source: azure_iot_hub_f767zi/trunk/azure_iot_sdk/c-utility/src/azure_base32.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 <stdint.h>
6#include <ctype.h>
7#include "azure_c_shared_utility/buffer_.h"
8#include "azure_c_shared_utility/xlogging.h"
9#include "azure_c_shared_utility/gballoc.h"
10#include "azure_c_shared_utility/strings.h"
11
12#include "azure_c_shared_utility/azure_base32.h"
13
14static const unsigned char BASE32_EQUAL_SIGN = 32;
15
16static const char BASE32_VALUES[] = "abcdefghijklmnopqrstuvwxyz234567=";
17#define TARGET_BLOCK_SIZE 5
18#define INVALID_CHAR_POS 260
19
20#define BASE32_INPUT_SIZE 8
21
22#define ASCII_VALUE_MAX 0x80
23
24static size_t base32_encoding_length(size_t src_len)
25{
26 return (((src_len + TARGET_BLOCK_SIZE - 1) / TARGET_BLOCK_SIZE) * 8);
27}
28
29static size_t base32_decoding_length(size_t src_len)
30{
31 return ((src_len*TARGET_BLOCK_SIZE) / 8);
32}
33
34static unsigned char convert_value_to_base32_char(unsigned char value)
35{
36 unsigned char result;
37
38 if (value >= 50 && value <= 55)
39 {
40 result = 0x1a+(value-50);
41 }
42 else if (value == 61)
43 {
44 result = 0x20;
45 }
46 else if ((value <= 49) || (value >= 56 && value <= 64))
47 {
48 result = 0xFF;
49 }
50 else if (value >= 65 && value <= 90)
51 {
52 result = 0x00 + (value - 65);
53 }
54 else if (value >= 91 && value <= 96)
55 {
56 result = 0xFF;
57 }
58 else if (value >= 97 && value <= 123)
59 {
60 result = 0x00 + (value - 97);
61 }
62 else // value > 123
63 {
64 result = 0xFF;
65 }
66 return result;
67}
68
69static char* base32_encode_impl(const unsigned char* source, size_t src_size)
70{
71 char* result;
72
73 // Allocate target buffer
74 size_t output_len = base32_encoding_length(src_size);
75 /* Codes_SRS_BASE32_07_009: [ base32_encode_impl shall allocate the buffer to the size of the encoding value. ] */
76 if ((result = (char*)malloc(output_len + 1)) == NULL)
77 {
78 LogError("Failure allocating output buffer");
79 }
80 else
81 {
82 const unsigned char* iterator = source;
83 size_t block_len = 0;
84 size_t result_len = 0;
85 unsigned char pos1 = 0;
86 unsigned char pos2 = 0;
87 unsigned char pos3 = 0;
88 unsigned char pos4 = 0;
89 unsigned char pos5 = 0;
90 unsigned char pos6 = 0;
91 unsigned char pos7 = 0;
92 unsigned char pos8 = 0;
93
94 memset(result, 0, output_len + 1);
95
96 // Go through the source buffer sectioning off blocks of 5
97 /* Codes_SRS_BASE32_07_010: [ base32_encode_impl shall look through source and separate each block into 5 bit chunks ] */
98 while (src_size >= 1 && result != NULL)
99 {
100 pos1 = pos2 = pos3 = pos4 = pos5 = pos6 = pos7 = pos8 = 0;
101 block_len = src_size > TARGET_BLOCK_SIZE ? TARGET_BLOCK_SIZE : src_size;
102 // Fall through switch block to process the 5 (or smaller) block
103 switch (block_len)
104 {
105 case 5:
106 pos8 = (iterator[4] & 0x1f);
107 pos7 = ((iterator[4] & 0xe0) >> 5);
108 // fall through
109 case 4:
110 pos7 |= ((iterator[3] & 0x03) << 3);
111 pos6 = ((iterator[3] & 0x7c) >> 2);
112 pos5 = ((iterator[3] & 0x80) >> 7);
113 // fall through
114 case 3:
115 pos5 |= ((iterator[2] & 0x0f) << 1);
116 pos4 = ((iterator[2] & 0xf0) >> 4);
117 // fall through
118 case 2:
119 pos4 |= ((iterator[1] & 0x01) << 4);
120 pos3 = ((iterator[1] & 0x3e) >> 1);
121 pos2 = ((iterator[1] & 0xc0) >> 6);
122 // fall through
123 case 1:
124 pos2 |= ((iterator[0] & 0x07) << 2);
125 pos1 = ((iterator[0] & 0xf8) >> 3);
126 break;
127 }
128 // Move the iterator the block size
129 iterator += block_len;
130 // and decrement the src_size;
131 src_size -= block_len;
132
133 /* Codes_SRS_BASE32_07_012: [ If the src_size is not divisible by 8, base32_encode_impl shall pad the remaining places with =. ] */
134 switch (block_len)
135 {
136 case 1: pos3 = pos4 = 32; // fall through
137 case 2: pos5 = 32; // fall through
138 case 3: pos6 = pos7 = 32; // fall through
139 case 4: pos8 = 32; // fall through
140 case 5:
141 break;
142 }
143
144 /* Codes_SRS_BASE32_07_011: [ base32_encode_impl shall then map the 5 bit chunks into one of the BASE32 values (a-z,2,3,4,5,6,7) values. ] */
