1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel (at) 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 /* The last 3 #include files should be in this order */ 35 #include "curl_printf.h" 36 #include "curl_memory.h" 37 #include "memdebug.h" 38 39 /* Portable character check (remember EBCDIC). Do not use isalnum() because 40 its behavior is altered by the current locale. 41 See https://tools.ietf.org/html/rfc3986#section-2.3 42 */ 43 static bool Curl_isunreserved(unsigned char in) 44 { 45 switch (in) { 46 case '0': case '1': case '2': case '3': case '4': 47 case '5': case '6': case '7': case '8': case '9': 48 case 'a': case 'b': case 'c': case 'd': case 'e': 49 case 'f': case 'g': case 'h': case 'i': case 'j': 50 case 'k': case 'l': case 'm': case 'n': case 'o': 51 case 'p': case 'q': case 'r': case 's': case 't': 52 case 'u': case 'v': case 'w': case 'x': case 'y': case 'z': 53 case 'A': case 'B': case 'C': case 'D': case 'E': 54 case 'F': case 'G': case 'H': case 'I': case 'J': 55 case 'K': case 'L': case 'M': case 'N': case 'O': 56 case 'P': case 'Q': case 'R': case 'S': case 'T': 57 case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z': 58 case '-': case '.': case '_': case '~': 59 return TRUE; 60 default: 61 break; 62 } 63 return FALSE; 64 } 65 66 /* for ABI-compatibility with previous versions */ 67 char *curl_escape(const char *string, int inlength) 68 { 69 return curl_easy_escape(NULL, string, inlength); 70 } 71 72 /* for ABI-compatibility with previous versions */ 73 char *curl_unescape(const char *string, int length) 74 { 75 return curl_easy_unescape(NULL, string, length, NULL); 76 } 77 78 char *curl_easy_escape(struct Curl_easy *data, const char *string, 79 int inlength) 80 { 81 size_t alloc = (inlength?(size_t)inlength:strlen(string))+1; 82 char *ns; 83 char *testing_ptr = NULL; 84 unsigned char in; /* we need to treat the characters unsigned */ 85 size_t newlen = alloc; 86 size_t strindex=0; 87 size_t length; 88 CURLcode result; 89 90 ns = malloc(alloc); 91 if(!ns) 92 return NULL; 93 94 length = alloc-1; 95 while(length--) { 96 in = *string; 97 98 if(Curl_isunreserved(in)) 99 /* just copy this */ 100 ns[strindex++]=in; 101 else { 102 /* encode it */ 103 newlen += 2; /* the size grows with two, since this'll become a %XX */ 104 if(newlen > alloc) { 105 alloc *= 2; 106 testing_ptr = realloc(ns, alloc); 107 if(!testing_ptr) { 108 free(ns); 109 return NULL; 110 } 111 else { 112 ns = testing_ptr; 113 } 114 } 115 116 result = Curl_convert_to_network(data, &in, 1); 117 if(result) { 118 /* Curl_convert_to_network calls failf if unsuccessful */ 119 free(ns); 120 return NULL; 121 } 122 123 snprintf(&ns[strindex], 4, "%%%02X", in); 124 125 strindex+=3; 126 } 127 string++; 128 } 129 ns[strindex]=0; /* terminate it */ 130 return ns; 131 } 132 133 /* 134 * Curl_urldecode() URL decodes the given string. 135 * 136 * Optionally detects control characters (byte codes lower than 32) in the 137 * data and rejects such data. 138 * 139 * Returns a pointer to a malloced string in *ostring with length given in 140 * *olen. If length == 0, the length is assumed to be strlen(string). 141 * 142 */ 143 CURLcode Curl_urldecode(struct Curl_easy *data, 144 const char *string, size_t length, 145 char **ostring, size_t *olen, 146 bool reject_ctrl) 147 { 148 size_t alloc = (length?length:strlen(string))+1; 149 char *ns = malloc(alloc); 150 unsigned char in; 151 size_t strindex=0; 152 unsigned long hex; 153 CURLcode result; 154 155 if(!ns) 156 return CURLE_OUT_OF_MEMORY; 157 158 while(--alloc > 0) { 159 in = *string; 160 if(('%' == in) && (alloc > 2) && 161 ISXDIGIT(string[1]) && ISXDIGIT(string[2])) { 162 /* this is two hexadecimal digits following a '%' */ 163 char hexstr[3]; 164 char *ptr; 165 hexstr[0] = string[1]; 166 hexstr[1] = string[2]; 167 hexstr[2] = 0; 168 169 hex = strtoul(hexstr, &ptr, 16); 170 171 in = curlx_ultouc(hex); /* this long is never bigger than 255 anyway */ 172 173 result = Curl_convert_from_network(data, &in, 1); 174 if(result) { 175 /* Curl_convert_from_network calls failf if unsuccessful */ 176 free(ns); 177 return result; 178 } 179 180 string+=2; 181 alloc-=2; 182 } 183 184 if(reject_ctrl && (in < 0x20)) { 185 free(ns); 186 return CURLE_URL_MALFORMAT; 187 } 188 189 ns[strindex++] = in; 190 string++; 191 } 192 ns[strindex]=0; /* terminate it */ 193 194 if(olen) 195 /* store output size */ 196 *olen = strindex; 197 198 /* store output string */ 199 *ostring = ns; 200 201 return CURLE_OK; 202 } 203 204 /* 205 * Unescapes the given URL escaped string of given length. Returns a 206 * pointer to a malloced string with length given in *olen. 207 * If length == 0, the length is assumed to be strlen(string). 208 * If olen == NULL, no output length is stored. 209 */ 210 char *curl_easy_unescape(struct Curl_easy *data, const char *string, 211 int length, int *olen) 212 { 213 char *str = NULL; 214 size_t inputlen = length; 215 size_t outputlen; 216 CURLcode res = Curl_urldecode(data, string, inputlen, &str, &outputlen, 217 FALSE); 218 if(res) 219 return NULL; 220 if(olen) 221 *olen = curlx_uztosi(outputlen); 222 return str; 223 } 224 225 /* For operating systems/environments that use different malloc/free 226 systems for the app and for this library, we provide a free that uses 227 the library's memory system */ 228 void curl_free(void *p) 229 { 230 free(p); 231 } 232
