mewin/libpng
1
0
Fork 0
mirror of https://git.code.sf.net/p/libpng/code.git synced 2025-07-10 18:04:09 +02:00
Code Issues Projects Releases Wiki Activity

[libpng16] If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,

Browse Source 
ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
This commit is contained in:
Glenn Randers-Pehrson
2016-09-25 17:42:15 -05:00
parent 7835716cef
commit 89ea081433
3 changed files with 26 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
ANNOUNCE
View File

@@ -1,4 +1,4 @@
Libpng 1.6.26beta01 - September 19, 2016
Libpng 1.6.26beta01 - September 25, 2016
This is not intended to be a public release. It will be replaced
within a few weeks by a public version or by another test version.
@@ -25,7 +25,7 @@ Other information:
Changes since the last public release (1.6.25):
Version 1.6.26beta01 [September 19, 2016]
Version 1.6.26beta01 [September 25, 2016]
Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
bugfix by John Bowler).
Do not issue a png_error() on read in png_set_pCAL() because png_handle_pCAL
@@ -35,6 +35,8 @@ Version 1.6.26beta01 [September 19, 2016]
while decoding compressed data chunks.
Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngpriv.h, pngstruct.h, and
pngrutil.c.
If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

4
CHANGES
View File

@@ -5703,7 +5703,7 @@ Version 1.6.25rc05 [August 30, 2016]
Version 1.6.25 [September 1, 2016]
No changes.
Version 1.6.26beta01 [September 19, 2016]
Version 1.6.26beta01 [September 25, 2016]
Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
bugfix by John Bowler).
Do not issue a png_error() on read in png_set_pCAL() because png_handle_pCAL
@@ -5713,6 +5713,8 @@ Version 1.6.26beta01 [September 19, 2016]
while decoding compressed data chunks.
Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngpriv.h, pngstruct.h, and
pngrutil.c.
If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

32
pngrutil.c
View File

@@ -1,7 +1,7 @@
/* pngrutil.c - utilities to read a PNG file
*
* Last changed in libpng 1.6.25 [September 1, 2016]
* Last changed in libpng 1.6.26 [(PENDING RELEASE)]
* Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -371,10 +371,9 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
{
int ret; /* zlib return code */
#if ZLIB_VERNUM >= 0x1240
int window_bits = 0;
# if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW)
int window_bits;
if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
PNG_OPTION_ON)
{
@@ -384,13 +383,11 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
else
{
window_bits = 0;
png_ptr->zstream_start = 1;
}
# else
# define window_bits 0
# endif
#endif
#endif /* ZLIB_VERNUM >= 0x1240 */
/* Set this for safety, just in case the previous owner left pointers to
* memory allocations.
@@ -402,25 +399,31 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
{
#if ZLIB_VERNUM < 0x1240
ret = inflateReset(&png_ptr->zstream);
#else
#if ZLIB_VERNUM >= 0x1240
ret = inflateReset2(&png_ptr->zstream, window_bits);
#else
ret = inflateReset(&png_ptr->zstream);
#endif
}
else
{
#if ZLIB_VERNUM < 0x1240
ret = inflateInit(&png_ptr->zstream);
#else
#if ZLIB_VERNUM >= 0x1240
ret = inflateInit2(&png_ptr->zstream, window_bits);
#else
ret = inflateInit(&png_ptr->zstream);
#endif
if (ret == Z_OK)
png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
}
#if ZLIB_VERNUM >= 0x1240
/* Turn off validation of the ADLER32 checksum */
if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
ret = inflateReset2(&png_ptr->zstream, -window_bits);
#endif
if (ret == Z_OK)
png_ptr->zowner = owner;
@@ -4103,7 +4106,10 @@ png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
if (output != NULL)
{
if(!strncmp(png_ptr->zstream.msg,"incorrect data check",20))
{
png_chunk_benign_error(png_ptr, "ADLER32 checksum mismatch");
continue;
}
else
png_chunk_error(png_ptr, png_ptr->zstream.msg);
}