source: azure_iot_hub_f767zi/trunk/azure_iot_sdk/c-utility/src/urlencode.c@ 457

Last change on this file since 457 was 457, checked in by coas-nagasima, 4 years ago

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1// Copyright (c) Microsoft. All rights reserved.
2// Licensed under the MIT license. See LICENSE file in the project root for full license information.
3
4#include <stdlib.h>
5#include <string.h>
6#include "azure_c_shared_utility/gballoc.h"
7#include "azure_c_shared_utility/urlencode.h"
8#include "azure_c_shared_utility/xlogging.h"
9#include "azure_c_shared_utility/strings.h"
10#include "azure_c_shared_utility/crt_abstractions.h"
11
12#define NIBBLE_TO_STRING(c) (char)((c) < 10 ? (c) + '0' : (c) - 10 + 'a')
13#define NIBBLE_FROM_STRING(c) (char)(ISDIGIT(c) ? (c) - '0' : TOUPPER(c) + 10 - 'A')
14#define IS_HEXDIGIT(c) ( \
15 ((c >= '0') && (c <= '9')) || \
16 ((c >= 'A') && (c <= 'F')) || \
17 ((c >= 'a') && (c <= 'f')) \
18)
19#define IS_PRINTABLE(c) ( \
20 (c == 0) || \
21 (c == '!') || \
22 (c == '(') || (c == ')') || (c == '*') || \
23 (c == '-') || (c == '.') || \
24 ((c >= '0') && (c <= '9')) || \
25 ((c >= 'A') && (c <= 'Z')) || \
26 (c == '_') || \
27 ((c >= 'a') && (c <= 'z')) \
28)
29
30/*The below macros are to be called on the big nibble of a hex value*/
31#define IS_IN_ASCII_RANGE(c) ( \
32 (c >= '0') && (c <= '7') \
33)
34#define IS_IN_EXTENDED_ASCII_RANGE(c) ( \
35 ((c >= '8') && (c <= '9')) || \
36 ((c >= 'A') && (c <= 'F')) || \
37 ((c >= 'a') && (c <= 'f')) \
38)
39#define IS_IN_CONTINUATION_BYTE_RANGE(c) ( \
40 (c == '8') || (c == '9') || \
41 (c == 'A') || (c == 'B') || \
42 (c == 'a') || (c == 'b') \
43)
44#define IS_IN_LEADING_BYTE_RANGE(c) ( \
45 ((c >= 'C') && (c <= 'F')) || \
46 ((c >= 'c') && (c <= 'f')) \
47)
48#define IS_IN_UNSUPPORTED_LEADING_BYTE_RANGE(c) ( \
49 ((c >= 'D') && (c <= 'F')) || \
50 ((c >= 'd') && (c <= 'f')) \
51)
52
53static size_t URL_PrintableChar(unsigned char charVal, char* buffer)
54{
55 size_t size;
56 if (IS_PRINTABLE(charVal))
57 {
58 buffer[0] = (char)charVal;
59 size = 1;
60 }
61 else
62 {
63 char bigNibbleStr;
64 char littleNibbleStr;
65 unsigned char bigNibbleVal = charVal >> 4;
66 unsigned char littleNibbleVal = charVal & 0x0F;
67
68 if (bigNibbleVal >= 0x0C)
69 {
70 bigNibbleVal -= 0x04;
71 }
72
73 bigNibbleStr = NIBBLE_TO_STRING(bigNibbleVal);
74 littleNibbleStr = NIBBLE_TO_STRING(littleNibbleVal);
75
76 buffer[0] = '%';
77
78 if (charVal < 0x80)
79 {
80 buffer[1] = bigNibbleStr;
81 buffer[2] = littleNibbleStr;
82 size = 3;
83 }
84 else
85 {
86 buffer[1] = 'c';
87 buffer[3] = '%';
88 buffer[4] = bigNibbleStr;
89 buffer[5] = littleNibbleStr;
90 if (charVal < 0xC0)
91 {
92 buffer[2] = '2';
93 }
94 else
95 {
96 buffer[2] = '3';
97 }
98 size = 6;
99 }
100 }
101
102 return size;
103}
104
105static size_t calculateDecodedStringSize(const char* encodedString, size_t len)
106{
107 size_t decodedSize = 0;
108
109 if (encodedString == NULL)
110 {
111 LogError("Null encoded string");
112 }
113 else if (len == 0)
114 {
115 decodedSize = 1; //for null terminator
116 }
117 else
118 {
119 size_t remaining_len = len;
120 size_t next_step = 0;
121 size_t i = 0;
122 while (i < len)
123 {
124 //percent encoded character
125 if (encodedString[i] == '%')
126 {
127 if (remaining_len < 3 || !IS_HEXDIGIT(encodedString[i+1]) || !IS_HEXDIGIT(encodedString[i+2]))
128 {
129 LogError("Incomplete or invalid percent encoding");
130 break;
131 }
132 else if (!IS_IN_ASCII_RANGE(encodedString[i+1]))
133 {
134 LogError("Out of range of characters accepted by this decoder");
135 break;
136 }
137 else
138 {
139 decodedSize++;
140 next_step = 3;
141 }
142 }
143 else if (!IS_PRINTABLE(encodedString[i]))
144 {
145 LogError("Unprintable value in encoded string");
146 break;
147 }
148 //safe character
149 else
150 {
151 decodedSize++;
152 next_step = 1;
153 }
154
155 i += next_step;
156 remaining_len -= next_step;
157 }
158
159 if (encodedString[i] != '\0') //i.e. broke out of above loop due to error
160 {
161 decodedSize = 0;
162 }
163 else
164 {
165 decodedSize++; //add space for the null terminator
166 }
167 }
168 return decodedSize;
169}
170
171static unsigned char charFromNibbles(char bigNibbleStr, char littleNibbleStr)
172{
173 unsigned char bigNibbleVal = NIBBLE_FROM_STRING(bigNibbleStr);
