hash.c revision 1.8
1 /* $NetBSD: hash.c,v 1.8 2024/02/21 22:52:28 christos Exp $ */ 2 3 /* 4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 5 * 6 * SPDX-License-Identifier: MPL-2.0 7 * 8 * This Source Code Form is subject to the terms of the Mozilla Public 9 * License, v. 2.0. If a copy of the MPL was not distributed with this 10 * file, you can obtain one at https://mozilla.org/MPL/2.0/. 11 * 12 * See the COPYRIGHT file distributed with this work for additional 13 * information regarding copyright ownership. 14 */ 15 16 #include <inttypes.h> 17 #include <stdbool.h> 18 #include <stddef.h> 19 20 #include "entropy_private.h" 21 #include "isc/hash.h" /* IWYU pragma: keep */ 22 #include "isc/once.h" 23 #include "isc/random.h" 24 #include "isc/result.h" 25 #include "isc/siphash.h" 26 #include "isc/string.h" 27 #include "isc/types.h" 28 #include "isc/util.h" 29 30 static uint8_t isc_hash_key[16]; 31 static uint8_t isc_hash32_key[8]; 32 static bool hash_initialized = false; 33 static isc_once_t isc_hash_once = ISC_ONCE_INIT; 34 35 static void 36 isc_hash_initialize(void) { 37 /* 38 * Set a constant key to help in problem reproduction should 39 * fuzzing find a crash or a hang. 40 */ 41 uint64_t key[2] = { 0, 1 }; 42 #if !FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 43 isc_entropy_get(key, sizeof(key)); 44 #endif /* if FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */ 45 memmove(isc_hash_key, key, sizeof(isc_hash_key)); 46 #if !FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 47 isc_entropy_get(key, sizeof(key)); 48 #endif /* if FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */ 49 memmove(isc_hash32_key, key, sizeof(isc_hash32_key)); 50 hash_initialized = true; 51 } 52 53 static uint8_t maptolower[] = { 54 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 55 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 56 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 57 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 58 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 59 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 60 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 61 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 62 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 63 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 64 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 65 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 66 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 67 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 68 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 69 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 70 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 71 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 72 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 73 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 74 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 75 0xfc, 0xfd, 0xfe, 0xff 76 }; 77 78 const void * 79 isc_hash_get_initializer(void) { 80 if (!hash_initialized) { 81 RUNTIME_CHECK( 82 isc_once_do(&isc_hash_once, isc_hash_initialize) == 83 ISC_R_SUCCESS); 84 } 85 86 return (isc_hash_key); 87 } 88 89 void 90 isc_hash_set_initializer(const void *initializer) { 91 REQUIRE(initializer != NULL); 92 93 /* 94 * Ensure that isc_hash_initialize() is not called after 95 * isc_hash_set_initializer() is called. 96 */ 97 if (!hash_initialized) { 98 RUNTIME_CHECK( 99 isc_once_do(&isc_hash_once, isc_hash_initialize) == 100 ISC_R_SUCCESS); 101 } 102 103 memmove(isc_hash_key, initializer, sizeof(isc_hash_key)); 104 } 105 106 uint64_t 107 isc_hash64(const void *data, const size_t length, const bool case_sensitive) { 108 uint64_t hval; 109 110 REQUIRE(length == 0 || data != NULL); 111 112 RUNTIME_CHECK(isc_once_do(&isc_hash_once, isc_hash_initialize) == 113 ISC_R_SUCCESS); 114 115 if (case_sensitive) { 116 isc_siphash24(isc_hash_key, data, length, (uint8_t *)&hval); 117 } else { 118 uint8_t input[1024]; 119 REQUIRE(length <= 1024); 120 for (unsigned int i = 0; i < length; i++) { 121 input[i] = maptolower[((const uint8_t *)data)[i]]; 122 } 123 isc_siphash24(isc_hash_key, input, length, (uint8_t *)&hval); 124 } 125 126 return (hval); 127 } 128 129 uint32_t 130 isc_hash32(const void *data, const size_t length, const bool case_sensitive) { 131 uint32_t hval; 132 133 REQUIRE(length == 0 || data != NULL); 134 135 RUNTIME_CHECK(isc_once_do(&isc_hash_once, isc_hash_initialize) == 136 ISC_R_SUCCESS); 137 138 if (case_sensitive) { 139 isc_halfsiphash24(isc_hash_key, data, length, (uint8_t *)&hval); 140 } else { 141 uint8_t input[1024]; 142 REQUIRE(length <= 1024); 143 for (unsigned int i = 0; i < length; i++) { 144 input[i] = maptolower[((const uint8_t *)data)[i]]; 145 } 146 isc_halfsiphash24(isc_hash_key, input, length, 147 (uint8_t *)&hval); 148 } 149 150 return (hval); 151 } 152
Indexes created Wed Mar 04 05:31:52 UTC 2026