sup

commit 1d01edf1832cdc3da92b58f95e65191fd8d7f39e
parent 37a623c9da8fd711bf522e444e4772bc185ab340
Author: Gaudenz Steinlin <gaudenz@soziologie.ch>
Date:   Thu,  7 Oct 2010 13:50:13 -0400

Explicitly specify signature hashing algorithm

Sup used to add a micalg=pgp-sha1 parameter in Content-Type header of a
signed message, but used whatever the user had configured as his
preferred hasing algorithm in gpg.conf. This lead to unverifiable
signatures in some MUAs.

This adds an explicit --digest-algo option to the gpg call to override
any user configured setting. It also upgrades the algorithm to sha256 as
sha1 is being phased out now.

Diffstat:

1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/sup/crypto.rb b/lib/sup/crypto.rb
@@ -45,14 +45,14 @@ EOS
 
     sig_fn = Tempfile.new "redwood.signature"; sig_fn.close
 
-    message = run_gpg "--output #{sig_fn.path} --yes --armor --detach-sign --textmode --local-user '#{from}' #{payload_fn.path}", :interactive => true
+    message = run_gpg "--output #{sig_fn.path} --yes --armor --detach-sign --textmode --digest-algo sha256 --local-user '#{from}' #{payload_fn.path}", :interactive => true
     unless $?.success?
       info "Error while running gpg: #{message}"
       raise Error, "GPG command failed. See log for details."
     end
 
     envelope = RMail::Message.new
-    envelope.header["Content-Type"] = 'multipart/signed; protocol=application/pgp-signature; micalg=pgp-sha1'
+    envelope.header["Content-Type"] = 'multipart/signed; protocol=application/pgp-signature; micalg=pgp-sha256'
 
     envelope.add_part payload
     signature = RMail::Message.make_attachment IO.read(sig_fn.path), "application/pgp-signature", nil, "signature.asc"