Problem interoperating with PGP Univeral?

[Patrick Brunschwig]

Blumenthal, Uri wrote:
> I am trying to get cleartext-signed PGP/MIME messages produced by PGP
> Universal 2.5.3, verified by email clients (Thunderbird-1.5.0.10 +
> Enigmail-0.94.2 + GPG-1.4.7).
> 
> So far my experience is:
> 
> - Pure plaintext (neither PGP/MIME nor PGP/Partitioned) messages are
> verified OK.
> 
> - PGP/MIME encrypted and signed messages are decrypted and verified OK.
> 
> - PGP/MIME or PGP/Partitioned messages (HTML body and/or attachments)
> fail signature verification, with error message from GPG:
> 
>   Cleartext signature without data
> 
> I've submitted help request to Enigmail list, but perhaps somebody here
> can advise me regarding this issue? Maybe there are settings at PGP
> Universal that should be changed to make its output "friendlier"? Or
> maybe there are GPG setting that would allow verification of those
> emails? 
> 
> I'll be grateful for any help!
> 
> Thank you!

I can provide some more details on this. GnuPG 1.4.7 returns with this
error message "gpg: can't handle this ambiguous signature data".

This is the detached signature that comes with such a message:

-----BEGIN PGP SIGNATURE-----
Version: PGP Universal 2.5.3

qANQR1DEDQMBAhH9zteyosL+MwHCPwMFAUYL2iX9zteyosL+MxECC8QAnRhWP2Sx
Ex7VcRL+wBVB2C7lksYAAKCYHvRP7E8vA5jKNgigU0o4kbFn4w==
=lOCI
-----END PGP SIGNATURE-----

-Patrick