X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fbn%2Fbn_recp.c;h=20585b9d4b8675b521b0482aff36551f5dfd413b;hb=6db2b1490e5da1255f4158dc8c2d4a2dd87cbe7b;hp=72cd69d3fc9c76efbf06c43df8724a221dba6226;hpb=7dfb0b774e6592dcbfe47015168a0ac8b44e2a17;p=oweals%2Fopenssl.git diff --git a/crypto/bn/bn_recp.c b/crypto/bn/bn_recp.c index 72cd69d3fc..20585b9d4b 100644 --- a/crypto/bn/bn_recp.c +++ b/crypto/bn/bn_recp.c @@ -1,125 +1,199 @@ -/* crypto/bn/bn_recp.c */ -/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) - * All rights reserved. +/* + * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. * - * This package is an SSL implementation written - * by Eric Young (eay@cryptsoft.com). - * The implementation was written so as to conform with Netscapes SSL. - * - * This library is free for commercial and non-commercial use as long as - * the following conditions are aheared to. The following conditions - * apply to all code found in this distribution, be it the RC4, RSA, - * lhash, DES, etc., code; not just the SSL code. The SSL documentation - * included with this distribution is covered by the same copyright terms - * except that the holder is Tim Hudson (tjh@cryptsoft.com). - * - * Copyright remains Eric Young's, and as such any Copyright notices in - * the code are not to be removed. - * If this package is used in a product, Eric Young should be given attribution - * as the author of the parts of the library used. - * This can be in the form of a textual message at program startup or - * in documentation (online or textual) provided with the package. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * "This product includes cryptographic software written by - * Eric Young (eay@cryptsoft.com)" - * The word 'cryptographic' can be left out if the rouines from the library - * being used are not cryptographic related :-). - * 4. If you include any Windows specific code (or a derivative thereof) from - * the apps directory (application code) you must include an acknowledgement: - * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" - * - * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * The licence and distribution terms for any publically available version or - * derivative of this code cannot be changed. i.e. this code cannot simply be - * copied and put under another distribution licence - * [including the GNU Public Licence.] + * 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 */ -#include -#include "cryptlib.h" +#include "internal/cryptlib.h" #include "bn_lcl.h" -int BN_mod_mul_reciprocal(r, x, y, m, i, nb, ctx) -BIGNUM *r; -BIGNUM *x; -BIGNUM *y; -BIGNUM *m; -BIGNUM *i; -int nb; -BN_CTX *ctx; - { - int ret=0,j; - BIGNUM *a,*b,*c,*d; - - a=ctx->bn[ctx->tos++]; - b=ctx->bn[ctx->tos++]; - c=ctx->bn[ctx->tos++]; - d=ctx->bn[ctx->tos++]; - - if (x == y) - { if (!BN_sqr(a,x,ctx)) goto err; } - else - { if (!BN_mul(a,x,y)) goto err; } - if (!BN_rshift(d,a,nb)) goto err; - if (!BN_mul(b,d,i)) goto err; - if (!BN_rshift(c,b,nb)) goto err; - if (!BN_mul(b,m,c)) goto err; - if (!BN_sub(r,a,b)) goto err; - j=0; - while (BN_cmp(r,m) >= 0) - { - if (j++ > 2) - { - BNerr(BN_F_BN_MOD_MUL_RECIPROCAL,BN_R_BAD_RECIPROCAL); - goto err; - } - if (!BN_sub(r,r,m)) goto err; - } - - ret=1; -err: - ctx->tos-=4; - return(ret); - } - -int BN_reciprocal(r, m,ctx) -BIGNUM *r; -BIGNUM *m; -BN_CTX *ctx; - { - int nm,ret= -1; - BIGNUM *t; - - t=ctx->bn[ctx->tos++]; - - nm=BN_num_bits(m); - if (!BN_lshift(t,BN_value_one(),nm*2)) goto err; - - if (!BN_div(r,NULL,t,m,ctx)) goto err; - ret=nm; -err: - ctx->tos--; - return(ret); - } +void BN_RECP_CTX_init(BN_RECP_CTX *recp) +{ + memset(recp, 