From 3d4cd004309469fb1fddbf3f89afc5ab111823ac Mon Sep 17 00:00:00 2001
From: Mechiel Lukkien <mechiel@ueber.net>
Date: Sun, 10 Nov 2024 23:13:38 +0100
Subject: [PATCH] when opening an account by email address, such as during
 login attempts, and address is an alias, fail with proper error "no such
 credentials" instead of with error "no such account", which printing a stack
 trace

was encountered during smtp session. but could also happen for imapserver and
webmail.

in smtpserver, we now log error messages for smtp errors that cause us to print
a stack trace. would have made logging output more helpful (without having to
turn on trace-level logging).

hopefully solves issue #238 by mwyvr, thanks for reporting!
---
 mox-/lookup.go           | 5 ++++-
 smtpserver/alias_test.go | 7 +++++++
 smtpserver/server.go     | 1 +
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/mox-/lookup.go b/mox-/lookup.go
index 8eaf0a2..1fae8d5 100644
--- a/mox-/lookup.go
+++ b/mox-/lookup.go
@@ -63,7 +63,10 @@ func LookupAddress(localpart smtp.Localpart, domain dns.Domain, allowPostmaster,
 	canonical := smtp.NewAddress(localpart, domain).String()
 
 	accAddr, alias, ok := Conf.AccountDestination(canonical)
-	if ok && alias != nil && allowAlias {
+	if ok && alias != nil {
+		if !allowAlias {
+			return "", nil, "", config.Destination{}, ErrAddressNotFound
+		}
 		return "", alias, canonical, config.Destination{}, nil
 	} else if !ok {
 		if accAddr, alias, ok = Conf.AccountDestination("@" + domain.Name()); !ok || alias != nil {
diff --git a/smtpserver/alias_test.go b/smtpserver/alias_test.go
index 9312de2..b32374b 100644
--- a/smtpserver/alias_test.go
+++ b/smtpserver/alias_test.go
@@ -1,6 +1,7 @@
 package smtpserver
 
 import (
+	"errors"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -62,6 +63,12 @@ func TestAliasSubmitMsgFromDenied(t *testing.T) {
 	ts := newTestServer(t, filepath.FromSlash("../testdata/smtp/mox.conf"), dns.MockResolver{})
 	defer ts.close()
 
+	// Trying to open account by alias should result in proper error.
+	_, _, err := store.OpenEmail(pkglog, "public@mox.example")
+	if err == nil || !errors.Is(err, store.ErrUnknownCredentials) {
+		t.Fatalf("opening alias, got err %v, expected store.ErrUnknownCredentials", err)
+	}
+
 	acc, err := store.OpenAccount(pkglog, "☺")
 	tcheck(t, err, "open account")
 	err = acc.SetPassword(pkglog, password0)
diff --git a/smtpserver/server.go b/smtpserver/server.go
index f4ea91c..43ff2ca 100644
--- a/smtpserver/server.go
+++ b/smtpserver/server.go
@@ -751,6 +751,7 @@ func command(c *conn) {
 		if errors.As(err, &serr) {
 			c.writecodeline(serr.code, serr.secode, fmt.Sprintf("%s (%s)", serr.errmsg, mox.ReceivedID(c.cid)), serr.err)
 			if serr.printStack {
+				c.log.Errorx("smtp error", serr.err, slog.Int("code", serr.code), slog.String("secode", serr.secode))
 				debug.PrintStack()
 			}
 		} else {