From 16297da29856ac5a5c6d30c072a482d95b3ead67 Mon Sep 17 00:00:00 2001
From: thameezb <13134870+thameezb@users.noreply.github.com>
Date: Wed, 13 May 2020 16:33:40 +0200
Subject: [PATCH] Email Notifications: Add StartTLSPolicy config flag (#24574)

---
 conf/defaults.ini                          |  1 +
 conf/sample.ini                            |  2 ++
 docs/sources/installation/configuration.md |  3 +++
 pkg/services/notifications/mailer.go       | 12 ++++++++++++
 pkg/setting/setting_smtp.go                | 22 ++++++++++++----------
 5 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/conf/defaults.ini b/conf/defaults.ini
index 7bdbb97a47d..c1912f6b0c3 100644
--- a/conf/defaults.ini
+++ b/conf/defaults.ini
@@ -464,6 +464,7 @@ skip_verify = false
 from_address = admin@grafana.localhost
 from_name = Grafana
 ehlo_identity =
+startTLS_policy =
 
 [emails]
 welcome_email_on_sign_up = false
diff --git a/conf/sample.ini b/conf/sample.ini
index d0a1fffdff9..8c4b125a7a9 100644
--- a/conf/sample.ini
+++ b/conf/sample.ini
@@ -454,6 +454,8 @@
 ;from_name = Grafana
 # EHLO identity in SMTP dialog (defaults to instance_name)
 ;ehlo_identity = dashboard.example.com
+# SMTP startTLS policy (defaults to 'OpportunisticStartTLS') 
+;startTLS_policy = NoStartTLS
 
 [emails]
 ;welcome_email_on_sign_up = false
diff --git a/docs/sources/installation/configuration.md b/docs/sources/installation/configuration.md
index 1cd9b92f547..48e751dae6d 100644
--- a/docs/sources/installation/configuration.md
+++ b/docs/sources/installation/configuration.md
@@ -560,6 +560,9 @@ Name to be used when sending out emails, defaults to `Grafana`
 ### ehlo_identity
 Name to be used as client identity for EHLO in SMTP dialog, defaults to instance_name.
 
+### startTLS_policy
+Either "OpportunisticStartTLS", "MandatoryStartTLS", "NoStartTLS". Default is "OpportunisticStartTLS"
+
 ## [log]
 
 ### mode
diff --git a/pkg/services/notifications/mailer.go b/pkg/services/notifications/mailer.go
index 903294509a4..2538d686929 100644
--- a/pkg/services/notifications/mailer.go
+++ b/pkg/services/notifications/mailer.go
@@ -111,6 +111,7 @@ func (ns *NotificationService) createDialer() (*gomail.Dialer, error) {
 
 	d := gomail.NewDialer(host, iPort, ns.Cfg.Smtp.User, ns.Cfg.Smtp.Password)
 	d.TLSConfig = tlsconfig
+	d.StartTLSPolicy = getStartTLSPolicy(ns.Cfg.Smtp.StartTLSPolicy)
 
 	if ns.Cfg.Smtp.EhloIdentity != "" {
 		d.LocalName = ns.Cfg.Smtp.EhloIdentity
@@ -120,6 +121,17 @@ func (ns *NotificationService) createDialer() (*gomail.Dialer, error) {
 	return d, nil
 }
 
+func getStartTLSPolicy(policy string) gomail.StartTLSPolicy {
+	switch policy {
+	case "NoStartTLS":
+		return -1
+	case "MandatoryStartTLS":
+		return 1
+	default:
+		return 0
+	}
+}
+
 func (ns *NotificationService) buildEmailMessage(cmd *models.SendEmailCommand) (*Message, error) {
 	if !ns.Cfg.Smtp.Enabled {
 		return nil, models.ErrSmtpNotEnabled
diff --git a/pkg/setting/setting_smtp.go b/pkg/setting/setting_smtp.go
index 5df774dc691..2e56b12e419 100644
--- a/pkg/setting/setting_smtp.go
+++ b/pkg/setting/setting_smtp.go
@@ -1,16 +1,17 @@
 package setting
 
 type SmtpSettings struct {
-	Enabled      bool
-	Host         string
-	User         string
-	Password     string
-	CertFile     string
-	KeyFile      string
-	FromAddress  string
-	FromName     string
-	EhloIdentity string
-	SkipVerify   bool
+	Enabled        bool
+	Host           string
+	User           string
+	Password       string
+	CertFile       string
+	KeyFile        string
+	FromAddress    string
+	FromName       string
+	EhloIdentity   string
+	StartTLSPolicy string
+	SkipVerify     bool
 
 	SendWelcomeEmailOnSignUp bool
 	TemplatesPattern         string
@@ -27,6 +28,7 @@ func (cfg *Cfg) readSmtpSettings() {
 	cfg.Smtp.FromAddress = sec.Key("from_address").String()
 	cfg.Smtp.FromName = sec.Key("from_name").String()
 	cfg.Smtp.EhloIdentity = sec.Key("ehlo_identity").String()
+	cfg.Smtp.StartTLSPolicy = sec.Key("startTLS_policy").String()
 	cfg.Smtp.SkipVerify = sec.Key("skip_verify").MustBool(false)
 
 	emails := cfg.Raw.Section("emails")