2016-05-17 18:51:04 +00:00
|
|
|
/*
|
2018-01-19 09:49:22 +00:00
|
|
|
* Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
|
2006-06-14 08:55:23 +00:00
|
|
|
*
|
2016-05-17 18:51:04 +00:00
|
|
|
* Licensed under the OpenSSL license (the "License"). You may not use
|
|
|
|
* this file except in compliance with the License. You can obtain a copy
|
|
|
|
* in the file LICENSE in the source distribution or at
|
|
|
|
* https://www.openssl.org/source/license.html
|
2006-06-14 08:55:23 +00:00
|
|
|
*/
|
1998-12-21 10:52:47 +00:00
|
|
|
|
1999-02-25 08:00:57 +00:00
|
|
|
/*
|
2000-01-27 12:52:41 +00:00
|
|
|
* Details about Montgomery multiplication algorithms can be found at
|
|
|
|
* http://security.ece.orst.edu/publications.html, e.g.
|
|
|
|
* http://security.ece.orst.edu/koc/papers/j37acmon.pdf and
|
|
|
|
* sections 3.8 and 4.2 in http://security.ece.orst.edu/koc/papers/r01rsasw.pdf
|
1999-02-25 08:00:57 +00:00
|
|
|
*/
|
|
|
|
|
2015-05-14 14:56:48 +00:00
|
|
|
#include "internal/cryptlib.h"
|
1998-12-21 10:52:47 +00:00
|
|
|
#include "bn_lcl.h"
|
|
|
|
|
2015-01-22 03:40:55 +00:00
|
|
|
#define MONT_WORD /* use the faster word-based algorithm */
|
2000-02-05 18:23:05 +00:00
|
|
|
|
2005-10-06 13:12:28 +00:00
|
|
|
#ifdef MONT_WORD
|
2018-07-06 13:13:15 +00:00
|
|
|
static int bn_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont);
|
2005-10-06 13:12:28 +00:00
|
|
|
#endif
|
|
|
|
|
2000-11-06 21:15:54 +00:00
|
|
|
int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
|
2015-01-22 03:40:55 +00:00
|
|
|
BN_MONT_CTX *mont, BN_CTX *ctx)
|
2018-07-06 13:13:15 +00:00
|
|
|
{
|
|
|
|
int ret = bn_mul_mont_fixed_top(r, a, b, mont, ctx);
|
|
|
|
|
|
|
|
bn_correct_top(r);
|
|
|
|
bn_check_top(r);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
int bn_mul_mont_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
|
|
|
|
BN_MONT_CTX *mont, BN_CTX *ctx)
|
2015-01-22 03:40:55 +00:00
|
|
|
{
|
|
|
|
BIGNUM *tmp;
|
|
|
|
int ret = 0;
|
|
|
|
int num = mont->N.top;
|
|
|
|
|
2018-07-06 11:46:07 +00:00
|
|
|
#if defined(OPENSSL_BN_ASM_MONT) && defined(MONT_WORD)
|
2015-01-22 03:40:55 +00:00
|
|
|
if (num > 1 && a->top == num && b->top == num) {
|
|
|
|
if (bn_wexpand(r, num) == NULL)
|
2017-10-17 14:04:09 +00:00
|
|
|
return 0;
|
2015-01-22 03:40:55 +00:00
|
|
|
if (bn_mul_mont(r->d, a->d, b->d, mont->N.d, mont->n0, num)) {
|
|
|
|
r->neg = a->neg ^ b->neg;
|
|
|
|
r->top = num;
|
2018-07-06 13:13:15 +00:00
|
|
|
r->flags |= BN_FLG_FIXED_TOP;
|
