Commit d263e6ee authored by Josh Coalson's avatar Josh Coalson
Browse files

disallow non-shortest-form encodings in utf-8 checking; when converting utf-8...

disallow non-shortest-form encodings in utf-8 checking; when converting utf-8 to ucs-2, replace code points outside of ucs-2 with ? character
parent f2a8e069
......@@ -33,19 +33,54 @@ static __inline unsigned local__wide_strlen(const FLAC__uint16 *s)
return n;
}
/*
* also disallows non-shortest-form encodings, c.f.
* http://www.unicode.org/versions/corrigendum1.html
* and a more clear explanation at the end of this section:
* http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
*/
static __inline unsigned local__utf8len(const FLAC__byte *utf8)
{
FLAC__ASSERT(0 != utf8);
if ((utf8[0] & 0x80) == 0)
if ((utf8[0] & 0x80) == 0) {
return 1;
else if ((utf8[0] & 0xE0) == 0xC0 && (utf8[1] & 0xC0) == 0x80)
}
else if ((utf8[0] & 0xE0) == 0xC0 && (utf8[1] & 0xC0) == 0x80) {
if ((utf8[0] & 0x01) == 0xC0) /* overlong sequence check */
return 0;
return 2;
else if ((utf8[0] & 0xF0) == 0xE0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80)
}
else if ((utf8[0] & 0xF0) == 0xE0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80) {
if (utf8[0] == 0xE0 && (utf8[1] & 0xE0) == 0x80) /* overlong sequence check */
return 0;
/* illegal surrogates check (U+D800...U+DFFF and U+FFFE...U+FFFF) */
if (utf8[0] == 0xED && (utf8[1] & 0xE0) == 0xA0) /* D800-DFFF */
return 0;
if (utf8[0] == 0xEF && utf8[1] == 0xBF && (utf8[2] & 0xFE) == 0xBE) /* FFFE-FFFF */
return 0;
return 3;
else
}
else if ((utf8[0] & 0xF8) == 0xF0 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80) {
if (utf8[0] == 0xF0 && (utf8[1] & 0xF0) == 0x80) /* overlong sequence check */
return 0;
return 4;
}
else if ((utf8[0] & 0xFC) == 0xF8 && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80 && (utf8[4] & 0xC0) == 0x80) {
if (utf8[0] == 0xF8 && (utf8[1] & 0xF8) == 0x80) /* overlong sequence check */
return 0;
return 5;
}
else if ((utf8[0] & 0xFE) == 0xFC && (utf8[1] & 0xC0) == 0x80 && (utf8[2] & 0xC0) == 0x80 && (utf8[3] & 0xC0) == 0x80 && (utf8[4] & 0xC0) == 0x80 && (utf8[5] & 0xC0) == 0x80) {
if (utf8[0] == 0xFC && (utf8[1] & 0xFC) == 0x80) /* overlong sequence check */
return 0;
return 6;
}
else {
return 0;
}
}
static __inline unsigned local__utf8_to_ucs2(const FLAC__byte *utf8, FLAC__uint16 *ucs2)
{
const unsigned len = local__utf8len(utf8);
......@@ -58,6 +93,8 @@ static __inline unsigned local__utf8_to_ucs2(const FLAC__byte *utf8, FLAC__uint1
*ucs2 = (*utf8 & 0x3F)<<6 | (*(utf8+1) & 0x3F);
else if (len == 3)
*ucs2 = (*utf8 & 0x1F)<<12 | (*(utf8+1) & 0x3F)<<6 | (*(utf8+2) & 0x3F);
else
*ucs2 = '?';
return len;
}
......@@ -71,8 +108,8 @@ static FLAC__uint16 *local__convert_utf8_to_ucs2(const char *src, unsigned lengt
/* calculate length */
{
const char *s, *end;
for (s=src, end=src+length; s<end; chars++) {
const unsigned char *s, *end;
for (s=(const unsigned char *)src, end=s+length; s<end; chars++) {
const unsigned n = local__utf8len(s);
if (n == 0)
return 0;
......@@ -90,9 +127,10 @@ static FLAC__uint16 *local__convert_utf8_to_ucs2(const char *src, unsigned lengt
/* convert */
{
const unsigned char *s = (const unsigned char *)src;
FLAC__uint16 *u = out;
for ( ; chars; chars--)
src += local__utf8_to_ucs2(src, u++);
s += local__utf8_to_ucs2(s, u++);
}
return out;
......@@ -148,7 +186,7 @@ static char *local__convert_ucs2_to_utf8(const FLAC__uint16 *src, unsigned lengt
/* convert */
{
char *u = out;
unsigned char *u = (unsigned char *)out;
for ( ; *src; src++)
u += local__ucs2_to_utf8(*src, u);
local__ucs2_to_utf8(*src, u);
......@@ -226,7 +264,7 @@ void FLAC_plugin__tags_destroy(FLAC__StreamMetadata **tags)
const char *FLAC_plugin__tags_get_tag_utf8(const FLAC__StreamMetadata *tags, const char *name)
{
const int i = FLAC__metadata_object_vorbiscomment_find_entry_from(tags, /*offset=*/0, name);
return (i < 0? 0 : strchr(tags->data.vorbis_comment.comments[i].entry, '=')+1);
return (i < 0? 0 : strchr((const char *)tags->data.vorbis_comment.comments[i].entry, '=')+1);
}
FLAC__uint16 *FLAC_plugin__tags_get_tag_ucs2(const FLAC__StreamMetadata *tags, const char *name)
......
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