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 #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 static 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 unsigned char in; /* we need to treat the characters unsigned */ 86 size_t newlen; 87 size_t strindex=0; 88 size_t length; 89 CURLcode result; 90 91 if(inlength < 0) 92 return NULL; 93 94 alloc = (inlength?(size_t)inlength:strlen(string))+1; 95 newlen = alloc; 96 97 ns = malloc(alloc); 98 if(!ns) 99 return NULL; 100 101 length = alloc-1; 102 while(length--) { 103 in = *string; 104 105 if(Curl_isunreserved(in)) 106 /* just copy this */ 107 ns[strindex++]=in; 108 else { 109 /* encode it */ 110 newlen += 2; /* the size grows with two, since this'll become a %XX */ 111 if(newlen > alloc) { 112 alloc *= 2; 113 testing_ptr = Curl_saferealloc(ns, alloc); 114 if(!testing_ptr) 115 return NULL; 116 else { 117 ns = testing_ptr; 118 } 119 } 120 121 result = Curl_convert_to_network(data, &in, 1); 122 if(result) { 123 /* Curl_convert_to_network calls failf if unsuccessful */ 124 free(ns); 125 return NULL; 126 } 127 128 snprintf(&ns[strindex], 4, "%%%02X", in); 129 130 strindex+=3; 131 } 132 string++; 133 } 134 ns[strindex]=0; /* terminate it */ 135 return ns; 136 } 137 138 /* 139 * Curl_urldecode() URL decodes the given string. 140 * 141 * Optionally detects control characters (byte codes lower than 32) in the 142 * data and rejects such data. 143 * 144 * Returns a pointer to a malloced string in *ostring with length given in 145 * *olen. If length == 0, the length is assumed to be strlen(string). 146 * 147 */ 148 CURLcode Curl_urldecode(struct Curl_easy *data, 149 const char *string, size_t length, 150 char **ostring, size_t *olen, 151 bool reject_ctrl) 152 { 153 size_t alloc = (length?length:strlen(string))+1; 154 char *ns = malloc(alloc); 155 unsigned char in; 156 size_t strindex=0; 157 unsigned long hex; 158 CURLcode result; 159 160 if(!ns) 161 return CURLE_OUT_OF_MEMORY; 162 163 while(--alloc > 0) { 164 in = *string; 165 if(('%' == in) && (alloc > 2) && 166 ISXDIGIT(string[1]) && ISXDIGIT(string[2])) { 167 /* this is two hexadecimal digits following a '%' */ 168 char hexstr[3]; 169 char *ptr; 170 hexstr[0] = string[1]; 171 hexstr[1] = string[2]; 172 hexstr[2] = 0; 173 174 hex = strtoul(hexstr, &ptr, 16); 175 176 in = curlx_ultouc(hex); /* this long is never bigger than 255 anyway */ 177 178 result = Curl_convert_from_network(data, &in, 1); 179 if(result) { 180 /* Curl_convert_from_network calls failf if unsuccessful */ 181 free(ns); 182 return result; 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 } 245