2017-10-09 11:05:58 +00:00
|
|
|
return 1;
|
2015-01-22 03:40:55 +00:00
|
|
|
}
|
|
|
|
}
|
2005-10-04 06:19:29 +00:00
|
|
|
#endif
|
1998-12-21 11:00:56 +00:00
|
|
|
|
2018-07-06 11:46:07 +00:00
|
|
|
if ((a->top + b->top) > 2 * num)
|
|
|
|
return 0;
|
|
|
|
|
2015-01-22 03:40:55 +00:00
|
|
|
BN_CTX_start(ctx);
|
|
|
|
tmp = BN_CTX_get(ctx);
|
|
|
|
if (tmp == NULL)
|
|
|
|
goto err;
|
|
|
|
|
|
|
|
bn_check_top(tmp);
|
|
|
|
if (a == b) {
|
|
|
|
if (!BN_sqr(tmp, a, ctx))
|
|
|
|
goto err;
|
|
|
|
} else {
|
|
|
|
if (!BN_mul(tmp, a, b, ctx))
|
|
|
|
goto err;
|
|
|
|
}
|
|
|
|
/* reduce from aRR to aR */
|
2005-10-06 13:12:28 +00:00
|
|
|
#ifdef MONT_WORD
|
2018-07-06 13:13:15 +00:00
|
|
|
if (!bn_from_montgomery_word(r, tmp, mont))
|
2015-01-22 03:40:55 +00:00
|
|
|
goto err;
|
2005-10-06 13:12:28 +00:00
|
|
|
#else
|
2015-01-22 03:40:55 +00:00
|
|
|
if (!BN_from_montgomery(r, tmp, mont, ctx))
|
|
|
|
goto err;
|
2005-10-06 13:12:28 +00:00
|
|
|
#endif
|
2015-01-22 03:40:55 +00:00
|
|
|
ret = 1;
|
|
|
|
err:
|
|
|
|
BN_CTX_end(ctx);
|
2017-10-17 14:04:09 +00:00
|
|
|
return ret;
|
2015-01-22 03:40:55 +00:00
|
|
|
}
|
1998-12-21 10:52:47 +00:00
|
|
|
|
2000-02-05 18:23:05 +00:00
|
|
|
#ifdef MONT_WORD
|
2018-07-06 13:13:15 +00:00
|
|
|
static int bn_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
|
2015-01-22 03:40:55 +00:00
|
|
|
{
|
|
|
|
BIGNUM *n;
|
|
|
|
BN_ULONG *ap, *np, *rp, n0, v, carry;
|
|
|
|
int nl, max, i;
|
|
|
|
|
|
|
|
n = &(mont->N);
|
|
|
|
nl = n->top;
|
|
|
|
if (nl == 0) {
|
|
|
|
ret->top = 0;
|
2017-10-09 11:05:58 +00:00
|
|
|
return 1;
|
2015-01-22 03:40:55 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
max = (2 * nl); /* carry is stored separately */
|
|
|
|
if (bn_wexpand(r, max) == NULL)
|
2017-10-17 14:04:09 +00:00
|
|
|
return 0;
|
2015-01-22 03:40:55 +00:00
|
|
|
|
|
|
|
r->neg ^= n->neg;
|
|
|
|
np = n->d;
|
|
|
|
rp = r->d;
|
|
|
|
|
|
|
|
/* clear the top words of T */
|
2015-07-22 10:44:50 +00:00
|
|
|
i = max - r->top;
|
|
|
|
if (i)
|
|
|
|
memset(&rp[r->top], 0, sizeof(*rp) * i);
|
2015-01-22 03:40:55 +00:00
|
|
|
|
|
|
|
r->top = max;
|
2018-07-06 13:13:15 +00:00
|
|
|
r->flags |= BN_FLG_FIXED_TOP;
|
2015-01-22 03:40:55 +00:00
|
|
|
n0 = mont->n0[0];
|
|
|
|
|
2018-01-31 19:47:41 +00:00
|
|
|
/*
|
|
|
|
* Add multiples of |n| to |r| until R = 2^(nl * BN_BITS2) divides it. On
|
|
|
|
* input, we had |r| < |n| * R, so now |r| < 2 * |n| * R. Note that |r|
|
|
|
|
* includes |carry| which is stored separately.
