More tests for TLS configuration

caddytls/config.go

@@ -379,8 +379,8 @@ func MakeTLSConfig(configs []*Config) (*tls.Config, error) {
 		config.CipherSuites = defaultCiphers
 	}
 
-	// For security, ensure TLS_FALLBACK_SCSV is always included
-	if config.CipherSuites[0] != tls.TLS_FALLBACK_SCSV {
+	// For security, ensure TLS_FALLBACK_SCSV is always included first
+	if len(config.CipherSuites) == 0 || config.CipherSuites[0] != tls.TLS_FALLBACK_SCSV {
 		config.CipherSuites = append([]uint16{tls.TLS_FALLBACK_SCSV}, config.CipherSuites...)
 	}
 

caddytls/config_test.go

@@ -8,7 +8,7 @@ import (
 	"testing"
 )
 
-func TestMakeTLSConfig(t *testing.T) {
+func TestMakeTLSConfigProtocolVersions(t *testing.T) {
 	// same min and max protocol versions
 	configs := []*Config{
 		{
@@ -29,6 +29,68 @@ func TestMakeTLSConfig(t *testing.T) {
 	}
 }
 
+func TestMakeTLSConfigPreferServerCipherSuites(t *testing.T) {
+	// prefer server cipher suites
+	configs := []*Config{{Enabled: true, PreferServerCipherSuites: true}}
+	result, err := MakeTLSConfig(configs)
+	if err != nil {
+		t.Fatalf("Did not expect an error, but got %v", err)
+	}
+	if got, want := result.PreferServerCipherSuites, true; got != want {
+		t.Errorf("Expected PreferServerCipherSuites==%v but got %v", want, got)
+	}
+}
+
+func TestMakeTLSConfigTLSEnabledDisabled(t *testing.T) {
+	// verify handling when Enabled is true and false
+	configs := []*Config{
+		{Enabled: true},
+		{Enabled: false},
+	}
+	_, err := MakeTLSConfig(configs)
+	if err == nil {
+		t.Fatalf("Expected an error, but got %v", err)
+	}
+
+	// verify that when disabled, a nil pair is returned
+	configs = []*Config{{}, {}}
+	result, err := MakeTLSConfig(configs)
+	if err != nil {
+		t.Errorf("Did not expect an error, but got %v", err)
+	}
+	if result != nil {
+		t.Errorf("Expected a nil *tls.Config result, got %+v", result)
+	}
+}
+
+func TestMakeTLSConfigCipherSuites(t *testing.T) {
+	// ensure cipher suites are unioned and
+	// that TLS_FALLBACK_SCSV is prepended
+	configs := []*Config{
+		{Enabled: true, Ciphers: []uint16{0xc02c, 0xc030}},
+		{Enabled: true, Ciphers: []uint16{0xc012, 0xc030, 0xc00a}},
+	}
+	result, err := MakeTLSConfig(configs)
+	if err != nil {
+		t.Fatalf("Did not expect an error, but got %v", err)
+	}
+	expected := []uint16{tls.TLS_FALLBACK_SCSV, 0xc02c, 0xc030, 0xc012, 0xc00a}
+	if !reflect.DeepEqual(result.CipherSuites, expected) {
+		t.Errorf("Expected ciphers %v but got %v", expected, result.CipherSuites)
+	}
+
+	// use default suites if none specified
+	configs = []*Config{{Enabled: true}}
+	result, err = MakeTLSConfig(configs)
+	if err != nil {
+		t.Fatalf("Did not expect an error, but got %v", err)
+	}
+	expected = append([]uint16{tls.TLS_FALLBACK_SCSV}, defaultCiphers...)
+	if !reflect.DeepEqual(result.CipherSuites, expected) {
+		t.Errorf("Expected default ciphers %v but got %v", expected, result.CipherSuites)
+	}
+}
+
 func TestStorageForNoURL(t *testing.T) {
 	c := &Config{}
 	if _, err := c.StorageFor(""); err == nil {