120 lines
2.7 KiB
Go
120 lines
2.7 KiB
Go
package common
|
|
|
|
import (
|
|
"crypto/rand"
|
|
"crypto/tls"
|
|
"encoding/base64"
|
|
"errors"
|
|
"fmt"
|
|
"net/smtp"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
type loginAuth struct {
|
|
username, password string
|
|
}
|
|
|
|
func LoginAuth(username, password string) smtp.Auth {
|
|
return &loginAuth{username, password}
|
|
}
|
|
|
|
func (a *loginAuth) Start(_ *smtp.ServerInfo) (string, []byte, error) {
|
|
return "LOGIN", []byte(a.username), nil
|
|
}
|
|
|
|
func (a *loginAuth) Next(fromServer []byte, more bool) ([]byte, error) {
|
|
if more {
|
|
switch string(fromServer) {
|
|
case "Username:":
|
|
return []byte(a.username), nil
|
|
case "Password:":
|
|
return []byte(a.password), nil
|
|
default:
|
|
return nil, errors.New("unknown command from server during login auth")
|
|
}
|
|
}
|
|
return nil, nil
|
|
}
|
|
|
|
func SendEmail(subject string, receiver string, content string) error {
|
|
if SMTPFrom == "" { // for compatibility
|
|
SMTPFrom = SMTPAccount
|
|
}
|
|
encodedSubject := fmt.Sprintf("=?UTF-8?B?%s?=", base64.StdEncoding.EncodeToString([]byte(subject)))
|
|
|
|
// Extract domain from SMTPFrom
|
|
parts := strings.Split(SMTPFrom, "@")
|
|
var domain string
|
|
if len(parts) > 1 {
|
|
domain = parts[1]
|
|
}
|
|
// Generate a unique Message-ID
|
|
buf := make([]byte, 16)
|
|
_, err := rand.Read(buf)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
messageId := fmt.Sprintf("<%x@%s>", buf, domain)
|
|
|
|
mail := []byte(fmt.Sprintf("To: %s\r\n"+
|
|
"From: %s<%s>\r\n"+
|
|
"Subject: %s\r\n"+
|
|
"Message-ID: %s\r\n"+ // add Message-ID header to avoid being treated as spam, RFC 5322
|
|
"Date: %s\r\n"+
|
|
"Content-Type: text/html; charset=UTF-8\r\n\r\n%s\r\n",
|
|
receiver, SystemName, SMTPFrom, encodedSubject, messageId, time.Now().Format(time.RFC1123Z), content))
|
|
|
|
var auth smtp.Auth
|
|
if SMTPAuthLoginEnabled {
|
|
auth = LoginAuth(SMTPAccount, SMTPToken)
|
|
} else {
|
|
auth = smtp.PlainAuth("", SMTPAccount, SMTPToken, SMTPServer)
|
|
}
|
|
addr := fmt.Sprintf("%s:%d", SMTPServer, SMTPPort)
|
|
to := strings.Split(receiver, ";")
|
|
|
|
if SMTPPort == 465 {
|
|
tlsConfig := &tls.Config{
|
|
InsecureSkipVerify: true,
|
|
ServerName: SMTPServer,
|
|
}
|
|
conn, err := tls.Dial("tcp", fmt.Sprintf("%s:%d", SMTPServer, SMTPPort), tlsConfig)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
client, err := smtp.NewClient(conn, SMTPServer)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer client.Close()
|
|
if err = client.Auth(auth); err != nil {
|
|
return err
|
|
}
|
|
if err = client.Mail(SMTPFrom); err != nil {
|
|
return err
|
|
}
|
|
receiverEmails := strings.Split(receiver, ";")
|
|
for _, receiver := range receiverEmails {
|
|
if err = client.Rcpt(receiver); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
w, err := client.Data()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = w.Write(mail)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = w.Close()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
} else {
|
|
err = smtp.SendMail(addr, auth, SMTPAccount, to, mail)
|
|
}
|
|
return err
|
|
}
|