lib/httpserver: follow up after def0032c7d

docs/CHANGELOG.md

@@ -16,6 +16,7 @@ The following tip changes can be tested by building VictoriaMetrics components f
 ## tip
 
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): add support for DNS-based discovery for notifiers in the same way as Prometheus does. See [these docs](https://docs.victoriametrics.com/vmalert.html#notifier-configuration-file) and [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2460).
+* FEATURE: allow specifying TLS cipher suites for incoming https requests via `-tlsCipherSuites` command-line flag. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2404).
 
 * BUGFIX: [vmctl](https://docs.victoriametrics.com/vmctl.html): return non-zero exit code on error. This allows handling `vmctl` errors in shell scripts. Previously `vmctl` was returning 0 exit code on error. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2322).
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): properly show `scrape_timeout` and `scrape_interval` options at `http://vmagent:8429/config` page. Previously these options weren't displayed even if they were set in `-promscrape.config`.

docs/README.md

@@ -1923,6 +1923,9 @@ Pass `-help` to VictoriaMetrics in order to see the list of supported command-li
      Path to file with TLS certificate. Used only if -tls is set. Prefer ECDSA certs instead of RSA certs as RSA certs are slower. The provided certificate file is automatically re-read every second, so it can be dynamically updated
   -tlsKeyFile string
      Path to file with TLS key. Used only if -tls is set. The provided key file is automatically re-read every second, so it can be dynamically updated
+  -tlsCipherSuites array
+     Optional list of TLS cipher suites for incoming requests over HTTPS if -tls flag is set. See the list of supported cipher suites at https://pkg.go.dev/crypto/tls#pkg-constants
+     Supports an array of values separated by comma or specified via multiple flags.
   -version
      Show VictoriaMetrics version
 ```

docs/Single-server-VictoriaMetrics.md

@@ -1927,6 +1927,9 @@ Pass `-help` to VictoriaMetrics in order to see the list of supported command-li
      Path to file with TLS certificate. Used only if -tls is set. Prefer ECDSA certs instead of RSA certs as RSA certs are slower. The provided certificate file is automatically re-read every second, so it can be dynamically updated
   -tlsKeyFile string
      Path to file with TLS key. Used only if -tls is set. The provided key file is automatically re-read every second, so it can be dynamically updated
+  -tlsCipherSuites array
+     Optional list of TLS cipher suites for incoming requests over HTTPS if -tls flag is set. See the list of supported cipher suites at https://pkg.go.dev/crypto/tls#pkg-constants
+     Supports an array of values separated by comma or specified via multiple flags.
   -version
      Show VictoriaMetrics version
 ```

lib/httpserver/httpserver.go

@@ -33,7 +33,7 @@ var (
 	tlsEnable       = flag.Bool("tls", false, "Whether to enable TLS (aka HTTPS) for incoming requests. -tlsCertFile and -tlsKeyFile must be set if -tls is set")
 	tlsCertFile     = flag.String("tlsCertFile", "", "Path to file with TLS certificate. Used only if -tls is set. Prefer ECDSA certs instead of RSA certs as RSA certs are slower. The provided certificate file is automatically re-read every second, so it can be dynamically updated")
 	tlsKeyFile      = flag.String("tlsKeyFile", "", "Path to file with TLS key. Used only if -tls is set. The provided key file is automatically re-read every second, so it can be dynamically updated")
-	tlsCipherSuites = flagutil.NewArray("tlsCipherSuites", "Cipher suites names for TLS encryption. For example, TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA. Used only if -tls flag is set")
+	tlsCipherSuites = flagutil.NewArray("tlsCipherSuites", "Optional list of TLS cipher suites for incoming requests over HTTPS if -tls flag is set. See the list of supported cipher suites at https://pkg.go.dev/crypto/tls#pkg-constants")
 
 	pathPrefix = flag.String("http.pathPrefix", "", "An optional prefix to add to all the paths handled by http server. For example, if '-http.pathPrefix=/foo/bar' is set, "+
 		"then all the http requests will be handled on '/foo/bar/*' paths. This may be useful for proxied requests. "+

lib/netutil/tls.go

@@ -20,7 +20,7 @@ func GetServerTLSConfig(tlsCAFile, tlsCertFile, tlsKeyFile string, tlsCipherSuit
 	if err != nil {
 		return nil, fmt.Errorf("cannot load TLS cert from certFile=%q, keyFile=%q: %w", tlsCertFile, tlsKeyFile, err)
 	}
-	cipherSuites, err := collectCipherSuites(tlsCipherSuites)
+	cipherSuites, err := cipherSuitesFromNames(tlsCipherSuites)
 	if err != nil {
 		return nil, fmt.Errorf("cannot use TLS cipher suites from tlsCipherSuites=%q: %w", tlsCipherSuites, err)
 	}
@@ -59,18 +59,20 @@ func GetServerTLSConfig(tlsCAFile, tlsCertFile, tlsKeyFile string, tlsCipherSuit
 	return cfg, nil
 }
 
-func collectCipherSuites(definedCipherSuites []string) ([]uint16, error) {
-	var cipherSuites []uint16
-
-	supportedCipherSuites := tls.CipherSuites()
-	supportedCipherSuitesMap := make(map[string]uint16, len(supportedCipherSuites))
-	for _, scf := range supportedCipherSuites {
-		supportedCipherSuitesMap[strings.ToLower(scf.Name)] = scf.ID
+func cipherSuitesFromNames(cipherSuiteNames []string) ([]uint16, error) {
+	if len(cipherSuiteNames) == 0 {
+		return nil, nil
 	}
-	for _, gotSuite := range definedCipherSuites {
-		id, ok := supportedCipherSuitesMap[strings.ToLower(gotSuite)]
+	css := tls.CipherSuites()
+	cssMap := make(map[string]uint16, len(css))
+	for _, cs := range css {
+		cssMap[strings.ToLower(cs.Name)] = cs.ID
+	}
+	cipherSuites := make([]uint16, 0, len(cipherSuiteNames))
+	for _, name := range cipherSuiteNames {
+		id, ok := cssMap[strings.ToLower(name)]
 		if !ok {
-			return nil, fmt.Errorf("got unsupported cipher suite name: %s", gotSuite)
+			return nil, fmt.Errorf("unsupported TLS cipher suite name: %s", name)
 		}
 		cipherSuites = append(cipherSuites, id)
 	}

lib/netutil/tls_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 )
 
-func Test_validateCipherSuites(t *testing.T) {
+func TestCipherSuitesFromNames(t *testing.T) {
 	type args struct {
 		definedCipherSuites []string
 	}
@@ -65,9 +65,9 @@ func Test_validateCipherSuites(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := collectCipherSuites(tt.args.definedCipherSuites)
+			got, err := cipherSuitesFromNames(tt.args.definedCipherSuites)
 			if (err != nil) != tt.wantErr {
-				t.Errorf("collectCipherSuites() error = %v, wantErr %v", err, tt.wantErr)
+				t.Errorf("cipherSuitesFromNames() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
 			if !reflect.DeepEqual(got, tt.want) {