func smtpSendMailPart2(c *smtp.Client, smtpHost string, a smtp.Auth, from string, to []string, msg []byte) (err error) {
defer c.Close()
if err = c.Hello("localhost"); err != nil {
return err
}
if ok, _ := c.Extension("STARTTLS"); ok {
config := &tls.Config{ServerName: smtpHost}
if err = c.StartTLS(config); err != nil {
return err
}
}
if a != nil {
if ok, _ := c.Extension("AUTH"); ok {
if err = c.Auth(a); err != nil {
return err
}
}
}
if err = c.Mail(from); err != nil {
return err
}
for _, addr := range to {
if err = c.Rcpt(addr); err != nil {
return err
}
}
w, err := c.Data()
if err != nil {
return err
}
_, err = w.Write(msg)
if err != nil {
return err
}
err = w.Close()
if err != nil {
return err
}
return c.Quit()
}
// Attempt to connect to the specified server. The connection attempt is
// performed in a separate goroutine, allowing it to be aborted if the host
// queue is shut down.
func (h *Host) tryMailServer(server, hostname string) (*smtp.Client, error) {
var (
c *smtp.Client
err error
done = make(chan bool)
)
go func() {
c, err = smtp.Dial(fmt.Sprintf("%s:25", server))
close(done)
}()
select {
case <-done:
case <-h.stop:
return nil, nil
}
if err != nil {
return nil, err
}
if err := c.Hello(hostname); err != nil {
return nil, err
}
if ok, _ := c.Extension("STARTTLS"); ok {
config := &tls.Config{ServerName: server}
if h.config.DisableSSLVerification {
config.InsecureSkipVerify = true
}
if err := c.StartTLS(config); err != nil {
return nil, err
}
}
return c, nil
}
func NewSmtpClient(addr string, a smtp.Auth, concurrency int) (client *SmtpClient, err error) {
pool := make(chan *smtp.Client, concurrency)
for i := 0; i < concurrency; i++ {
var c *smtp.Client
c, err = smtp.Dial(addr)
if err != nil {
return
}
if err = c.Hello("localhost"); err != nil {
return
}
if ok, _ := c.Extension("STARTTLS"); ok {
if err = c.StartTLS(nil); err != nil {
return
}
}
if ok, _ := c.Extension("AUTH"); ok {
if err = c.Auth(a); err != nil {
return
}
}
pool <- c
}
client = &SmtpClient{pool, &sync.Mutex{}, false}
return
}
// TestSMTP tests if can connect with the server and send some commands.
func TestSMTP(addr string, a smtp.Auth, hello string, timeout time.Duration, insecureSkipVerify bool) error {
serverName := addr
port := ""
s := strings.SplitN(addr, ":", 2)
if len(s) >= 2 {
serverName = s[0]
port = s[1]
}
if serverName == "" || port == "" {
return e.New("addrs is invalid")
}
hosts, err := dns.LookupHostCache(serverName)
if err != nil {
return e.Forward(err)
}
if len(hosts) == 0 {
return e.New("can't resolve the addr")
}
conn, err := net.DialTimeout("tcp", hosts[0]+":"+port, timeout)
if err != nil {
return e.Forward(err)
}
defer conn.Close()
command := &Command{
Timeout: timeout,
Conn: conn,
}
var c *smtp.Client
r := command.Exec(smtp.NewClient, conn, serverName)
r(&c, &err)
if err != nil {
return e.Forward(err)
}
defer c.Close()
if hello != "" {
r = command.Exec(c.Hello, hello)
r(&err)
if err != nil {
return e.Forward(err)
}
}
if ok, _ := c.Extension("STARTTLS"); ok {
r = command.Exec(c.StartTLS, &tls.Config{
ServerName: serverName,
InsecureSkipVerify: insecureSkipVerify,
})
r(&err)
if err != nil {
return e.Forward(err)
}
}
if a != nil {
found, _ := c.Extension("AUTH")
if found {
r = command.Exec(c.Auth, a)
r(&err)
if err != nil {
return e.Forward(err)
}
}
}
r = command.Exec(c.Reset)
r(&err)
if err != nil {
return e.New(err)
}
r = command.Exec(c.Quit)
r(&err)
if err != nil {
return e.New(err)
}
return nil
}
// SendMail send a message to specific destination (to) using smtp server in addrs
// and a auth.
