1c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* crypto/constant_time_locl.h */ 2c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* 3c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Utilities for constant-time cryptography. 4c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 5c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Author: Emilia Kasper (emilia@openssl.org) 6c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Based on previous work by Bodo Moeller, Emilia Kasper, Adam Langley 7c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * (Google). 8c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * ==================================================================== 9c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Copyright (c) 2014 The OpenSSL Project. All rights reserved. 10c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 11c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Redistribution and use in source and binary forms, with or without 12c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * modification, are permitted provided that the following conditions 13c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * are met: 14c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 1. Redistributions of source code must retain the copyright 15c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * notice, this list of conditions and the following disclaimer. 16c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 2. Redistributions in binary form must reproduce the above copyright 17c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * notice, this list of conditions and the following disclaimer in the 18c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * documentation and/or other materials provided with the distribution. 19c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 3. All advertising materials mentioning features or use of this software 20c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * must display the following acknowledgement: 21c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * "This product includes cryptographic software written by 22c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Eric Young (eay@cryptsoft.com)" 23c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * The word 'cryptographic' can be left out if the rouines from the library 24c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * being used are not cryptographic related :-). 25c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 4. If you include any Windows specific code (or a derivative thereof) from 26c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * the apps directory (application code) you must include an acknowledgement: 27c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 28c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 29c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 30c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 33c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * SUCH DAMAGE. 40c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 41c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * The licence and distribution terms for any publically available version or 42c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * derivative of this code cannot be changed. i.e. this code cannot simply be 43c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * copied and put under another distribution licence 44c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * [including the GNU Public Licence.] 45c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root */ 46c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 47c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root#ifndef HEADER_CONSTANT_TIME_LOCL_H 48c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root#define HEADER_CONSTANT_TIME_LOCL_H 49c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 50c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root#include "e_os.h" /* For 'inline' */ 51c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 52c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root#ifdef __cplusplus 53c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootextern "C" { 54c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root#endif 55c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 56c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* 57c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * The boolean methods return a bitmask of all ones (0xff...f) for true 58c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * and 0 for false. This is useful for choosing a value based on the result 59c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * of a conditional in constant time. For example, 60c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 61c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * if (a < b) { 62c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * c = a; 63c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * } else { 64c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * c = b; 65c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * } 66c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 67c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * can be written as 68c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 69c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * unsigned int lt = constant_time_lt(a, b); 70c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * c = constant_time_select(lt, a, b); 71c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root */ 72c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 73c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* 74c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Returns the given value with the MSB copied to all the other 75c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * bits. Uses the fact that arithmetic shift shifts-in the sign bit. 76c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * However, this is not ensured by the C standard so you may need to 77c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * replace this with something else on odd CPUs. 78c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root */ 79c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_msb(unsigned int a); 80c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 81c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* 82c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Returns 0xff..f if a < b and 0 otherwise. 83c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root */ 84c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_lt(unsigned int a, unsigned int b); 85c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* Convenience method for getting an 8-bit mask. */ 86c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_lt_8(unsigned int a, unsigned int b); 87c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 88c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* 89c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Returns 0xff..f if a >= b and 0 otherwise. 90c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root */ 91c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_ge(unsigned int a, unsigned int b); 92c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* Convenience method for getting an 8-bit mask. */ 93c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_ge_8(unsigned int a, unsigned int b); 94c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 95c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* 96c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Returns 0xff..f if a == 0 and 0 otherwise. 97c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root */ 98c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_is_zero(unsigned int a); 99c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* Convenience method for getting an 8-bit mask. */ 100c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_is_zero_8(unsigned int a); 101c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 102c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 103c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* 104c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Returns 0xff..f if a == b and 0 otherwise. 