|
|
|
|
*/
|
2015-01-22 03:40:55 +00:00
|
|
|
for (carry = 0, i = 0; i < nl; i++, rp++) {
|
|
|
|
v = bn_mul_add_words(rp, np, nl, (rp[0] * n0) & BN_MASK2);
|
|
|
|
v = (v + carry + rp[nl]) & BN_MASK2;
|
|
|
|
carry |= (v != rp[nl]);
|
|
|
|
carry &= (v <= rp[nl]);
|
|
|
|
rp[nl] = v;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (bn_wexpand(ret, nl) == NULL)
|
2017-10-17 14:04:09 +00:00
|
|
|
return 0;
|
2015-01-22 03:40:55 +00:00
|
|
|
ret->top = nl;
|
2018-07-06 13:13:15 +00:00
|
|
|
ret->flags |= BN_FLG_FIXED_TOP;
|
2015-01-22 03:40:55 +00:00
|
|
|
ret->neg = r->neg;
|
|
|
|
|
|
|
|
rp = ret->d;
|
2018-01-31 19:47:41 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Shift |nl| words to divide by R. We have |ap| < 2 * |n|. Note that |ap|
|
|
|
|
* includes |carry| which is stored separately.
|
|
|
|
*/
|
2015-01-22 03:40:55 +00:00
|
|
|
ap = &(r->d[nl]);
|
|
|
|
|
2018-07-06 12:54:34 +00:00
|
|
|
carry -= bn_sub_words(rp, ap, np, nl);
|
2018-01-31 19:47:41 +00:00
|
|
|
/*
|
2018-07-06 12:54:34 +00:00
|
|
|
* |carry| is -1 if |ap| - |np| underflowed or zero if it did not. Note
|
|
|
|
* |carry| cannot be 1. That would imply the subtraction did not fit in
|
|
|
|
* |nl| words, and we know at most one subtraction is needed.
|
2018-01-31 19:47:41 +00:00
|
|
|
*/
|
|
|
|
for (i = 0; i < nl; i++) {
|
2018-07-06 12:54:34 +00:00
|
|
|
rp[i] = (carry & ap[i]) | (~carry & rp[i]);
|
2018-01-31 19:47:41 +00:00
|
|
|
ap[i] = 0;
|
2015-01-22 03:40:55 +00:00
|
|
|
}
|
|
|
|
|
2017-10-09 11:05:58 +00:00
|
|
|
return 1;
|
2015-01-22 03:40:55 +00:00
|
|
|
}
|
|
|
|
#endif /* MONT_WORD */
|
2005-10-06 13:12:28 +00:00
|
|
|
|
|
|
|
int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
|
2015-01-22 03:40:55 +00:00
|
|
|
BN_CTX *ctx)
|
|
|
|
{
|
|
|
|
int retn = 0;
|
2005-10-06 13:12:28 +00:00
|
|
|
#ifdef MONT_WORD
|
2015-01-22 03:40:55 +00:00
|
|
|
BIGNUM *t;
|
|
|
|
|
|
|
|
BN_CTX_start(ctx);
|
2018-07-06 13:13:15 +00:00
|
|
|
if ((t = BN_CTX_get(ctx)) && BN_copy(t, a)) {
|
|
|
|
retn = bn_from_montgomery_word(ret, t, mont);
|
|
|
|
bn_correct_top(ret);
|
|
|
|
bn_check_top(ret);
|
|
|
|
}
|
2015-01-22 03:40:55 +00:00
|
|
|
BN_CTX_end(ctx);
|
|
|
|
#else /* !MONT_WORD */
|
|
|
|
BIGNUM *t1, *t2;
|
|
|
|
|
|
|
|
BN_CTX_start(ctx);
|
|
|
|
t1 = BN_CTX_get(ctx);
|
|
|
|
t2 = BN_CTX_get(ctx);
|
2017-06-22 10:52:29 +00:00
|
|
|
if (t2 == NULL)
|
2015-01-22 03:40:55 +00:00
|
|
|
goto err;
|
|
|
|
|
|
|
|
