pgp-provider: set default value to auto

Change the default provider to gpg unless the internal keyring is
initialized and contains one key.

This should be more user friendly.

Link: https://lists.sr.ht/~rjarry/aerc-discuss/%3CCO783CI3IU9F.184DBQTPMIPBS%40paul%3E
Signed-off-by: Robin Jarry <robin@jarry.cc>
Acked-by: Moritz Poldrack <moritz@poldrack.dev>

2 files changed, 25 insertions, 3 deletions

diff --git a/lib/crypto/crypto.go b/lib/crypto/crypto.go
index b7afe638..cb026696 100644
--- a/lib/crypto/crypto.go
+++ b/lib/crypto/crypto.go
@@ -6,6 +6,7 @@ import (
 
 	"git.sr.ht/~rjarry/aerc/lib/crypto/gpg"
 	"git.sr.ht/~rjarry/aerc/lib/crypto/pgp"
+	"git.sr.ht/~rjarry/aerc/log"
 	"git.sr.ht/~rjarry/aerc/models"
 	"github.com/ProtonMail/go-crypto/openpgp"
 	"github.com/emersion/go-message/mail"
@@ -25,10 +26,20 @@ type Provider interface {
 
 func New(s string) Provider {
 	switch s {
+	case "auto":
+		internal := &pgp.Mail{}
+		if internal.KeyringExists() {
+			log.Debugf("internal pgp keyring exists")
+			return internal
+		}
+		log.Debugf("no internal pgp keyring, using system gpg")
+		fallthrough
 	case "gpg":
 		return &gpg.Mail{}
-	default:
+	case "internal":
 		return &pgp.Mail{}
+	default:
+		return nil
 	}
 }
 
diff --git a/lib/crypto/pgp/pgp.go b/lib/crypto/pgp/pgp.go
index b2f5fa24..8d7c135a 100644
--- a/lib/crypto/pgp/pgp.go
+++ b/lib/crypto/pgp/pgp.go
@@ -28,6 +28,17 @@ var (
 	locked bool
 )
 
+func (m *Mail) KeyringExists() bool {
+	keypath := path.Join(xdg.DataHome(), "aerc", "keyring.asc")
+	keyfile, err := os.Open(keypath)
+	if err != nil {
+		return false
+	}
+	defer keyfile.Close()
+	_, err = openpgp.ReadKeyRing(keyfile)
+	return err == nil
+}
+
 func (m *Mail) Init() error {
 	log.Debugf("Initializing PGP keyring")
 	err := os.MkdirAll(path.Join(xdg.DataHome(), "aerc"), 0o700)
@@ -50,13 +61,13 @@ func (m *Mail) Init() error {
 	if os.IsNotExist(err) {
 		return nil
 	} else if err != nil {
-		panic(err)
+		return err
 	}
 	defer keyfile.Close()
 
 	Keyring, err = openpgp.ReadKeyRing(keyfile)
 	if err != nil {
-		panic(err)
+		return err
 	}
 	return nil
 }