summaryrefslogtreecommitdiff
path: root/lib/escape.c
blob: 9552b0f31652eef663eecf704baaa9f5d3f63655 (plain)
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
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2006, 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 http://curl.haxx.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.
 *
 * $Id$
 ***************************************************************************/

/* Escape and unescape URL encoding in strings. The functions return a new
 * allocated string or NULL if an error occurred.  */

#include "setup.h"
#include <ctype.h>
#include <curl/curl.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "memory.h"
/* urldata.h and easyif.h are included for Curl_convert_... prototypes */
#include "urldata.h"
#include "easyif.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

/* The last #include file should be: */
#include "memdebug.h"

/* 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);
}

char *curl_easy_escape(CURL *handle, const char *string, int inlength)
{
  size_t alloc = (inlength?(size_t)inlength:strlen(string))+1;
  char *ns;
  char *testing_ptr = NULL;
  unsigned char in;
  size_t newlen = alloc;
  int strindex=0;
  size_t length;

#ifndef CURL_DOES_CONVERSIONS
  /* avoid compiler warnings */
  (void)handle;
#endif
  ns = malloc(alloc);
  if(!ns)
    return NULL;

  length = alloc-1;
  while(length--) {
    in = *string;
    if(!(in >= 'a' && in <= 'z') &&
       !(in >= 'A' && in <= 'Z') &&
       !(in >= '0' && in <= '9')) {
      /* encode it */
      newlen += 2; /* the size grows with two, since this'll become a %XX */
      if(newlen > alloc) {
        alloc *= 2;
        testing_ptr = realloc(ns, alloc);
        if(!testing_ptr) {
          free( ns );
          return NULL;
        }
        else {
          ns = testing_ptr;
        }
      }

#ifdef CURL_DOES_CONVERSIONS
/* escape sequences are always in ASCII so convert them on non-ASCII hosts */
      if (!handle ||
          (Curl_convert_to_network(handle, &in, 1) != CURLE_OK)) {
        /* Curl_convert_to_network calls failf if unsuccessful */
        free(ns);
        return NULL;
      }
#endif /* CURL_DOES_CONVERSIONS */

      snprintf(&ns[strindex], 4, "%%%02X", in);

      strindex+=3;
    }
    else {
      /* just copy this */
      ns[strindex++]=in;
    }
    string++;
  }
  ns[strindex]=0; /* terminate it */
  return ns;
}

char *curl_easy_unescape(CURL *handle, const char *string, int length,
                         int *olen)
{
  int alloc = (length?length:(int)strlen(string))+1;
  char *ns = malloc(alloc);
  unsigned char in;
  int strindex=0;
  long hex;

#ifndef CURL_DOES_CONVERSIONS
  /* avoid compiler warnings */
  (void)handle;
#endif
  if( !ns )
    return NULL;

  while(--alloc > 0) {
    in = *string;
    if(('%' == in) && 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 = strtol(hexstr, &ptr, 16);

      in = (unsigned char)hex; /* this long is never bigger than 255 anyway */

#ifdef CURL_DOES_CONVERSIONS
/* escape sequences are always in ASCII so convert them on non-ASCII hosts */
      if (!handle ||
          (Curl_convert_from_network(handle, &in, 1) != CURLE_OK)) {
        /* Curl_convert_from_network calls failf if unsuccessful */
        free(ns);
        return NULL;
      }
#endif /* CURL_DOES_CONVERSIONS */

      string+=2;
      alloc-=2;
    }

    ns[strindex++] = in;
    string++;
  }
  ns[strindex]=0; /* terminate it */

  if(olen)
    /* store output size */
    *olen = strindex;
  return ns;
}

/* For operating systems/environments that use different malloc/free
   ssystems for the app and for this library, we provide a free that uses
   the library's memory system */
void curl_free(void *p)
{
  if(p)
    free(p);
}