compose: allow automatic attachment of signing key

Add a new pgp-attach-key boolean setting in accounts.conf. When set to
true, enabling message signing (either automatically via pgp-auto-sign
or manually with :sign) will imply attaching the (public) key that will
be used to sign the message before sending.

The automatically attached key can be unattached like any other
attachment with :detach.

Implements: https://todo.sr.ht/~rjarry/aerc/207
Changelog-added: Automatically attach signing key with `pgp-attach-key`
 in `accounts.conf`.
Requested-by: Drew Devault <sir@cmpwn.com>
Signed-off-by: Robin Jarry <robin@jarry.cc>
Tested-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Thomas Böhler <witcher@wiredspace.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/app/compose.go b/app/compose.go
index a54f534b..56b8f350 100644
--- a/app/compose.go
+++ b/app/compose.go
@@ -326,6 +326,11 @@ func (c *Composer) Archive() string {
 }
 
 func (c *Composer) SetAttachKey(attach bool) error {
+	if c.crypto == nil {
+		if err := c.updateCrypto(); err != nil {
+			return err
+		}
+	}
 	if !attach {
 		name := c.crypto.signKey + ".asc"
 		found := false
@@ -397,6 +402,11 @@ func (c *Composer) SetSign(sign bool) error {
 		c.sign = !sign
 		return fmt.Errorf("Cannot sign message: %w", err)
 	}
+	if c.acct.acct.PgpAttachKey {
+		if err := c.SetAttachKey(sign); err != nil {
+			return err
+		}
+	}
 	return nil
 }