X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_word.c;h=1af13a53fb1c81e93328da7eb0b828759a5efbad;hp=1bcb37e29222f76dce1baefd9d1bf949389e725e;hb=e8e5597606d10fcb5620399dd751be4ecf3dcd1d;hpb=cf9056cfda3976fc53a630f9965b68569d656e27 diff --git a/crypto/bn/bn_word.c b/crypto/bn/bn_word.c index 1bcb37e292..1af13a53fb 100644 --- a/crypto/bn/bn_word.c +++ b/crypto/bn/bn_word.c @@ -1,238 +1,201 @@ -/* crypto/bn/bn_word.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" BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w) - { +{ #ifndef BN_LLONG - BN_ULONG ret=0; + BN_ULONG ret = 0; #else - BN_ULLONG ret=0; + BN_ULLONG ret = 0; #endif - int i; + int i; + + if (w == 0) + return (BN_ULONG)-1; - bn_check_top(a); - w&=BN_MASK2; - for (i=a->top-1; i>=0; i--) - { #ifndef BN_LLONG - ret=((ret<d[i]>>BN_BITS4)&BN_MASK2l))%w; - ret=((ret<d[i]&BN_MASK2l))%w; + /* + * If |w| is too long and we don't have BN_ULLONG then we need to fall + * back to using BN_div_word + */ + if (w > ((BN_ULONG)1 << BN_BITS4)) { + BIGNUM *tmp = BN_dup(a); + if (tmp == NULL) + return (BN_ULONG)-1; + + ret = BN_div_word(tmp, w); + BN_free(tmp); + + return ret; + } +#endif + + bn_check_top(a); + w &= BN_MASK2; + for (i = a->top - 1; i >= 0; i--) { +#ifndef BN_LLONG + /* + * We can assume here that | w <= ((BN_ULONG)1 << BN_BITS4) | and so + * | ret < ((BN_ULONG)1 << BN_BITS4) | and therefore the shifts here are + * safe and will not overflow + */ + ret = ((ret << BN_BITS4) | ((a->d[i] >> BN_BITS4) & BN_MASK2l)) % w; + ret = ((ret << BN_BITS4) | (a->d[i] & BN_MASK2l)) % w; #else - ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])% - (BN_ULLONG)w); + ret = (BN_ULLONG) (((ret << (BN_ULLONG) BN_BITS2) | a->d[i]) % + (BN_ULLONG) w); #endif - } - return((BN_ULONG)ret); - } + } + return ((BN_ULONG)ret); +} BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w) - { - BN_ULONG ret = 0; - int i, j; - - bn_check_top(a); - w &= BN_MASK2; - - if (!w) - /* actually this an error (division by zero) */ - return 0; - if (a->top == 0) - return 0; - - /* normalize input (so bn_div_words doesn't complain) */ - j = BN_BITS2 - BN_num_bits_word(w); - w <<= j; - if (!BN_lshift(a, a, j)) - return 0; - - for (i=a->top-1; i>=0; i--) - { - BN_ULONG l,d; - - l=a->d[i]; - d=bn_div_words(ret,l,w); - ret=(l-((d*w)&BN_MASK2))&BN_MASK2; - a->d[i]=d; - } - if ((a->top > 0) && (a->d[a->top-1] == 0)) - a->top--; - ret >>= j; - bn_check_top(a); - return(ret); - } +{ + BN_ULONG ret = 0; + int i, j; + + bn_check_top(a); + w &= BN_MASK2; + + if (!w) + /* actually this an error (division by zero) */ + return (BN_ULONG)-1; + if (a->top == 0) + return 0; + + /* normalize input (so bn_div_words doesn't complain) */ + j = BN_BITS2 - BN_num_bits_word(w); + w <<= j; + if (!BN_lshift(a, a, j)) + return (BN_ULONG)-1; + + for (i = a->top - 1; i >= 0; i--) { + BN_ULONG l, d; + + l = a->d[i]; + d = bn_div_words(ret, l, w); + ret = (l - ((d * w) & BN_MASK2)) & BN_MASK2; + a->d[i] = d; + } + if ((a->top > 0) && (a->d[a->top - 1] == 0)) + a->top--; + ret >>= j; + if (!a->top) + a->neg = 0; /* don't allow negative zero */ + bn_check_top(a); + return (ret); +} int BN_add_word(BIGNUM *a, BN_ULONG w) - { - BN_ULONG l; - int i; - - bn_check_top(a); - w &= BN_MASK2; - - /* degenerate case: w is zero */ - if (!w) return 1; - /* degenerate case: a is zero */ - if(BN_is_zero(a)) return BN_set_word(a, w); - /* handle 'a' when negative */ - if (a->neg) - { - a->neg=0; - i=BN_sub_word(a,w); - if (!BN_is_zero(a)) - a->neg=!