Re: [openpgp] "OpenPGP Simple"

[Peter Gutmann <[e-mail]>]

David Shaw <[e-mail]> writes:

>What if the encoding was really simple - something like 4 bytes always, and
>the leftmost bit would mean "partial".  So any packet 2^31 or less could be
>encoded in one piece, but we could still do partial for those situations that
>needed it.  We could have any number of partial lengths, but it would always
>end with a non-partial final length.

That's kind of ugly because now you're stuffing metadata into the length
field.  A better approach is the one used in BER indefinite-length encodings,
you have a flag at the start saying "lengths are indefinite", then a series of
partial lengths followed by an end-of-contents value, tag 0 and length 0.  In
other words it's something like:

  |len|  data  |len|  data  |len|  data  |0|

So once you hit a partial length of zero you know you're done.

Peter.