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.*/
32 static const unsigned char touppermap[256] = {
33 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
34 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
35 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
36 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,
37 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 65,
38 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84,
39 85, 86, 87, 88, 89, 90, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133,
40 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149,
41 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165,
42 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181,
43 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197,
44 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213,
45 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229,
46 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245,
47 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
48 };
49
50 /* Mapping table to go from uppercase to lowercase for plain ASCII.*/
51 static const unsigned char tolowermap[256] = {
52 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
53 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
54 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
55 62, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110,
56 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 91, 92, 93, 94, 95,
57 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
58 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
59 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
60 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
61 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
62 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
63 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
64 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
65 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
66 240, 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. */
Curl_raw_toupper(char in)72 char Curl_raw_toupper(char in)
73 {
74 return (char)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. */
Curl_raw_tolower(char in)80 char Curl_raw_tolower(char in)
81 {
82 return (char)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
casecompare(const char * first,const char * second)92 static 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 do not match */
97 return 0;
98 first++;
99 second++;
100 }
101 /* If we are 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 --- */
curl_strequal(const char * first,const char * second)109 int 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
ncasecompare(const char * first,const char * second,size_t max)119 static 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 --- */
curl_strnequal(const char * first,const char * second,size_t max)135 int 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 */
Curl_strntoupper(char * dest,const char * src,size_t n)149 void 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 */
Curl_strntolower(char * dest,const char * src,size_t n)164 void 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 */
Curl_safecmp(char * a,char * b)177 bool 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 */
Curl_timestrcmp(const char * a,const char * b)188 int 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
