Glenn Lagasse wrote: > 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? > > IMO, generating of the hashes should be part of the same finalizer script that generates the associated images, that way, there's no ambiguity about which image the hashes are being generated for. If we were to generate the hashes in a separate finalizer script, one will have to check whether the given image exist or not, and the name also need to be pass in. It can work, but I think it is not as clean of a solution.
I agree with Dave that generating so many hashes could take extra time. So, perhaps we make it an argument that get passed into the create_iso and create_usb scripts via the manifest? Thanks, --Karen
