Utilities/cmcurl/escape.c

   1 /***************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * Copyright (C) 1998 - 2006, 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  * $Id: escape.c,v 1.2 2007-03-15 19:22:13 andy Exp $
  22  ***************************************************************************/
  23
  24 /* Escape and unescape URL encoding in strings. The functions return a new
  25  * allocated string or NULL if an error occurred.  */
  26
  27 #include "setup.h"
  28 #include <ctype.h>
  29 #include <curl/curl.h>
  30
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include "memory.h"
  35 /* urldata.h and easyif.h are included for Curl_convert_... prototypes */
  36 #include "urldata.h"
  37 #include "easyif.h"
  38
  39 #define _MPRINTF_REPLACE /* use our functions only */
  40 #include <curl/mprintf.h>
  41
  42 /* The last #include file should be: */
  43 #include "memdebug.h"
  44
  45 /* for ABI-compatibility with previous versions */
  46 char *curl_escape(const char *string, int inlength)
  47 {
  48   return curl_easy_escape(NULL, string, inlength);
  49 }
  50
  51 /* for ABI-compatibility with previous versions */
  52 char *curl_unescape(const char *string, int length)
  53 {
  54   return curl_easy_unescape(NULL, string, length, NULL);
  55 }
  56
  57 char *curl_easy_escape(CURL *handle, const char *string, int inlength)
  58 {
  59   size_t alloc = (inlength?(size_t)inlength:strlen(string))+1;
  60   char *ns;
  61   char *testing_ptr = NULL;
  62   unsigned char in;
  63   size_t newlen = alloc;
  64   int strindex=0;
  65   size_t length;
  66
  67 #ifndef CURL_DOES_CONVERSIONS
  68   /* avoid compiler warnings */
  69   (void)handle;
  70 #endif
  71   ns = malloc(alloc);
  72   if(!ns)
  73     return NULL;
  74
  75   length = alloc-1;
  76   while(length--) {
  77     in = *string;
  78     if(!(in >= 'a' && in <= 'z') &&
  79        !(in >= 'A' && in <= 'Z') &&
  80        !(in >= '0' && in <= '9')) {
  81       /* encode it */
  82       newlen += 2; /* the size grows with two, since this'll become a %XX */
  83       if(newlen > alloc) {
  84         alloc *= 2;
  85         testing_ptr = realloc(ns, alloc);
  86         if(!testing_ptr) {
  87           free( ns );
  88           return NULL;
  89         }
  90         else {
  91           ns = testing_ptr;
  92         }
  93       }
  94
  95 #ifdef CURL_DOES_CONVERSIONS
  96 /* escape sequences are always in ASCII so convert them on non-ASCII hosts */
  97       if (!handle ||
  98           (Curl_convert_to_network(handle, &in, 1) != CURLE_OK)) {
  99         /* Curl_convert_to_network calls failf if unsuccessful */
 100         free(ns);
 101         return NULL;
 102       }
 103 #endif /* CURL_DOES_CONVERSIONS */
 104
 105       snprintf(&ns[strindex], 4, "%%%02X", in);
 106
 107       strindex+=3;
 108     }
 109     else {
 110       /* just copy this */
 111       ns[strindex++]=in;
 112     }
 113     string++;
 114   }
 115   ns[strindex]=0; /* terminate it */
 116   return ns;
 117 }
 118
 119 char *curl_easy_unescape(CURL *handle, const char *string, int length,
 120                          int *olen)
 121 {
 122   int alloc = (length?length:(int)strlen(string))+1;
 123   char *ns = malloc(alloc);
 124   unsigned char in;
 125   int strindex=0;
 126   long hex;
 127
 128 #ifndef CURL_DOES_CONVERSIONS
 129   /* avoid compiler warnings */
 130   (void)handle;
 131 #endif
 132   if( !ns )
 133     return NULL;
 134
 135   while(--alloc > 0) {
 136     in = *string;
 137     if(('%' == in) && ISXDIGIT(string[1]) && ISXDIGIT(string[2])) {
 138       /* this is two hexadecimal digits following a '%' */
 139       char hexstr[3];
 140       char *ptr;
 141       hexstr[0] = string[1];
 142       hexstr[1] = string[2];
 143       hexstr[2] = 0;
 144
 145       hex = strtol(hexstr, &ptr, 16);
 146
 147       in = (unsigned char)hex; /* this long is never bigger than 255 anyway */
 148
 149 #ifdef CURL_DOES_CONVERSIONS
 150 /* escape sequences are always in ASCII so convert them on non-ASCII hosts */
 151       if (!handle ||
 152           (Curl_convert_from_network(handle, &in, 1) != CURLE_OK)) {
 153         /* Curl_convert_from_network calls failf if unsuccessful */
 154         free(ns);
 155         return NULL;
 156       }
 157 #endif /* CURL_DOES_CONVERSIONS */
 158
 159       string+=2;
 160       alloc-=2;
 161     }
 162
 163     ns[strindex++] = in;
 164     string++;
 165   }
 166   ns[strindex]=0; /* terminate it */
 167
 168   if(olen)
 169     /* store output size */
 170     *olen = strindex;
 171   return ns;
 172 }
 173
 174 /* For operating systems/environments that use different malloc/free
 175    ssystems for the app and for this library, we provide a free that uses
 176    the library's memory system */
 177 void curl_free(void *p)
 178 {
 179   if(p)
 180     free(p);
 181 }