if (!BN_copy(t1, a))
|
|
|
|
goto err;
|
|
|
|
BN_mask_bits(t1, mont->ri);
|
|
|
|
|
|
|
|
if (!BN_mul(t2, t1, &mont->Ni, ctx))
|
|
|
|
goto err;
|
|
|
|
BN_mask_bits(t2, mont->ri);
|
|
|
|
|
|
|
|
if (!BN_mul(t1, t2, &mont->N, ctx))
|
|
|
|
goto err;
|
|
|
|
if (!BN_add(t2, a, t1))
|
|
|
|
goto err;
|
|
|
|
if (!BN_rshift(ret, t2, mont->ri))
|
|
|
|
goto err;
|
|
|
|
|
|
|
|
if (BN_ucmp(ret, &(mont->N)) >= 0) {
|
|
|
|
if (!BN_usub(ret, ret, &(mont->N)))
|
|
|
|
goto err;
|
|
|
|
}
|
|
|
|
retn = 1;
|
|
|
|
bn_check_top(ret);
|
2000-01-27 01:50:42 +00:00
|
|
|
err:
|
2015-01-22 03:40:55 +00:00
|
|
|
BN_CTX_end(ctx);
|
|
|
|
#endif /* MONT_WORD */
|
2017-10-17 14:04:09 +00:00
|
|
|
return retn;
|
2015-01-22 03:40:55 +00:00
|
|
|
}
|
1998-12-21 10:52:47 +00:00
|
|
|
|
2018-07-06 13:13:15 +00:00
|
|
|
int bn_to_mont_fixed_top(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont,
|
|
|
|
BN_CTX *ctx)
|
|
|
|
{
|
|
|
|
return bn_mul_mont_fixed_top(r, a, &(mont->RR), mont, ctx);
|
|
|
|
}
|
|
|
|
|
1999-04-19 21:31:43 +00:00
|
|
|
BN_MONT_CTX *BN_MONT_CTX_new(void)
|
2015-01-22 03:40:55 +00:00
|
|
|
{
|
|
|
|
BN_MONT_CTX *ret;
|
1998-12-21 10:52:47 +00:00
|
|
|
|
2018-04-26 16:06:17 +00:00
|
|
|
if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) {
|
|
|
|
BNerr(BN_F_BN_MONT_CTX_NEW, ERR_R_MALLOC_FAILURE);
|
2017-10-17 14:04:09 +00:00
|
|
|
return NULL;
|
2018-04-26 16:06:17 +00:00
|
|
|
}
|
1998-12-21 11:00:56 +00:00
|
|
|
|
2015-01-22 03:40:55 +00:00
|
|
|
BN_MONT_CTX_init(ret);
|
|
|
|
ret->flags = BN_FLG_MALLOCED;
|
2017-10-17 14:04:09 +00:00
|
|
|
return ret;
|
2015-01-22 03:40:55 +00:00
|
|
|
}
|
1998-12-21 10:52:47 +00:00
|
|
|
|
1999-04-19 21:31:43 +00:00
|
|
|
void BN_MONT_CTX_init(BN_MONT_CTX *ctx)
|
2015-01-22 03:40:55 +00:00
|
|
|
{
|
|
|
|
ctx->ri = 0;
|
2018-03-27 20:25:08 +00:00
|
|
|
bn_init(&ctx->RR);
|
|
|
|
bn_init(&ctx->N);
|
|
|
|
bn_init(&ctx->Ni);
|
2015-01-22 03:40:55 +00:00
|
|
|
ctx->n0[0] = ctx->n0[1] = 0;
|
|
|
|
ctx->flags = 0;
|
|
|
|
}
|
1998-12-21 11:00:56 +00:00
|
|
|
|
1999-04-19 21:31:43 +00:00
|
|
|
void BN_MONT_CTX_free(BN_MONT_CTX *mont)
|
2015-01-22 03:40:55 +00:00
|
|
|
{
|
2018-03-27 20:25:08 +00:00
|
|
|
if (mont == NULL)
|
|
|
|
return;
|
|
|
|
BN_clear_free(&mont->RR);
|
|
|
|
BN_clear_free(&mont->N);
|
|
|
|
BN_clear_free(&mont->Ni);
|
2015-01-22 03:40:55 +00:00
|
|
|
if (mont->flags & BN_FLG_MALLOCED)
|
|
|
|
OPENSSL_free(mont);
|
|
|
|
}
|
1998-12-21 10:52:47 +00:00
