2
0
forked from drew/smtprelay
Files
smtprelay/main.go

87 lines
2.3 KiB
Go

package main
import (
"crypto/tls"
"flag"
"fmt"
"log"
"net/smtp"
"strings"
"time"
"github.com/chrj/smtpd"
"github.com/vharitonsky/iniflags"
)
var (
hostName = flag.String("hostname", "localhost.localdomain", "Server hostname")
welcomeMsg = flag.String("welcome_msg", "", "Welcome message for SMTP session")
listen = flag.String("listen", "127.0.0.1:25 [::1]:25", "Address and port to listen for incoming SMTP")
localCert = flag.String("local_cert", "", "SSL certificate for STARTTLS/TLS")
localKey = flag.String("local_key", "", "SSL private key for STARTTLS/TLS")
localForceTLS = flag.Bool("local_forcetls", false, "Force STARTTLS (needs local_cert and local_key)")
remoteHost = flag.String("remote_host", "smtp.gmail.com", "Outgoing SMTP server")
remotePort = flag.Int("remote_port", 587, "Outgoing SMTP port")
remoteUser = flag.String("remote_user", "", "Username for authentication on outgoing SMTP server")
remotePass = flag.String("remote_pass", "", "Password for authentication on outgoing SMTP server")
)
func handler(peer smtpd.Peer, env smtpd.Envelope) error {
return smtp.SendMail(
fmt.Sprintf("%s:%d", *remoteHost, *remotePort),
smtp.PlainAuth("", *remoteUser, *remotePass, *remoteHost),
env.Sender,
env.Recipients,
env.Data,
)
}
func main() {
iniflags.Parse()
server := &smtpd.Server{
Hostname: *hostName,
WelcomeMessage: *welcomeMsg,
Handler: handler,
ForceTLS: *localForceTLS,
}
listeners := strings.Split(*listen, " ")
for i := range(listeners) {
listener := listeners[i]
if strings.Index(listeners[i], "://") == -1 {
;
} else if strings.HasPrefix(listeners[i], "tls://") || strings.HasPrefix(listeners[i], "starttls://") {
listener = strings.TrimPrefix(listener, "tls://")
listener = strings.TrimPrefix(listener, "starttls://")
if *localCert == "" || *localKey == "" {
log.Fatal("TLS certificate/key not defined in config")
}
cert, err := tls.LoadX509KeyPair(*localCert, *localKey)
if err != nil {
log.Fatal(err)
}
server.TLSConfig = &tls.Config {
Certificates: [] tls.Certificate{cert},
}
} else {
log.Fatal("Unknown protocol in listener ", listener)
}
log.Printf("Listen on %s ...\n", listener)
go server.ListenAndServe(listener)
}
for true {
time.Sleep(time.Minute)
}
}