xref: /xnu-11417.140.69/bsd/libkern/url_encode.c (revision 43a90889846e00bfb5cf1d255cdc0a701a1e05a4)
1*43a90889SApple OSS Distributions /*
2*43a90889SApple OSS Distributions  * Copyright (c) 2016 Apple Inc. All rights reserved.
3*43a90889SApple OSS Distributions  *
4*43a90889SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*43a90889SApple OSS Distributions  *
6*43a90889SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*43a90889SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*43a90889SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*43a90889SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*43a90889SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*43a90889SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*43a90889SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*43a90889SApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*43a90889SApple OSS Distributions  *
15*43a90889SApple OSS Distributions  * Please obtain a copy of the License at
16*43a90889SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*43a90889SApple OSS Distributions  *
18*43a90889SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*43a90889SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*43a90889SApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*43a90889SApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*43a90889SApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*43a90889SApple OSS Distributions  * Please see the License for the specific language governing rights and
24*43a90889SApple OSS Distributions  * limitations under the License.
25*43a90889SApple OSS Distributions  *
26*43a90889SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*43a90889SApple OSS Distributions  */
28*43a90889SApple OSS Distributions 
29*43a90889SApple OSS Distributions #include <libkern/libkern.h>
30*43a90889SApple OSS Distributions 
31*43a90889SApple OSS Distributions static int
hex2int(int c)32*43a90889SApple OSS Distributions hex2int(int c)
33*43a90889SApple OSS Distributions {
34*43a90889SApple OSS Distributions 	if (c >= '0' && c <= '9') {
35*43a90889SApple OSS Distributions 		return c - '0';
36*43a90889SApple OSS Distributions 	} else if (c >= 'A' && c <= 'F') {
37*43a90889SApple OSS Distributions 		return c - 'A' + 10;
38*43a90889SApple OSS Distributions 	} else if (c >= 'a' && c <= 'f') {
39*43a90889SApple OSS Distributions 		return c - 'a' + 10;
40*43a90889SApple OSS Distributions 	}
41*43a90889SApple OSS Distributions 	return 0;
42*43a90889SApple OSS Distributions }
43*43a90889SApple OSS Distributions 
44*43a90889SApple OSS Distributions static bool
isprint(int ch)45*43a90889SApple OSS Distributions isprint(int ch)
46*43a90889SApple OSS Distributions {
47*43a90889SApple OSS Distributions 	return ch >= 0x20 && ch <= 0x7e;
48*43a90889SApple OSS Distributions }
49*43a90889SApple OSS Distributions 
50*43a90889SApple OSS Distributions /*
51*43a90889SApple OSS Distributions  * In-place decode of URL percent-encoded str
52*43a90889SApple OSS Distributions  */
53*43a90889SApple OSS Distributions void
url_decode(char * str)54*43a90889SApple OSS Distributions url_decode(char *str)
55*43a90889SApple OSS Distributions {
56*43a90889SApple OSS Distributions 	if (!str) {
57*43a90889SApple OSS Distributions 		return;
58*43a90889SApple OSS Distributions 	}
59*43a90889SApple OSS Distributions 
60*43a90889SApple OSS Distributions 	while (*str) {
61*43a90889SApple OSS Distributions 		if (*str == '%') {
62*43a90889SApple OSS Distributions 			char c = 0;
63*43a90889SApple OSS Distributions 			char *esc = str++; /* remember the start of the escape sequence */
64*43a90889SApple OSS Distributions 
65*43a90889SApple OSS Distributions 			if (*str) {
66*43a90889SApple OSS Distributions 				c += hex2int(*str++);
67*43a90889SApple OSS Distributions 			}
68*43a90889SApple OSS Distributions 			if (*str) {
69*43a90889SApple OSS Distributions 				c = (char)((c << 4) + hex2int(*str++));
70*43a90889SApple OSS Distributions 			}
71*43a90889SApple OSS Distributions 
72*43a90889SApple OSS Distributions 			if (isprint(c)) {
73*43a90889SApple OSS Distributions 				/* overwrite the '%' with the new char, and bump the rest of the
74*43a90889SApple OSS Distributions 				 * string down a few characters */
75*43a90889SApple OSS Distributions 				*esc++ = c;
76*43a90889SApple OSS Distributions 				str = memmove(esc, str, strlen(str) + 1);
77*43a90889SApple OSS Distributions 			}
78*43a90889SApple OSS Distributions 		} else {
79*43a90889SApple OSS Distributions 			str++;
80*43a90889SApple OSS Distributions 		}
81*43a90889SApple OSS Distributions 	}
82*43a90889SApple OSS Distributions }
83