|
|
|
|
1999-06-04 22:23:10 +00:00
|
|
|
int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
|
2015-01-22 03:40:55 +00:00
|
|
|
{
|
2018-07-06 13:13:15 +00:00
|
|
|
int i, ret = 0;
|
2015-01-22 03:40:55 +00:00
|
|
|
BIGNUM *Ri, *R;
|
|
|
|
|
2015-08-10 11:00:29 +00:00
|
|
|
if (BN_is_zero(mod))
|
|
|
|
return 0;
|
|
|
|
|
2015-01-22 03:40:55 +00:00
|
|
|
BN_CTX_start(ctx);
|
|
|
|
if ((Ri = BN_CTX_get(ctx)) == NULL)
|
|
|
|
goto err;
|
|
|
|
R = &(mont->RR); /* grab RR as a temp */
|
|
|
|
if (!BN_copy(&(mont->N), mod))
|
|
|
|
goto err; /* Set N */
|
2018-01-15 11:23:07 +00:00
|
|
|
if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
|
|
|
|
BN_set_flags(&(mont->N), BN_FLG_CONSTTIME);
|
2015-01-22 03:40:55 +00:00
|
|
|
mont->N.neg = 0;
|
1998-12-21 11:00:56 +00:00
|
|
|
|
2000-02-05 18:23:05 +00:00
|
|
|
#ifdef MONT_WORD
|
2015-01-22 03:40:55 +00:00
|
|
|
{
|
|
|
|
BIGNUM tmod;
|
|
|
|
BN_ULONG buf[2];
|
|
|
|
|
2015-11-21 13:27:46 +00:00
|
|
|
bn_init(&tmod);
|
2015-01-22 03:40:55 +00:00
|
|
|
tmod.d = buf;
|
|
|
|
tmod.dmax = 2;
|
|
|
|
tmod.neg = 0;
|
|
|
|
|
2017-09-15 20:12:53 +00:00
|
|
|
if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
|
|
|
|
BN_set_flags(&tmod, BN_FLG_CONSTTIME);
|
|
|
|
|
2015-01-22 03:40:55 +00:00
|
|
|
mont->ri = (BN_num_bits(mod) + (BN_BITS2 - 1)) / BN_BITS2 * BN_BITS2;
|
|
|
|
|
|
|
|
# if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)
|
|
|
|
/*
|
|
|
|
* Only certain BN_BITS2<=32 platforms actually make use of n0[1],
|
|
|
|
* and we could use the #else case (with a shorter R value) for the
|
|
|
|
* others. However, currently only the assembler files do know which
|
|
|
|
* is which.
|
|
|
|
*/
|
|
|
|
|
|
|
|
BN_zero(R);
|
|
|
|
if (!(BN_set_bit(R, 2 * BN_BITS2)))
|
|
|
|
goto err;
|
|
|
|
|
|
|
|
tmod.top = 0;
|
|
|
|
if ((buf[0] = mod->d[0]))
|
|
|
|
tmod.top = 1;
|
|
|
|
if ((buf[1] = mod->top > 1 ? mod->d[1] : 0))
|
|
|
|
tmod.top = 2;
|
|
|
|
|
2018-04-27 16:36:11 +00:00
|
|
|
if (BN_is_one(&tmod))
|
|
|
|
BN_zero(Ri);
|
|
|
|
else if ((BN_mod_inverse(Ri, R, &tmod, ctx)) == NULL)
|
2015-01-22 03:40:55 +00:00
|
|
|
goto err;
|
|
|
|
if (!BN_lshift(Ri, Ri, 2 * BN_BITS2))
|
|
|
|
goto err; /* R*Ri */
|
|
|
|
if (!BN_is_zero(Ri)) {
|
|
|
|
if (!BN_sub_word(Ri, 1))
|
|
|
|
goto err;
|
|
|
|
} else { /* if N mod word size == 1 */
|
|
|
|
|
|
|
|
if (bn_expand(Ri, (int)sizeof(BN_ULONG) * 2) == NULL)
|
|
|
|
goto err;
|
|
|
|