func SendMail(addr string, a smtp.Auth, from string, to []string, hello string, msg []byte, timeout time.Duration, insecureSkipVerify bool) error {
serverName := addr
port := ""
serverName, port, err := net.SplitHostPort(addr)
if err != nil {
return e.Push(err, "invalid adderess")
}
if serverName == "" || port == "" {
return e.New("addrs is invalid")
}
conn, err := net.DialTimeout("tcp", addr, timeout)
if err != nil {
return e.New(err)
}
defer conn.Close()
command := &Command{
Timeout: timeout,
Conn: conn,
}
var c *smtp.Client
r := command.Exec(smtp.NewClient, conn, serverName)
r(&c, &err)
if err != nil {
return e.Forward(err)
}
defer c.Close()
if hello != "" {
r = command.Exec(c.Hello, hello)
r(&err)
if err != nil {
return e.Forward(err)
}
}
if ok, _ := c.Extension("STARTTLS"); ok {
r = command.Exec(c.StartTLS, &tls.Config{
ServerName: serverName,
InsecureSkipVerify: insecureSkipVerify,
})
r(&err)
if err != nil {
return e.Forward(err)
}
}
if a != nil {
found, _ := c.Extension("AUTH")
if found {
r = command.Exec(c.Auth, a)
r(&err)
if err != nil {
return e.Forward(err)
}
}
}
r = command.Exec(c.Mail, from)
r(&err)
if err != nil {
return e.Forward(err)
}
for _, addr := range to {
r = command.Exec(c.Rcpt, addr)
r(&err)
if err != nil {
return e.New(err)
}
}
var w io.WriteCloser
r = command.ExecTimeout(0, c.Data)
r(&w, &err)
if err != nil {
return e.New(err)
}
_, err = w.Write(msg)
if err != nil {
return e.New(err)
}
err = w.Close()
if err != nil {
return e.New(err)
}
r = command.Exec(c.Quit)
r(&err)
if err != nil {
return e.New(err)
}
return nil
}
// SendMailMessage handles outgoing message to SMTP server.
//
// - The connections to the service can be either plain (port 25)
// or SSL/TLS (port 465)
//
// - If the server supports STARTTLS and the channel is not already
// encrypted (via SSL), the application will use the "STLS" command
// to initiate a channel encryption.
//
// - Connections can be tunneled through any SOCKS5 proxy (like Tor)
func SendMailMessage(host, proxy, fromAddr, toAddr string, body []byte) error {
var (
c0 net.Conn
c1 *tls.Conn
cli *smtp.Client
)
defer func() {
if cli != nil {
cli.Close()
}
if c1 != nil {
c1.Close()
}
if c0 != nil {
c0.Close()
}
}()
uSrv, err := url.Parse(host)
if err != nil {
return err
}
if proxy == "" {
c0, err = net.Dial("tcp", uSrv.Host)
} else {
host, port, err := SplitHost(uSrv.Host)
if err != nil {
return err
}
c0, err = Socks5Connect("tcp", host, port, proxy)
}
if err != nil {
return err
}
if c0 == nil {
return errors.New("Can't estabish connection to " + uSrv.Host)
}
sslConfig := &tls.Config{InsecureSkipVerify: true}
if uSrv.Scheme == "smtps" {
c1 = tls.Client(c0, sslConfig)
if err = c1.Handshake(); err != nil {
return err
}
cli, err = smtp.NewClient(c1, uSrv.Host)
} else {
cli, err = smtp.NewClient(c0, uSrv.Host)
if err == nil {
if ok, _ := cli.Extension("STLS"); ok {
err = cli.StartTLS(sslConfig)
}
}
}
if err != nil {
return err
}
pw, _ := uSrv.User.Password()
auth := smtp.PlainAuth("", uSrv.User.Username(), pw, uSrv.Host)
if err = cli.Auth(auth); err != nil {
return err
}
if err = cli.Mail(fromAddr); err != nil {
return err
}
if err = cli.Rcpt(toAddr); err != nil {
return err
}
wrt, err := cli.Data()
if err != nil {
return err
}
wrt.Write(body)
wrt.Close()
if err = cli.Quit(); err != nil {
return err
}
return nil
}
func SendMail(timeout time.Duration, addr string, from string, to string, msg []byte) error {
response := make(chan error, 1)
var conn *smtp.Client
var err error
go func() {
conn, err = smtp.Dial(addr)
if err != nil {
response <- err
return
}
response <- nil
}()
select {
case res := <-response:
