Annotation of embedaddon/curl/lib/escape.c, revision 1.1.1.1

1.1       misho       1: /***************************************************************************
                      2:  *                                  _   _ ____  _
                      3:  *  Project                     ___| | | |  _ \| |
                      4:  *                             / __| | | | |_) | |
                      5:  *                            | (__| |_| |  _ <| |___
                      6:  *                             \___|\___/|_| \_\_____|
                      7:  *
                      8:  * Copyright (C) 1998 - 2018, 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 https://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 "curl_setup.h"
                     27: 
                     28: #include <curl/curl.h>
                     29: 
                     30: #include "urldata.h"
                     31: #include "warnless.h"
                     32: #include "non-ascii.h"
                     33: #include "escape.h"
                     34: #include "strdup.h"
                     35: /* The last 3 #include files should be in this order */
                     36: #include "curl_printf.h"
                     37: #include "curl_memory.h"
                     38: #include "memdebug.h"
                     39: 
                     40: /* Portable character check (remember EBCDIC). Do not use isalnum() because
                     41:    its behavior is altered by the current locale.
                     42:    See https://tools.ietf.org/html/rfc3986#section-2.3
                     43: */
                     44: bool Curl_isunreserved(unsigned char in)
                     45: {
                     46:   switch(in) {
                     47:     case '0': case '1': case '2': case '3': case '4':
                     48:     case '5': case '6': case '7': case '8': case '9':
                     49:     case 'a': case 'b': case 'c': case 'd': case 'e':
                     50:     case 'f': case 'g': case 'h': case 'i': case 'j':
                     51:     case 'k': case 'l': case 'm': case 'n': case 'o':
                     52:     case 'p': case 'q': case 'r': case 's': case 't':
                     53:     case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
                     54:     case 'A': case 'B': case 'C': case 'D': case 'E':
                     55:     case 'F': case 'G': case 'H': case 'I': case 'J':
                     56:     case 'K': case 'L': case 'M': case 'N': case 'O':
                     57:     case 'P': case 'Q': case 'R': case 'S': case 'T':
                     58:     case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
                     59:     case '-': case '.': case '_': case '~':
                     60:       return TRUE;
                     61:     default:
                     62:       break;
                     63:   }
                     64:   return FALSE;
                     65: }
                     66: 
                     67: /* for ABI-compatibility with previous versions */
                     68: char *curl_escape(const char *string, int inlength)
                     69: {
                     70:   return curl_easy_escape(NULL, string, inlength);
                     71: }
                     72: 
                     73: /* for ABI-compatibility with previous versions */
                     74: char *curl_unescape(const char *string, int length)
                     75: {
                     76:   return curl_easy_unescape(NULL, string, length, NULL);
                     77: }
                     78: 
                     79: char *curl_easy_escape(struct Curl_easy *data, const char *string,
                     80:                        int inlength)
                     81: {
                     82:   size_t alloc;
                     83:   char *ns;
                     84:   char *testing_ptr = NULL;
                     85:   size_t newlen;
                     86:   size_t strindex = 0;
                     87:   size_t length;
                     88:   CURLcode result;
                     89: 
                     90:   if(inlength < 0)
                     91:     return NULL;
                     92: 
                     93:   alloc = (inlength?(size_t)inlength:strlen(string)) + 1;
                     94:   newlen = alloc;
                     95: 
                     96:   ns = malloc(alloc);
                     97:   if(!ns)
                     98:     return NULL;
                     99: 
                    100:   length = alloc-1;
                    101:   while(length--) {
                    102:     unsigned char in = *string; /* we need to treat the characters unsigned */
                    103: 
                    104:     if(Curl_isunreserved(in))
                    105:       /* just copy this */
                    106:       ns[strindex++] = in;
                    107:     else {
                    108:       /* encode it */
                    109:       newlen += 2; /* the size grows with two, since this'll become a %XX */
                    110:       if(newlen > alloc) {
                    111:         alloc *= 2;
                    112:         testing_ptr = Curl_saferealloc(ns, alloc);
                    113:         if(!testing_ptr)
                    114:           return NULL;
                    115:         ns = testing_ptr;
                    116:       }
                    117: 
                    118:       result = Curl_convert_to_network(data, (char *)&in, 1);
                    119:       if(result) {
                    120:         /* Curl_convert_to_network calls failf if unsuccessful */
                    121:         free(ns);
                    122:         return NULL;
                    123:       }
                    124: 
                    125:       msnprintf(&ns[strindex], 4, "%%%02X", in);
                    126: 
                    127:       strindex += 3;
                    128:     }
                    129:     string++;
                    130:   }
                    131:   ns[strindex] = 0; /* terminate it */
                    132:   return ns;
                    133: }
                    134: 
                    135: /*
                    136:  * Curl_urldecode() URL decodes the given string.
