add config options for mail encryption and authentication

changelog/unreleased/enhancement-mail-authentication-encryption-settings.md

@@ -0,0 +1,10 @@
+Enhancement: Add configuration options for mail authentication and encryption
+
+We've added configuration options to configure the authentication and encryption
+for sending mails in the notifications service.
+
+Furthermore there is now a distinguished configuration option for the username to use
+for authentication against the mail server. This allows you to customize the sender address
+to your liking. For example sender addresses like `my oCIS instance <ocis@owncloud.test>` are now possible, too.
+
+https://github.com/owncloud/ocis/pull/4443

deployments/examples/ocis_traefik/docker-compose.yml

@@ -68,7 +68,8 @@ services:
       # email server (in this case inbucket acts as mail catcher)
       NOTIFICATIONS_SMTP_HOST: inbucket
       NOTIFICATIONS_SMTP_PORT: 2500
-      NOTIFICATIONS_SMTP_SENDER: notifications@${OCIS_DOMAIN:-ocis.owncloud.test}
+      NOTIFICATIONS_SMTP_SENDER: oCIS notifications <notifications@${OCIS_DOMAIN:-ocis.owncloud.test}>
+      NOTIFICATIONS_SMTP_USERNAME: notifications@${OCIS_DOMAIN:-ocis.owncloud.test}
       NOTIFICATIONS_SMTP_INSECURE: true # the mail catcher uses self signed certificates
     volumes:
       - ocis-config:/etc/ocis

services/notifications/pkg/channels/channels.go

@@ -4,6 +4,7 @@ package channels
 import (
 	"context"
 	"crypto/tls"
+	"strings"
 
 	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
 	groups "github.com/cs3org/go-cs3apis/cs3/identity/group/v1beta1"
@@ -45,6 +46,59 @@ type Mail struct {
 	logger        log.Logger
 }
 
+func (m Mail) getMailClient() (*mail.SMTPClient, error) {
+	server := mail.NewSMTPClient()
+	server.Host = m.conf.Notifications.SMTP.Host
+	server.Port = m.conf.Notifications.SMTP.Port
+	server.Username = m.conf.Notifications.SMTP.Username
+	if server.Username == "" {
+		// compatibility fallback
+		server.Username = m.conf.Notifications.SMTP.Sender
+	}
+	server.Password = m.conf.Notifications.SMTP.Password
+	if server.TLSConfig == nil {
+		server.TLSConfig = &tls.Config{}
+	}
+	server.TLSConfig.InsecureSkipVerify = m.conf.Notifications.SMTP.Insecure
+
+	switch strings.ToLower(m.conf.Notifications.SMTP.Authentication) {
+	case "login":
+		server.Authentication = mail.AuthLogin
+	case "plain":
+		server.Authentication = mail.AuthPlain
+	case "crammd5":
+		server.Authentication = mail.AuthCRAMMD5
+	case "none":
+		server.Authentication = mail.AuthNone
+	default:
+		return nil, errors.New("unknown mail authentication method")
+	}
+
+	switch strings.ToLower(m.conf.Notifications.SMTP.Encryption) {
+	case "tls":
+		server.Encryption = mail.EncryptionTLS
+		server.TLSConfig.ServerName = m.conf.Notifications.SMTP.Host
+	case "starttls":
+		server.Encryption = mail.EncryptionSTARTTLS
+		server.TLSConfig.ServerName = m.conf.Notifications.SMTP.Host
+	case "ssl":
+		server.Encryption = mail.EncryptionSSL
+	case "ssltls":
+		server.Encryption = mail.EncryptionSSLTLS
+	case "none":
+		server.Encryption = mail.EncryptionNone
+	default:
+		return nil, errors.New("unknown mail encryption method")
+	}
+
+	smtpClient, err := server.Connect()
+	if err != nil {
+		return nil, err
+	}
+
+	return smtpClient, nil
+}
+
 // SendMessage sends a message to all given users.
 func (m Mail) SendMessage(userIDs []string, msg string) error {
 	if m.conf.Notifications.SMTP.Host == "" {
@@ -56,22 +110,13 @@ func (m Mail) SendMessage(userIDs []string, msg string) error {
 		return err
 	}
 
