xref: /xnu-8796.121.2/bsd/libkern/url_encode.c (revision c54f35ca767986246321eb901baf8f5ff7923f6a)
1*c54f35caSApple OSS Distributions /*
2*c54f35caSApple OSS Distributions  * Copyright (c) 2016 Apple Inc. All rights reserved.
3*c54f35caSApple OSS Distributions  *
4*c54f35caSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*c54f35caSApple OSS Distributions  *
6*c54f35caSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*c54f35caSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*c54f35caSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*c54f35caSApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*c54f35caSApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*c54f35caSApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*c54f35caSApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*c54f35caSApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*c54f35caSApple OSS Distributions  *
15*c54f35caSApple OSS Distributions  * Please obtain a copy of the License at
16*c54f35caSApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*c54f35caSApple OSS Distributions  *
18*c54f35caSApple OSS Distributions  * The Original Code and all software distributed under the License are
19*c54f35caSApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*c54f35caSApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*c54f35caSApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*c54f35caSApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*c54f35caSApple OSS Distributions  * Please see the License for the specific language governing rights and
24*c54f35caSApple OSS Distributions  * limitations under the License.
25*c54f35caSApple OSS Distributions  *
26*c54f35caSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*c54f35caSApple OSS Distributions  */
28*c54f35caSApple OSS Distributions 
29*c54f35caSApple OSS Distributions #include <libkern/libkern.h>
30*c54f35caSApple OSS Distributions 
31*c54f35caSApple OSS Distributions static int
hex2int(int c)32*c54f35caSApple OSS Distributions hex2int(int c)
33*c54f35caSApple OSS Distributions {
34*c54f35caSApple OSS Distributions 	if (c >= '0' && c <= '9') {
35*c54f35caSApple OSS Distributions 		return c - '0';
36*c54f35caSApple OSS Distributions 	} else if (c >= 'A' && c <= 'F') {
37*c54f35caSApple OSS Distributions 		return c - 'A' + 10;
38*c54f35caSApple OSS Distributions 	} else if (c >= 'a' && c <= 'f') {
39*c54f35caSApple OSS Distributions 		return c - 'a' + 10;
40*c54f35caSApple OSS Distributions 	}
41*c54f35caSApple OSS Distributions 	return 0;
42*c54f35caSApple OSS Distributions }
43*c54f35caSApple OSS Distributions 
44*c54f35caSApple OSS Distributions static bool
isprint(int ch)45*c54f35caSApple OSS Distributions isprint(int ch)
46*c54f35caSApple OSS Distributions {
47*c54f35caSApple OSS Distributions 	return ch >= 0x20 && ch <= 0x7e;
48*c54f35caSApple OSS Distributions }
49*c54f35caSApple OSS Distributions 
50*c54f35caSApple OSS Distributions /*
51*c54f35caSApple OSS Distributions  * In-place decode of URL percent-encoded str
52*c54f35caSApple OSS Distributions  */
53*c54f35caSApple OSS Distributions void
url_decode(char * str)54*c54f35caSApple OSS Distributions url_decode(char *str)
55*c54f35caSApple OSS Distributions {
56*c54f35caSApple OSS Distributions 	if (!str) {
57*c54f35caSApple OSS Distributions 		return;
58*c54f35caSApple OSS Distributions 	}
59*c54f35caSApple OSS Distributions 
60*c54f35caSApple OSS Distributions 	while (*str) {
61*c54f35caSApple OSS Distributions 		if (*str == '%') {
62*c54f35caSApple OSS Distributions 			char c = 0;
63*c54f35caSApple OSS Distributions 			char *esc = str++; /* remember the start of the escape sequence */
64*c54f35caSApple OSS Distributions 
65*c54f35caSApple OSS Distributions 			if (*str) {
66*c54f35caSApple OSS Distributions 				c += hex2int(*str++);
67*c54f35caSApple OSS Distributions 			}
68*c54f35caSApple OSS Distributions 			if (*str) {
69*c54f35caSApple OSS Distributions 				c = (char)((c << 4) + hex2int(*str++));
70*c54f35caSApple OSS Distributions 			}
71*c54f35caSApple OSS Distributions 
72*c54f35caSApple OSS Distributions 			if (isprint(c)) {
73*c54f35caSApple OSS Distributions 				/* overwrite the '%' with the new char, and bump the rest of the
74*c54f35caSApple OSS Distributions 				 * string down a few characters */
75*c54f35caSApple OSS Distributions 				*esc++ = c;
76*c54f35caSApple OSS Distributions 				str = memmove(esc, str, strlen(str) + 1);
77*c54f35caSApple OSS Distributions 			}
78*c54f35caSApple OSS Distributions 		} else {
79*c54f35caSApple OSS Distributions 			str++;
80*c54f35caSApple OSS Distributions 		}
81*c54f35caSApple OSS Distributions 	}
82*c54f35caSApple OSS Distributions }
83