Added flag for user configurable cipher suites

Configuration of list of cipher suites allows a user to disable use
of weak ciphers or continue to support them for legacy usage if they
so choose.

List of available cipher suites at:
https://golang.org/pkg/crypto/tls/#pkg-constants

Default cipher suites have been updated to:
- TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305
- TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305
- TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_AES_128_GCM_SHA256
- TLS_CHACHA20_POLY1305_SHA256
- TLS_AES_256_GCM_SHA384

MinimumTLS has also been updated to include TLS 1.3 as an option
and now defaults to TLS 1.2 since 1.0 and 1.1 have been deprecated.

Signed-off-by: David Luu <david@davidluu.info>

configuration/configuration.go

@@ -108,6 +108,12 @@ type Configuration struct {
 			// A file may contain multiple CA certificates encoded as PEM
 			ClientCAs []string `yaml:"clientcas,omitempty"`
 
+			// Specifies the lowest TLS version allowed
+			MinimumTLS string `yaml:"minimumtls,omitempty"`
+
+			// Specifies a list of cipher suites allowed
+			CipherSuites []string `yaml:"ciphersuites,omitempty"`
+
 			// LetsEncrypt is used to configuration setting up TLS through
 			// Let's Encrypt instead of manually specifying certificate and
 			// key. If a TLS certificate is specified, the Let's Encrypt

configuration/configuration_test.go

@@ -83,6 +83,8 @@ var configStruct = Configuration{
 			Certificate  string   `yaml:"certificate,omitempty"`
 			Key          string   `yaml:"key,omitempty"`
 			ClientCAs    []string `yaml:"clientcas,omitempty"`
+			MinimumTLS   string   `yaml:"minimumtls,omitempty"`
+			CipherSuites []string `yaml:"ciphersuites,omitempty"`
 			LetsEncrypt  struct {
 				CacheFile string   `yaml:"cachefile,omitempty"`
 				Email     string   `yaml:"email,omitempty"`
@@ -105,6 +107,8 @@ var configStruct = Configuration{
 			Certificate  string   `yaml:"certificate,omitempty"`
 			Key          string   `yaml:"key,omitempty"`
 			ClientCAs    []string `yaml:"clientcas,omitempty"`
+			MinimumTLS   string   `yaml:"minimumtls,omitempty"`
+			CipherSuites []string `yaml:"ciphersuites,omitempty"`
 			LetsEncrypt  struct {
 				CacheFile string   `yaml:"cachefile,omitempty"`
 				Email     string   `yaml:"email,omitempty"`

docs/configuration.md

@@ -782,6 +782,10 @@ http:
     clientcas:
       - /path/to/ca.pem
       - /path/to/another/ca.pem
+    minimumtls: tls1.2
+    ciphersuites:
+      - TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
+      - TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
     letsencrypt:
       cachefile: /path/to/cache-file
       email: emailused@letsencrypt.com
@@ -820,6 +824,46 @@ and proxy connections to the registry server.
 | `certificate`  | yes  | Absolute path to the x509 certificate file.           |
 | `key`          | yes  | Absolute path to the x509 private key file.           |
 | `clientcas`    | no   | An array of absolute paths to x509 CA files.          |
+| `minimumtls`   | no   | Minimum TLS version allowed (tls1.0, tls1.1, tls1.2, tls1.3). Defaults to tls1.2 |
+| `ciphersuites` | no   | Cipher suites allowed. Please see below for allowed values and default. |
+
+Available cipher suites:
+- TLS_RSA_WITH_RC4_128_SHA
+- TLS_RSA_WITH_3DES_EDE_CBC_SHA
+- TLS_RSA_WITH_AES_128_CBC_SHA
+- TLS_RSA_WITH_AES_256_CBC_SHA
+- TLS_RSA_WITH_AES_128_CBC_SHA256
+- TLS_RSA_WITH_AES_128_GCM_SHA256
+- TLS_RSA_WITH_AES_256_GCM_SHA384
+- TLS_ECDHE_ECDSA_WITH_RC4_128_SHA
+- TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
+- TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
+- TLS_ECDHE_RSA_WITH_RC4_128_SHA
+- TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
+- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
+- TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
+- TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
+- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
+- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
+- TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
+- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
+- TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
+- TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
+- TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
+- TLS_AES_128_GCM_SHA256
+- TLS_AES_256_GCM_SHA384
+- TLS_CHACHA20_POLY1305_SHA256
+
+Default cipher suites:
+- TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
+- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
+- TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
+- TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
+- TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
+- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
+- TLS_AES_128_GCM_SHA256
+- TLS_CHACHA20_POLY1305_SHA256
+- TLS_AES_256_GCM_SHA384
 
 ### `letsencrypt`
 

registry/registry.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"strings"
 	"syscall"
 	"time"
 
@@ -31,6 +32,60 @@ import (
 	"github.com/yvasiyarov/gorelic"
 )
 
