forked from anuarishe/gomail
/
smtp.go
344 lines (295 loc) · 7.2 KB
/
smtp.go
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package gomail
import (
"bufio"
"crypto/tls"
"fmt"
"golang.org/x/net/proxy"
"io"
"net"
"net/http"
"net/smtp"
"net/url"
"strings"
"time"
)
// A Dialer is a dialer to an SMTP server.
type Dialer struct {
// Host represents the host of the SMTP server.
Host string
// Port represents the port of the SMTP server.
Port int
// Username is the username to use to authenticate to the SMTP server.
Username string
// Password is the password to use to authenticate to the SMTP server.
Password string
// Auth represents the authentication mechanism used to authenticate to the
// SMTP server.
Auth smtp.Auth
// SSL defines whether an SSL connection is used. It should be false in
// most cases since the authentication mechanism should use the STARTTLS
// extension instead.
SSL bool
// TSLConfig represents the TLS configuration used for the TLS (when the
// STARTTLS extension is used) or SSL connection.
TLSConfig *tls.Config
// LocalName is the hostname sent to the SMTP server with the HELO command.
// By default, "localhost" is sent.
LocalName string
Proxy Proxy
}
type Proxy struct {
Address string
Username string
Password string
Type string
}
type direct struct{}
func init() {
proxy.RegisterDialerType("http", newHTTPProxy)
}
func newHTTPProxy(uri *url.URL, forward proxy.Dialer) (proxy.Dialer, error) {
s := new(httpProxy)
s.host = uri.Host
s.forward = forward
if uri.User != nil {
s.haveAuth = true
s.username = uri.User.Username()
s.password, _ = uri.User.Password()
}
return s, nil
}
// httpProxy is a HTTP/HTTPS connect proxy.
type httpProxy struct {
host string
haveAuth bool
username string
password string
forward proxy.Dialer
}
func (s *httpProxy) Dial(network, addr string) (net.Conn, error) {
// Dial and create the https client connection.
c, err := s.forward.Dial("tcp", s.host)
if err != nil {
return nil, err
}
// HACK. http.ReadRequest also does this.
reqURL, err := url.Parse("http://" + addr)
if err != nil {
c.Close()
return nil, err
}
reqURL.Scheme = ""
req, err := http.NewRequest("CONNECT", reqURL.String(), nil)
if err != nil {
c.Close()
return nil, err
}
req.Close = false
if s.haveAuth {
req.SetBasicAuth(s.username, s.password)
}
req.Header.Set("User-Agent", "Powerby Gota")
err = req.Write(c)
if err != nil {
c.Close()
return nil, err
}
resp, err := http.ReadResponse(bufio.NewReader(c), req)
if err != nil {
// TODO close resp body ?
resp.Body.Close()
c.Close()
return nil, err
}
resp.Body.Close()
if resp.StatusCode != 200 {
c.Close()
err = fmt.Errorf("Connect server using proxy error, StatusCode [%d]", resp.StatusCode)
return nil, err
}
return c, nil
}
// Direct is a direct proxy: one that makes network connections directly.
var Direct = direct{}
func (direct) Dial(network, addr string) (net.Conn, error) {
return net.Dial(network, addr)
}
// NewDialer returns a new SMTP Dialer. The given parameters are used to connect
// to the SMTP server.
func NewDialer(host string, port int, username, password string) *Dialer {
return &Dialer{
Host: host,
Port: port,
Username: username,
Password: password,
SSL: port == 465,
}
}
func NewDialerWithProxy(host string, port int, username, password string, proxy Proxy) *Dialer {
dialer := NewDialer(host, port, username, password)
dialer.Proxy = proxy
return dialer
}
// NewPlainDialer returns a new SMTP Dialer. The given parameters are used to
// connect to the SMTP server.
