1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
/*
* Functions for RFC 3986 percent-encoding.
*
* NOTE:
*
* This file was originally imported from the Squid project but has been
* significantly altered. The licence below is reproduced intact, but refers
* to files in Squid's repository, not in Samba. See COPYING for the GPLv3
* notice (being the later version mentioned below).
*/
/*
* $Id$
*
* DEBUG:
* AUTHOR: Harvest Derived
*
* SQUID Web Proxy Cache http://www.squid-cache.org/
* ----------------------------------------------------------
*
* Squid is the result of efforts by numerous individuals from
* the Internet community; see the CONTRIBUTORS file for full
* details. Many organizations have provided support for Squid's
* development; see the SPONSORS file for full details. Squid is
* Copyrighted (C) 2001 by the Regents of the University of
* California; see the COPYRIGHT file for full details. Squid
* incorporates software developed and/or copyrighted by other
* sources; see the CREDITS file for full details.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
*
*/
#include "replace.h"
#include <talloc.h>
#include "lib/util/samba_util.h"
#define RFC1738_ENCODE 1
#define RFC1738_RESERVED 2
/*
* According to RFC 1738, "$-_.+!*'()," are not reserved or unsafe, but as
* that has been obsolete since 2004, we sm instead for RFC 3986, where:
*
* reserved = : / ? # [ ] @ ! $ & ' ( ) * + , ; =
* unreserved = ALPHA DIGIT - . _ ~
*
* and whatever is not in either of those are what RFC 1738 called "unsafe",
* meaning that they should are canonically but not mandatorily escaped.
*
* Characters below 0x20 or above 0x7E are always encoded.
*/
static const unsigned char escapees[127] = {
[' '] = RFC1738_ENCODE,
['"'] = RFC1738_ENCODE,
['%'] = RFC1738_ENCODE,
['<'] = RFC1738_ENCODE,
['>'] = RFC1738_ENCODE,
['\\'] = RFC1738_ENCODE,
['^'] = RFC1738_ENCODE,
['`'] = RFC1738_ENCODE,
['{'] = RFC1738_ENCODE,
['|'] = RFC1738_ENCODE,
['}'] = RFC1738_ENCODE,
/* reserved : / ? # [ ] @ ! $ & ' ( ) * + , ; = */
[':'] = RFC1738_RESERVED,
['/'] = RFC1738_RESERVED,
['?'] = RFC1738_RESERVED,
['#'] = RFC1738_RESERVED,
['['] = RFC1738_RESERVED,
[']'] = RFC1738_RESERVED,
['@'] = RFC1738_RESERVED,
['!'] = RFC1738_RESERVED,
['$'] = RFC1738_RESERVED,
['&'] = RFC1738_RESERVED,
['\''] = RFC1738_RESERVED,
['('] = RFC1738_RESERVED,
[')'] = RFC1738_RESERVED,
['*'] = RFC1738_RESERVED,
['+'] = RFC1738_RESERVED,
[','] = RFC1738_RESERVED,
[';'] = RFC1738_RESERVED,
['='] = RFC1738_RESERVED,
};
/*
* rfc1738_do_escape - fills a preallocated buffer with an escaped version of
* the given string.
*
* For canonical escaping, mask should be RFC1738_ENCODE | RFC1738_RESERVED.
* For mandatory escaping, mask should be RFC1738_RESERVED.
*/
static char *
rfc1738_do_escape(char *buf, size_t bufsize,
const char *url, size_t len, unsigned char mask)
{
size_t i;
size_t j = 0;
for (i = 0; i < len; i++) {
unsigned int c = (unsigned char) url[i];
if (c > 126 || c < 32 || (escapees[c] & mask)) {
if (j + 3 >= bufsize) {
return NULL;
}
(void) snprintf(&buf[j], 4, "%%%02X", c);
j += 3;
} else {
if (j + 1 >= bufsize) {
return NULL;
}
buf[j] = c;
j++;
}
}
buf[j] = '\0';
return buf;
}
/*
* rfc1738_escape_part - Returns a talloced buffer that contains the RFC 3986
* compliant, escaped version of the given url segment.
*/
char *
rfc1738_escape_part(TALLOC_CTX *mem_ctx, const char *url)
{
size_t bufsize = 0;
char *buf = NULL;
size_t len = strlen(url);
if (len >= SIZE_MAX / 3) {
return NULL;
}
bufsize = len * 3 + 1;
buf = talloc_array(mem_ctx, char, bufsize);
if (buf == NULL) {
return NULL;
}
talloc_set_name_const(buf, buf);
return rfc1738_do_escape(buf, bufsize, url, len,
RFC1738_ENCODE | RFC1738_RESERVED);
}
/*
* rfc1738_unescape() - Converts url-escaped characters in the string.
*
* The two characters following a '%' in a string should be hex digits that
* describe an encoded byte. For example, "%25" is hex 0x25 or '%' in ASCII;
* this is the only way to include a % in the unescaped string. Any character
* can be escaped, including plain letters (e.g. "%61" for "a"). Anything
* other than 2 hex characters following the % is an error.
*
* The conversion is done in-place, which is always safe as unescapes can only
* shorten the string.
*
* Returns a pointer to the end of the string (that is, the '\0' byte), or
* NULL on error, at which point s is in an undefined state.
*
* Note that after `char *e = rfc_unescape(s)`, `strlen(s)` will not equal
* `e - s` if s originally contained "%00". You might want to check for this.
*/
_PUBLIC_ char *rfc1738_unescape(char *s)
{
size_t i, j; /* i is write, j is read */
for (i = 0, j = 0; s[j] != '\0'; i++, j++) {
if (s[j] == '%') {
uint8_t v;
bool ok;
ok = hex_byte(&s[j+1], &v);
if (!ok) {
return NULL;
}
j += 2; /* OK; hex_byte() has checked ahead */
s[i] = (unsigned char)v;
} else {
s[i] = s[j];
}
}
s[i] = '\0';
return s + i;
}
|
