Subject: Re: signed binary pkgs [was: Re: BPG call for use cases]
To: Malcolm Herbert <>
From: Alistair Crooks <>
List: tech-pkg
Date: 07/28/2005 18:43:13
On Tue, Jul 26, 2005 at 02:46:56PM +1000, Malcolm Herbert wrote:
> On Mon, Jul 25, 2005 at 09:20:28PM -0700, Jason Thorpe wrote:
> |On Jul 25, 2005, at 5:20 PM, John Kohl wrote:
> |>separate mounted file system).  If we're talking about serious  
> |>rework of
> |>packaging for signing, how about switching to a zip or similar archive
> |>format with random access to members?
> |
> |I would certainly not object to such a change.
> I seem to recall that the GNU tar group were looking to do gzip
> compression of individual files before being placed in an archive stream
> rather than after it as this would have provided better support for
> things like backups via rsync, but I don't know how much progress they
> made in this area ...
> it doesn't get you random access though, I grant you ... :)

Just to blow my own trumpet, take a look at pkgsrc/archivers/archangel.

Taken from its description:

	Archangel is an archiver for 2005 and beyond. Some features are:

	+ cross-platform
	+ individually {compressed,bzip2ed,gzipped} entries
	+ individually {signed,encrypted,signed+encrypted} entries
	+ entries can be padded to arbitrary lengths

	All in all, a combination of zip, tar, and gpg on steroids

	You can now backup files, and not be worried about people reading them,
	either in transit or at their destination.

	Entries have a maximum size of 1 MB (by default) internally, so that
	media problems mean that you can recover the parts that aren't affected.

Just to elaborate on the last sentence - large files are broken into
chunks, the default size of which is 1 MB.  This is to reduce the
impact of a medium error, or similar - the lost data is reduced to 1
MB.  Other sizes can be chosen as desired and needed.

When I get some time, I will add an option to sign and/or encrypt
the entry's metadata, in addition to the entry itself.

Right now, archangel uses a callout to gpg. This will be changed to
use bpg when it becomes available.