174 unsigned char littleNibbleVal = NIBBLE_FROM_STRING(littleNibbleStr);
175
176 return bigNibbleVal << 4 | littleNibbleVal;
177}
178
179static void createDecodedString(const char* input, size_t input_size, char* output)
180{
181 /* Note that there is no danger of reckless indexing here, as calculateDecodedStringSize()
182 has already checked lengths of strings to ensure the formatting is always correct*/
183 size_t i = 0;
184 while (i <= input_size) //the <= instead of < ensures the '\0' will be copied
185 {
186 if (input[i] != '%')
187 {
188 *output++ = input[i];
189 i++;
190 }
191 else
192 {
193 *output++ = charFromNibbles(input[i+1], input[i+2]);
194 i += 3;
195 }
196 }
197}
198
199static size_t URL_PrintableCharSize(unsigned char charVal)
200{
201 size_t size;
202 if (IS_PRINTABLE(charVal))
203 {
204 size = 1;
205 }
206 else
207 {
208 if (charVal < 0x80)
209 {
210 size = 3;
211 }
212 else
213 {
214 size = 6;
215 }
216 }
217 return size;
218}
219
220static STRING_HANDLE encode_url_data(const char* text)
221{
222 STRING_HANDLE result;
223 size_t lengthOfResult = 0;
224 char* encodedURL;
225 unsigned char currentUnsignedChar;
226 const char* iterator = text;
227
228 /*Codes_SRS_URL_ENCODE_06_003: [If input is a zero length string then URL_Encode will return a zero length string.]*/
229 do
230 {
231 currentUnsignedChar = (unsigned char)(*iterator++);
232 lengthOfResult += URL_PrintableCharSize(currentUnsignedChar);
233 } while (currentUnsignedChar != 0);
234
235 if ((encodedURL = (char*)malloc(lengthOfResult)) == NULL)
236 {
237 /*Codes_SRS_URL_ENCODE_06_002: [If an error occurs during the encoding of input then URL_Encode will return NULL.]*/
238 result = NULL;
239 LogError("URL_Encode:: MALLOC failure on encode.");
240 }
241 else
242 {
243 size_t currentEncodePosition = 0;
244 iterator = text;;
245 do
246 {
247 currentUnsignedChar = (unsigned char)(*iterator++);
248 currentEncodePosition += URL_PrintableChar(currentUnsignedChar, &encodedURL[currentEncodePosition]);
249 } while (currentUnsignedChar != 0);
250
251 result = STRING_new_with_memory(encodedURL);
252 if (result == NULL)
253 {
254 LogError("URL_Encode:: MALLOC failure on encode.");
255 free(encodedURL);
256 }
257 }
258 return result;
259}
260
261STRING_HANDLE URL_EncodeString(const char* textEncode)
262{
263 STRING_HANDLE result;
264 if (textEncode == NULL)
265 {
266 result = NULL;
267 }
268 else
269 {
270 result = encode_url_data(textEncode);
271 }
272 return result;
273}
274
275STRING_HANDLE URL_Encode(STRING_HANDLE input)
276{
277 STRING_HANDLE result;
278 if (input == NULL)
279 {
280 /*Codes_SRS_URL_ENCODE_06_001: [If input is NULL then URL_Encode will return NULL.]*/
281 result = NULL;
282 LogError("URL_Encode:: NULL input");
283 }
284 else
285 {
286 result = encode_url_data(STRING_c_str(input));
287 }
288 return result;
289}
290
291STRING_HANDLE URL_DecodeString(const char* textDecode)
292{
293 STRING_HANDLE result;
294 if (textDecode == NULL)
295 {
296 result = NULL;
297 }
298 else
299 {
300 STRING_HANDLE tempString = STRING_construct(textDecode);
301 if (tempString == NULL)
302 {
303 result = NULL;
304 }
305 else
306 {
307 result = URL_Decode(tempString);
308 STRING_delete(tempString);
309 }
310 }
311 return result;
312}
313
314STRING_HANDLE URL_Decode(STRING_HANDLE input)
315{
316 STRING_HANDLE result;
317 if (input == NULL)
318 {
319 LogError("URL_Decode:: NULL input");
320 result = NULL;
321 }
322 else
323 {
324 size_t decodedStringSize;
325 char* decodedString;
326 const char* inputString = STRING_c_str(input);
327 size_t inputLen = strlen(inputString);
328 if ((decodedStringSize = calculateDecodedStringSize(inputString, inputLen)) == 0)
329 {
330 LogError("URL_Decode:: Invalid input string");
331 result = NULL;
332 }
333 else if ((decodedString = (char*)malloc(decodedStringSize)) == NULL)
334 {
335 LogError("URL_Decode:: MALLOC failure on decode.");
336 result = NULL;
337 }
338 else
339 {
340 createDecodedString(inputString, inputLen, decodedString);
341 result = STRING_new_with_memory(decodedString);
342 if (result == NULL)
343 {
344 LogError("URL_Decode:: MALLOC failure on decode");
345 free(decodedString);
346 }
347 }
348 }
349 return result;
350}
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