero(buffer, sz);
|
---|
| 964 | mp_forcezero(kInv);
|
---|
| 965 | mp_forcezero(k);
|
---|
| 966 | #ifndef WOLFSSL_MP_INVMOD_CONSTANT_TIME
|
---|
| 967 | mp_forcezero(b);
|
---|
| 968 | #endif
|
---|
| 969 | mp_clear(H);
|
---|
| 970 | mp_clear(s);
|
---|
| 971 | mp_clear(r);
|
---|
| 972 | }
|
---|
| 973 | #endif
|
---|
[457] | 974 |
|
---|
| 975 | return ret;
|
---|
| 976 | }
|
---|
| 977 |
|
---|
| 978 |
|
---|
| 979 | int wc_DsaVerify(const byte* digest, const byte* sig, DsaKey* key, int* answer)
|
---|
| 980 | {
|
---|
[464] | 981 | #ifdef WOLFSSL_SMALL_STACK
|
---|
| 982 | mp_int *w = (mp_int *)XMALLOC(sizeof *w,
|
---|
| 983 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 984 | mp_int *u1 = (mp_int *)XMALLOC(sizeof *u1,
|
---|
| 985 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 986 | mp_int *u2 = (mp_int *)XMALLOC(sizeof *u2,
|
---|
| 987 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 988 | mp_int *v = (mp_int *)XMALLOC(sizeof *v,
|
---|
| 989 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 990 | mp_int *r = (mp_int *)XMALLOC(sizeof *r,
|
---|
| 991 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 992 | mp_int *s = (mp_int *)XMALLOC(sizeof *s,
|
---|
| 993 | key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 994 | #else
|
---|
| 995 | mp_int w[1], u1[1], u2[1], v[1], r[1], s[1];
|
---|
| 996 | #endif
|
---|
[457] | 997 | int ret = 0;
|
---|
| 998 |
|
---|
[464] | 999 | do {
|
---|
| 1000 | if (mp_init_multi(w, u1, u2, v, r, s) != MP_OKAY) {
|
---|
| 1001 | ret = MP_INIT_E;
|
---|
| 1002 | break;
|
---|
| 1003 | }
|
---|
[457] | 1004 |
|
---|
[464] | 1005 | if (digest == NULL || sig == NULL || key == NULL || answer == NULL) {
|
---|
| 1006 | ret = BAD_FUNC_ARG;
|
---|
| 1007 | break;
|
---|
| 1008 | }
|
---|
[457] | 1009 |
|
---|
[464] | 1010 | #ifdef WOLFSSL_SMALL_STACK
|
---|
| 1011 | if ((w == NULL) ||
|
---|
| 1012 | (u1 == NULL) ||
|
---|
| 1013 | (u2 == NULL) ||
|
---|
| 1014 | (v == NULL) ||
|
---|
| 1015 | (r == NULL) ||
|
---|
| 1016 | (s == NULL)) {
|
---|
| 1017 | ret = MEMORY_E;
|
---|
| 1018 | break;
|
---|
| 1019 | }
|
---|
| 1020 | #endif
|
---|
[457] | 1021 |
|
---|
[464] | 1022 | /* set r and s from signature */
|
---|
| 1023 | if (mp_read_unsigned_bin(r, sig, DSA_HALF_SIZE) != MP_OKAY ||
|
---|
| 1024 | mp_read_unsigned_bin(s, sig + DSA_HALF_SIZE, DSA_HALF_SIZE) != MP_OKAY) {
|
---|
| 1025 | ret = MP_READ_E;
|
---|
| 1026 | break;
|
---|
| 1027 | }
|
---|
| 1028 |
|
---|
| 1029 | /* sanity checks */
|
---|
| 1030 | if (mp_iszero(r) == MP_YES || mp_iszero(s) == MP_YES ||
|
---|
| 1031 | mp_cmp(r, &key->q) != MP_LT || mp_cmp(s, &key->q) != MP_LT) {
|
---|
[457] | 1032 | ret = MP_ZERO_E;
|
---|
[464] | 1033 | break;
|
---|
[457] | 1034 | }
|
---|
| 1035 |
|
---|
[464] | 1036 | /* put H into u1 from sha digest */
|
---|
| 1037 | if (mp_read_unsigned_bin(u1,digest,WC_SHA_DIGEST_SIZE) != MP_OKAY) {
|
---|
| 1038 | ret = MP_READ_E;
|
---|
| 1039 | break;
|
---|
| 1040 | }
|
---|
[457] | 1041 |
|
---|
[464] | 1042 | /* w = s invmod q */
|
---|
