bitwriter: Add overflow check
The old version of `FLAC__bitwriter_write_raw_uint32()` assumes that the
unused bits of the `val` argument are equal to zero, but don't check it.
This patch adds a new version of that function which does have the check
and then calls a new function `FLAC__bitwriter_write_raw_uint32_nocheck()`
which behaves like the old one.
Code updated to use these two functions as needed.
Patch-from: lvqcl <lvqcl.mail@gmail.com>
diff --git a/src/libFLAC/bitwriter.c b/src/libFLAC/bitwriter.c
index bc4717e..7d867b3 100644
--- a/src/libFLAC/bitwriter.c
+++ b/src/libFLAC/bitwriter.c
@@ -321,7 +321,7 @@
return true;
}
-inline FLAC__bool FLAC__bitwriter_write_raw_uint32(FLAC__BitWriter *bw, FLAC__uint32 val, unsigned bits)
+static inline FLAC__bool FLAC__bitwriter_write_raw_uint32_nocheck(FLAC__BitWriter *bw, FLAC__uint32 val, unsigned bits)
{
register unsigned left;
@@ -337,12 +337,12 @@
if(bits == 0)
return true;
+ FLAC__ASSERT((bits == 32) || (val>>bits == 0));
+
/* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+bits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
if(bw->capacity <= bw->words + bits && !bitwriter_grow_(bw, bits))
return false;
- FLAC__ASSERT((bits == 32) || (val>>bits == 0));
-
left = FLAC__BITS_PER_WORD - bw->bits;
if(bits < left) {
bw->accum <<= bits;
@@ -362,13 +362,22 @@
return true;
}
+inline FLAC__bool FLAC__bitwriter_write_raw_uint32(FLAC__BitWriter *bw, FLAC__uint32 val, unsigned bits)
+{
+ /* check that unused bits are unset */
+ if((bits < 32) && (val>>bits != 0))
+ return false;
+
+ return FLAC__bitwriter_write_raw_uint32_nocheck(bw, val, bits);
+}
+
inline FLAC__bool FLAC__bitwriter_write_raw_int32(FLAC__BitWriter *bw, FLAC__int32 val, unsigned bits)
{
/* zero-out unused bits */
if(bits < 32)
val &= (~(0xffffffff << bits));
- return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, bits);
+ return FLAC__bitwriter_write_raw_uint32_nocheck(bw, (FLAC__uint32)val, bits);
}
inline FLAC__bool FLAC__bitwriter_write_raw_uint64(FLAC__BitWriter *bw, FLAC__uint64 val, unsigned bits)
@@ -377,7 +386,7 @@
if(bits > 32) {
return
FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)(val>>32), bits-32) &&
- FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, 32);
+ FLAC__bitwriter_write_raw_uint32_nocheck(bw, (FLAC__uint32)val, 32);
}
else
return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, bits);
@@ -387,13 +396,13 @@
{
/* this doesn't need to be that fast as currently it is only used for vorbis comments */
- if(!FLAC__bitwriter_write_raw_uint32(bw, val & 0xff, 8))
+ if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, val & 0xff, 8))
return false;
- if(!FLAC__bitwriter_write_raw_uint32(bw, (val>>8) & 0xff, 8))
+ if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, (val>>8) & 0xff, 8))
return false;
- if(!FLAC__bitwriter_write_raw_uint32(bw, (val>>16) & 0xff, 8))
+ if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, (val>>16) & 0xff, 8))
return false;
- if(!FLAC__bitwriter_write_raw_uint32(bw, val>>24, 8))
+ if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, val>>24, 8))
return false;
return true;
@@ -405,7 +414,7 @@
/* this could be faster but currently we don't need it to be since it's only used for writing metadata */
for(i = 0; i < nvals; i++) {
- if(!FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)(vals[i]), 8))
+ if(!FLAC__bitwriter_write_raw_uint32_nocheck(bw, (FLAC__uint32)(vals[i]), 8))
return false;
}
@@ -415,11 +424,11 @@
FLAC__bool FLAC__bitwriter_write_unary_unsigned(FLAC__BitWriter *bw, unsigned val)
{
if(val < 32)
- return FLAC__bitwriter_write_raw_uint32(bw, 1, ++val);
+ return FLAC__bitwriter_write_raw_uint32_nocheck(bw, 1, ++val);
else
return
FLAC__bitwriter_write_zeroes(bw, val) &&
- FLAC__bitwriter_write_raw_uint32(bw, 1, 1);
+ FLAC__bitwriter_write_raw_uint32_nocheck(bw, 1, 1);
}
unsigned FLAC__bitwriter_rice_bits(FLAC__int32 val, unsigned parameter)
@@ -756,37 +765,37 @@
FLAC__ASSERT(!(val & 0x80000000)); /* this version only handles 31 bits */
if(val < 0x80) {
- return FLAC__bitwriter_write_raw_uint32(bw, val, 8);
+ return FLAC__bitwriter_write_raw_uint32_nocheck(bw, val, 8);
}
else if(val < 0x800) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xC0 | (val>>6), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xC0 | (val>>6), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
}
else if(val < 0x10000) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xE0 | (val>>12), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xE0 | (val>>12), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