145 result[result_len++] = BASE32_VALUES[pos1];
146 result[result_len++] = BASE32_VALUES[pos2];
147 result[result_len++] = BASE32_VALUES[pos3];
148 result[result_len++] = BASE32_VALUES[pos4];
149 result[result_len++] = BASE32_VALUES[pos5];
150 result[result_len++] = BASE32_VALUES[pos6];
151 result[result_len++] = BASE32_VALUES[pos7];
152 result[result_len++] = BASE32_VALUES[pos8];
153 }
154 }
155 return result;
156}
157
158static BUFFER_HANDLE base32_decode_impl(const char* source)
159{
160 BUFFER_HANDLE result;
161
162 size_t src_length = strlen(source);
163 if (src_length % BASE32_INPUT_SIZE != 0)
164 {
165 /* Codes_SRS_BASE32_07_021: [ If the source length is not evenly divisible by 8, base32_decode_impl shall return NULL. ] */
166 LogError("Failure invalid input length %lu", (unsigned long)src_length);
167 result = NULL;
168 }
169 else
170 {
171 size_t dest_size = 0;
172 unsigned char* temp_buffer;
173 unsigned char* dest_buff;
174 bool continue_processing = true;
175 unsigned char input[8];
176 const char* iterator = source;
177
178 /* Codes_SRS_BASE32_07_022: [ base32_decode_impl shall allocate a temp buffer to store the in process value. ] */
179 size_t allocation_len = base32_decoding_length(src_length);
180 if ((temp_buffer = (unsigned char*)malloc(allocation_len)) == NULL)
181 {
182 /* Codes_SRS_BASE32_07_023: [ If an error is encountered, base32_decode_impl shall return NULL. ] */
183 LogError("Failure allocating buffer");
184 result = NULL;
185 }
186 else
187 {
188 dest_buff = temp_buffer;
189 while (*iterator != '\0')
190 {
191 size_t index = 0;
192 /* Codes_SRS_BASE32_07_024: [ base32_decode_impl shall loop through and collect 8 characters from the source variable. ] */
193 for (index = 0; index < BASE32_INPUT_SIZE; index++)
194 {
195 input[index] = *iterator;
196 iterator++;
197 if (input[index] >= ASCII_VALUE_MAX)
198 {
199 LogError("Failure source encoding");
200 continue_processing = false;
201 break;
202 }
203
204 input[index] = convert_value_to_base32_char(input[index]);
205 }
206
207 if (!continue_processing)
208 {
209 result = NULL;
210 break;
211 }
212 else if ((dest_size + TARGET_BLOCK_SIZE) > allocation_len)
213 {
214 LogError("Failure target length exceeded");
215 result = NULL;
216 continue_processing = false;
217 break;
218 }
219 else
220 {
221 // Codes_SRS_BASE32_07_025: [ base32_decode_impl shall group 5 bytes at a time into the temp buffer. ]
222 *dest_buff++ = ((input[0] & 0x1f) << 3) | ((input[1] & 0x1c) >> 2);
223 *dest_buff++ = ((input[1] & 0x03) << 6) | ((input[2] & 0x1f) << 1) | ((input[3] & 0x10) >> 4);
224 *dest_buff++ = ((input[3] & 0x0f) << 4) | ((input[4] & 0x1e) >> 1);
225 *dest_buff++ = ((input[4] & 0x01) << 7) | ((input[5] & 0x1f) << 2) | ((input[6] & 0x18) >> 3);
226 *dest_buff++ = ((input[6] & 0x07) << 5) | (input[7] & 0x1f);
227 dest_size += TARGET_BLOCK_SIZE;
228 // If there is padding remove it
229 // Because we are packing 5 bytes into an 8 byte variable we need to check every other
230 // variable for padding
231 if (input[7] == BASE32_EQUAL_SIGN)
232 {
233 --dest_size;
234 if (input[5] == BASE32_EQUAL_SIGN)
235 {
236 --dest_size;
237 if (input[4] == BASE32_EQUAL_SIGN)
238 {
239 --dest_size;
240 if (input[2] == BASE32_EQUAL_SIGN)
241 {
242 --dest_size;
243 }
244 }
245 }
246 }
247 }
248 }
249
250 if (!continue_processing)
251 {
252 result = NULL;
253 }
254 else
255 {
256 /* Codes_SRS_BASE32_07_026: [ Once base32_decode_impl is complete it shall create a BUFFER with the temp buffer. ] */
257 result = BUFFER_create(temp_buffer, dest_size);
258 if (result == NULL)
259 {
260 LogError("Failure: BUFFER_create failed to create decoded buffer");
261 }
262 }
263 free(temp_buffer);
264 }
265 }
266 return result;
267}
268
269BUFFER_HANDLE Azure_Base32_Decode(STRING_HANDLE handle)
270{
271 BUFFER_HANDLE result;
272 if (handle == NULL)
273 {
274 /* Codes_SRS_BASE32_07_016: [ If source is NULL Azure_Base32_Decode shall return NULL. ] */
275 LogError("invalid parameter handle");
276 result = NULL;
277 }
278 else
279 {
280 const char* str_source = STRING_c_str(handle);
