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Re: interesting creatures // ? for the open-pgp bestiary

2006-07-31 15:08:44

On Mon, Jul 31, 2006 at 04:53:35PM -0400, vedaal(_at_)hush(_dot_)com wrote:

in rfc 2440 bis-18, section 6.2 
ASCII Armor is described, as well as the different types of header 
lines

in commandline versions of pgp and gnupg,
it is possible to just Armor a file,
not armor sign, or armor encrypt, 
just armor

this is a useful way for including any file type as part of an 
inline message, and then signing and encrypting the entire message,
thereby avoiding any attachments, and questions as to the safety 
and authorship of the attachment,
but also not leaving one's signature on the file itself

this type of pgp 'output' is not described anywhere in rfc 2440

It is a "Literal Message" and consists of a single literal data packet
(whether armored or not).  It is described in section 10.3.

[1] from pgp classic,
using the command: pgp -a filename

[3] from gnupg,
using the command: gpg -a --store filename

Both of these create literal messages.

[2] from gnupg,
using the command: gpg --enarmor filename

This does not create a literal message, and is not an OpenPGP feature
(and is thus not part of 2440 bis or otherwise).  It is mainly used as
a OpenPGP packet hacking tool and for the GPG selftest.

one unusual feature in all three examples,
is that the line of armored message block is less than 64 
characters.

is there a minimum length to a line of pgp armor?

There is no minimum.  The maximum is 76 (section 6.3):

    The encoded output stream must be represented in lines of no more
    than 76 characters each.

David

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