}
else if(val < 0x200000) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF0 | (val>>18), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>12)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xF0 | (val>>18), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>12)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
}
else if(val < 0x4000000) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF8 | (val>>24), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>18)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>12)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xF8 | (val>>24), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>18)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>12)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
}
else {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFC | (val>>30), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>24)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>18)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>12)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | ((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xFC | (val>>30), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>24)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>18)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>12)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | ((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (val&0x3F), 8);
}
return ok;
@@ -799,49 +808,50 @@
FLAC__ASSERT(0 != bw);
FLAC__ASSERT(0 != bw->buffer);
- FLAC__ASSERT(!(val & FLAC__U64L(0xFFFFFFF000000000))); /* this version only handles 36 bits */
+ if((val & FLAC__U64L(0xFFFFFFF000000000)) != 0) /* this version only handles 36 bits */
+ return false;
if(val < 0x80) {
- return FLAC__bitwriter_write_raw_uint32(bw, (FLAC__uint32)val, 8);
+ return FLAC__bitwriter_write_raw_uint32_nocheck(bw, (FLAC__uint32)val, 8);
}
else if(val < 0x800) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xC0 | (FLAC__uint32)(val>>6), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xC0 | (FLAC__uint32)(val>>6), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
}
else if(val < 0x10000) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xE0 | (FLAC__uint32)(val>>12), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xE0 | (FLAC__uint32)(val>>12), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
}
else if(val < 0x200000) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF0 | (FLAC__uint32)(val>>18), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xF0 | (FLAC__uint32)(val>>18), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
}
else if(val < 0x4000000) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xF8 | (FLAC__uint32)(val>>24), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xF8 | (FLAC__uint32)(val>>24), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
}
else if(val < 0x80000000) {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFC | (FLAC__uint32)(val>>30), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>24)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xFC | (FLAC__uint32)(val>>30), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>24)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
}
else {
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0xFE, 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>30)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>24)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
- ok &= FLAC__bitwriter_write_raw_uint32(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0xFE, 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>30)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>24)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>18)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>12)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)((val>>6)&0x3F), 8);
+ ok &= FLAC__bitwriter_write_raw_uint32_nocheck(bw, 0x80 | (FLAC__uint32)(val&0x3F), 8);
}
return ok;
@@ -865,6 +875,7 @@
* fix that we add extern declarations here.
*/
extern FLAC__bool FLAC__bitwriter_write_zeroes(FLAC__BitWriter *bw, unsigned bits);
+extern FLAC__bool FLAC__bitwriter_write_raw_uint32(FLAC__BitWriter *bw, FLAC__uint32 val, unsigned bits);
extern FLAC__bool FLAC__bitwriter_write_raw_int32(FLAC__BitWriter *bw, FLAC__int32 val, unsigned bits);
extern FLAC__bool FLAC__bitwriter_write_raw_uint64(FLAC__BitWriter *bw, FLAC__uint64 val, unsigned bits);
extern FLAC__bool FLAC__bitwriter_write_raw_uint32_little_endian(FLAC__BitWriter *bw, FLAC__uint32 val);