281 if (str_source == NULL)
282 {
283 /* Codes_SRS_BASE32_07_027: [ If the string in source value is NULL, Azure_Base32_Decode shall return NULL. ] */
284 LogError("NULL value specified in string");
285 result = NULL;
286 }
287 else
288 {
289 /* Codes_SRS_BASE32_07_018: [ Azure_Base32_Decode shall call base32_decode_impl to decode the base64 value. ] */
290 result = base32_decode_impl(str_source);
291 }
292 }
293 /* Codes_SRS_BASE32_07_017: [ On success Azure_Base32_Decode shall return a BUFFER_HANDLE that contains the decoded bytes for source. ] */
294 return result;
295}
296
297BUFFER_HANDLE Azure_Base32_Decode_String(const char* source)
298{
299 BUFFER_HANDLE result;
300 if (source == NULL)
301 {
302 /* Codes_SRS_BASE32_07_008: [ If source is NULL Azure_Base32_Decode_String shall return NULL. ] */
303 LogError("invalid parameter source=NULL");
304 result = NULL;
305 }
306 else
307 {
308 /* Codes_SRS_BASE32_07_020: [ Azure_Base32_Decode_String shall call base32_decode_impl to decode the base64 value. ] */
309 result = base32_decode_impl(source);
310 }
311 /* Codes_SRS_BASE32_07_019: [ On success Azure_Base32_Decode_String shall return a BUFFER_HANDLE that contains the decoded bytes for source. ] */
312 return result;
313}
314
315char* Azure_Base32_Encode_Bytes(const unsigned char* source, size_t size)
316{
317 char* result;
318 if (source == NULL)
319 {
320 /* Codes_SRS_BASE32_07_004: [ If source is NULL Azure_Base32_Encode_Bytes shall return NULL. ] */
321 result = NULL;
322 LogError("Failure: Invalid input parameter source");
323 }
324 else if (size == 0)
325 {
326 /* Codes_SRS_BASE32_07_005: [ If size is 0 Azure_Base32_Encode_Bytes shall return an empty string. ] */
327 if ((result = malloc(1)) != NULL)
328 {
329 strcpy(result, "");
330 }
331 else
332 {
333 LogError("unable to allocate memory for result");
334 }
335 }
336 else
337 {
338 /* Codes_SRS_BASE32_07_007: [ Azure_Base32_Encode_Bytes shall call into base32_Encode_impl to encode the source data. ] */
339 result = base32_encode_impl(source, size);
340 if (result == NULL)
341 {
342 /* Codes_SRS_BASE32_07_014: [ Upon failure Azure_Base32_Encode_Bytes shall return NULL. ] */
343 LogError("encoding of unsigned char failed.");
344 }
345 }
346 /* Codes_SRS_BASE32_07_006: [ If successful Azure_Base32_Encode_Bytes shall return the base32 value of input. ] */
347 return result;
348}
349
350STRING_HANDLE Azure_Base32_Encode(BUFFER_HANDLE source)
351{
352 STRING_HANDLE result;
353 if (source == NULL)
354 {
355 /* Codes_SRS_BASE32_07_001: [ If source is NULL Azure_Base32_Encode shall return NULL. ] */
356 result = NULL;
357 LogError("Failure: Invalid input parameter");
358 }
359 else
360 {
361 size_t input_len = BUFFER_length(source);
362 const unsigned char* input_value = BUFFER_u_char(source);
363 if (input_value == NULL || input_len == 0)
364 {
365 /* Codes_SRS_BASE32_07_015: [ If size is 0 Azure_Base32_Encode shall return an empty string. ] */
366 result = STRING_new();
367 if (result == NULL)
368 {
369 LogError("Failure constructing new string.");
370 }
371 }
372 else
373 {
374 /* Codes_SRS_BASE32_07_003: [ Azure_Base32_Encode shall call into base32_Encode_impl to encode the source data. ] */
375 char* encoded = base32_encode_impl(input_value, input_len);
376 if (encoded == NULL)
377 {
378 /* Codes_SRS_BASE32_07_014: [ Upon failure Azure_Base32_Encode shall return NULL. ] */
379 LogError("base32 encode implementation failed.");
380 result = NULL;
381 }
382 else
383 {
384 /* Codes_SRS_BASE32_07_012: [ Azure_Base32_Encode shall wrap the base32_Encode_impl result into a STRING_HANDLE. ] */
385 result = STRING_construct(encoded);
386 if (result == NULL)
387 {
388 /* Codes_SRS_BASE32_07_014: [ Upon failure Azure_Base32_Encode shall return NULL. ] */
389 LogError("string construction failed.");
390 }
391 free(encoded);
392 }
393 }
394 }
395 /* Codes_SRS_BASE32_07_002: [ If successful Azure_Base32_Encode shall return the base32 value of source. ] */
396 return result;
397}
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