source: azure_iot_hub_f767zi/trunk/azure_iot_sdk/c-utility/src/utf8_checker.c@ 457

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

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File size: 5.7 KB
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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#ifdef __cplusplus
5#include <cstdlib>
6#include <cstdint>
7#else
8#include <stdlib.h>
9#include <stdbool.h>
10#include <stdint.h>
11#endif
12
13#include "azure_c_shared_utility/utf8_checker.h"
14
15bool utf8_checker_is_valid_utf8(const unsigned char* utf8_str, size_t length)
16{
17 bool result;
18
19 if (utf8_str == NULL)
20 {
21 /* Codes_SRS_UTF8_CHECKER_01_002: [ If utf8_checker_is_valid_utf8 is called with NULL utf8_str it shall return false. ]*/
22 result = false;
23 }
24 else
25 {
26 size_t pos = 0;
27
28 /* Codes_SRS_UTF8_CHECKER_01_003: [ If length is 0, utf8_checker_is_valid_utf8 shall consider utf8_str to be valid UTF-8 and return true. ]*/
29 result = true;
30
31 while ((result == true) &&
32 (pos < length))
33 {
34 /* Codes_SRS_UTF8_CHECKER_01_001: [ utf8_checker_is_valid_utf8 shall verify that the sequence of chars pointed to by utf8_str represent UTF-8 encoded codepoints. ]*/
35 if ((utf8_str[pos] >> 3) == 0x1E)
36 {
37 /* 4 bytes */
38 /* Codes_SRS_UTF8_CHECKER_01_009: [ 000uuuuu zzzzyyyy yyxxxxxx 11110uuu 10uuzzzz 10yyyyyy 10xxxxxx ]*/
39 uint32_t code_point = (utf8_str[pos] & 0x07);
40
41 pos++;
42 if ((pos < length) &&
43 ((utf8_str[pos] >> 6) == 0x02))
44 {
45 code_point <<= 6;
46 code_point += utf8_str[pos] & 0x3F;
47
48 pos++;
49 if ((pos < length) &&
50 ((utf8_str[pos] >> 6) == 0x02))
51 {
52 code_point <<= 6;
53 code_point += utf8_str[pos] & 0x3F;
54
55 pos++;
56 if ((pos < length) &&
57 ((utf8_str[pos] >> 6) == 0x02))
58 {
59 code_point <<= 6;
60 code_point += utf8_str[pos] & 0x3F;
61
62 if (code_point <= 0xFFFF)
63 {
64 result = false;
65 }
66 else
67 {
68 /* Codes_SRS_UTF8_CHECKER_01_005: [ On success it shall return true. ]*/
69 result = true;
70 pos++;
71 }
72 }
73 else
74 {
75 result = false;
76 }
77 }
78 else
79 {
80 result = false;
81 }
82 }
83 else
84 {
85 result = false;
86 }
87 }
88 else if ((utf8_str[pos] >> 4) == 0x0E)
89 {
90 /* 3 bytes */
91 /* Codes_SRS_UTF8_CHECKER_01_008: [ zzzzyyyy yyxxxxxx 1110zzzz 10yyyyyy 10xxxxxx ]*/
92 uint32_t code_point = (utf8_str[pos] & 0x0F);
93
94 pos++;
95 if ((pos < length) &&
96 ((utf8_str[pos] >> 6) == 0x02))
97 {
98 code_point <<= 6;
99 code_point += utf8_str[pos] & 0x3F;
100
101 pos++;
102 if ((pos < length) &&
103 ((utf8_str[pos] >> 6) == 0x02))
104 {
105 code_point <<= 6;
106 code_point += utf8_str[pos] & 0x3F;
107
108 if (code_point <= 0x7FF)
109 {
110 result = false;
111 }
112 else
113 {
114 /* Codes_SRS_UTF8_CHECKER_01_005: [ On success it shall return true. ]*/
115 result = true;
116 pos++;
117 }
118 }
119 else
120 {
121 result = false;
122 }
123 }
124 else
125 {
126 result = false;
127 }
128 }
129 else if ((utf8_str[pos] >> 5) == 0x06)
130 {
131 /* 2 bytes */
132 /* Codes_SRS_UTF8_CHECKER_01_007: [ 00000yyy yyxxxxxx 110yyyyy 10xxxxxx ]*/
133 uint32_t code_point = (utf8_str[pos] & 0x1F);
134
135 pos++;
136 if ((pos < length) &&
137 ((utf8_str[pos] >> 6) == 0x02))
138 {
139 code_point <<= 6;
140 code_point += utf8_str[pos] & 0x3F;
141
142 if (code_point <= 0x7F)
143 {
144 result = false;
145 }
146 else
147 {
148 /* Codes_SRS_UTF8_CHECKER_01_005: [ On success it shall return true. ]*/
149 result = true;
150 pos++;
151 }
152 }
153 else
154 {
155 result = false;
156 }
157 }
158 else if ((utf8_str[pos] >> 7) == 0x00)
159 {
160 /* 1 byte */
161 /* Codes_SRS_UTF8_CHECKER_01_006: [ 00000000 0xxxxxxx 0xxxxxxx ]*/
162 /* Codes_SRS_UTF8_CHECKER_01_005: [ On success it shall return true. ]*/
163 result = true;
164 pos++;
165 }
166 else
167 {
168 /* error */
169 result = false;
170 }
171 }
172 }
173
174 return result;
175}
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