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