silent mode; signing headers

[Zack Weinberg]

There are two features I would really like to see in G10.

First, a `silent mode' for verifying signatures.  In this mode g10
reads a file and indicates whether the signature is good or not by
its exit status, but produces no output.  Exit codes should
distinguish good sig, bad sig, unknown key, no sig, and program
failure.  This feature is for checking signatures from inside some
automated system, such as a netnews server.

Second, it would be nice to be able to sign some of the headers of a
message as well as its content.  This allows the recipient to check
that the envelope wasn't tampered with.  At least Date, From, To,
Subject, Sender, and Reply-To should be signable for email messages;
in Usenet one would like to sign Control and Approved (if present)
also.  There's an existing semistandard for this, the X-PGP-Sig and
X-Signed-Headers headers used by pgpverify.

zw

p.s. --verify is documented to not print the contents of the file
verified, but in 0.2.19 it does (at least with --clearsign
signatures).