/* Ri-- (mod double word size) */
|
|
|
|
Ri->neg = 0;
|
|
|
|
Ri->d[0] = BN_MASK2;
|
|
|
|
Ri->d[1] = BN_MASK2;
|
|
|
|
Ri->top = 2;
|
|
|
|
}
|
|
|
|
if (!BN_div(Ri, NULL, Ri, &tmod, ctx))
|
|
|
|
goto err;
|
|
|
|
/*
|
|
|
|
* Ni = (R*Ri-1)/N, keep only couple of least significant words:
|
|
|
|
*/
|
|
|
|
mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
|
|
|
|
mont->n0[1] = (Ri->top > 1) ? Ri->d[1] : 0;
|
|
|
|
# else
|
|
|
|
BN_zero(R);
|
|
|
|
if (!(BN_set_bit(R, BN_BITS2)))
|
|
|
|
goto err; /* R */
|
|
|
|
|
|
|
|
buf[0] = mod->d[0]; /* tmod = N mod word size */
|
|
|
|
buf[1] = 0;
|
|
|
|
tmod.top = buf[0] != 0 ? 1 : 0;
|
|
|
|
/* Ri = R^-1 mod N */
|
2018-04-27 16:36:11 +00:00
|
|
|
if (BN_is_one(&tmod))
|
|
|
|
BN_zero(Ri);
|
|
|
|
else if ((BN_mod_inverse(Ri, R, &tmod, ctx)) == NULL)
|
2015-01-22 03:40:55 +00:00
|
|
|
goto err;
|
|
|
|
if (!BN_lshift(Ri, Ri, BN_BITS2))
|
|
|
|
goto err; /* R*Ri */
|
|
|
|
if (!BN_is_zero(Ri)) {
|
|
|
|
if (!BN_sub_word(Ri, 1))
|
|
|
|
goto err;
|
|
|
|
} else { /* if N mod word size == 1 */
|
|
|
|
|
|
|
|
if (!BN_set_word(Ri, BN_MASK2))
|
|
|
|
goto err; /* Ri-- (mod word size) */
|
|
|
|
}
|
|
|
|
if (!BN_div(Ri, NULL, Ri, &tmod, ctx))
|
|
|
|
goto err;
|
|
|
|
/*
|
|
|
|
* Ni = (R*Ri-1)/N, keep only least significant word:
|
|
|
|
*/
|
|
|
|
mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
|
|
|
|
mont->n0[1] = 0;
|
|
|
|
# endif
|
|
|
|
}
|
|
|
|
#else /* !MONT_WORD */
|
|
|
|
{ /* bignum version */
|
|
|
|
mont->ri = BN_num_bits(&mont->N);
|
|
|
|
BN_zero(R);
|
|
|
|
if (!BN_set_bit(R, mont->ri))
|
|
|
|
goto err; /* R = 2^ri */
|
|
|
|
/* Ri = R^-1 mod N */
|
|
|
|
if ((BN_mod_inverse(Ri, R, &mont->N, ctx)) == NULL)
|
|
|
|
goto err;
|
|
|
|
if (!BN_lshift(Ri, Ri, mont->ri))
|
|
|
|
goto err; /* R*Ri */
|
|
|
|
if (!BN_sub_word(Ri, 1))
|
|
|
|
goto err;
|
|
|
|
/*
|
|
|
|
* Ni = (R*Ri-1) / N
|
|
|
|
*/
|
|
|
|
if (!BN_div(&(mont->Ni), NULL, Ri, &mont->N, ctx))
|
|
|
|
goto err;
|
|
|
|
}
|
1998-12-21 10:52:47 +00:00
|
|
|
#endif
|
|
|
|
|
2015-01-22 03:40:55 +00:00
|
|
|
/* setup RR for conversions */
|
|
|
|
BN_zero(&(mont->RR));
|
|
|
|
if (!BN_set_bit(&(mont->RR), mont->ri * 2))
|
|
|
|
goto err;
|
|
|
|
if (!BN_mod(&(mont->RR), &(mont->RR), &(mont->N), ctx))
|
|
|
|
goto err;
|
1998-12-21 10:52:47 +00:00
|
|
|
|
2018-07-06 13:13:15 +00:00
|
|
|
for (i = mont->RR.top, ret = mont->N.top; i < ret; i++)
|
|
|
|
mont->RR.d[i] = 0;
|
|
|
|
mont->RR.top = ret;