(a->neg); - return(i); - } - /* Only expand (and risk failing) if it's possibly necessary */ - if (((BN_ULONG)(a->d[a->top - 1] + 1) == 0) && - (bn_wexpand(a,a->top+1) == NULL)) - return(0); - i=0; - for (;;) - { - if (i >= a->top) - l=w; - else - l=(a->d[i]+w)&BN_MASK2; - a->d[i]=l; - if (w > l) - w=1; - else - break; - i++; - } - if (i >= a->top) - a->top++; - bn_check_top(a); - return(1); - } +{ + BN_ULONG l; + int i; + + bn_check_top(a); + w &= BN_MASK2; + + /* degenerate case: w is zero */ + if (!w) + return 1; + /* degenerate case: a is zero */ + if (BN_is_zero(a)) + return BN_set_word(a, w); + /* handle 'a' when negative */ + if (a->neg) { + a->neg = 0; + i = BN_sub_word(a, w); + if (!BN_is_zero(a)) + a->neg = !(a->neg); + return (i); + } + for (i = 0; w != 0 && i < a->top; i++) { + a->d[i] = l = (a->d[i] + w) & BN_MASK2; + w = (w > l) ? 1 : 0; + } + if (w && i == a->top) { + if (bn_wexpand(a, a->top + 1) == NULL) + return 0; + a->top++; + a->d[i] = w; + } + bn_check_top(a); + return (1); +} int BN_sub_word(BIGNUM *a, BN_ULONG w) - { - int i; - - bn_check_top(a); - w &= BN_MASK2; - - /* degenerate case: w is zero */ - if (!w) return 1; - /* degenerate case: a is zero */ - if(BN_is_zero(a)) return BN_set_word(a,w); - /* handle 'a' when negative */ - if (a->neg) - { - a->neg=0; - i=BN_add_word(a,w); - a->neg=1; - return(i); - } - - if ((a->top == 1) && (a->d[0] < w)) - { - a->d[0]=w-a->d[0]; - a->neg=1; - return(1); - } - i=0; - for (;;) - { - if (a->d[i] >= w) - { - a->d[i]-=w; - break; - } - else - { - a->d[i]=(a->d[i]-w)&BN_MASK2; - i++; - w=1; - } - } - if ((a->d[i] == 0) && (i == (a->top-1))) - a->top--; - bn_check_top(a); - return(1); - } +{ + int i; + + bn_check_top(a); + w &= BN_MASK2; + + /* degenerate case: w is zero */ + if (!w) + return 1; + /* degenerate case: a is zero */ + if (BN_is_zero(a)) { + i = BN_set_word(a, w); + if (i != 0) + BN_set_negative(a, 1); + return i; + } + /* handle 'a' when negative */ + if (a->neg) { + a->neg = 0; + i = BN_add_word(a, w); + a->neg = 1; + return (i); + } + + if ((a->top == 1) && (a->d[0] < w)) { + a->d[0] = w - a->d[0]; + a->neg = 1; + return (1); + } + i = 0; + for (;;) { + if (a->d[i] >= w) { + a->d[i] -= w; + break; + } else { + a->d[i] = (a->d[i] - w) & BN_MASK2; + i++; + w = 1; + } + } + if ((a->d[i] == 0) && (i == (a->top - 1))) + a->top--; + bn_check_top(a); + return (1); +} int BN_mul_word(BIGNUM *a, BN_ULONG w) - { - BN_ULONG ll; - - bn_check_top(a); - w&=BN_MASK2; - if (a->top) - { - if (w == 0) - BN_zero(a); - else - { - ll=bn_mul_words(a->d,a->d,a->top,w); - if (ll) - { - if (bn_wexpand(a,a->top+1) == NULL) return(0); - a->d[a->top++]=ll; - } - } - } - bn_check_top(a); - return(1); - } - +{ + BN_ULONG ll; + + bn_check_top(a); + w &= BN_MASK2; + if (a->top) { + if (w == 0) + BN_zero(a); + else { + ll = bn_mul_words(a->d, a->d, a->top, w); + if (ll) { + if (bn_wexpand(a, a->top + 1) == NULL) + return (0); + a->d[a->top++] = ll; + } + } + } + bn_check_top(a); + return (1); +}