105c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root */ 106c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_eq(unsigned int a, unsigned int b); 107c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* Convenience method for getting an 8-bit mask. */ 108c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_eq_8(unsigned int a, unsigned int b); 109c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* Signed integers. */ 110c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_eq_int(int a, int b); 111c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* Convenience method for getting an 8-bit mask. */ 112c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_eq_int_8(int a, int b); 113c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 114c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 115c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* 116c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * Returns (mask & a) | (~mask & b). 117c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * 118c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * When |mask| is all 1s or all 0s (as returned by the methods above), 119c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * the select methods return either |a| (if |mask| is nonzero) or |b| 120c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root * (if |mask| is zero). 121c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root */ 122c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_select(unsigned int mask, 123c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root unsigned int a, unsigned int b); 124c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* Convenience method for unsigned chars. */ 125c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_select_8(unsigned char mask, 126c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root unsigned char a, unsigned char b); 127c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root/* Convenience method for signed integers. */ 128c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline int constant_time_select_int(unsigned int mask, int a, int b); 129c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 130c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_msb(unsigned int a) 131c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 132c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return (unsigned int)((int)(a) >> (sizeof(int) * 8 - 1)); 133c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 134c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 135c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_lt(unsigned int a, unsigned int b) 136c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 137c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root unsigned int lt; 138c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root /* Case 1: msb(a) == msb(b). a < b iff the MSB of a - b is set.*/ 139c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root lt = ~(a ^ b) & (a - b); 140c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root /* Case 2: msb(a) != msb(b). a < b iff the MSB of b is set. */ 141c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root lt |= ~a & b; 142c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return constant_time_msb(lt); 143c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 144c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 145c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_lt_8(unsigned int a, unsigned int b) 146c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 147c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return (unsigned char)(constant_time_lt(a, b)); 148c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 149c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 150c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_ge(unsigned int a, unsigned int b) 151c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 152c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root unsigned int ge; 153c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root /* Case 1: msb(a) == msb(b). a >= b iff the MSB of a - b is not set.*/ 154c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root ge = ~((a ^ b) | (a - b)); 155c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root /* Case 2: msb(a) != msb(b). a >= b iff the MSB of a is set. */ 156c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root ge |= a & ~b; 157c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return constant_time_msb(ge); 158c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 159c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 160c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_ge_8(unsigned int a, unsigned int b) 161c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 162c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return (unsigned char)(constant_time_ge(a, b)); 163c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 164c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 165c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_is_zero(unsigned int a) 166c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 167c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return constant_time_msb(~a & (a - 1)); 168c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 169c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 170c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_is_zero_8(unsigned int a) 171c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 172c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return (unsigned char)(constant_time_is_zero(a)); 173c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 174c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 175c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_eq(unsigned int a, unsigned int b) 176c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 177c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return constant_time_is_zero(a ^ b); 178c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 179c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 180c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_eq_8(unsigned int a, unsigned int b) 181c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 182c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return (unsigned char)(constant_time_eq(a, b)); 183c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 184c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 185c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_eq_int(int a, int b) 186c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 187c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return constant_time_eq((unsigned)(a), (unsigned)(b)); 188c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 189c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 190c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_eq_int_8(int a, int b) 191c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 192c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return constant_time_eq_8((unsigned)(a), (unsigned)(b)); 193c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 194c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 195c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned int constant_time_select(unsigned int mask, 196c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root unsigned int a, unsigned int b) 197c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 198c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return (mask & a) | (~mask & b); 199c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 200c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 201c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootstatic inline unsigned char constant_time_select_8(unsigned char mask, 202c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root unsigned char a, unsigned char b) 203c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 204c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return (unsigned char)(constant_time_select(mask, a, b)); 205c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 206c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 207c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Rootinline int constant_time_select_int(unsigned int mask, int a, int b) 208c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root { 209c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root return (int)(constant_time_select(mask, (unsigned)(a), (unsigned)(b))); 210c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root } 211c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 212c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root#ifdef __cplusplus 213c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root} 214c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root#endif 215c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root 216c64f6fe2be99cb3fa8e491b5bede9a217de87a4cKenny Root#endif /* HEADER_CONSTANT_TIME_LOCL_H */ 217