xref: /xnu-10063.141.1/bsd/libkern/url_encode.c (revision d8b80295118ef25ac3a784134bcf95cd8e88109f)
1*d8b80295SApple OSS Distributions /*
2*d8b80295SApple OSS Distributions  * Copyright (c) 2016 Apple Inc. All rights reserved.
3*d8b80295SApple OSS Distributions  *
4*d8b80295SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*d8b80295SApple OSS Distributions  *
6*d8b80295SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*d8b80295SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*d8b80295SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*d8b80295SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*d8b80295SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*d8b80295SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*d8b80295SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*d8b80295SApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*d8b80295SApple OSS Distributions  *
15*d8b80295SApple OSS Distributions  * Please obtain a copy of the License at
16*d8b80295SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*d8b80295SApple OSS Distributions  *
18*d8b80295SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*d8b80295SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*d8b80295SApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*d8b80295SApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*d8b80295SApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*d8b80295SApple OSS Distributions  * Please see the License for the specific language governing rights and
24*d8b80295SApple OSS Distributions  * limitations under the License.
25*d8b80295SApple OSS Distributions  *
26*d8b80295SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*d8b80295SApple OSS Distributions  */
28*d8b80295SApple OSS Distributions 
29*d8b80295SApple OSS Distributions #include <libkern/libkern.h>
30*d8b80295SApple OSS Distributions 
31*d8b80295SApple OSS Distributions static int
hex2int(int c)32*d8b80295SApple OSS Distributions hex2int(int c)
33*d8b80295SApple OSS Distributions {
34*d8b80295SApple OSS Distributions 	if (c >= '0' && c <= '9') {
35*d8b80295SApple OSS Distributions 		return c - '0';
36*d8b80295SApple OSS Distributions 	} else if (c >= 'A' && c <= 'F') {
37*d8b80295SApple OSS Distributions 		return c - 'A' + 10;
38*d8b80295SApple OSS Distributions 	} else if (c >= 'a' && c <= 'f') {
39*d8b80295SApple OSS Distributions 		return c - 'a' + 10;
40*d8b80295SApple OSS Distributions 	}
41*d8b80295SApple OSS Distributions 	return 0;
42*d8b80295SApple OSS Distributions }
43*d8b80295SApple OSS Distributions 
44*d8b80295SApple OSS Distributions static bool
isprint(int ch)45*d8b80295SApple OSS Distributions isprint(int ch)
46*d8b80295SApple OSS Distributions {
47*d8b80295SApple OSS Distributions 	return ch >= 0x20 && ch <= 0x7e;
48*d8b80295SApple OSS Distributions }
49*d8b80295SApple OSS Distributions 
50*d8b80295SApple OSS Distributions /*
51*d8b80295SApple OSS Distributions  * In-place decode of URL percent-encoded str
52*d8b80295SApple OSS Distributions  */
53*d8b80295SApple OSS Distributions void
url_decode(char * str)54*d8b80295SApple OSS Distributions url_decode(char *str)
55*d8b80295SApple OSS Distributions {
56*d8b80295SApple OSS Distributions 	if (!str) {
57*d8b80295SApple OSS Distributions 		return;
58*d8b80295SApple OSS Distributions 	}
59*d8b80295SApple OSS Distributions 
60*d8b80295SApple OSS Distributions 	while (*str) {
61*d8b80295SApple OSS Distributions 		if (*str == '%') {
62*d8b80295SApple OSS Distributions 			char c = 0;
63*d8b80295SApple OSS Distributions 			char *esc = str++; /* remember the start of the escape sequence */
64*d8b80295SApple OSS Distributions 
65*d8b80295SApple OSS Distributions 			if (*str) {
66*d8b80295SApple OSS Distributions 				c += hex2int(*str++);
67*d8b80295SApple OSS Distributions 			}
68*d8b80295SApple OSS Distributions 			if (*str) {
69*d8b80295SApple OSS Distributions 				c = (char)((c << 4) + hex2int(*str++));
70*d8b80295SApple OSS Distributions 			}
71*d8b80295SApple OSS Distributions 
72*d8b80295SApple OSS Distributions 			if (isprint(c)) {
73*d8b80295SApple OSS Distributions 				/* overwrite the '%' with the new char, and bump the rest of the
74*d8b80295SApple OSS Distributions 				 * string down a few characters */
75*d8b80295SApple OSS Distributions 				*esc++ = c;
76*d8b80295SApple OSS Distributions 				str = memmove(esc, str, strlen(str) + 1);
77*d8b80295SApple OSS Distributions 			}
78*d8b80295SApple OSS Distributions 		} else {
79*d8b80295SApple OSS Distributions 			str++;
80*d8b80295SApple OSS Distributions 		}
81*d8b80295SApple OSS Distributions 	}
82*d8b80295SApple OSS Distributions }
83