Re: [Ocf-linux-users] Computing SHA1 for large files

[David M. <dav...@mc...>]

Jivin Ajay Matai lays it down ...
> At this point, I am wondering if it is even possible to use OCF SHA1 for any buffers greater than 32K?
> If I call single CIOCCRYPT with 32K data block that works fine.
> 
> If I break the same 32K block into 2 of 16k each and call CIOCCRYPT in a rolling fashion - the result is total garbage.

Yes,  I am not sure if it's possible myself,  but I will look into it when I
get a chance,  just been very busy this week.

> Also, not able to get anything bigger than 32K block working: get a ioctl: Invalid argument error.

Yes,  that limit is imposed by the OCF API.

Cheers,
Davidm

> -----Original Message-----
> From: Ajay Matai 
> Sent: Tuesday, June 19, 2012 4:02 PM
> To: 'ocf...@li...'
> Subject: Computing SHA1 for large files
> 
> Hello,
>   I am a beginner at OCF interface. I have been trying to compute SHA1 hash for a large file (say 2GB).
> 
>   I thought, I could read the file say 8192 sized block at a time,  call CIOCCRYPT with updated buffer.
>   In the end, call CIOCCRYPT one last time with src=NULL and len=0.
>   I should be able to get the mac back in the buffer pointed by mac.
> 
> Tried it but this doesn't seem to work. What is the right way of working with large files and OCF framework.
> 
> I know very basic question but any amount of googling and stack-overflowing didn't help.
> 
> Thanks!
> -ajay 
> 
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and 
> threat landscape has changed and how IT managers can respond. Discussions 
> will include endpoint security, mobile security and the latest in malware 
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Ocf-linux-users mailing list
> Ocf...@li...
> https://lists.sourceforge.net/lists/listinfo/ocf-linux-users
> 
> 

-- 
David McCullough,      dav...@mc...,  Ph:+61 734352815
McAfee - SnapGear      http://www.mcafee.com         http://www.uCdot.org