|
|
|
|
mont->RR.flags |= BN_FLG_FIXED_TOP;
|
|
|
|
|
2015-01-22 03:40:55 +00:00
|
|
|
ret = 1;
|
|
|
|
err:
|
|
|
|
BN_CTX_end(ctx);
|
|
|
|
return ret;
|
|
|
|
}
|
1998-12-21 10:52:47 +00:00
|
|
|
|
1999-04-19 21:31:43 +00:00
|
|
|
BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from)
|
2015-01-22 03:40:55 +00:00
|
|
|
{
|
|
|
|
if (to == from)
|
2017-10-17 14:04:09 +00:00
|
|
|
return to;
|
2015-01-22 03:40:55 +00:00
|
|
|
|
|
|
|
if (!BN_copy(&(to->RR), &(from->RR)))
|
|
|
|
return NULL;
|
|
|
|
if (!BN_copy(&(to->N), &(from->N)))
|
|
|
|
return NULL;
|
|
|
|
if (!BN_copy(&(to->Ni), &(from->Ni)))
|
|
|
|
return NULL;
|
|
|
|
to->ri = from->ri;
|
|
|
|
to->n0[0] = from->n0[0];
|
|
|
|
to->n0[1] = from->n0[1];
|
2017-10-17 14:04:09 +00:00
|
|
|
return to;
|
2015-01-22 03:40:55 +00:00
|
|
|
}
|
1998-12-21 11:00:56 +00:00
|
|
|
|
2016-03-04 15:43:46 +00:00
|
|
|
BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_RWLOCK *lock,
|
2015-01-22 03:40:55 +00:00
|
|
|
const BIGNUM *mod, BN_CTX *ctx)
|
|
|
|
{
|
|
|
|
BN_MONT_CTX *ret;
|
|
|
|
|
2016-03-04 15:43:46 +00:00
|
|
|
CRYPTO_THREAD_read_lock(lock);
|
2015-01-22 03:40:55 +00:00
|
|
|
ret = *pmont;
|
2016-03-04 15:43:46 +00:00
|
|
|
CRYPTO_THREAD_unlock(lock);
|
2015-01-22 03:40:55 +00:00
|
|
|
if (ret)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We don't want to serialise globally while doing our lazy-init math in
|
|
|
|
* BN_MONT_CTX_set. That punishes threads that are doing independent
|
|
|
|
* things. Instead, punish the case where more than one thread tries to
|
|
|
|
* lazy-init the same 'pmont', by having each do the lazy-init math work
|
|
|
|
* independently and only use the one from the thread that wins the race
|
|
|
|
* (the losers throw away the work they've done).
|
|
|
|
*/
|
|
|
|
ret = BN_MONT_CTX_new();
|
2015-10-30 11:12:26 +00:00
|
|
|
if (ret == NULL)
|
2015-01-22 03:40:55 +00:00
|
|
|
return NULL;
|
|
|
|
if (!BN_MONT_CTX_set(ret, mod, ctx)) {
|
|
|
|
BN_MONT_CTX_free(ret);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* The locked compare-and-set, after the local work is done. */
|
2016-03-04 15:43:46 +00:00
|
|
|
CRYPTO_THREAD_write_lock(lock);
|
2015-01-22 03:40:55 +00:00
|
|
|
if (*pmont) {
|
|
|
|
BN_MONT_CTX_free(ret);
|
|
|
|
ret = *pmont;
|
|
|
|
} else
|
|
|
|
*pmont = ret;
|
2016-03-04 15:43:46 +00:00
|
|
|
CRYPTO_THREAD_unlock(lock);
|
2015-01-22 03:40:55 +00:00
|
|
|
return ret;
|
|
|
|
}
|