Re: [Sks-devel] Re: zero-length MPIs (was: Re: mpi error with check-trustdb in 1.4.2 - resolved)

[Jason Harris]

On Thu, Aug 11, 2005 at 09:54:59PM +0200, Peter Palfrader wrote:
> On Thu, 11 Aug 2005, Jason Harris wrote:

> > Fetching them from keyserver.kjsl.com is now possible with gnupg-1.4.2.
> > To patch pks, add this to the middle of decode_mpi() (in pgputil.c):
> > 
> >   /* skip packets with 0-length MPIs for GPG's benefit (gnupg-1.4.2) */
> >   if (mpi->nbits == 0) {
> >     return (0);
> >   }
> 
> can we do that in SKS too?  please!

Try the patch below.  0x1A9537E7 is another offending key, and all eight
work now:

  %gpg --recv 0xA0B3E88B 0xFC05DA69 0x0FCF6738 0xCC78C893 0x98FDE37C 0x74C9DE33 
0x57023F00 0x1A9537E7
  ...
  gpg: Total number processed: 8
  gpg:              unchanged: 8

===================================================================
RCS file: parsePGP.ml,v
retrieving revision 1.1
diff -u -r1.1 parsePGP.ml
--- parsePGP.ml 2005/08/12 00:03:16     1.1
+++ parsePGP.ml 2005/08/12 00:03:54
@@ -23,6 +23,7 @@
 open Printf
 
 exception Overlong_mpi
+exception Zerolen_mpi
 exception Partial_body_length of int
 
 (********************************************************)
@@ -109,6 +110,7 @@
   try
     let byte2 = cin#read_byte in
     let length = (byte1 lsl 8) + byte2 in
+    if length <= 0 then raise Zerolen_mpi;
     let data = cin#read_string 
                 ((length + 7)/8)
     in

-- 
Jason Harris           |  NIC:  JH329, PGP:  This _is_ PGP-signed, isn't it?
address@hidden _|_ web:  http://keyserver.kjsl.com/~jharris/
          Got photons?   (TM), (C) 2004

pgpJBp1tuWFyO.pgp
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