1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
/*
* Copyright (c) 2015-2022, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Intel Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "utf8_validate.h"
#include "ue2common.h"
#include "util/unicode_def.h"
#include <cstring>
namespace ue2 {
static
bool hasValidContBytes(const u8 *s, size_t num) {
/* continuer bytes must all be of the form 10xx xxxx */
for (size_t i = 0; i < num; i++) {
if ((s[i] & 0xc0) != UTF_CONT_BYTE_HEADER) {
return false;
}
}
return true;
}
static
bool isAllowedCodepoint(u32 val) {
if (val >= 0xd800 && val <= 0xdfff) {
return false; // High and low surrogate halves
}
if (val > 0x10ffff) {
return false; // As per limit in RFC 3629
}
return true;
}
bool isValidUtf8(const char *expression, const size_t len) {
if (!expression) {
return true;
}
const u8 *s = (const u8 *)expression;
u32 val;
size_t i = 0;
while (i < len) {
DEBUG_PRINTF("byte %zu: 0x%02x\n", i, s[i]);
// One octet.
if (s[i] <= 0x7f) {
DEBUG_PRINTF("one octet\n");
i++;
continue;
}
// Two octets.
if ((s[i] & 0xe0) == UTF_TWO_BYTE_HEADER) {
DEBUG_PRINTF("two octets\n");
if (i + 2 > len) {
break;
}
if (!hasValidContBytes(&s[i] + 1, 1)) {
break;
}
val = ((s[i] & 0x1f) << 6) | (s[i + 1] & UTF_CONT_BYTE_VALUE_MASK);
DEBUG_PRINTF("val=0x%x\n", val);
if (val < 1U << 7) {
DEBUG_PRINTF("overlong encoding\n");
break;
}
if (!isAllowedCodepoint(val)) {
DEBUG_PRINTF("codepoint not allowed\n");
break;
}
i += 2;
continue;
}
// Three octets.
if ((s[i] & 0xf0) == UTF_THREE_BYTE_HEADER) {
DEBUG_PRINTF("three octets\n");
if (i + 3 > len) {
break;
}
if (!hasValidContBytes(&s[i] + 1, 2)) {
break;
}
val = ((s[i] & 0xf) << 12) |
((s[i + 1] & UTF_CONT_BYTE_VALUE_MASK) << 6) |
(s[i + 2] & UTF_CONT_BYTE_VALUE_MASK);
if (val < 1U << 11) {
DEBUG_PRINTF("overlong encoding\n");
break;
}
if (!isAllowedCodepoint(val)) {
DEBUG_PRINTF("codepoint not allowed\n");
break;
}
i += 3;
continue;
}
// Four octets.
if ((s[i] & 0xf8) == UTF_FOUR_BYTE_HEADER) {
DEBUG_PRINTF("four octets\n");
if (i + 4 > len) {
break;
}
if (!hasValidContBytes(&s[i] + 1, 3)) {
break;
}
val = ((s[i] & 0xf) << 18) |
((s[i + 1] & UTF_CONT_BYTE_VALUE_MASK) << 12) |
((s[i + 2] & UTF_CONT_BYTE_VALUE_MASK) << 6) |
(s[i + 3] & UTF_CONT_BYTE_VALUE_MASK);
if (val < 1U << 16) {
DEBUG_PRINTF("overlong encoding\n");
break;
}
if (!isAllowedCodepoint(val)) {
DEBUG_PRINTF("codepoint not allowed\n");
break;
}
i += 4;
continue;
}
// Something else?
DEBUG_PRINTF("bad byte 0x%02x\n", s[i]);
break;
}
DEBUG_PRINTF("i=%zu, len=%zu\n", i, len);
return i == len;
}
} // namespace ue2
|
