1/*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 9 * 10 * This software is licensed as described in the file COPYING, which 11 * you should have received as part of this distribution. The terms 12 * are also available at https://curl.se/docs/copyright.html. 13 * 14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 15 * copies of the Software, and permit persons to whom the Software is 16 * furnished to do so, under the terms of the COPYING file. 17 * 18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 19 * KIND, either express or implied. 20 * 21 * SPDX-License-Identifier: curl 22 * 23 ***************************************************************************/ 24 25#include "curl_setup.h" 26 27#include <curl/curl.h> 28 29#include "strcase.h" 30 31/* Mapping table to go from lowercase to uppercase for plain ASCII.*/ 32static const unsigned char touppermap[256] = { 330, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 3422, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 3541, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 3660, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 3779, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 65, 3866, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 3985, 86, 87, 88, 89, 90, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 40134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 41150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 42166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 43182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 44198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 45214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 46230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 47246, 247, 248, 249, 250, 251, 252, 253, 254, 255 48}; 49 50/* Mapping table to go from uppercase to lowercase for plain ASCII.*/ 51static const unsigned char tolowermap[256] = { 520, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 5322, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 5442, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 5562, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 56111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 91, 92, 93, 94, 95, 5796, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 58112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 59128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 60144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 61160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 62176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 63192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 64208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 65224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 66240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255 67}; 68 69 70/* Portable, consistent toupper. Do not use toupper() because its behavior is 71 altered by the current locale. */ 72char Curl_raw_toupper(char in) 73{ 74 return touppermap[(unsigned char) in]; 75} 76 77 78/* Portable, consistent tolower. Do not use tolower() because its behavior is 79 altered by the current locale. */ 80char Curl_raw_tolower(char in) 81{ 82 return tolowermap[(unsigned char) in]; 83} 84 85/* 86 * curl_strequal() is for doing "raw" case insensitive strings. This is meant 87 * to be locale independent and only compare strings we know are safe for 88 * this. See https://daniel.haxx.se/blog/2008/10/15/strcasecmp-in-turkish/ for 89 * further explanations as to why this function is necessary. 90 */ 91 92static int casecompare(const char *first, const char *second) 93{ 94 while(*first && *second) { 95 if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second)) 96 /* get out of the loop as soon as they don't match */ 97 return 0; 98 first++; 99 second++; 100 } 101 /* If we're here either the strings are the same or the length is different. 102 We can just test if the "current" character is non-zero for one and zero 103 for the other. Note that the characters may not be exactly the same even 104 if they match, we only want to compare zero-ness. */ 105 return !*first == !*second; 106} 107 108/* --- public function --- */ 109int curl_strequal(const char *first, const char *second) 110{ 111 if(first && second) 112 /* both pointers point to something then compare them */ 113 return casecompare(first, second); 114 115 /* if both pointers are NULL then treat them as equal */ 116 return (NULL == first && NULL == second); 117} 118 119static int ncasecompare(const char *first, const char *second, size_t max) 120{ 121 while(*first && *second && max) { 122 if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second)) 123 return 0; 124 max--; 125 first++; 126 second++; 127 } 128 if(0 == max) 129 return 1; /* they are equal this far */ 130 131 return Curl_raw_toupper(*first) == Curl_raw_toupper(*second); 132} 133 134/* --- public function --- */ 135int curl_strnequal(const char *first, const char *second, size_t max) 136{ 137 if(first && second) 138 /* both pointers point to something then compare them */ 139 return ncasecompare(first, second, max); 140 141 /* if both pointers are NULL then treat them as equal if max is non-zero */ 142 return (NULL == first && NULL == second && max); 143} 144/* Copy an upper case version of the string from src to dest. The 145 * strings may overlap. No more than n characters of the string are copied 146 * (including any NUL) and the destination string will NOT be 147 * NUL-terminated if that limit is reached. 148 */ 149void Curl_strntoupper(char *dest, const char *src, size_t n) 150{ 151 if(n < 1) 152 return; 153 154 do { 155 *dest++ = Curl_raw_toupper(*src); 156 } while(*src++ && --n); 157} 158 159/* Copy a lower case version of the string from src to dest. The 160 * strings may overlap. No more than n characters of the string are copied 161 * (including any NUL) and the destination string will NOT be 162 * NUL-terminated if that limit is reached. 163 */ 164void Curl_strntolower(char *dest, const char *src, size_t n) 165{ 166 if(n < 1) 167 return; 168 169 do { 170 *dest++ = Curl_raw_tolower(*src); 171 } while(*src++ && --n); 172} 173 174/* Compare case-sensitive NUL-terminated strings, taking care of possible 175 * null pointers. Return true if arguments match. 176 */ 177bool Curl_safecmp(char *a, char *b) 178{ 179 if(a && b) 180 return !strcmp(a, b); 181 return !a && !b; 182} 183 184/* 185 * Curl_timestrcmp() returns 0 if the two strings are identical. The time this 186 * function spends is a function of the shortest string, not of the contents. 187 */ 188int Curl_timestrcmp(const char *a, const char *b) 189{ 190 int match = 0; 191 int i = 0; 192 193 if(a && b) { 194 while(1) { 195 match |= a[i]^b[i]; 196 if(!a[i] || !b[i]) 197 break; 198 i++; 199 } 200 } 201 else 202 return a || b; 203 return match; 204} 205