Initial SMTP server

email.go

@@ -0,0 +1,108 @@
+package main
+
+import (
+	"crypto/tls"
+	"flag"
+	"io"
+	"log"
+	"time"
+
+	smtp "github.com/emersion/go-smtp"
+)
+
+func startSMTPServer() {
+	keyPath := flag.Arg(1)
+	if keyPath == "" {
+		log.Println("No argument given for key files. smtp signing off...")
+		quitChan <- "smtp arg"
+		return
+	}
+	tlsCert, err := tls.LoadX509KeyPair(keyPath+"/fullchain.pem", keyPath+"/key.pem")
+	if err != nil {
+		log.Println("Error while loading tls certificate:", err)
+		quitChan <- "smtp err"
+		return
+	}
+	cfg := &tls.Config{Certificates: []tls.Certificate{tlsCert}}
+	serv := smtp.NewServer(&SMTPBackend{
+		tlsConfig: cfg,
+	})
+	serv.Network = "tcp"
+	serv.Addr = ":587"
+	serv.TLSConfig = cfg
+	serv.Domain = "darkstorm.tech"
+	serv.WriteTimeout = 10 * time.Second
+	serv.ReadTimeout = 10 * time.Second
+	serv.MaxMessageBytes = 1024 * 1024
+	serv.AllowInsecureAuth = true
+	serv.MaxRecipients = 2
+	err = serv.ListenAndServeTLS()
+	log.Println("Error while serving smtp:", err)
+	quitChan <- "smtp err"
+}
+
+type SMTPBackend struct {
+	tlsConfig *tls.Config
+}
+
+func (b *SMTPBackend) NewSession(c *smtp.Conn) (smtp.Session, error) {
+	return NewSession(b.tlsConfig, c.Server().Addr)
+}
+
+type SMTPSession struct {
+	tlsConfig *tls.Config
+	client    *smtp.Client
+	addr      string
+}
+
+func NewSession(tlsConfig *tls.Config, addr string) (*SMTPSession, error) {
+	client, err := smtp.DialTLS(addr, tlsConfig)
+	if err != nil {
+		return nil, err
+	}
+	return &SMTPSession{
+		tlsConfig: tlsConfig,
+		client:    client,
+		addr:      addr,
+	}, nil
+}
+
+func (s *SMTPSession) Reset() {
+	var err error
+	s.client, err = smtp.DialTLS(s.addr, s.tlsConfig)
+	if err != nil {
+		log.Println("Error while resetting smtp session:", err)
+	}
+}
+
+func (s *SMTPSession) Logout() error {
+	return s.client.Quit()
+}
+
+func (s *SMTPSession) AuthPlain(username, password string) error {
+	//TODO
+	return nil
+}
+
+func (s *SMTPSession) Mail(from string, opts *smtp.MailOptions) error {
+	return s.client.Mail(from, opts)
+}
+
+func (s *SMTPSession) Rcpt(to string, opts *smtp.RcptOptions) error {
+	return s.client.Rcpt(to, opts)
+}
+
+func (s *SMTPSession) Data(r io.Reader) error {
+	wrt, err := s.client.Data()
+	if err != nil {
+		log.Println("Error while writing smtp data:", err)
+		return err
+	}
+	_, err = io.Copy(wrt, r)
+	if err != nil {
+		log.Println("Error while writing smtp data:", err)
+		return err
+	}
+	wrt.Close()
+	return nil
+}

go.mod

@@ -11,7 +11,10 @@ require (
 	go.mongodb.org/mongo-driver v1.13.1
 )
 
+require github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 // indirect
+
 require (
+	github.com/emersion/go-smtp v0.20.2
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/klauspost/compress v1.17.6 // indirect

go.sum

@@ -16,6 +16,10 @@ github.com/CalebQ42/swassistant-backend v0.2.1 h1:DqBx1pvPgMOE7LbzxvSoasH83FDgGL
 github.com/CalebQ42/swassistant-backend v0.2.1/go.mod h1:WY+3UvzBcTUoZMtYCVhNWfFW/Cx3lBActCJfk+EUD0s=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21 h1:OJyUGMJTzHTd1XQp98QTaHernxMYzRaOasRir9hUlFQ=
+github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21/go.mod h1:iL2twTeMvZnrg54ZoPDNfJaJaqy0xIQFuBdrLsmspwQ=
+github.com/emersion/go-smtp v0.20.2 h1:peX42Qnh5Q0q3vrAnRy43R/JwTnnv75AebxbkTL7Ia4=
+github.com/emersion/go-smtp v0.20.2/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
 github.com/golang/snappy v0.0.1/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/golang/snappy v0.0.4 h1:yAGX7huGHXlcLOEtBnF4w7FQwA26wojNCwOYAEhLjQM=
 github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=

main.go

@@ -13,6 +13,7 @@ func main() {
 	flag.Parse()
 	go linker()
 	go webserver(*mongoStr)
+	go startSMTPServer()
 	for failure := <-quitChan; ; failure = <-quitChan {
 		switch failure {
 		case "tcp conf":
@@ -23,6 +24,11 @@ func main() {
 			continue
 		case "web err":
 			go websiteRestart(*mongoStr)
+		case "smtp arg":
+			continue
+		case "smtp err":
+			//TODO: restart smtp server
+			continue
 		}
 	}
 }