[OpenJDK 2D-Dev] [15] RFR JDK-8242557: Add length limit for strings in PNGImageWriter

[Jayathirth D v]

Hi Phil,

Thanks for your approval.
I also noticed no limit on language tag in reader for iTXt and raised JDK-8243674 <https://bugs.openjdk.java.net/browse/JDK-8243674> before sending this review. It's on my todo list but not on high priority.

Regards,
Jay 

> On 27-Apr-2020, at 10:51 PM, Philip Race <philip.race at oracle.com> wrote:
> 
> I reviewed  http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html <http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html>
> and I think you covered all the cases.
> 
> I also reviewed the reader and it seems we already check only up to 80 chars there.
> 
> I note we assume the same max length of 80 for the language tag for iTxt.
> The spec. doesn't specify a limit but I think 80 is more than generous here.
> 
> +1
> 
> -phil.
> 
> On 4/27/20, 9:59 AM, Jayathirth D v wrote:
>> 
>> Hello All,
>> 
>> Please review the following fix for JDK 15:
>> 
>> Bug : https://bugs.openjdk.java.net/browse/JDK-8242557 <https://bugs.openjdk.java.net/browse/JDK-8242557> 
>> Webrev : http://cr.openjdk.java.net/~jdv/8242557/webrev.00/ <http://cr.openjdk.java.net/%7Ejdv/8242557/webrev.00/> 
>> 
>> Issue : PNG specification restricts length of strings in some chunks to 79(http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html <http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html> ) excluding null termination. But our writer implementation has no such check.
>> Solution : Add checks in different chunks where there must be restrictions.
>> 
>> Thanks,
>> Jay

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.java.net/pipermail/2d-dev/attachments/20200427/2e956d1c/attachment.htm>