From: Robert Sesek <rsesek@bluestatic.org>
Date: Mon, 2 Jan 2017 01:22:00 +0000 (-0500)
Subject: Fix post-STARTTLS protocol bug.
X-Git-Tag: v1.1.0~8
X-Git-Url: https://src.bluestatic.org/?a=commitdiff_plain;h=c83dcc2e3c0d291f8cf71dac6f900e72e630a554;p=mailpopbox.git

Fix post-STARTTLS protocol bug.

After the TLS handshake, the server should *not* reply with a greeting again,
but it should wait for an EHLO, per RFC 3207 § 4.2 & 5. Previously the server
would re-send the greeting, which un-syncs the protocol.
---

diff --git a/smtp/conn.go b/smtp/conn.go
index ca24c10..1837027 100644
--- a/smtp/conn.go
+++ b/smtp/conn.go
@@ -188,21 +188,17 @@ func (conn *connection) doSTARTTLS() {
 	conn.log.Info("doSTARTTLS()")
 	conn.writeReply(220, "initiate TLS connection")
 
-	newConn := tls.Server(conn.nc, tlsConfig)
-	tp := textproto.NewConn(newConn)
-
-	err := tp.PrintfLine("220 %s ESMTPS [%s] (mailpopbox)",
-		conn.server.Name(), newConn.LocalAddr())
-	if err != nil {
+	tlsConn := tls.Server(conn.nc, tlsConfig)
+	if err := tlsConn.Handshake(); err != nil {
 		conn.log.Error("failed to do TLS handshake", zap.Error(err))
 		return
 	}
 
-	conn.nc = newConn
-	conn.tp = tp
+	conn.nc = tlsConn
+	conn.tp = textproto.NewConn(tlsConn)
 	conn.state = stateNew
 
-	connState := newConn.ConnectionState()
+	connState := tlsConn.ConnectionState()
 	conn.tls = &connState
 
 	conn.log.Info("TLS connection done", zap.String("state", conn.getTransportString()))