1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2022, Daniel Stenberg, <[email protected]>, 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
31static char raw_tolower(char in);
32
33/* Mapping table to go from lowercase to uppercase for plain ASCII.*/
34static const unsigned char touppermap[256] = {
350, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
3622, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
3741, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
3860, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,
3979, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 65,
4066, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84,
4185, 86, 87, 88, 89, 90, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133,
42134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149,
43150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165,
44166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181,
45182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197,
46198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213,
47214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229,
48230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245,
49246, 247, 248, 249, 250, 251, 252, 253, 254, 255
50};
51
52/* Mapping table to go from uppercase to lowercase for plain ASCII.*/
53static const unsigned char tolowermap[256] = {
540, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
5522, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
5642, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
5762, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110,
58111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 91, 92, 93, 94, 95,
5996, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
60112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
61128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
62144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
63160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
64176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
65192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
66208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
67224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
68240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
69};
70
71
72/* Portable, consistent toupper. Do not use toupper() because its behavior is
73 altered by the current locale. */
74char Curl_raw_toupper(char in)
75{
76 return touppermap[(unsigned char) in];
77}
78
79
80/* Portable, consistent tolower. Do not use tolower() because its behavior is
81 altered by the current locale. */
82static char raw_tolower(char in)
83{
84 return tolowermap[(unsigned char) in];
85}
86
87/*
88 * Curl_strcasecompare() is for doing "raw" case insensitive strings. This is
89 * meant to be locale independent and only compare strings we know are safe
90 * for this. See
91 * https://daniel.haxx.se/blog/2008/10/15/strcasecmp-in-turkish/ for some
92 * further explanation to why this function is necessary.
93 *
94 * @unittest: 1301
95 */
96
97int Curl_strcasecompare(const char *first, const char *second)
98{
99 while(*first && *second) {
100 if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second))
101 /* get out of the loop as soon as they don't match */
102 return 0;
103 first++;
104 second++;
105 }
106 /* If we're here either the strings are the same or the length is different.
107 We can just test if the "current" character is non-zero for one and zero
108 for the other. Note that the characters may not be exactly the same even
109 if they match, we only want to compare zero-ness. */
110 return !*first == !*second;
111}
112
113int Curl_safe_strcasecompare(const char *first, const char *second)
114{
115 if(first && second)
116 /* both pointers point to something then compare them */
117 return Curl_strcasecompare(first, second);
118
119 /* if both pointers are NULL then treat them as equal */
120 return (NULL == first && NULL == second);
121}
122
123/*
124 * @unittest: 1301
125 */
126int Curl_strncasecompare(const char *first, const char *second, size_t max)
127{
128 while(*first && *second && max) {
129 if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second)) {
130 break;
131 }
132 max--;
133 first++;
134 second++;
135 }
136 if(0 == max)
137 return 1; /* they are equal this far */
138
139 return Curl_raw_toupper(*first) == Curl_raw_toupper(*second);
140}
141
142/* Copy an upper case version of the string from src to dest. The
143 * strings may overlap. No more than n characters of the string are copied
144 * (including any NUL) and the destination string will NOT be
145 * NUL-terminated if that limit is reached.
146 */
147void Curl_strntoupper(char *dest, const char *src, size_t n)
148{
149 if(n < 1)
150 return;
151
152 do {
153 *dest++ = Curl_raw_toupper(*src);
154 } while(*src++ && --n);
155}
156
157/* Copy a lower case version of the string from src to dest. The
158 * strings may overlap. No more than n characters of the string are copied
159 * (including any NUL) and the destination string will NOT be
160 * NUL-terminated if that limit is reached.
161 */
162void Curl_strntolower(char *dest, const char *src, size_t n)
163{
164 if(n < 1)
165 return;
166
167 do {
168 *dest++ = raw_tolower(*src);
169 } while(*src++ && --n);
170}
171
172/* Compare case-sensitive NUL-terminated strings, taking care of possible
173 * null pointers. Return true if arguments match.
174 */
175bool Curl_safecmp(char *a, char *b)
176{
177 if(a && b)
178 return !strcmp(a, b);
179 return !a && !b;
180}
181
182/* --- public functions --- */
183
184int curl_strequal(const char *first, const char *second)
185{
186 return Curl_strcasecompare(first, second);
187}
188int curl_strnequal(const char *first, const char *second, size_t max)
189{
190 return Curl_strncasecompare(first, second, max);
191}
192