                    137:  *
                    138:  * Optionally detects control characters (byte codes lower than 32) in the
                    139:  * data and rejects such data.
                    140:  *
                    141:  * Returns a pointer to a malloced string in *ostring with length given in
                    142:  * *olen. If length == 0, the length is assumed to be strlen(string).
                    143:  *
                    144:  * 'data' can be set to NULL but then this function can't convert network
                    145:  * data to host for non-ascii.
                    146:  */
                    147: CURLcode Curl_urldecode(struct Curl_easy *data,
                    148:                         const char *string, size_t length,
                    149:                         char **ostring, size_t *olen,
                    150:                         bool reject_ctrl)
                    151: {
                    152:   size_t alloc = (length?length:strlen(string)) + 1;
                    153:   char *ns = malloc(alloc);
                    154:   size_t strindex = 0;
                    155:   unsigned long hex;
                    156:   CURLcode result = CURLE_OK;
                    157: 
                    158:   if(!ns)
                    159:     return CURLE_OUT_OF_MEMORY;
                    160: 
                    161:   while(--alloc > 0) {
                    162:     unsigned char in = *string;
                    163:     if(('%' == in) && (alloc > 2) &&
                    164:        ISXDIGIT(string[1]) && ISXDIGIT(string[2])) {
                    165:       /* this is two hexadecimal digits following a '%' */
                    166:       char hexstr[3];
                    167:       char *ptr;
                    168:       hexstr[0] = string[1];
                    169:       hexstr[1] = string[2];
                    170:       hexstr[2] = 0;
                    171: 
                    172:       hex = strtoul(hexstr, &ptr, 16);
                    173: 
                    174:       in = curlx_ultouc(hex); /* this long is never bigger than 255 anyway */
                    175: 
                    176:       if(data) {
                    177:         result = Curl_convert_from_network(data, (char *)&in, 1);
                    178:         if(result) {
                    179:           /* Curl_convert_from_network calls failf if unsuccessful */
                    180:           free(ns);
                    181:           return result;
                    182:         }
                    183:       }
                    184: 
                    185:       string += 2;
                    186:       alloc -= 2;
                    187:     }
                    188: 
                    189:     if(reject_ctrl && (in < 0x20)) {
                    190:       free(ns);
                    191:       return CURLE_URL_MALFORMAT;
                    192:     }
                    193: 
                    194:     ns[strindex++] = in;
                    195:     string++;
                    196:   }
                    197:   ns[strindex] = 0; /* terminate it */
                    198: 
                    199:   if(olen)
                    200:     /* store output size */
                    201:     *olen = strindex;
                    202: 
                    203:   /* store output string */
                    204:   *ostring = ns;
                    205: 
                    206:   return CURLE_OK;
                    207: }
                    208: 
                    209: /*
                    210:  * Unescapes the given URL escaped string of given length. Returns a
                    211:  * pointer to a malloced string with length given in *olen.
                    212:  * If length == 0, the length is assumed to be strlen(string).
                    213:  * If olen == NULL, no output length is stored.
                    214:  */
                    215: char *curl_easy_unescape(struct Curl_easy *data, const char *string,
                    216:                          int length, int *olen)
                    217: {
                    218:   char *str = NULL;
                    219:   if(length >= 0) {
                    220:     size_t inputlen = length;
                    221:     size_t outputlen;
                    222:     CURLcode res = Curl_urldecode(data, string, inputlen, &str, &outputlen,
                    223:                                   FALSE);
                    224:     if(res)
                    225:       return NULL;
                    226: 
                    227:     if(olen) {
                    228:       if(outputlen <= (size_t) INT_MAX)
                    229:         *olen = curlx_uztosi(outputlen);
                    230:       else
                    231:         /* too large to return in an int, fail! */
                    232:         Curl_safefree(str);
                    233:     }
                    234:   }
                    235:   return str;
                    236: }
                    237: 
                    238: /* For operating systems/environments that use different malloc/free
                    239:    systems for the app and for this library, we provide a free that uses
                    240:    the library's memory system */
                    241: void curl_free(void *p)
                    242: {
                    243:   free(p);
                    244: }

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