pgp: PGP/MIME encryption for outgoing emails

implements PGP/MIME encryption with go-pgpmail. The Encrypt() function of
go-pgpmail requires a list of public keys which are taken from the
keystore. The keystore is searched for the email addresses of all
recipients (to, cc, and bcc).
If you want to be able to read the encrypted email afterwards, add
yourself as a recipient in either to, cc, or bcc as well.

Public keys can be exported from gpg into aerc as follows:
$ gpg --export  >> ~/.local/share/aerc/keyring.asc

When composing a message, the encryption is enabled with the
":encrypt" command. This sets a bool flag in the Composer struct.
A reapted application of this command will toggle the flag.
The encrypted message can also be signed by using the ":sign"
command before or after ":encrypt".

References: https://todo.sr.ht/~rjarry/aerc/6
Signed-off-by: Koni Marti <koni.marti@gmail.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/keystore.go b/lib/keystore.go
index c2110676..0b9d41af 100644
--- a/lib/keystore.go
+++ b/lib/keystore.go
@@ -53,6 +53,16 @@ func UnlockKeyring() {
 	os.Remove(lockpath)
 }
 
+func GetEntityByEmail(email string) (e *openpgp.Entity, err error) {
+	for _, entity := range Keyring {
+		ident := entity.PrimaryIdentity()
+		if ident != nil && ident.UserId.Email == email {
+			return entity, nil
+		}
+	}
+	return nil, fmt.Errorf("entity not found in keyring")
+}
+
 func GetSignerEntityByEmail(email string) (e *openpgp.Entity, err error) {
 	for _, key := range Keyring.DecryptionKeys() {
 		if key.Entity == nil {