Hey Dave,
* Dave Miner (dminer at opensolaris.org) wrote:
> Glenn Lagasse wrote:
>> Could I get a reviewer (or more) to have a look at the changes I'm
>> proposing for 5265 (Distro constructor should auto-generate image
>> hashes) please?
>>
>> http://defect.opensolaris.org/bz/show_bug.cgi?id=5265
>> http://cr.opensolaris.org/~glagasse/slim_source/
>>
>> In case anyone is curious, I'm generating MD5, SHA-1 and SHA-256
>> cryptographic hashes. SHA-256 may be a little overkill but it's *more
>> secure* than the others and I figured I'd try and appease the security
>> conscious crowd while I was at it (SHA-256 checksums are also starting
>> to show up in the wild from other distributors of electronic media such
>> as ours so I figured I'd get a jump up).
>>
>
> I'd suggested this be an option controllable in the manifest, which
> perhaps is overkill, though on many systems it's going to be a bit
> time-consuming to compute three different hashes on gigabyte-ish files.
> That could also be accomplished somewhat more obliquely if this were
> made a separate step in the finalizer, at least; any reason you didn't
> choose that design?
I did actually consider those designs (manifest option, finalizer
script). In the end I didn't really see any compelling reason to
implement them. They're more flexible certainly but I didn't think this
sort of feature needed that. I considered image checksums part of the
same process of preparing the image done in create_{iso|usb}. I suppose
it's possible that someone may not want to generate checksums for their
images. In my testing (on a quad core 2 duo with 8g of ram) generating
checksums took on the order of seconds to generate the hashes for the
liveCD and usb images (less than 20 for a complete set for both) so I
didn't consider time as a significant issue even if you consider
building on 'slower' hardware.
But, it's not difficult to implement either of the other designs. I
think I'd lean more towards a combination of both, specify which hashes
you want in the manifest which a new finalizer script then parses. You
then have flexibility in deciding which hashes you want generated as
well as checkpoint/resume ability when generating them.
How does that sound?
Thanks!
--
Glenn