-	server := mail.NewSMTPClient()
-	server.Host = m.conf.Notifications.SMTP.Host
-	server.Port = m.conf.Notifications.SMTP.Port
-	server.Username = m.conf.Notifications.SMTP.Sender
-	server.Password = m.conf.Notifications.SMTP.Password
-	server.TLSConfig = &tls.Config{InsecureSkipVerify: m.conf.Notifications.SMTP.Insecure}
-
-	smtpClient, err := server.Connect()
+	smtpClient, err := m.getMailClient()
 	if err != nil {
 		return err
 	}
 
 	email := mail.NewMSG()
-
 	email.SetFrom(m.conf.Notifications.SMTP.Sender).AddTo(to...)
-
 	email.SetBody(mail.TextPlain, msg)
 
 	return email.Send(smtpClient)

services/notifications/pkg/config/config.go

@@ -30,11 +30,14 @@ type Notifications struct {
 
 // SMTP combines the smtp configuration options.
 type SMTP struct {
-	Host     string `yaml:"smtp_host" env:"NOTIFICATIONS_SMTP_HOST" desc:"SMTP host to connect to."`
-	Port     int    `yaml:"smtp_port" env:"NOTIFICATIONS_SMTP_PORT" desc:"Port of the SMTP host to connect to."`
-	Sender   string `yaml:"smtp_sender" env:"NOTIFICATIONS_SMTP_SENDER" desc:"Sender of emails that will be sent."`
-	Password string `yaml:"smtp_password" env:"NOTIFICATIONS_SMTP_PASSWORD" desc:"Password of the SMTP host to connect to."`
-	Insecure bool   `yaml:"insecure" env:"NOTIFICATIONS_SMTP_INSECURE" desc:"Allow insecure connections to the SMTP server."`
+	Host           string `yaml:"smtp_host" env:"NOTIFICATIONS_SMTP_HOST" desc:"SMTP host to connect to."`
+	Port           int    `yaml:"smtp_port" env:"NOTIFICATIONS_SMTP_PORT" desc:"Port of the SMTP host to connect to."`
+	Sender         string `yaml:"smtp_sender" env:"NOTIFICATIONS_SMTP_SENDER" desc:"Sender address of emails that will be sent."`
+	Username       string `yaml:"smtp_username" env:"NOTIFICATIONS_SMTP_USERNAME" desc:"Username for the SMTP host to connect to."`
+	Password       string `yaml:"smtp_password" env:"NOTIFICATIONS_SMTP_PASSWORD" desc:"Password for the SMTP host to connect to."`
+	Insecure       bool   `yaml:"insecure" env:"NOTIFICATIONS_SMTP_INSECURE" desc:"Allow insecure connections to the SMTP server."`
+	Authentication string `yaml:"smtp_authentication" env:"NOTIFICATIONS_SMTP_AUTHENTICATION" desc:"Authentication method for the SMTP communication. Possible values are 'login', 'plain', 'crammd5', 'none'"`
+	Encryption     string `yaml:"smtp_encryption" env:"NOTIFICATIONS_SMTP_ENCRYPTION" desc:"Encryption method for the SMTP communication. Possible values  are 'starttls', 'ssl', 'ssltls', 'tls'  and 'none'."`
 }
 
 // Events combines the configuration options for the event bus.

services/notifications/pkg/config/defaults/defaultconfig.go

@@ -24,9 +24,11 @@ func DefaultConfig() *config.Config {
 		},
 		Notifications: config.Notifications{
 			SMTP: config.SMTP{
-				Host:   "",
-				Port:   1025,
-				Sender: "noreply@example.com",
+				Host:           "",
+				Port:           1025,
+				Sender:         "ownCloud <noreply@example.com>",
+				Authentication: "none",
+				Encryption:     "none",
 			},
 			Events: config.Events{
 				Endpoint:      "127.0.0.1:9233",