| 1043 | if (mp_invmod(s, &key->q, w) != MP_OKAY) {
|
---|
| 1044 | ret = MP_INVMOD_E;
|
---|
| 1045 | break;
|
---|
| 1046 | }
|
---|
[457] | 1047 |
|
---|
[464] | 1048 | /* u1 = (H * w) % q */
|
---|
| 1049 | if (mp_mulmod(u1, w, &key->q, u1) != MP_OKAY) {
|
---|
| 1050 | ret = MP_MULMOD_E;
|
---|
| 1051 | break;
|
---|
| 1052 | }
|
---|
[457] | 1053 |
|
---|
[464] | 1054 | /* u2 = (r * w) % q */
|
---|
| 1055 | if (mp_mulmod(r, w, &key->q, u2) != MP_OKAY) {
|
---|
| 1056 | ret = MP_MULMOD_E;
|
---|
| 1057 | break;
|
---|
| 1058 | }
|
---|
[457] | 1059 |
|
---|
[464] | 1060 | /* verify v = ((g^u1 * y^u2) mod p) mod q */
|
---|
| 1061 | if (mp_exptmod(&key->g, u1, &key->p, u1) != MP_OKAY) {
|
---|
| 1062 | ret = MP_EXPTMOD_E;
|
---|
| 1063 | break;
|
---|
| 1064 | }
|
---|
[457] | 1065 |
|
---|
[464] | 1066 | if (mp_exptmod(&key->y, u2, &key->p, u2) != MP_OKAY) {
|
---|
| 1067 | ret = MP_EXPTMOD_E;
|
---|
| 1068 | break;
|
---|
| 1069 | }
|
---|
[457] | 1070 |
|
---|
[464] | 1071 | if (mp_mulmod(u1, u2, &key->p, v) != MP_OKAY) {
|
---|
| 1072 | ret = MP_MULMOD_E;
|
---|
| 1073 | break;
|
---|
| 1074 | }
|
---|
[457] | 1075 |
|
---|
[464] | 1076 | if (mp_mod(v, &key->q, v) != MP_OKAY) {
|
---|
| 1077 | ret = MP_MULMOD_E;
|
---|
| 1078 | break;
|
---|
| 1079 | }
|
---|
[457] | 1080 |
|
---|
[464] | 1081 | /* do they match */
|
---|
| 1082 | if (mp_cmp(r, v) == MP_EQ)
|
---|
| 1083 | *answer = 1;
|
---|
| 1084 | else
|
---|
| 1085 | *answer = 0;
|
---|
| 1086 | } while (0);
|
---|
[457] | 1087 |
|
---|
[464] | 1088 | #ifdef WOLFSSL_SMALL_STACK
|
---|
| 1089 | if (s) {
|
---|
| 1090 | if (ret != MP_INIT_E)
|
---|
| 1091 | mp_clear(s);
|
---|
| 1092 | XFREE(s, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 1093 | }
|
---|
| 1094 | if (r) {
|
---|
| 1095 | if (ret != MP_INIT_E)
|
---|
| 1096 | mp_clear(r);
|
---|
| 1097 | XFREE(r, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 1098 | }
|
---|
| 1099 | if (u1) {
|
---|
| 1100 | if (ret != MP_INIT_E)
|
---|
| 1101 | mp_clear(u1);
|
---|
| 1102 | XFREE(u1, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 1103 | }
|
---|
| 1104 | if (u2) {
|
---|
| 1105 | if (ret != MP_INIT_E)
|
---|
| 1106 | mp_clear(u2);
|
---|
| 1107 | XFREE(u2, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 1108 | }
|
---|
| 1109 | if (w) {
|
---|
| 1110 | if (ret != MP_INIT_E)
|
---|
| 1111 | mp_clear(w);
|
---|
| 1112 | XFREE(w, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 1113 | }
|
---|
| 1114 | if (v) {
|
---|
| 1115 | if (ret != MP_INIT_E)
|
---|
| 1116 | mp_clear(v);
|
---|
| 1117 | XFREE(v, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
|
---|
| 1118 | }
|
---|
| 1119 | #else
|
---|
| 1120 | if (ret != MP_INIT_E) {
|
---|
| 1121 | mp_clear(s);
|
---|
| 1122 | mp_clear(r);
|
---|
| 1123 | mp_clear(u1);
|
---|
| 1124 | mp_clear(u2);
|
---|
| 1125 | mp_clear(w);
|
---|
| 1126 | mp_clear(v);
|
---|
| 1127 | }
|
---|
| 1128 | #endif
|
---|
[457] | 1129 |
|
---|
| 1130 | return ret;
|
---|
| 1131 | }
|
---|
| 1132 |
|
---|
| 1133 |
|
---|
| 1134 | #endif /* NO_DSA */
|
---|
| 1135 |
|
---|