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shared: json - support escaping utf16 surrogate pairs 

We originally only supported escaping ucs2 encoded characters (as \uxxxx). This
only covers the BMP. Support escaping also utf16 surrogate pairs (on the form
\uxxxx\uyyyy) to cover all of unicode.
This commit is contained in:
Tom Gundersen 2014-12-22 14:53:40 +01:00
parent 04166cb7dd
commit 9bae67d49b
2 changed files with 66 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

89
src/shared/json.c
View File

@ -53,6 +53,42 @@ static void inc_lines(unsigned *line, const char *s, size_t n) {
}
}
static int unhex_ucs2(const char *c, uint16_t *ret) {
int aa, bb, cc, dd;
uint16_t x;
assert(c);
assert(ret);
aa = unhexchar(c[0]);
if (aa < 0)
return -EINVAL;
bb = unhexchar(c[1]);
if (bb < 0)
return -EINVAL;
cc = unhexchar(c[2]);
if (cc < 0)
return -EINVAL;
dd = unhexchar(c[3]);
if (dd < 0)
return -EINVAL;
x = ((uint16_t) aa << 12) |
((uint16_t) bb << 8) |
((uint16_t) cc << 4) |
((uint16_t) dd);
if (x <= 0)
return -EINVAL;
*ret = x;
return 0;
}
static int json_parse_string(const char **p, char **ret) {
_cleanup_free_ char *s = NULL;
size_t n = 0, allocated = 0;
@ -119,39 +155,40 @@ static int json_parse_string(const char **p, char **ret) {
else if (*c == 't')
ch = '\t';
else if (*c == 'u') {
int aa, bb, cc, dd;
uint16_t x;
int r;
aa = unhexchar(c[1]);
if (aa < 0)
return -EINVAL;
r = unhex_ucs2(c + 1, &x);
if (r < 0)
return r;
bb = unhexchar(c[2]);
if (bb < 0)
return -EINVAL;
cc = unhexchar(c[3]);
if (cc < 0)
return -EINVAL;
dd = unhexchar(c[4]);
if (dd < 0)
return -EINVAL;
x = ((uint16_t) aa << 12) |
((uint16_t) bb << 8) |
((uint16_t) cc << 4) |
((uint16_t) dd);
if (x <= 0)
return -EINVAL;
c += 5;
if (!GREEDY_REALLOC(s, allocated, n + 4))
return -ENOMEM;
n += utf8_encode_unichar(s + n, x);
c += 5;
if (!utf16_is_surrogate(x))
n += utf8_encode_unichar(s + n, x);
else if (utf16_is_trailing_surrogate(x))
return -EINVAL;
else {
uint16_t y;
if (c[0] != '\\' || c[1] != 'u')
return -EINVAL;
r = unhex_ucs2(c + 2, &y);
if (r < 0)
return r;
c += 6;
if (!utf16_is_trailing_surrogate(y))
return -EINVAL;
n += utf8_encode_unichar(s + n, utf16_surrogate_pair_to_unichar(x, y));
}
continue;
} else
return -EINVAL;

3
src/test/test-json.c
View File

@ -99,6 +99,9 @@ int main(int argc, char *argv[]) {
test_one("\"\xef\xbf\xbd\"", JSON_STRING, "\xef\xbf\xbd", JSON_END);
test_one("\"\\ufffd\"", JSON_STRING, "\xef\xbf\xbd", JSON_END);
test_one("\"\\uf\"", -EINVAL);
test_one("\"\\ud800a\"", -EINVAL);
test_one("\"\\udc00\\udc00\"", -EINVAL);
test_one("\"\\ud801\\udc37\"", JSON_STRING, "\xf0\x90\x90\xb7", JSON_END);
return 0;
}