1 files changed, 448 insertions, 0 deletions
diff --git a/services/mailer/mailer.go b/services/mailer/mailer.go
new file mode 100644
index 0000000..0a723f9
--- /dev/null
+++ b/services/mailer/mailer.go
@@ -0,0 +1,448 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package mailer
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"fmt"
+	"hash/fnv"
+	"io"
+	"net"
+	"net/smtp"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/graceful"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/process"
+	"code.gitea.io/gitea/modules/queue"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/templates"
+	notify_service "code.gitea.io/gitea/services/notify"
+
+	ntlmssp "github.com/Azure/go-ntlmssp"
+	"github.com/jaytaylor/html2text"
+	"gopkg.in/gomail.v2"
+)
+
+// Message mail body and log info
+type Message struct {
+	Info            string // Message information for log purpose.
+	FromAddress     string
+	FromDisplayName string
+	To              string // Use only one recipient to prevent leaking of addresses
+	ReplyTo         string
+	Subject         string
+	Date            time.Time
+	Body            string
+	Headers         map[string][]string
+}
+
+// ToMessage converts a Message to gomail.Message
+func (m *Message) ToMessage() *gomail.Message {
+	msg := gomail.NewMessage()
+	msg.SetAddressHeader("From", m.FromAddress, m.FromDisplayName)
+	msg.SetHeader("To", m.To)
+	if m.ReplyTo != "" {
+		msg.SetHeader("Reply-To", m.ReplyTo)
+	}
+	for header := range m.Headers {
+		msg.SetHeader(header, m.Headers[header]...)
+	}
+
+	if setting.MailService.SubjectPrefix != "" {
+		msg.SetHeader("Subject", setting.MailService.SubjectPrefix+" "+m.Subject)
+	} else {
+		msg.SetHeader("Subject", m.Subject)
+	}
+	msg.SetDateHeader("Date", m.Date)
+	msg.SetHeader("X-Auto-Response-Suppress", "All")
+
+	plainBody, err := html2text.FromString(m.Body)
+	if err != nil || setting.MailService.SendAsPlainText {
+		if strings.Contains(base.TruncateString(m.Body, 100), "<html>") {
+			log.Warn("Mail contains HTML but configured to send as plain text.")
+		}
+		msg.SetBody("text/plain", plainBody)
+	} else {
+		msg.SetBody("text/plain", plainBody)
+		msg.AddAlternative("text/html", m.Body)
+	}
+
+	if len(msg.GetHeader("Message-ID")) == 0 {
+		msg.SetHeader("Message-ID", m.generateAutoMessageID())
+	}
+
+	for k, v := range setting.MailService.OverrideHeader {
+		if len(msg.GetHeader(k)) != 0 {
+			log.Debug("Mailer override header '%s' as per config", k)
+		}
+		msg.SetHeader(k, v...)
+	}
+
+	return msg
+}
+
+// SetHeader adds additional headers to a message
+func (m *Message) SetHeader(field string, value ...string) {
+	m.Headers[field] = value
+}
+
+func (m *Message) generateAutoMessageID() string {
+	dateMs := m.Date.UnixNano() / 1e6
+	h := fnv.New64()
+	if len(m.To) > 0 {
+		_, _ = h.Write([]byte(m.To))
+	}
+	_, _ = h.Write([]byte(m.Subject))
+	_, _ = h.Write([]byte(m.Body))
+	return fmt.Sprintf("<autogen-%d-%016x@%s>", dateMs, h.Sum64(), setting.Domain)
+}
+
+// NewMessageFrom creates new mail message object with custom From header.
+func NewMessageFrom(to, fromDisplayName, fromAddress, subject, body string) *Message {
+	log.Trace("NewMessageFrom (body):\n%s", body)
+
+	return &Message{
+		FromAddress:     fromAddress,
+		FromDisplayName: fromDisplayName,
+		To:              to,
+		Subject:         subject,
+		Date:            time.Now(),
+		Body:            body,
+		Headers:         map[string][]string{},
+	}
+}
+
+// NewMessage creates new mail message object with default From header.
