1/* 2 * Copyright (c) 2000-2001,2011,2014 Apple Inc. All Rights Reserved. 3 * 4 * The contents of this file constitute Original Code as defined in and are 5 * subject to the Apple Public Source License Version 1.2 (the 'License'). 6 * You may not use this file except in compliance with the License. Please obtain 7 * a copy of the License at http://www.apple.com/publicsource and read it before 8 * using this file. 9 * 10 * This Original Code and all software distributed under the License are 11 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS 12 * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT 13 * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 14 * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the 15 * specific language governing rights and limitations under the License. 16 */ 17 18 19/* crypto/bn/bn_word.c */ 20/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 21 * All rights reserved. 22 * 23 * This package is an SSL implementation written 24 * by Eric Young (eay@cryptsoft.com). 25 * The implementation was written so as to conform with Netscapes SSL. 26 * 27 * This library is free for commercial and non-commercial use as long as 28 * the following conditions are aheared to. The following conditions 29 * apply to all code found in this distribution, be it the RC4, RSA, 30 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 31 * included with this distribution is covered by the same copyright terms 32 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 33 * 34 * Copyright remains Eric Young's, and as such any Copyright notices in 35 * the code are not to be removed. 36 * If this package is used in a product, Eric Young should be given attribution 37 * as the author of the parts of the library used. 38 * This can be in the form of a textual message at program startup or 39 * in documentation (online or textual) provided with the package. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 3. All advertising materials mentioning features or use of this software 50 * must display the following acknowledgement: 51 * "This product includes cryptographic software written by 52 * Eric Young (eay@cryptsoft.com)" 53 * The word 'cryptographic' can be left out if the rouines from the library 54 * being used are not cryptographic related :-). 55 * 4. If you include any Windows specific code (or a derivative thereof) from 56 * the apps directory (application code) you must include an acknowledgement: 57 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 58 * 59 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * The licence and distribution terms for any publically available version or 72 * derivative of this code cannot be changed. i.e. this code cannot simply be 73 * copied and put under another distribution licence 74 * [including the GNU Public Licence.] 75 */ 76 77#include <stdio.h> 78#include "cryptlib.h" 79#include "bn_lcl.h" 80 81BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w) 82 { 83#ifndef BN_LLONG 84 BN_ULONG ret=0; 85#else 86 BN_ULLONG ret=0; 87#endif 88 int i; 89 90 w&=BN_MASK2; 91 for (i=a->top-1; i>=0; i--) 92 { 93#ifndef BN_LLONG 94 ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%w; 95 ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%w; 96#else 97 ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])% 98 (BN_ULLONG)w); 99#endif 100 } 101 return((BN_ULONG)ret); 102 } 103 104BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w) 105 { 106 BN_ULONG ret; 107 int i; 108 109 if (a->top == 0) return(0); 110 ret=0; 111 w&=BN_MASK2; 112 for (i=a->top-1; i>=0; i--) 113 { 114 BN_ULONG l,d; 115 116 l=a->d[i]; 117 d=bn_div_words(ret,l,w); 118 ret=(l-((d*w)&BN_MASK2))&BN_MASK2; 119 a->d[i]=d; 120 } 121 if ((a->top > 0) && (a->d[a->top-1] == 0)) 122 a->top--; 123 return(ret); 124 } 125 126int BN_add_word(BIGNUM *a, BN_ULONG w) 127 { 128 BN_ULONG l; 129 int i; 130 131 if (a->neg) 132 { 133 a->neg=0; 134 i=BN_sub_word(a,w); 135 if (!BN_is_zero(a)) 136 a->neg=1; 137 return(i); 138 } 139 w&=BN_MASK2; 140 if (bn_wexpand(a,a->top+1) == NULL) return(0); 141 i=0; 142 for (;;) 143 { 144 l=(a->d[i]+(BN_ULONG)w)&BN_MASK2; 145 a->d[i]=l; 146 if (w > l) 147 w=1; 148 else 149 break; 150 i++; 151 } 152 if (i >= a->top) 153 a->top++; 154 return(1); 155 } 156 157int BN_sub_word(BIGNUM *a, BN_ULONG w) 158 { 159 int i; 160 161 if (a->neg) 162 { 163 a->neg=0; 164 i=BN_add_word(a,w); 165 a->neg=1; 166 return(i); 167 } 168 169 w&=BN_MASK2; 170 if ((a->top == 1) && (a->d[0] < w)) 171 { 172 a->d[0]=w-a->d[0]; 173 a->neg=1; 174 return(1); 175 } 176 i=0; 177 for (;;) 178 { 179 if (a->d[i] >= w) 180 { 181 a->d[i]-=w; 182 break; 183 } 184 else 185 { 186 a->d[i]=(a->d[i]-w)&BN_MASK2; 187 i++; 188 w=1; 189 } 190 } 191 if ((a->d[i] == 0) && (i == (a->top-1))) 192 a->top--; 193 return(1); 194 } 195 196int BN_mul_word(BIGNUM *a, BN_ULONG w) 197 { 198 BN_ULONG ll; 199 200 w&=BN_MASK2; 201 if (a->top) 202 { 203 ll=bn_mul_words(a->d,a->d,a->top,w); 204 if (ll) 205 { 206 if (bn_wexpand(a,a->top+1) == NULL) return(0); 207 a->d[a->top++]=ll; 208 } 209 } 210 return(1); 211 } 212 213