Add support TLS renegotiation (#5353) (#5360)

This PR adds support for enabling TLS renegotiation. The setting is `ssl.renegotiation` and the options are `never` (default), `once`, and `freely`. This exposes the three options from https://golang.org/pkg/crypto/tls/#RenegotiationSupport.

Fixes #4386

(cherry picked from commit 28cee61)

CHANGELOG.asciidoc

@@ -42,6 +42,8 @@ https://github.com/elastic/beats/compare/v5.6.3...5.6[Check the HEAD diff]
 
 *Affecting all Beats*
 
+- Add support for enabling TLS renegotiation. {issue}4386[4386]
+
 *Filebeat*
 
 *Heartbeat*

filebeat/filebeat.full.yml

@@ -563,6 +563,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #----------------------------- Logstash output ---------------------------------
 #output.logstash:
@@ -627,6 +631,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Kafka output ----------------------------------
 #output.kafka:
   # Boolean flag to enable or disable the output module.
@@ -762,6 +770,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Redis output ----------------------------------
 #output.redis:
   # Boolean flag to enable or disable the output module.
@@ -859,6 +871,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #------------------------------- File output -----------------------------------
 #output.file:

heartbeat/heartbeat.full.yml

@@ -398,6 +398,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #----------------------------- Logstash output ---------------------------------
 #output.logstash:
@@ -462,6 +466,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Kafka output ----------------------------------
 #output.kafka:
   # Boolean flag to enable or disable the output module.
@@ -597,6 +605,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Redis output ----------------------------------
 #output.redis:
   # Boolean flag to enable or disable the output module.
@@ -694,6 +706,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #------------------------------- File output -----------------------------------
 #output.file:

libbeat/_meta/config.full.yml

@@ -200,6 +200,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #----------------------------- Logstash output ---------------------------------
 #output.logstash:
@@ -264,6 +268,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Kafka output ----------------------------------
 #output.kafka:
   # Boolean flag to enable or disable the output module.
@@ -399,6 +407,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Redis output ----------------------------------
 #output.redis:
   # Boolean flag to enable or disable the output module.
@@ -496,6 +508,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #------------------------------- File output -----------------------------------
 #output.file:

libbeat/docs/outputconfig.asciidoc

@@ -1233,6 +1233,15 @@ The following elliptic curve types are available:
 * P-384
 * P-521
 
+===== renegotiation
+
+This configures what types of TLS renegotiation are supported. The valid options
+are `never`, `once`, and `freely`. The default value is never.
+
+* `never` - Disables renegotiation.
+* `once` - Allows a remote server to request renegotiation once per connection.
+* `freely` - Allows a remote server to repeatedly request renegotiation.
+
 [[configuration-output-codec]]
 === Output Codec
 

libbeat/outputs/tls.go

@@ -35,6 +35,7 @@ type TLSConfig struct {
 	CAs              []string                      `config:"certificate_authorities"`
 	Certificate      CertificateConfig             `config:",inline"`
 	CurveTypes       []tlsCurveType                `config:"curve_types"`
+	Renegotiation    tlsRenegotiationSupport       `config:"renegotiation"`
 }
 
 type CertificateConfig struct {
@@ -47,6 +48,8 @@ type tlsCipherSuite uint16
 
 type tlsCurveType tls.CurveID
 
+type tlsRenegotiationSupport tls.RenegotiationSupport
+
 var tlsCipherSuites = map[string]tlsCipherSuite{
 	"ECDHE-ECDSA-AES-128-CBC-SHA":    tlsCipherSuite(tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA),
 	"ECDHE-ECDSA-AES-128-GCM-SHA256": tlsCipherSuite(tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256),
@@ -73,6 +76,12 @@ var tlsCurveTypes = map[string]tlsCurveType{
 	"P-521": tlsCurveType(tls.CurveP521),
 }
 
