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
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
/* Escape and unescape URL encoding in strings. The functions return a new
* allocated string or NULL if an error occurred. */
#include "curl_setup.h"
#include <curl/curl.h>
#include "urldata.h"
#include "warnless.h"
#include "escape.h"
#include "strdup.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
/* Portable character check (remember EBCDIC). Do not use isalnum() because
its behavior is altered by the current locale.
See https://datatracker.ietf.org/doc/html/rfc3986#section-2.3
*/
bool Curl_isunreserved(unsigned char in)
{
switch(in) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
case 'a': case 'b': case 'c': case 'd': case 'e':
case 'f': case 'g': case 'h': case 'i': case 'j':
case 'k': case 'l': case 'm': case 'n': case 'o':
case 'p': case 'q': case 'r': case 's': case 't':
case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
case 'A': case 'B': case 'C': case 'D': case 'E':
case 'F': case 'G': case 'H': case 'I': case 'J':
case 'K': case 'L': case 'M': case 'N': case 'O':
case 'P': case 'Q': case 'R': case 'S': case 'T':
case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
case '-': case '.': case '_': case '~':
return TRUE;
default:
break;
}
return FALSE;
}
/* for ABI-compatibility with previous versions */
char *curl_escape(const char *string, int inlength)
{
return curl_easy_escape(NULL, string, inlength);
}
/* for ABI-compatibility with previous versions */
char *curl_unescape(const char *string, int length)
{
return curl_easy_unescape(NULL, string, length, NULL);
}
/* Escapes for URL the given unescaped string of given length.
* 'data' is ignored since 7.82.0.
*/
char *curl_easy_escape(struct Curl_easy *data, const char *string,
int inlength)
{
size_t length;
struct dynbuf d;
(void)data;
if(inlength < 0)
return NULL;
Curl_dyn_init(&d, CURL_MAX_INPUT_LENGTH * 3);
length = (inlength?(size_t)inlength:strlen(string));
if(!length)
return strdup("");
while(length--) {
unsigned char in = *string; /* we need to treat the characters unsigned */
if(Curl_isunreserved(in)) {
/* append this */
if(Curl_dyn_addn(&d, &in, 1))
return NULL;
}
else {
/* encode it */
if(Curl_dyn_addf(&d, "%%%02X", in))
return NULL;
}
string++;
}
return Curl_dyn_ptr(&d);
}
/*
* Curl_urldecode() URL decodes the given string.
*
* Returns a pointer to a malloced string in *ostring with length given in
* *olen. If length == 0, the length is assumed to be strlen(string).
*
* ctrl options:
* - REJECT_NADA: accept everything
* - REJECT_CTRL: rejects control characters (byte codes lower than 32) in
* the data
* - REJECT_ZERO: rejects decoded zero bytes
*
* The values for the enum starts at 2, to make the assert detect legacy
* invokes that used TRUE/FALSE (0 and 1).
*/
CURLcode Curl_urldecode(const char *string, size_t length,
char **ostring, size_t *olen,
enum urlreject ctrl)
{
size_t alloc;
char *ns;
size_t strindex = 0;
unsigned long hex;
DEBUGASSERT(string);
DEBUGASSERT(ctrl >= REJECT_NADA); /* crash on TRUE/FALSE */
alloc = (length?length:strlen(string)) + 1;
ns = malloc(alloc);
if(!ns)
return CURLE_OUT_OF_MEMORY;
while(--alloc > 0) {
unsigned char in = *string;
if(('%' == in) && (alloc > 2) &&
ISXDIGIT(string[1]) && ISXDIGIT(string[2])) {
/* this is two hexadecimal digits following a '%' */
char hexstr[3];
char *ptr;
hexstr[0] = string[1];
hexstr[1] = string[2];
hexstr[2] = 0;
hex = strtoul(hexstr, &ptr, 16);
in = curlx_ultouc(hex); /* this long is never bigger than 255 anyway */
string += 2;
alloc -= 2;
}
if(((ctrl == REJECT_CTRL) && (in < 0x20)) ||
((ctrl == REJECT_ZERO) && (in == 0))) {
free(ns);
return CURLE_URL_MALFORMAT;
}
ns[strindex++] = in;
string++;
}
ns[strindex] = 0; /* terminate it */
if(olen)
/* store output size */
*olen = strindex;
/* store output string */
*ostring = ns;
return CURLE_OK;
}
/*
* Unescapes the given URL escaped string of given length. Returns a
* pointer to a malloced string with length given in *olen.
* If length == 0, the length is assumed to be strlen(string).
* If olen == NULL, no output length is stored.
* 'data' is ignored since 7.82.0.
*/
char *curl_easy_unescape(struct Curl_easy *data, const char *string,
int length, int *olen)
{
char *str = NULL;
(void)data;
if(length >= 0) {
size_t inputlen = (size_t)length;
size_t outputlen;
CURLcode res = Curl_urldecode(string, inputlen, &str, &outputlen,
REJECT_NADA);
if(res)
return NULL;
if(olen) {
if(outputlen <= (size_t) INT_MAX)
*olen = curlx_uztosi(outputlen);
else
/* too large to return in an int, fail! */
Curl_safefree(str);
}
}
return str;
}
/* For operating systems/environments that use different malloc/free
systems for the app and for this library, we provide a free that uses
the library's memory system */
void curl_free(void *p)
{
free(p);
}
|
