Added TLS param to Peer. Added option to prepend Received header to envelope data.

envelope.go

@@ -0,0 +1,54 @@
+package smtpd
+
+import (
+	"crypto/tls"
+	"fmt"
+	"strings"
+	"time"
+)
+
+// Envelope holds a message
+type Envelope struct {
+	Sender     string
+	Recipients []string
+	Data       []byte
+}
+
+// AddReceivedLine prepends a Received header to the Data
+func (env *Envelope) AddReceivedLine(peer Peer, serverName string) {
+
+	tlsDetails := ""
+
+	tlsVersions := map[uint16]string{
+		tls.VersionSSL30: "SSL3.0",
+		tls.VersionTLS10: "TLS1.0",
+		tls.VersionTLS11: "TLS1.1",
+		tls.VersionTLS12: "TLS1.2",
+	}
+
+	if peer.TLS != nil {
+		tlsDetails = fmt.Sprintf(
+			"\r\n\t(version=%s cipher=0x%x);",
+			tlsVersions[peer.TLS.Version],
+			peer.TLS.CipherSuite,
+		)
+	}
+
+	line := wrap([]byte(fmt.Sprintf(
+		"Received: from %s [%s] by %s with %s;%s\r\n\t%s\r\n",
+		peer.HeloName,
+		strings.Split(peer.Addr.String(), ":")[0],
+		serverName,
+		peer.Protocol,
+		tlsDetails,
+		time.Now().Format("Mon Jan 2 15:04:05 -0700 2006"),
+	)))
+
+	env.Data = append(env.Data, line...)
+
+	// Move the new Received line up front
+
+	copy(env.Data[len(line):], env.Data[0:len(env.Data)-len(line)])
+	copy(env.Data, line)
+
+}

protocol.go

@@ -272,6 +272,10 @@ func (session *session) handleSTARTTLS(cmd command) {
 	session.scanner = bufio.NewScanner(session.reader)
 	session.tls = true
 
+	// Save connection state on peer
+	state := tlsConn.ConnectionState()
+	session.peer.TLS = &state
+
 	// Flush the connection to set new timeout deadlines
 	session.flush()
 

smtpd.go

@@ -63,13 +63,7 @@ type Peer struct {
 	Password string               // Password from authentication, if authenticated
 	Protocol Protocol             // Protocol used, SMTP or ESMTP
 	Addr     net.Addr             // Network address
-}
+	TLS      *tls.ConnectionState // TLS Connection details, if on TLS
-
-// Envelope holds a message
-type Envelope struct {
-	Sender     string
-	Recipients []string
-	Data       []byte
 }
 
 // Error represents an Error reported in the SMTP session.

smtpd_test.go

@@ -1,7 +1,7 @@
 package smtpd_test
 
 import (
-	"bitbucket.org/chrj/smtpd"
+	"bytes"
 	"crypto/tls"
 	"errors"
 	"fmt"
@@ -10,6 +10,8 @@ import (
 	"strings"
 	"testing"
 	"time"
+
+	"bitbucket.org/chrj/smtpd"
 )
 
 var localhostCert = []byte(`-----BEGIN CERTIFICATE-----
@@ -1145,3 +1147,60 @@ func TestXCLIENT(t *testing.T) {
 	}
 
 }
+
+func TestEnvelopeReceived(t *testing.T) {
+
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("Listen failed: %v", err)
+	}
+
+	defer ln.Close()
+
+	server := &smtpd.Server{
+		Handler: func(peer smtpd.Peer, env smtpd.Envelope) error {
+			env.AddReceivedLine(peer, "foobar.example.net")
+			if !bytes.HasPrefix(env.Data, []byte("Received: from localhost [127.0.0.1] by foobar.example.net with ESMTP;")) {
+				t.Fatal("Wrong received line.")
+			}
+			return nil
+		},
+	}
+
+	go func() {
+		server.Serve(ln)
+	}()
+
+	c, err := smtp.Dial(ln.Addr().String())
+	if err != nil {
+		t.Fatalf("Dial failed: %v", err)
+	}
+
+	if err := c.Mail("sender@example.org"); err != nil {
+		t.Fatalf("MAIL failed: %v", err)
+	}
+
+	if err := c.Rcpt("recipient@example.net"); err != nil {
+		t.Fatalf("RCPT failed: %v", err)
+	}
+
+	wc, err := c.Data()
+	if err != nil {
+		t.Fatalf("Data failed: %v", err)
+	}
+
+	_, err = fmt.Fprintf(wc, "This is the email body")
+	if err != nil {
+		t.Fatalf("Data body failed: %v", err)
+	}
+
+	err = wc.Close()
+	if err != nil {
+		t.Fatalf("Data close failed: %v", err)
+	}
+
+	if err := c.Quit(); err != nil {
+		t.Fatalf("QUIT failed: %v", err)
+	}
+
+}

wrap.go

@@ -0,0 +1,22 @@
+package smtpd
+
+// Wrap a byte slice paragraph for use in SMTP header
+func wrap(sl []byte) []byte {
+	length := 0
+	for i := 0; i < len(sl); i++ {
+		if length > 76 && sl[i] == ' ' {
+			sl = append(sl, 0, 0)
+			copy(sl[i+2:], sl[i:])
+			sl[i] = '\r'
+			sl[i+1] = '\n'
+			sl[i+2] = '\t'
+			i += 2
+			length = 0
+		}
+		if sl[i] == '\n' {
+			length = 0
+		}
+		length++
+	}
+	return sl
+}

wrap_test.go

@@ -0,0 +1,24 @@
+package smtpd
+
+import (
+	"testing"
+)
+
+func TestWrap(t *testing.T) {
+
+	cases := map[string]string{
+		"foobar":         "foobar",
+		"foobar quux":    "foobar quux",
+		"foobar\r\n":     "foobar\r\n",
+		"foobar\r\nquux": "foobar\r\nquux",
+		"foobar quux foobar quux foobar quux foobar quux foobar quux foobar quux foobar quux foobar quux":      "foobar quux foobar quux foobar quux foobar quux foobar quux foobar quux foobar\r\n\tquux foobar quux",
+		"foobar quux foobar quux foobar quux foobar quux foobar quux foobar\r\n\tquux foobar quux foobar quux": "foobar quux foobar quux foobar quux foobar quux foobar quux foobar\r\n\tquux foobar quux foobar quux",
+	}
+
+	for k, v := range cases {
+		if string(wrap([]byte(k))) != v {
+			t.Fatal("Didn't wrap correctly.")
+		}
+	}
+
+}