hash.c revision 1.6
1/* $NetBSD: hash.c,v 1.6 2021/02/19 16:42:19 christos Exp $ */ 2 3/* 4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 5 * 6 * This Source Code Form is subject to the terms of the Mozilla Public 7 * License, v. 2.0. If a copy of the MPL was not distributed with this 8 * file, you can obtain one at https://mozilla.org/MPL/2.0/. 9 * 10 * See the COPYRIGHT file distributed with this work for additional 11 * information regarding copyright ownership. 12 */ 13 14#include <inttypes.h> 15#include <stdbool.h> 16#include <stddef.h> 17#if defined(WIN32) || defined(WIN64) 18#include <malloc.h> 19#endif /* if defined(WIN32) || defined(WIN64) */ 20 21#include "entropy_private.h" 22#include "isc/hash.h" /* IWYU pragma: keep */ 23#include "isc/likely.h" 24#include "isc/once.h" 25#include "isc/random.h" 26#include "isc/result.h" 27#include "isc/siphash.h" 28#include "isc/string.h" 29#include "isc/types.h" 30#include "isc/util.h" 31 32static uint8_t isc_hash_key[16]; 33static uint8_t isc_hash32_key[8]; 34static bool hash_initialized = false; 35static isc_once_t isc_hash_once = ISC_ONCE_INIT; 36 37static void 38isc_hash_initialize(void) { 39 /* 40 * Set a constant key to help in problem reproduction should 41 * fuzzing find a crash or a hang. 42 */ 43 uint64_t key[2] = { 0, 1 }; 44#if !FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 45 isc_entropy_get(key, sizeof(key)); 46#endif /* if FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */ 47 memmove(isc_hash_key, key, sizeof(isc_hash_key)); 48#if !FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 49 isc_entropy_get(key, sizeof(key)); 50#endif /* if FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */ 51 memmove(isc_hash32_key, key, sizeof(isc_hash32_key)); 52 hash_initialized = true; 53} 54 55static uint8_t maptolower[] = { 56 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 57 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 58 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 59 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 60 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 61 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 62 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 63 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 64 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 65 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 66 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 67 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 68 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 69 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 70 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 71 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 72 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 73 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 74 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 75 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 76 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 77 0xfc, 0xfd, 0xfe, 0xff 78}; 79 80const void * 81isc_hash_get_initializer(void) { 82 if (ISC_UNLIKELY(!hash_initialized)) { 83 RUNTIME_CHECK( 84 isc_once_do(&isc_hash_once, isc_hash_initialize) == 85 ISC_R_SUCCESS); 86 } 87 88 return (isc_hash_key); 89} 90 91void 92isc_hash_set_initializer(const void *initializer) { 93 REQUIRE(initializer != NULL); 94 95 /* 96 * Ensure that isc_hash_initialize() is not called after 97 * isc_hash_set_initializer() is called. 98 */ 99 if (ISC_UNLIKELY(!hash_initialized)) { 100 RUNTIME_CHECK( 101 isc_once_do(&isc_hash_once, isc_hash_initialize) == 102 ISC_R_SUCCESS); 103 } 104 105 memmove(isc_hash_key, initializer, sizeof(isc_hash_key)); 106} 107 108uint64_t 109isc_hash64(const void *data, const size_t length, const bool case_sensitive) { 110 uint64_t hval; 111 112 REQUIRE(length == 0 || data != NULL); 113 114 RUNTIME_CHECK(isc_once_do(&isc_hash_once, isc_hash_initialize) == 115 ISC_R_SUCCESS); 116 117 if (case_sensitive) { 118 isc_siphash24(isc_hash_key, data, length, (uint8_t *)&hval); 119 } else { 120 uint8_t input[1024]; 121 REQUIRE(length <= 1024); 122 for (unsigned int i = 0; i < length; i++) { 123 input[i] = maptolower[((const uint8_t *)data)[i]]; 124 } 125 isc_siphash24(isc_hash_key, input, length, (uint8_t *)&hval); 126 } 127 128 return (hval); 129} 130 131uint32_t 132isc_hash32(const void *data, const size_t length, const bool case_sensitive) { 133 uint32_t hval; 134 135 REQUIRE(length == 0 || data != NULL); 136 137 RUNTIME_CHECK(isc_once_do(&isc_hash_once, isc_hash_initialize) == 138 ISC_R_SUCCESS); 139 140 if (case_sensitive) { 141 isc_halfsiphash24(isc_hash_key, data, length, (uint8_t *)&hval); 142 } else { 143 uint8_t input[1024]; 144 REQUIRE(length <= 1024); 145 for (unsigned int i = 0; i < length; i++) { 146 input[i] = maptolower[((const uint8_t *)data)[i]]; 147 } 148 isc_halfsiphash24(isc_hash_key, input, length, 149 (uint8_t *)&hval); 150 } 151 152 return (hval); 153} 154