David,
I don't see the problem. If the MIME implementors want to
change the MIME specification to incorporate the security
features of PEM then I suggest that you contact the PEM RFC
authors.
If the problem is how to get MIME to carry PEM then I don't
follow the logic that it is the PEM developers and/or authors
problem to create this definition ! Your need doesn't translate
automatically into ours. If you can _demonstrate_ the coming
dominance of MIME then that may be a sufficient argument.
May I suggest an solution similar to P22 EncryptedBodyPart ?
Perhaps just creating a tag "pem" and 'uuencoding' the message.
If the problem is how to get PEM to carry MIME then I suggest
that there is no problem as PEM has figured this one already.
(It is entirely likely that I have missed a subtle or even gross
point here as I haven't much experience with MIME. However, the
rule that if any part of the "content" fails the RFC-822 rules
then it gets 3/4 encoded (ie 6 bit) seems to just about
cover everything.)
John Lowry