//
// Deprecated: Use NewDialer instead.
func NewPlainDialer(host string, port int, username, password string) *Dialer {
return NewDialer(host, port, username, password)
}
// Dial dials and authenticates to an SMTP server. The returned SendCloser
// should be closed when done using it.
func (d *Dialer) Dial() (SendCloser, error) {
var auth *proxy.Auth
var conn net.Conn
var err error
var dialer proxy.Dialer
if d.Proxy.Username != "" {
auth = &proxy.Auth{
User: d.Proxy.Username,
Password: d.Proxy.Password,
}
}
if d.Proxy.Address != "" {
if d.Proxy.Type == "HTTP" {
httpProxyURI, _ := url.Parse(d.Proxy.Address)
dialer, err = proxy.FromURL(httpProxyURI, Direct)
if err != nil {
return nil, err
}
conn, err = dialer.Dial("tcp", addr(d.Host, d.Port))
} else {
dialer, err = proxy.SOCKS5("tcp", d.Proxy.Address, auth, &net.Dialer{Timeout: 10 * time.Second})
if err != nil {
return nil, err
}
conn, err = dialer.Dial("tcp", addr(d.Host, d.Port))
}
} else {
conn, err = netDialTimeout("tcp", addr(d.Host, d.Port), 10*time.Second)
}
if err != nil {
return nil, err
}
if d.SSL {
conn = tlsClient(conn, d.tlsConfig())
}
c, err := smtpNewClient(conn, d.Host)
if err != nil {
return nil, err
}
if d.LocalName != "" {
if err := c.Hello(d.LocalName); err != nil {
return nil, err
}
}
if !d.SSL {
if ok, _ := c.Extension("STARTTLS"); ok {
if err := c.StartTLS(d.tlsConfig()); err != nil {
c.Close()
return nil, err
}
}
}
if d.Auth == nil && d.Username != "" {
if ok, auths := c.Extension("AUTH"); ok {
if strings.Contains(auths, "CRAM-MD5") {
d.Auth = smtp.CRAMMD5Auth(d.Username, d.Password)
} else if strings.Contains(auths, "LOGIN") &&
!strings.Contains(auths, "PLAIN") {
d.Auth = &loginAuth{
username: d.Username,
password: d.Password,
host: d.Host,
}
} else {
d.Auth = smtp.PlainAuth("", d.Username, d.Password, d.Host)
}
}
}
if d.Auth != nil {
if err = c.Auth(d.Auth); err != nil {
c.Close()
return nil, err
}
}
return &smtpSender{c, d}, nil
}
func (d *Dialer) tlsConfig() *tls.Config {
if d.TLSConfig == nil {
return &tls.Config{ServerName: d.Host}
}
return d.TLSConfig
}
func addr(host string, port int) string {
return fmt.Sprintf("%s:%d", host, port)
}
// DialAndSend opens a connection to the SMTP server, sends the given emails and
// closes the connection.
func (d *Dialer) DialAndSend(m ...*Message) error {
s, err := d.Dial()
if err != nil {
return err
}
defer s.Close()
return Send(s, m...)
}
type smtpSender struct {
smtpClient
d *Dialer
}
func (c *smtpSender) Send(from string, to []string, msg io.WriterTo) error {
if err := c.Mail(from); err != nil {
if err == io.EOF {
// This is probably due to a timeout, so reconnect and try again.
sc, derr := c.d.Dial()
if derr == nil {
if s, ok := sc.(*smtpSender); ok {
*c = *s
return c.Send(from, to, msg)
}
}
}
return err
}
for _, addr := range to {
if err := c.Rcpt(addr); err != nil {
return err
}
}
w, err := c.Data()
if err != nil {
return err
}
if _, err = msg.WriteTo(w); err != nil {
w.Close()
return err
}
return w.Close()
}
func (c *smtpSender) Close() error {
return c.Quit()
}
func (c *smtpSender) Reset() error {
return c.smtpClient.Reset()
}
// Stubbed out for tests.
var (
netDialTimeout = net.DialTimeout
tlsClient = tls.Client
smtpNewClient = func(conn net.Conn, host string) (smtpClient, error) {
return smtp.NewClient(conn, host)
}
)
type smtpClient interface {
Hello(string) error
Extension(string) (bool, string)
StartTLS(*tls.Config) error
Auth(smtp.Auth) error
Mail(string) error
Rcpt(string) error
Reset() error
Data() (io.WriteCloser, error)
Quit() error
Close() error
}