+func NewMessage(to, subject, body string) *Message {
+	return NewMessageFrom(to, setting.MailService.FromName, setting.MailService.FromEmail, subject, body)
+}
+
+type loginAuth struct {
+	username, password string
+}
+
+// LoginAuth SMTP AUTH LOGIN Auth Handler
+func LoginAuth(username, password string) smtp.Auth {
+	return &loginAuth{username, password}
+}
+
+// Start start SMTP login auth
+func (a *loginAuth) Start(server *smtp.ServerInfo) (string, []byte, error) {
+	return "LOGIN", []byte{}, nil
+}
+
+// Next next step of SMTP login auth
+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, fmt.Errorf("unknown fromServer: %s", string(fromServer))
+		}
+	}
+	return nil, nil
+}
+
+type ntlmAuth struct {
+	username, password, domain string
+	domainNeeded               bool
+}
+
+// NtlmAuth SMTP AUTH NTLM Auth Handler
+func NtlmAuth(username, password string) smtp.Auth {
+	user, domain, domainNeeded := ntlmssp.GetDomain(username)
+	return &ntlmAuth{user, password, domain, domainNeeded}
+}
+
+// Start starts SMTP NTLM Auth
+func (a *ntlmAuth) Start(server *smtp.ServerInfo) (string, []byte, error) {
+	negotiateMessage, err := ntlmssp.NewNegotiateMessage(a.domain, "")
+	return "NTLM", negotiateMessage, err
+}
+
+// Next next step of SMTP ntlm auth
+func (a *ntlmAuth) Next(fromServer []byte, more bool) ([]byte, error) {
+	if more {
+		if len(fromServer) == 0 {
+			return nil, fmt.Errorf("ntlm ChallengeMessage is empty")
+		}
+		authenticateMessage, err := ntlmssp.ProcessChallenge(fromServer, a.username, a.password, a.domainNeeded)
+		return authenticateMessage, err
+	}
+	return nil, nil
+}
+
+// Sender SMTP mail sender
+type smtpSender struct{}
+
+// Send send email
+func (s *smtpSender) Send(from string, to []string, msg io.WriterTo) error {
+	opts := setting.MailService
+
+	var network string
+	var address string
+	if opts.Protocol == "smtp+unix" {
+		network = "unix"
+		address = opts.SMTPAddr
+	} else {
+		network = "tcp"
+		address = net.JoinHostPort(opts.SMTPAddr, opts.SMTPPort)
+	}
+
+	conn, err := net.Dial(network, address)
+	if err != nil {
+		return fmt.Errorf("failed to establish network connection to SMTP server: %w", err)
+	}
+	defer conn.Close()
+
+	var tlsconfig *tls.Config
+	if opts.Protocol == "smtps" || opts.Protocol == "smtp+starttls" {
+		tlsconfig = &tls.Config{
+			InsecureSkipVerify: opts.ForceTrustServerCert,
+			ServerName:         opts.SMTPAddr,
+		}
+
+		if opts.UseClientCert {
+			cert, err := tls.LoadX509KeyPair(opts.ClientCertFile, opts.ClientKeyFile)
+			if err != nil {
+				return fmt.Errorf("could not load SMTP client certificate: %w", err)
+			}
+			tlsconfig.Certificates = []tls.Certificate{cert}
+		}
+	}
+
+	if opts.Protocol == "smtps" {
+		conn = tls.Client(conn, tlsconfig)
+	}
+
+	host := "localhost"
+	if opts.Protocol == "smtp+unix" {
+		host = opts.SMTPAddr
+	}
+	client, err := smtp.NewClient(conn, host)
+	if err != nil {
+		return fmt.Errorf("could not initiate SMTP session: %w", err)
+	}
+
+	if opts.EnableHelo {
+		hostname := opts.HeloHostname
+		if len(hostname) == 0 {
+			hostname, err = os.Hostname()
+			if err != nil {
+				return fmt.Errorf("could not retrieve system hostname: %w", err)
+			}
+		}
+
+		if err = client.Hello(hostname); err != nil {
+			return fmt.Errorf("failed to issue HELO command: %w", err)
+		}
+	}
+
+	if opts.Protocol == "smtp+starttls" {
+		hasStartTLS, _ := client.Extension("STARTTLS")
+		if hasStartTLS {
+			if err = client.StartTLS(tlsconfig); err != nil {
+				return fmt.Errorf("failed to start TLS connection: %w", err)
+			}
+		} else {
+			log.Warn("StartTLS requested, but SMTP server does not support it; falling back to regular SMTP")
+		}
+	}
+
+	canAuth, options := client.Extension("AUTH")
+	if len(opts.User) > 0 {
+		if !canAuth {
+			return fmt.Errorf("SMTP server does not support AUTH, but credentials provided")
+		}
+
+		var auth smtp.Auth
+
+		if strings.Contains(options, "CRAM-MD5") {
+			auth = smtp.CRAMMD5Auth(opts.User, opts.Passwd)
+		} else if strings.Contains(options, "PLAIN") {
+			auth = smtp.PlainAuth("", opts.User, opts.Passwd, host)
+		} else if strings.Contains(options, "LOGIN") {
+			// Patch for AUTH LOGIN
+			auth = LoginAuth(opts.User, opts.Passwd)
+		} else if strings.Contains(options, "NTLM") {
+			auth = NtlmAuth(opts.User, opts.Passwd)
+		}
+
+		if auth != nil {
+			if err = client.Auth(auth); err != nil {
+				return fmt.Errorf("failed to authenticate SMTP: %w", err)
+			}
+		}
+	}
+
+	if opts.OverrideEnvelopeFrom {
+		if err = client.Mail(opts.EnvelopeFrom); err != nil {
+			return fmt.Errorf("failed to issue MAIL command: %w", err)
+		}
+	} else {
+		if err = client.Mail(from); err != nil {
+			return fmt.Errorf("failed to issue MAIL command: %w", err)
+		}
+	}
+
+	for _, rec := range to {
+		if err = client.Rcpt(rec); err != nil {
+			return fmt.Errorf("failed to issue RCPT command: %w", err)
+		}
+	}
+
+	w, err := client.Data()
+	if err != nil {
+		return fmt.Errorf("failed to issue DATA command: %w", err)
+	} else if _, err = msg.WriteTo(w); err != nil {
+		return fmt.Errorf("SMTP write failed: %w", err)
+	} else if err = w.Close(); err != nil {
+		return fmt.Errorf("SMTP close failed: %w", err)
+	}
+
+	return client.Quit()
+}
+
+// Sender sendmail mail sender
+type sendmailSender struct{}
+
+// Send send email
+func (s *sendmailSender) Send(from string, to []string, msg io.WriterTo) error {
+	var err error
+	var closeError error
+	var waitError error
+
+	envelopeFrom := from
+	if setting.MailService.OverrideEnvelopeFrom {
+		envelopeFrom = setting.MailService.EnvelopeFrom
+	}
+
+	args := []string{"-f", envelopeFrom, "-i"}
+	args = append(args, setting.MailService.SendmailArgs...)