0, sizeof(*recp)); + bn_init(&(recp->N)); + bn_init(&(recp->Nr)); +} +BN_RECP_CTX *BN_RECP_CTX_new(void) +{ + BN_RECP_CTX *ret; + + if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL) + return (NULL); + + bn_init(&(ret->N)); + bn_init(&(ret->Nr)); + ret->flags = BN_FLG_MALLOCED; + return (ret); +} + +void BN_RECP_CTX_free(BN_RECP_CTX *recp) +{ + if (recp == NULL) + return; + + BN_free(&(recp->N)); + BN_free(&(recp->Nr)); + if (recp->flags & BN_FLG_MALLOCED) + OPENSSL_free(recp); +} + +int BN_RECP_CTX_set(BN_RECP_CTX *recp, const BIGNUM *d, BN_CTX *ctx) +{ + if (!BN_copy(&(recp->N), d)) + return 0; + BN_zero(&(recp->Nr)); + recp->num_bits = BN_num_bits(d); + recp->shift = 0; + return (1); +} + +int BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y, + BN_RECP_CTX *recp, BN_CTX *ctx) +{ + int ret = 0; + BIGNUM *a; + const BIGNUM *ca; + + BN_CTX_start(ctx); + if ((a = BN_CTX_get(ctx)) == NULL) + goto err; + if (y != NULL) { + if (x == y) { + if (!BN_sqr(a, x, ctx)) + goto err; + } else { + if (!BN_mul(a, x, y, ctx)) + goto err; + } + ca = a; + } else + ca = x; /* Just do the mod */ + + ret = BN_div_recp(NULL, r, ca, recp, ctx); + err: + BN_CTX_end(ctx); + bn_check_top(r); + return (ret); +} + +int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, + BN_RECP_CTX *recp, BN_CTX *ctx) +{ + int i, j, ret = 0; + BIGNUM *a, *b, *d, *r; + + BN_CTX_start(ctx); + a = BN_CTX_get(ctx); + b = BN_CTX_get(ctx); + if (dv != NULL) + d = dv; + else + d = BN_CTX_get(ctx); + if (rem != NULL) + r = rem; + else + r = BN_CTX_get(ctx); + if (a == NULL || b == NULL || d == NULL || r == NULL) + goto err; + + if (BN_ucmp(m, &(recp->N)) < 0) { + BN_zero(d); + if (!BN_copy(r, m)) { + BN_CTX_end(ctx); + return 0; + } + BN_CTX_end(ctx); + return (1); + } + + /* + * We want the remainder Given input of ABCDEF / ab we need multiply + * ABCDEF by 3 digests of the reciprocal of ab + */ + + /* i := max(BN_num_bits(m), 2*BN_num_bits(N)) */ + i = BN_num_bits(m); + j = recp->num_bits << 1; + if (j > i) + i = j; + + /* Nr := round(2^i / N) */ + if (i != recp->shift) + recp->shift = BN_reciprocal(&(recp->Nr), &(recp->N), i, ctx); + /* BN_reciprocal could have returned -1 for an error */ + if (recp->shift == -1) + goto err; + + /*- + * d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))| + * = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))| + * <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)| + * = |m/N| + */ + if (!BN_rshift(a, m, recp->num_bits)) + goto err; + if (!BN_mul(b, a, &(recp->Nr), ctx)) + goto err; + if (!BN_rshift(d, b, i - recp->num_bits)) + goto err; + d->neg = 0; + + if (!BN_mul(b, &(recp->N), d, ctx)) + goto err; + if (!BN_usub(r, m, b)) + goto err; + r->neg = 0; + + j = 0; + while (BN_ucmp(r, &(recp->N)) >= 0) { + if (j++ > 2) { + BNerr(BN_F_BN_DIV_RECP, BN_R_BAD_RECIPROCAL); + goto err; + } + if (!BN_usub(r, r, &(recp->N))) + goto err; + if (!BN_add_word(d, 1)) + goto err; + } + + r->neg = BN_is_zero(r) ? 0 : m->neg; + d->neg = m->neg ^ recp->N.neg; + ret = 1; + err: + BN_CTX_end(ctx); + bn_check_top(dv); + bn_check_top(rem); + return (ret); +} + +/* + * len is the expected size of the result We actually calculate with an extra + * word of precision, so we can do faster division if the remainder is not + * required. + */ +/* r := 2^len / m */ +int BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx) +{ + int ret = -1; + BIGNUM *t; + + BN_CTX_start(ctx); + if ((t = BN_CTX_get(ctx)) == NULL) + goto err; + + if (!BN_set_bit(t, len)) + goto err; + + if (!BN_div(r, NULL, t, m, ctx)) + goto err; + + ret = len; + err: + bn_check_top(r); + BN_CTX_end(ctx); + return (ret); +}