xref: /xnu-10063.121.3/bsd/libkern/url_encode.c (revision 2c2f96dc2b9a4408a43d3150ae9c105355ca3daa)
1*2c2f96dcSApple OSS Distributions /*
2*2c2f96dcSApple OSS Distributions  * Copyright (c) 2016 Apple Inc. All rights reserved.
3*2c2f96dcSApple OSS Distributions  *
4*2c2f96dcSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*2c2f96dcSApple OSS Distributions  *
6*2c2f96dcSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*2c2f96dcSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*2c2f96dcSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*2c2f96dcSApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*2c2f96dcSApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*2c2f96dcSApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*2c2f96dcSApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*2c2f96dcSApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*2c2f96dcSApple OSS Distributions  *
15*2c2f96dcSApple OSS Distributions  * Please obtain a copy of the License at
16*2c2f96dcSApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*2c2f96dcSApple OSS Distributions  *
18*2c2f96dcSApple OSS Distributions  * The Original Code and all software distributed under the License are
19*2c2f96dcSApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*2c2f96dcSApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*2c2f96dcSApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*2c2f96dcSApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*2c2f96dcSApple OSS Distributions  * Please see the License for the specific language governing rights and
24*2c2f96dcSApple OSS Distributions  * limitations under the License.
25*2c2f96dcSApple OSS Distributions  *
26*2c2f96dcSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*2c2f96dcSApple OSS Distributions  */
28*2c2f96dcSApple OSS Distributions 
29*2c2f96dcSApple OSS Distributions #include <libkern/libkern.h>
30*2c2f96dcSApple OSS Distributions 
31*2c2f96dcSApple OSS Distributions static int
hex2int(int c)32*2c2f96dcSApple OSS Distributions hex2int(int c)
33*2c2f96dcSApple OSS Distributions {
34*2c2f96dcSApple OSS Distributions 	if (c >= '0' && c <= '9') {
35*2c2f96dcSApple OSS Distributions 		return c - '0';
36*2c2f96dcSApple OSS Distributions 	} else if (c >= 'A' && c <= 'F') {
37*2c2f96dcSApple OSS Distributions 		return c - 'A' + 10;
38*2c2f96dcSApple OSS Distributions 	} else if (c >= 'a' && c <= 'f') {
39*2c2f96dcSApple OSS Distributions 		return c - 'a' + 10;
40*2c2f96dcSApple OSS Distributions 	}
41*2c2f96dcSApple OSS Distributions 	return 0;
42*2c2f96dcSApple OSS Distributions }
43*2c2f96dcSApple OSS Distributions 
44*2c2f96dcSApple OSS Distributions static bool
isprint(int ch)45*2c2f96dcSApple OSS Distributions isprint(int ch)
46*2c2f96dcSApple OSS Distributions {
47*2c2f96dcSApple OSS Distributions 	return ch >= 0x20 && ch <= 0x7e;
48*2c2f96dcSApple OSS Distributions }
49*2c2f96dcSApple OSS Distributions 
50*2c2f96dcSApple OSS Distributions /*
51*2c2f96dcSApple OSS Distributions  * In-place decode of URL percent-encoded str
52*2c2f96dcSApple OSS Distributions  */
53*2c2f96dcSApple OSS Distributions void
url_decode(char * str)54*2c2f96dcSApple OSS Distributions url_decode(char *str)
55*2c2f96dcSApple OSS Distributions {
56*2c2f96dcSApple OSS Distributions 	if (!str) {
57*2c2f96dcSApple OSS Distributions 		return;
58*2c2f96dcSApple OSS Distributions 	}
59*2c2f96dcSApple OSS Distributions 
60*2c2f96dcSApple OSS Distributions 	while (*str) {
61*2c2f96dcSApple OSS Distributions 		if (*str == '%') {
62*2c2f96dcSApple OSS Distributions 			char c = 0;
63*2c2f96dcSApple OSS Distributions 			char *esc = str++; /* remember the start of the escape sequence */
64*2c2f96dcSApple OSS Distributions 
65*2c2f96dcSApple OSS Distributions 			if (*str) {
66*2c2f96dcSApple OSS Distributions 				c += hex2int(*str++);
67*2c2f96dcSApple OSS Distributions 			}
68*2c2f96dcSApple OSS Distributions 			if (*str) {
69*2c2f96dcSApple OSS Distributions 				c = (char)((c << 4) + hex2int(*str++));
70*2c2f96dcSApple OSS Distributions 			}
71*2c2f96dcSApple OSS Distributions 
72*2c2f96dcSApple OSS Distributions 			if (isprint(c)) {
73*2c2f96dcSApple OSS Distributions 				/* overwrite the '%' with the new char, and bump the rest of the
74*2c2f96dcSApple OSS Distributions 				 * string down a few characters */
75*2c2f96dcSApple OSS Distributions 				*esc++ = c;
76*2c2f96dcSApple OSS Distributions 				str = memmove(esc, str, strlen(str) + 1);
77*2c2f96dcSApple OSS Distributions 			}
78*2c2f96dcSApple OSS Distributions 		} else {
79*2c2f96dcSApple OSS Distributions 			str++;
80*2c2f96dcSApple OSS Distributions 		}
81*2c2f96dcSApple OSS Distributions 	}
82*2c2f96dcSApple OSS Distributions }
83