+var tlsRenegotiationSupportTypes = map[string]tlsRenegotiationSupport{
+	"never":  tlsRenegotiationSupport(tls.RenegotiateNever),
+	"once":   tlsRenegotiationSupport(tls.RenegotiateOnceAsClient),
+	"freely": tlsRenegotiationSupport(tls.RenegotiateFreelyAsClient),
+}
+
 func (c *TLSConfig) Validate() error {
 	hasCertificate := c.Certificate.Certificate != ""
 	hasKey := c.Certificate.Key != ""
@@ -143,6 +152,7 @@ func LoadTLSConfig(config *TLSConfig) (*transport.TLSConfig, error) {
 		RootCAs:          cas,
 		CipherSuites:     cipherSuites,
 		CurvePreferences: curves,
+		Renegotiation:    tls.RenegotiationSupport(config.Renegotiation),
 	}, nil
 }
 
@@ -288,3 +298,13 @@ func (ct *tlsCurveType) Unpack(s string) error {
 	*ct = t
 	return nil
 }
+
+func (r *tlsRenegotiationSupport) Unpack(s string) error {
+	t, found := tlsRenegotiationSupportTypes[s]
+	if !found {
+		return fmt.Errorf("invalid tls renegotiation type '%v'", s)
+	}
+
+	*r = t
+	return nil
+}

libbeat/outputs/tls_test.go

@@ -84,6 +84,7 @@ func TestValuesSet(t *testing.T) {
     supported_protocols: [TLSv1.1, TLSv1.2]
     curve_types:
       - P-521
+    renegotiation: freely
   `)
 
 	if err != nil {
@@ -99,6 +100,9 @@ func TestValuesSet(t *testing.T) {
 		[]transport.TLSVersion{transport.TLSVersion11, transport.TLSVersion12},
 		cfg.Versions)
 	assert.Len(t, cfg.CurveTypes, 1)
+	assert.Equal(t,
+		tls.RenegotiateFreelyAsClient,
+		tls.RenegotiationSupport(cfg.Renegotiation))
 }
 
 func TestApplyEmptyConfig(t *testing.T) {
@@ -168,6 +172,10 @@ func TestCertificateFails(t *testing.T) {
 			"unknown curve type",
 			"curve_types: ['unknown curve type']",
 		},
+		{
+			"unknown renegotiation type",
+			"renegotiation: always",
+		},
 	}
 
 	for i, test := range tests {

libbeat/outputs/transport/tls.go

@@ -37,6 +37,10 @@ type TLSConfig struct {
 	// Types of elliptic curves that will be used in an ECDHE handshake. If empty,
 	// the implementation will choose a default.
 	CurvePreferences []tls.CurveID
+
+	// Renegotiation controls what types of renegotiation are supported.
+	// The default, never, is correct for the vast majority of applications.
+	Renegotiation tls.RenegotiationSupport
 }
 
 type TLSVersion uint16

metricbeat/metricbeat.full.yml

@@ -511,6 +511,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #----------------------------- Logstash output ---------------------------------
 #output.logstash:
@@ -575,6 +579,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Kafka output ----------------------------------
 #output.kafka:
   # Boolean flag to enable or disable the output module.
@@ -710,6 +718,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Redis output ----------------------------------
 #output.redis:
   # Boolean flag to enable or disable the output module.
@@ -807,6 +819,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #------------------------------- File output -----------------------------------
 #output.file:

packetbeat/packetbeat.full.yml

@@ -654,6 +654,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #----------------------------- Logstash output ---------------------------------
 #output.logstash:
@@ -718,6 +722,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Kafka output ----------------------------------
 #output.kafka:
   # Boolean flag to enable or disable the output module.
@@ -853,6 +861,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Redis output ----------------------------------
 #output.redis:
   # Boolean flag to enable or disable the output module.
@@ -950,6 +962,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #------------------------------- File output -----------------------------------
 #output.file:

winlogbeat/winlogbeat.full.yml

@@ -229,6 +229,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #----------------------------- Logstash output ---------------------------------
 #output.logstash:
@@ -293,6 +297,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Kafka output ----------------------------------
 #output.kafka:
   # Boolean flag to enable or disable the output module.
@@ -428,6 +436,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 #------------------------------- Redis output ----------------------------------
 #output.redis:
   # Boolean flag to enable or disable the output module.
@@ -525,6 +537,10 @@ output.elasticsearch:
   # Configure curve types for ECDHE based cipher suites
   #ssl.curve_types: []
 
+  # Configure what types of renegotiation are supported. Valid options are
+  # never, once, and freely. Default is never.
+  #ssl.renegotiation: never
+
 
 #------------------------------- File output -----------------------------------
 #output.file: