utf8_validator.hpp
5.42 KB
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
/*
* The following code is adapted from code originally written by Bjoern
* Hoehrmann <bjoern@hoehrmann.de>. See
* http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details.
*
* The original license:
*
* Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef UTF8_VALIDATOR_HPP
#define UTF8_VALIDATOR_HPP
#include <websocketpp/common/stdint.hpp>
#include <string>
namespace websocketpp {
namespace utf8_validator {
/// State that represents a valid utf8 input sequence
static unsigned int const utf8_accept = 0;
/// State that represents an invalid utf8 input sequence
static unsigned int const utf8_reject = 1;
/// Lookup table for the UTF8 decode state machine
static uint8_t const utf8d[] = {
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 00..1f
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 20..3f
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 40..5f
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 60..7f
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, // 80..9f
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, // a0..bf
8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, // c0..df
0xa,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x4,0x3,0x3, // e0..ef
0xb,0x6,0x6,0x6,0x5,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8, // f0..ff
0x0,0x1,0x2,0x3,0x5,0x8,0x7,0x1,0x1,0x1,0x4,0x6,0x1,0x1,0x1,0x1, // s0..s0
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,0,1,1,1,1,1,1, // s1..s2
1,2,1,1,1,1,1,2,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1, // s3..s4
1,2,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,3,1,3,1,1,1,1,1,1, // s5..s6
1,3,1,1,1,1,1,3,1,3,1,1,1,1,1,1,1,3,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // s7..s8
};
/// Decode the next byte of a UTF8 sequence
/**
* @param [out] state The decoder state to advance
* @param [out] codep The codepoint to fill in
* @param [in] byte The byte to input
* @return The ending state of the decode operation
*/
inline uint32_t decode(uint32_t * state, uint32_t * codep, uint8_t byte) {
uint32_t type = utf8d[byte];
*codep = (*state != utf8_accept) ?
(byte & 0x3fu) | (*codep << 6) :
(0xff >> type) & (byte);
*state = utf8d[256 + *state*16 + type];
return *state;
}
/// Provides streaming UTF8 validation functionality
class validator {
public:
/// Construct and initialize the validator
validator() : m_state(utf8_accept),m_codepoint(0) {}
/// Advance the state of the validator with the next input byte
/**
* @param byte The byte to advance the validation state with
* @return Whether or not the byte resulted in a validation error.
*/
bool consume (uint8_t byte) {
if (utf8_validator::decode(&m_state,&m_codepoint,byte) == utf8_reject) {
return false;
}
return true;
}
/// Advance validator state with input from an iterator pair
/**
* @param begin Input iterator to the start of the input range
* @param end Input iterator to the end of the input range
* @return Whether or not decoding the bytes resulted in a validation error.
*/
template <typename iterator_type>
bool decode (iterator_type begin, iterator_type end) {
for (iterator_type it = begin; it != end; ++it) {
unsigned int result = utf8_validator::decode(
&m_state,
&m_codepoint,
static_cast<uint8_t>(*it)
);
if (result == utf8_reject) {
return false;
}
}
return true;
}
/// Return whether the input sequence ended on a valid utf8 codepoint
/**
* @return Whether or not the input sequence ended on a valid codepoint.
*/
bool complete() {
return m_state == utf8_accept;
}
/// Reset the validator to decode another message
void reset() {
m_state = utf8_accept;
m_codepoint = 0;
}
private:
uint32_t m_state;
uint32_t m_codepoint;
};
/// Validate a UTF8 string
/**
* convenience function that creates a validator, validates a complete string
* and returns the result.
*/
inline bool validate(std::string const & s) {
validator v;
if (!v.decode(s.begin(),s.end())) {
return false;
}
return v.complete();
}
} // namespace utf8_validator
} // namespace websocketpp
#endif // UTF8_VALIDATOR_HPP