if res == nil {
go func() {
defer conn.Close()
if err = conn.Hello("localhost"); err != nil {
response <- err
return
}
if ok, _ := conn.Extension("STARTTLS"); ok {
config := &tls.Config{ServerName: addr}
if err = conn.StartTLS(config); err != nil {
response <- err
return
}
}
if err = conn.Mail(from); err != nil {
response <- err
return
}
if err = conn.Rcpt(to); err != nil {
response <- err
return
}
w, err := conn.Data()
if err != nil {
response <- err
return
}
_, err = w.Write(msg)
if err != nil {
response <- err
return
}
err = w.Close()
if err != nil {
response <- err
return
}
response <- conn.Quit()
}()
return <-response
} else {
return res
}
case <-time.After(time.Second * timeout): //don't do the smtp transaction, abandon the socket, it'll timeout after ~3 mins in syn_sent
return fmt.Errorf("Sending timeout")
}
}
// Send an email using the given host, SMTP auth (optional) and HELO hostname, returns any error thrown by smtp.SendMail
// This function merges the To, Cc, and Bcc fields and calls the smtp.SendMail function using the Email.Bytes() output as the message
func (e *Email) SendWithHELO(hostname string, port int32, a smtp.Auth, heloHostname string, esCerts *configprofile.CodeSigningCerts) error {
// format server address
addr := fmt.Sprintf("%s:%d", hostname, port)
// Merge the To, Cc, and Bcc fields
to := make([]string, 0, len(e.To)+len(e.Cc)+len(e.Bcc))
to = append(append(append(to, e.To...), e.Cc...), e.Bcc...)
for i := 0; i < len(to); i++ {
addr, err := mail.ParseAddress(to[i])
if err != nil {
return err
}
to[i] = addr.Address
}
// Check to make sure there is at least one recipient and one "From" address
if e.From == "" || len(to) == 0 {
return errors.New("Must specify at least one From address and one To address")
}
from, err := mail.ParseAddress(e.From)
if err != nil {
return err
}
// Sign the email with S/MIME
cmd := exec.Command("openssl", "smime", "-sign", "-signer", esCerts.Cert, "-inkey", esCerts.Key)
emailBytes, err := e.Bytes()
if err != nil {
return err
}
stdin, err := cmd.StdinPipe()
if err != nil {
return err
}
stdout, err := cmd.StdoutPipe()
if err != nil {
return err
}
err = cmd.Start()
if err != nil {
return err
}
stdin.Write(emailBytes)
stdin.Close()
signedData, err := ioutil.ReadAll(stdout)
if err != nil {
return err
}
err = cmd.Wait()
if err != nil {
return err
}
var signedEmail bytes.Buffer
headerToBytes(&signedEmail, e.msgHeaders())
signedEmail.Write(signedData)
raw := signedEmail.Bytes()
// Manually send email using net/smtp
var c *smtp.Client
if port == 465 {
// TLS config
tlsconfig := &tls.Config{
InsecureSkipVerify: true,
ServerName: hostname,
}
// Here is the key, you need to call tls.Dial instead of smtp.Dial
// for smtp servers running on 465 that require an ssl connection
// from the very beginning (no starttls)
conn, err := tls.Dial("tcp", addr, tlsconfig)
if err != nil {
return err
}
c, err = smtp.NewClient(conn, hostname)
if err != nil {
return err
}
} else {
c, err = smtp.Dial(addr)
if err != nil {
return err
}
}
defer c.Close()
if err = c.Hello(heloHostname); err != nil {
return err
}
if ok, _ := c.Extension("STARTTLS"); ok {
config := &tls.Config{ServerName: hostname}
if err = c.StartTLS(config); err != nil {
return err
}
}
if a != nil {
if ok, _ := c.Extension("AUTH"); ok {
if err = c.Auth(a); err != nil {
return err
}
}
}
if err = c.Mail(from.Address); err != nil {
return err
}
for _, addr := range to {
if err = c.Rcpt(addr); err != nil {
return err
}
}
w, err := c.Data()
if err != nil {
return err
}
_, err = w.Write(raw)
if err != nil {
return err
}
err = w.Close()
if err != nil {
return err
}
return c.Quit()
}