From 6a10123f4a361ae5c2e712752ea4c95b6724e678 Mon Sep 17 00:00:00 2001
From: Tim Culverhouse <tim@timculverhouse.com>
Date: Sat, 25 Jun 2022 09:22:49 -0500
Subject: [PATCH] gpg: don't send messages that failed encryption

Add error handling for messages that were unable to be encrypted.
Previously, messages that failed encryption would be sent with no
content. This patch adds error handling - when encryption fails, the
user is returned to the Review screen and instructed to check the public
keys for their recipients.

Reported-by: Moritz Poldrack <moritz@poldrack.dev>
Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Moritz Poldrack <moritz@poldrack.dev>
---
 lib/crypto/gpg/gpgbin/encrypt.go | 6 +++++-
 lib/crypto/gpg/gpgbin/gpgbin.go  | 2 ++
 widgets/compose.go               | 5 ++++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/lib/crypto/gpg/gpgbin/encrypt.go b/lib/crypto/gpg/gpgbin/encrypt.go
index 4cbac37..e72ba14 100644
--- a/lib/crypto/gpg/gpgbin/encrypt.go
+++ b/lib/crypto/gpg/gpgbin/encrypt.go
@@ -2,6 +2,7 @@ package gpgbin
 
 import (
 	"bytes"
+	"fmt"
 	"io"
 
 	"git.sr.ht/~rjarry/aerc/models"
@@ -27,7 +28,10 @@ func Encrypt(r io.Reader, to []string, from string) ([]byte, error) {
 	g.cmd.Run()
 	outRdr := bytes.NewReader(g.stdout.Bytes())
 	var md models.MessageDetails
-	parse(outRdr, &md)
+	err := parse(outRdr, &md)
+	if err != nil {
+		return nil, fmt.Errorf("gpg: failure to encrypt: %v. check public key(s)", err)
+	}
 	var buf bytes.Buffer
 	io.Copy(&buf, md.Body)
 
diff --git a/lib/crypto/gpg/gpgbin/gpgbin.go b/lib/crypto/gpg/gpgbin/gpgbin.go
index bce3097..9f79e97 100644
--- a/lib/crypto/gpg/gpgbin/gpgbin.go
+++ b/lib/crypto/gpg/gpgbin/gpgbin.go
@@ -228,6 +228,8 @@ func parse(r io.Reader, md *models.MessageDetails) error {
 			md.Micalg = micalgs[micalg]
 		case "NODATA":
 			md.SignatureError = "gpg: no signature packet found"
+		case "FAILURE":
+			return fmt.Errorf(strings.TrimPrefix(line, "[GNUPG:] "))
 		}
 	}
 	md.Body = bytes.NewReader(msgContent)
diff --git a/widgets/compose.go b/widgets/compose.go
index 49a8eff..2016abb 100644
--- a/widgets/compose.go
+++ b/widgets/compose.go
@@ -598,7 +598,10 @@ func (c *Composer) WriteMessage(header *mail.Header, writer io.Writer) error {
 		if err != nil {
 			return err
 		}
-		cleartext.Close()
+		err = cleartext.Close()
+		if err != nil {
+			return err
+		}
 		io.Copy(writer, &buf)
 		return nil