// Copyright (c) 2015 Mattermost, Inc. All Rights Reserved. // See License.txt for license information. package utils import ( "crypto/tls" "encoding/base64" "fmt" l4g "github.com/alecthomas/log4go" "github.com/mattermost/platform/model" "net" "net/mail" "net/smtp" "time" ) func encodeRFC2047Word(s string) string { // TODO: use `mime.BEncoding.Encode` instead when `go` >= 1.5 // return mime.BEncoding.Encode("utf-8", s) dst := base64.StdEncoding.EncodeToString([]byte(s)) return "=?utf-8?b?" + dst + "?=" } func connectToSMTPServer(config *model.Config) (net.Conn, *model.AppError) { var conn net.Conn var err error if config.EmailSettings.ConnectionSecurity == model.CONN_SECURITY_TLS { tlsconfig := &tls.Config{ InsecureSkipVerify: true, ServerName: config.EmailSettings.SMTPServer, } conn, err = tls.Dial("tcp", config.EmailSettings.SMTPServer+":"+config.EmailSettings.SMTPPort, tlsconfig) if err != nil { return nil, model.NewAppError("SendMail", "Failed to open TLS connection", err.Error()) } } else { conn, err = net.Dial("tcp", config.EmailSettings.SMTPServer+":"+config.EmailSettings.SMTPPort) if err != nil { return nil, model.NewAppError("SendMail", "Failed to open connection", err.Error()) } } return conn, nil } func newSMTPClient(conn net.Conn, config *model.Config) (*smtp.Client, *model.AppError) { c, err := smtp.NewClient(conn, config.EmailSettings.SMTPServer+":"+config.EmailSettings.SMTPPort) if err != nil { l4g.Error("Failed to open a connection to SMTP server %v", err) return nil, model.NewAppError("SendMail", "Failed to open TLS connection", err.Error()) } // GO does not support plain auth over a non encrypted connection. // so if not tls then no auth auth := smtp.PlainAuth("", config.EmailSettings.SMTPUsername, config.EmailSettings.SMTPPassword, config.EmailSettings.SMTPServer+":"+config.EmailSettings.SMTPPort) if config.EmailSettings.ConnectionSecurity == model.CONN_SECURITY_TLS { if err = c.Auth(auth); err != nil { return nil, model.NewAppError("SendMail", "Failed to authenticate on SMTP server", err.Error()) } } else if config.EmailSettings.ConnectionSecurity == model.CONN_SECURITY_STARTTLS { tlsconfig := &tls.Config{ InsecureSkipVerify: true, ServerName: config.EmailSettings.SMTPServer, } c.StartTLS(tlsconfig) if err = c.Auth(auth); err != nil { return nil, model.NewAppError("SendMail", "Failed to authenticate on SMTP server", err.Error()) } } return c, nil } func TestConnection(config *model.Config) { if !config.EmailSettings.SendEmailNotifications { return } conn, err1 := connectToSMTPServer(config) if err1 != nil { l4g.Error("SMTP server settings do not appear to be configured properly err=%v details=%v", err1.Message, err1.DetailedError) return } defer conn.Close() c, err2 := newSMTPClient(conn, config) if err2 != nil { l4g.Error("SMTP connection settings do not appear to be configured properly err=%v details=%v", err2.Message, err2.DetailedError) return } defer c.Quit() defer c.Close() } func SendMail(to, subject, body string) *model.AppError { return SendMailUsingConfig(to, subject, body, Cfg) } func SendMailUsingConfig(to, subject, body string, config *model.Config) *model.AppError { if !config.EmailSettings.SendEmailNotifications || len(config.EmailSettings.SMTPServer) == 0 { return nil } l4g.Debug("sending mail to " + to + " with subject of '" + subject + "'") fromMail := mail.Address{config.EmailSettings.FeedbackName, config.EmailSettings.FeedbackEmail} toMail := mail.Address{"", to} headers := make(map[string]string) headers["From"] = fromMail.String() headers["To"] = toMail.String() headers["Subject"] = encodeRFC2047Word(subject) headers["MIME-version"] = "1.0" headers["Content-Type"] = "text/html; charset=\"utf-8\"" headers["Content-Transfer-Encoding"] = "8bit" headers["Date"] = time.Now().Format(time.RFC1123Z) message := "" for k, v := range headers { message += fmt.Sprintf("%s: %s\r\n", k, v) } message += "\r\n" + body + "" conn, err1 := connectToSMTPServer(config) if err1 != nil { return err1 } defer conn.Close() c, err2 := newSMTPClient(conn, config) if err2 != nil { return err2 } defer c.Quit() defer c.Close() if err := c.Mail(fromMail.Address); err != nil { return model.NewAppError("SendMail", "Failed to add from email address", err.Error()) } if err := c.Rcpt(toMail.Address); err != nil { return model.NewAppError("SendMail", "Failed to add to email address", err.Error()) } w, err := c.Data() if err != nil { return model.NewAppError("SendMail", "Failed to add email messsage data", err.Error()) } _, err = w.Write([]byte(message)) if err != nil { return model.NewAppError("SendMail", "Failed to write email message", err.Error()) } err = w.Close() if err != nil { return model.NewAppError("SendMail", "Failed to close connection to SMTP server", err.Error()) } return nil }