X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_recp.c;h=8eb500b61a800d992271f40588c5bd0db0cf01da;hp=840408620115e50b7884ba13c76fc85718ab627f;hb=e6e9170d6e28038768895e1af18e3aad8093bf4b;hpb=e95bbc3ca628eecc6f005ee54126e2d27fc54859 diff --git a/crypto/bn/bn_recp.c b/crypto/bn/bn_recp.c index 8404086201..8eb500b61a 100644 --- a/crypto/bn/bn_recp.c +++ b/crypto/bn/bn_recp.c @@ -1,176 +1,125 @@ -/* crypto/bn/bn_recp.c */ -/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) - * All rights reserved. +/* + * Copyright 1995-2017 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 "cryptlib.h" +#include "internal/cryptlib.h" #include "bn_lcl.h" void BN_RECP_CTX_init(BN_RECP_CTX *recp) - { - BN_init(&(recp->N)); - BN_init(&(recp->Nr)); - recp->num_bits=0; - recp->flags=0; - } +{ + 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; +{ + BN_RECP_CTX *ret; - if ((ret=(BN_RECP_CTX *)OPENSSL_malloc(sizeof(BN_RECP_CTX))) == NULL) - return(NULL); + if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL) + return NULL; - BN_RECP_CTX_init(ret); - ret->flags=BN_FLG_MALLOCED; - return(ret); - } + 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); - } +{ + 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); - } +{ + 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); - } + 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)) 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; + BN_RECP_CTX *recp, BN_CTX *ctx) +{ + int i, j, ret = 0; + BIGNUM *a, *b, *d, *r; + + BN_CTX_start(ctx); + d = (dv != NULL) ? dv : BN_CTX_get(ctx); + r = (rem != NULL) ? rem : BN_CTX_get(ctx); + a = BN_CTX_get(ctx); + b = BN_CTX_get(ctx); + if (b == 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)))| @@ -178,59 +127,66 @@ int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, * <= |(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; - -#if 1 - 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; - } -#endif - - 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. + 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); - } +{ + 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; +}