I have a couple of questions about the creation and parsing of
encrypted data packets (Section 13.9).
The I-D draft copy I've got in front of me is bis19, but I don't think
the current version has any more info...
The answers might, of course, be blindingly obvious - in which case,
flame me privately please :-)
1] Parsing a Symmetrically Encrypted Data Packet (Tag 9)
Section 13.9 gives a good explanation of how to create the SE packet,
but there's no information on how you parse it. Do you need to do the
same sequence of XOR-ing and resyncing as in the creation? It would be
useful to have some explanation of this...
2] What happens if the plaintext doesn't fit neatly into the
blocksize? Is this algorithm-dependent? or do you just pad with
3] A suggestion for a future draft if there is one: it would be useful
to have in one section the list of all mandatory algorithms and packet
types for a minimum implementation, rather than having to trawl
through the doc to pick this info out.
P.S. Yes, I realise I could probably guess the answers to  and 
from looking at the GPG code, but I'd rather do the implementation
purely from the spec, rather than by reference to an existing
implementation, if possible...