Instead of blindly trusting the first byte, decode UTF-8 safely.

This commit is contained in:
Anthony J. Bentley
2016-01-28 23:16:42 -07:00
parent e241137508
commit 330a39596c
2 changed files with 75 additions and 21 deletions

View File

@@ -1,3 +1,57 @@
/*
* UTF-8 decoder copyright © 20082009 Björn Höhrmann <bjoern@hoehrmann.de>
* http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
*
* 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.
*/
#include <stdint.h>
static const uint8_t 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
};
uint32_t
decode(uint32_t* state, uint32_t* codep, uint32_t byte) {
uint32_t type = utf8d[byte];
*codep = (*state != 0) ?
(byte & 0x3fu) | (*codep << 6) :
(0xff >> type) & (byte);
*state = utf8d[256 + *state*16 + type];
return *state;
}
/*
* Copyright © 2013 stag019 <stag019@gmail.com>
*
@@ -28,30 +82,26 @@ struct Charmap globalCharmap = {0};
extern struct Section *pCurrentSection;
int
readUTF8Char(char *destination, char *source)
readUTF8Char(char *dest, char *src)
{
int size;
UBYTE first;
first = source[0];
uint32_t state;
uint32_t codep;
int i;
if (first >= 0xFC) {
size = 6;
} else if (first >= 0xF8) {
size = 5;
} else if (first >= 0xF0) {
size = 4;
} else if (first >= 0xE0) {
size = 3;
} else if (first >= 0xC0) {
size = 2;
} else if (first != '\0') {
size = 1;
} else {
size = 0;
for (i = 0, state = 0;; i++) {
if (decode(&state, &codep, (uint8_t)src[i]) == 1) {
fatalerror("invalid UTF-8 character");
}
dest[i] = src[i];
i++;
if (state == 0) {
dest[i] = '\0';
return i;
}
dest[i] = src[i];
}
strncpy(destination, source, size);
destination[size] = 0;
return size;
}
int