--textmode and signing/clearsigning

[Werner Koch]

On Tue, 12 Oct 2004 10:36:45 +0200, Dirk Traulsen said:

>    I assume, --text is the short of --textmode.

Yes.  Though thes abreviations work on the command line only.

>    Is his explanation correct and complete?

It is probably not complete but sufficient.

> 2. Why is there a difference between -t and --textmode? 
>    Why should it matter to pgp, whether gpg accepts a -t as a 
>    short form for --textmode?
   
There is no difference.  The only thing is that for PGP 2 command line
compatibility we use a few of the short option combinations in a
special way.  These PGP 2 kudges are however deprecated and may be
removed in future versions. 

> 3. Does this mean 
>    (gpg -seat) is clearsigning the message, but
>    (gpg -sea --textmode) is signing it?

You can't clearsign and encrypt a message.
"gpg -sat" is currently the same as "gpg --clearsign".  "gpg -sa
--texmode" is not.

> 4. The difference between signing and clearsigning is that with 
>    clearsigning, the original text is preserved and fully readable
>    even without a public key of the author and with 
>    signing, it gets compressed and safed in binary form.

It may or may not be comperssed depending on the other options.

>    When I encrypt a text, it gets compressed anyway.

By default yes.

>    Why does it make a difference, whether I use signing or
>    clearsigning on a compressed text?

The preferred method is to use PGP/MIME (rfc3156) and not
clearsigning. If you sign files you should in general use a detached
signature so that the file may be sued without processing it through
gpg.  

If you file is plain ASCII --clearsign may be used to avoid the
overhead of PGP/MIME and to make verification easier.  If you use a
different character set that ASCII or Latin-1 you better don't use
--clearsign.

  Werner