1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23/* Escape and unescape URL encoding in strings. The functions return a new
24 * allocated string or NULL if an error occurred.  */
25
26#include "setup.h"
27
28#include <curl/curl.h>
29
30#include "curl_memory.h"
31#include "urldata.h"
32#include "warnless.h"
33#include "non-ascii.h"
34
35#define _MPRINTF_REPLACE /* use our functions only */
36#include <curl/mprintf.h>
37
38/* The last #include file should be: */
39#include "memdebug.h"
40
41/* Portable character check (remember EBCDIC). Do not use isalnum() because
42   its behavior is altered by the current locale.
43   See http://tools.ietf.org/html/rfc3986#section-2.3
44*/
45static bool Curl_isunreserved(unsigned char in)
46{
47  switch (in) {
48    case '0': case '1': case '2': case '3': case '4':
49    case '5': case '6': case '7': case '8': case '9':
50    case 'a': case 'b': case 'c': case 'd': case 'e':
51    case 'f': case 'g': case 'h': case 'i': case 'j':
52    case 'k': case 'l': case 'm': case 'n': case 'o':
53    case 'p': case 'q': case 'r': case 's': case 't':
54    case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
55    case 'A': case 'B': case 'C': case 'D': case 'E':
56    case 'F': case 'G': case 'H': case 'I': case 'J':
57    case 'K': case 'L': case 'M': case 'N': case 'O':
58    case 'P': case 'Q': case 'R': case 'S': case 'T':
59    case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
60    case '-': case '.': case '_': case '~':
61      return TRUE;
62    default:
63      break;
64  }
65  return FALSE;
66}
67
68/* for ABI-compatibility with previous versions */
69char *curl_escape(const char *string, int inlength)
70{
71  return curl_easy_escape(NULL, string, inlength);
72}
73
74/* for ABI-compatibility with previous versions */
75char *curl_unescape(const char *string, int length)
76{
77  return curl_easy_unescape(NULL, string, length, NULL);
78}
79
80char *curl_easy_escape(CURL *handle, const char *string, int inlength)
81{
82  size_t alloc = (inlength?(size_t)inlength:strlen(string))+1;
83  char *ns;
84  char *testing_ptr = NULL;
85  unsigned char in; /* we need to treat the characters unsigned */
86  size_t newlen = alloc;
87  int strindex=0;
88  size_t length;
89  CURLcode res;
90
91  ns = malloc(alloc);
92  if(!ns)
93    return NULL;
94
95  length = alloc-1;
96  while(length--) {
97    in = *string;
98
99    if(Curl_isunreserved(in))
100      /* just copy this */
101      ns[strindex++]=in;
102    else {
103      /* encode it */
104      newlen += 2; /* the size grows with two, since this'll become a %XX */
105      if(newlen > alloc) {
106        alloc *= 2;
107        testing_ptr = realloc(ns, alloc);
108        if(!testing_ptr) {
109          free( ns );
110          return NULL;
111        }
112        else {
113          ns = testing_ptr;
114        }
115      }
116
117      res = Curl_convert_to_network(handle, &in, 1);
118      if(res) {
119        /* Curl_convert_to_network calls failf if unsuccessful */
120        free(ns);
121        return NULL;
122      }
123
124      snprintf(&ns[strindex], 4, "%%%02X", in);
125
126      strindex+=3;
127    }
128    string++;
129  }
130  ns[strindex]=0; /* terminate it */
131  return ns;
132}
133
134/*
135 * Unescapes the given URL escaped string of given length. Returns a
136 * pointer to a malloced string with length given in *olen.
137 * If length == 0, the length is assumed to be strlen(string).
138 * If olen == NULL, no output length is stored.
139 */
140char *curl_easy_unescape(CURL *handle, const char *string, int length,
141                         int *olen)
142{
143  int alloc = (length?length:(int)strlen(string))+1;
144  char *ns = malloc(alloc);
145  unsigned char in;
146  int strindex=0;
147  unsigned long hex;
148  CURLcode res;
149
150  if(!ns)
151    return NULL;
152
153  while(--alloc > 0) {
154    in = *string;
155    if(('%' == in) && ISXDIGIT(string[1]) && ISXDIGIT(string[2])) {
156      /* this is two hexadecimal digits following a '%' */
157      char hexstr[3];
158      char *ptr;
159      hexstr[0] = string[1];
160      hexstr[1] = string[2];
161      hexstr[2] = 0;
162
163      hex = strtoul(hexstr, &ptr, 16);
164
165      in = curlx_ultouc(hex); /* this long is never bigger than 255 anyway */
166
167      res = Curl_convert_from_network(handle, &in, 1);
168      if(res) {
169        /* Curl_convert_from_network calls failf if unsuccessful */
170        free(ns);
171        return NULL;
172      }
173
174      string+=2;
175      alloc-=2;
176    }
177
178    ns[strindex++] = in;
179    string++;
180  }
181  ns[strindex]=0; /* terminate it */
182
183  if(olen)
184    /* store output size */
185    *olen = strindex;
186  return ns;
187}
188
189/* For operating systems/environments that use different malloc/free
190   systems for the app and for this library, we provide a free that uses
191   the library's memory system */
192void curl_free(void *p)
193{
194  if(p)
195    free(p);
196}
197