feat: add TLS versions configuration

Add configuration options for TLSMinVersion and TLSMaxVersion. This enables setting TLS 1.3 as minimum version for example for both GRPC and Web, or enforcing TLS 1.2 only for easier debugging of secure connections. Signed-off-by: Tuomo Tanskanen <tuomo.tanskanen@est.tech>
dexidp · Jan 25, 2024 · 5bbdb44 · 5bbdb44
1 parent 7ca42d7
commit 5bbdb44
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Showing 4 changed files with 49 additions and 9 deletions.
diff --git a/cmd/dex/config.go b/cmd/dex/config.go
@@ -64,10 +64,16 @@ func (c Config) Validate() error {
 		{c.Web.HTTP == "" && c.Web.HTTPS == "", "must supply a HTTP/HTTPS  address to listen on"},
 		{c.Web.HTTPS != "" && c.Web.TLSCert == "", "no cert specified for HTTPS"},
 		{c.Web.HTTPS != "" && c.Web.TLSKey == "", "no private key specified for HTTPS"},
+		{c.Web.TLSMinVersion != "" && c.Web.TLSMinVersion != "1.2" && c.Web.TLSMinVersion != "1.3", "supported TLS versions are: 1.2, 1.3"},
+		{c.Web.TLSMaxVersion != "" && c.Web.TLSMaxVersion != "1.2" && c.Web.TLSMaxVersion != "1.3", "supported TLS versions are: 1.2, 1.3"},
+		{c.Web.TLSMaxVersion != "" && c.Web.TLSMinVersion != "" && c.Web.TLSMinVersion > c.Web.TLSMaxVersion, "TLSMinVersion greater than TLSMaxVersion"},
 		{c.GRPC.TLSCert != "" && c.GRPC.Addr == "", "no address specified for gRPC"},
 		{c.GRPC.TLSKey != "" && c.GRPC.Addr == "", "no address specified for gRPC"},
 		{(c.GRPC.TLSCert == "") != (c.GRPC.TLSKey == ""), "must specific both a gRPC TLS cert and key"},
 		{c.GRPC.TLSCert == "" && c.GRPC.TLSClientCA != "", "cannot specify gRPC TLS client CA without a gRPC TLS cert"},
+		{c.GRPC.TLSMinVersion != "" && c.GRPC.TLSMinVersion != "1.2" && c.GRPC.TLSMinVersion != "1.3", "supported TLS versions are: 1.2, 1.3"},
+		{c.GRPC.TLSMaxVersion != "" && c.GRPC.TLSMaxVersion != "1.2" && c.GRPC.TLSMaxVersion != "1.3", "supported TLS versions are: 1.2, 1.3"},
+		{c.GRPC.TLSMaxVersion != "" && c.GRPC.TLSMinVersion != "" && c.GRPC.TLSMinVersion > c.GRPC.TLSMaxVersion, "TLSMinVersion greater than TLSMaxVersion"},
 	}
 
 	var checkErrors []string
@@ -149,6 +155,8 @@ type Web struct {
 	HTTPS          string   `json:"https"`
 	TLSCert        string   `json:"tlsCert"`
 	TLSKey         string   `json:"tlsKey"`
+	TLSMinVersion  string   `json:"tlsMinVersion"`
+	TLSMaxVersion  string   `json:"tlsMaxVersion"`
 	AllowedOrigins []string `json:"allowedOrigins"`
 	AllowedHeaders []string `json:"allowedHeaders"`
 }
@@ -163,11 +171,13 @@ type Telemetry struct {
 // GRPC is the config for the gRPC API.
 type GRPC struct {
 	// The port to listen on.
-	Addr        string `json:"addr"`
-	TLSCert     string `json:"tlsCert"`
-	TLSKey      string `json:"tlsKey"`
-	TLSClientCA string `json:"tlsClientCA"`
-	Reflection  bool   `json:"reflection"`
+	Addr          string `json:"addr"`
+	TLSCert       string `json:"tlsCert"`
+	TLSKey        string `json:"tlsKey"`
+	TLSClientCA   string `json:"tlsClientCA"`
+	TLSMinVersion string `json:"tlsMinVersion"`
+	TLSMaxVersion string `json:"tlsMaxVersion"`
+	Reflection    bool   `json:"reflection"`
 }
 
 // Storage holds app's storage configuration.

diff --git a/cmd/dex/config_test.go b/cmd/dex/config_test.go
@@ -71,7 +71,9 @@ storage:
     connMaxLifetime: 30
     connectionTimeout: 3
 web:
-  http: 127.0.0.1:5556
+  https: 127.0.0.1:5556
+  tlsMinVersion: 1.3
+  tlsMaxVersion: 1.2
 
 frontend:
   dir: ./web
@@ -144,7 +146,9 @@ logger:
 			},
 		},
 		Web: Web{
-			HTTP: "127.0.0.1:5556",
+			HTTPS:         "127.0.0.1:5556",
+			TLSMinVersion: "1.3",
+			TLSMaxVersion: "1.2",
 		},
 		Frontend: server.WebConfig{
 			Dir: "./web",

diff --git a/cmd/dex/serve.go b/cmd/dex/serve.go
@@ -145,9 +145,23 @@ func runServe(options serveOptions) error {
 		tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
 	}
 
+	allowedTLSVersions := map[string]int{
+		"1.2": tls.VersionTLS12,
+		"1.3": tls.VersionTLS13,
+	}
+
 	if c.GRPC.TLSCert != "" {
+		tlsMinVersion := tls.VersionTLS12
+		if c.GRPC.TLSMinVersion != "" {
+			tlsMinVersion = allowedTLSVersions[c.GRPC.TLSMinVersion]
+		}
+		tlsMaxVersion := 0 // default for max is whatever Go defaults to
+		if c.GRPC.TLSMaxVersion != "" {
+			tlsMaxVersion = allowedTLSVersions[c.GRPC.TLSMaxVersion]
+		}
 		baseTLSConfig := &tls.Config{
-			MinVersion:               tls.VersionTLS12,
+			MinVersion:               uint16(tlsMinVersion),
+			MaxVersion:               uint16(tlsMaxVersion),
 			CipherSuites:             allowedTLSCiphers,
 			PreferServerCipherSuites: true,
 		}
@@ -422,8 +436,18 @@ func runServe(options serveOptions) error {
 			return fmt.Errorf("listening (%s) on %s: %v", name, c.Web.HTTPS, err)
 		}
 
+		tlsMinVersion := tls.VersionTLS12
+		if c.Web.TLSMinVersion != "" {
+			tlsMinVersion = allowedTLSVersions[c.Web.TLSMinVersion]
+		}
+		tlsMaxVersion := 0 // default for max is whatever Go defaults to
+		if c.Web.TLSMaxVersion != "" {
+			tlsMaxVersion = allowedTLSVersions[c.Web.TLSMaxVersion]
+		}
+
 		baseTLSConfig := &tls.Config{
-			MinVersion:               tls.VersionTLS12,
+			MinVersion:               uint16(tlsMinVersion),
+			MaxVersion:               uint16(tlsMaxVersion),
 			CipherSuites:             allowedTLSCiphers,
 			PreferServerCipherSuites: true,
 		}

diff --git a/config.yaml.dist b/config.yaml.dist
@@ -55,6 +55,8 @@ web:
   # https: 127.0.0.1:5554
   # tlsCert: /etc/dex/tls.crt
   # tlsKey: /etc/dex/tls.key
+  # tlsMinVersion: 1.2
+  # tlsMaxVersion: 1.3
 
 # Dex UI configuration
 # frontend: