PGP hole

[Michael Handler]

On Fri, 30 Sep 1994, Alan Barrett wrote:

> > The bug seems to be present in all versions (even the ViaCrypt versions
> > have this problem). It has been reported as a bug to the MIT pgp-keepers.
> 
> The "bug" looks like a deliberate design decision to me.  Everything from
> the "--- BEGIN PGP" line to the first blank line is ignored, and is not
> considered part of the signed message.  There's a comment in the source
> code (file armor.c in the versions I checked), saying "Skip header after
> BEGIN line". 

	Yes, this was a deliberate design decision, most probably so the 
same code could be used to parse --- BEGIN PGP ENCRYPTED MESSAGE --- and 
--- BEGIN PGP SIGNATURE ---. However, this is a _huge_ security hole, as 
it allows the nearly-undetectable modification of PGP-signed messages.

Mike
--
Michael Handler                                         <grendel at netaxs.com>
PGP public key available                         1984: We're Behind Schedule
                 Civil Liberty Through Complex Mathematics