Internet-Drafts(_at_)ietf(_dot_)org writes:
Title : MIME Security with OpenPGP
Author(s) : M. Elkins, D. Del Torto, R. Levien, T. Roessler
Filename : draft-ietf-openpgp-mime-06.txt
Pages : 13
Date : 10-Apr-01
I know it's too late know, but while reviewing the current USEFOR
draft, I discovered that the explanation
| Multipart/signed and multipart/encrypted are to be treated by agents
| as opaque, meaning that the data is not to be altered in any way [2],
| [7]. However, many existing mail gateways will detect if the next hop
| does not support MIME or 8-bit data and perform conversion to either
| Quoted-Printable or Base64. This presents serious problems for
| multipart/signed, in particular, where the signature is invalidated
| when such an operation occurs. For this reason all data signed
| according to this protocol MUST be constrained to 7 bits (8-bit data
| MUST be encoded using either Quoted-Printable or Base64).
of the 7 bit constraint fails to mention the binary/text mode
signature interoperability problem which can only be addressed if
there aren't any 8-bit characters.
(USEFOR currently overrides the analogous requirement in RFC 2015.)
--
Florian Weimer
Florian(_dot_)Weimer(_at_)RUS(_dot_)Uni-Stuttgart(_dot_)DE
University of Stuttgart http://cert.uni-stuttgart.de/
RUS-CERT +49-711-685-5973/fax +49-711-685-5898