+	args = append(args, to...)
+	log.Trace("Sending with: %s %v", setting.MailService.SendmailPath, args)
+
+	desc := fmt.Sprintf("SendMail: %s %v", setting.MailService.SendmailPath, args)
+
+	ctx, _, finished := process.GetManager().AddContextTimeout(graceful.GetManager().HammerContext(), setting.MailService.SendmailTimeout, desc)
+	defer finished()
+
+	cmd := exec.CommandContext(ctx, setting.MailService.SendmailPath, args...)
+	pipe, err := cmd.StdinPipe()
+	if err != nil {
+		return err
+	}
+	process.SetSysProcAttribute(cmd)
+
+	if err = cmd.Start(); err != nil {
+		_ = pipe.Close()
+		return err
+	}
+
+	if setting.MailService.SendmailConvertCRLF {
+		buf := &strings.Builder{}
+		_, err = msg.WriteTo(buf)
+		if err == nil {
+			_, err = strings.NewReplacer("\r\n", "\n").WriteString(pipe, buf.String())
+		}
+	} else {
+		_, err = msg.WriteTo(pipe)
+	}
+
+	// we MUST close the pipe or sendmail will hang waiting for more of the message
+	// Also we should wait on our sendmail command even if something fails
+	closeError = pipe.Close()
+	waitError = cmd.Wait()
+	if err != nil {
+		return err
+	} else if closeError != nil {
+		return closeError
+	}
+	return waitError
+}
+
+type dummySender struct{}
+
+func (s *dummySender) Send(from string, to []string, msg io.WriterTo) error {
+	buf := bytes.Buffer{}
+	if _, err := msg.WriteTo(&buf); err != nil {
+		return err
+	}
+	log.Info("Mail From: %s To: %v Body: %s", from, to, buf.String())
+	return nil
+}
+
+var mailQueue *queue.WorkerPoolQueue[*Message]
+
+// Sender sender for sending mail synchronously
+var Sender gomail.Sender
+
+// NewContext start mail queue service
+func NewContext(ctx context.Context) {
+	// Need to check if mailQueue is nil because in during reinstall (user had installed
+	// before but switched install lock off), this function will be called again
+	// while mail queue is already processing tasks, and produces a race condition.
+	if setting.MailService == nil || mailQueue != nil {
+		return
+	}
+
+	if setting.Service.EnableNotifyMail {
+		notify_service.RegisterNotifier(NewNotifier())
+	}
+
+	switch setting.MailService.Protocol {
+	case "sendmail":
+		Sender = &sendmailSender{}
+	case "dummy":
+		Sender = &dummySender{}
+	default:
+		Sender = &smtpSender{}
+	}
+
+	subjectTemplates, bodyTemplates = templates.Mailer(ctx)
+
+	mailQueue = queue.CreateSimpleQueue(graceful.GetManager().ShutdownContext(), "mail", func(items ...*Message) []*Message {
+		for _, msg := range items {
+			gomailMsg := msg.ToMessage()
+			log.Trace("New e-mail sending request %s: %s", gomailMsg.GetHeader("To"), msg.Info)
+			if err := gomail.Send(Sender, gomailMsg); err != nil {
+				log.Error("Failed to send emails %s: %s - %v", gomailMsg.GetHeader("To"), msg.Info, err)
+			} else {
+				log.Trace("E-mails sent %s: %s", gomailMsg.GetHeader("To"), msg.Info)
+			}
+		}
+		return nil
+	})
+	if mailQueue == nil {
+		log.Fatal("Unable to create mail queue")
+	}
+	go graceful.GetManager().RunWithCancel(mailQueue)
+}
+
+// SendAsync send emails asynchronously (make it mockable)
+var SendAsync = sendAsync
+
+func sendAsync(msgs ...*Message) {
+	if setting.MailService == nil {
+		log.Error("Mailer: SendAsync is being invoked but mail service hasn't been initialized")
+		return
+	}
+
+	go func() {
+		for _, msg := range msgs {
+			_ = mailQueue.Push(msg)
+		}
+	}()
+}