+// a map of TLS cipher suite names to constants in https://golang.org/pkg/crypto/tls/#pkg-constants
+var cipherSuites = map[string]uint16{
+	// TLS 1.0 - 1.2 cipher suites
+	"TLS_RSA_WITH_RC4_128_SHA":                      tls.TLS_RSA_WITH_RC4_128_SHA,
+	"TLS_RSA_WITH_3DES_EDE_CBC_SHA":                 tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+	"TLS_RSA_WITH_AES_128_CBC_SHA":                  tls.TLS_RSA_WITH_AES_128_CBC_SHA,
+	"TLS_RSA_WITH_AES_256_CBC_SHA":                  tls.TLS_RSA_WITH_AES_256_CBC_SHA,
+	"TLS_RSA_WITH_AES_128_CBC_SHA256":               tls.TLS_RSA_WITH_AES_128_CBC_SHA256,
+	"TLS_RSA_WITH_AES_128_GCM_SHA256":               tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
+	"TLS_RSA_WITH_AES_256_GCM_SHA384":               tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
+	"TLS_ECDHE_ECDSA_WITH_RC4_128_SHA":              tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
+	"TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA":          tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+	"TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA":          tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+	"TLS_ECDHE_RSA_WITH_RC4_128_SHA":                tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+	"TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA":           tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+	"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA":            tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+	"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA":            tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
+	"TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256":       tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
+	"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256":         tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
+	"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256":         tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+	"TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256":       tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+	"TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384":         tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+	"TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384":       tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+	"TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256":   tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+	"TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256": tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
+	// TLS 1.3 cipher suites
+	"TLS_AES_128_GCM_SHA256":       tls.TLS_AES_128_GCM_SHA256,
+	"TLS_AES_256_GCM_SHA384":       tls.TLS_AES_256_GCM_SHA384,
+	"TLS_CHACHA20_POLY1305_SHA256": tls.TLS_CHACHA20_POLY1305_SHA256,
+}
+
+// a list of default ciphersuites to utilize
+var defaultCipherSuites = []uint16{
+	tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+	tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+	tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
+	tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+	tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+	tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+	tls.TLS_AES_128_GCM_SHA256,
+	tls.TLS_CHACHA20_POLY1305_SHA256,
+	tls.TLS_AES_256_GCM_SHA384,
+}
+
+// maps tls version strings to constants
+var defaultTLSVersionStr = "tls1.2"
+var tlsVersions = map[string]uint16{
+	// user specified values
+	"tls1.0": tls.VersionTLS10,
+	"tls1.1": tls.VersionTLS11,
+	"tls1.2": tls.VersionTLS12,
+	"tls1.3": tls.VersionTLS13,
+}
+
 // this channel gets notified when process receives signal. It is global to ease unit testing
 var quit = make(chan os.Signal, 1)
 
@@ -125,6 +180,35 @@ func NewRegistry(ctx context.Context, config *configuration.Configuration) (*Reg
 	}, nil
 }
 
+// takes a list of cipher suites and converts it to a list of respective tls constants
+// if an empty list is provided, then the defaults will be used
+func getCipherSuites(names []string) ([]uint16, error) {
+	if len(names) == 0 {
+		return defaultCipherSuites, nil
+	}
+	cipherSuiteConsts := make([]uint16, len(names))
+	for i, name := range names {
+		cipherSuiteConst, ok := cipherSuites[name]
+		if !ok {
+			return nil, fmt.Errorf("unknown TLS cipher suite '%s' specified for http.tls.cipherSuites", name)
+		}
+		cipherSuiteConsts[i] = cipherSuiteConst
+	}
+	return cipherSuiteConsts, nil
+}
+
+// takes a list of cipher suite ids and converts it to a list of respective names
+func getCipherSuiteNames(ids []uint16) []string {
+	if len(ids) == 0 {
+		return nil
+	}
+	names := make([]string, len(ids))
+	for i, id := range ids {
+		names[i] = tls.CipherSuiteName(id)
+	}
+	return names
+}
+
 // ListenAndServe runs the registry's HTTP server.
 func (registry *Registry) ListenAndServe() error {
 	config := registry.config
@@ -135,19 +219,27 @@ func (registry *Registry) ListenAndServe() error {
 	}
 
 	if config.HTTP.TLS.Certificate != "" || config.HTTP.TLS.LetsEncrypt.CacheFile != "" {
+		if config.HTTP.TLS.MinimumTLS == "" {
+			config.HTTP.TLS.MinimumTLS = defaultTLSVersionStr
+		}
+		tlsMinVersion, ok := tlsVersions[config.HTTP.TLS.MinimumTLS]
+		if !ok {
+			return fmt.Errorf("unknown minimum TLS level '%s' specified for http.tls.minimumtls", config.HTTP.TLS.MinimumTLS)
+		}
+		dcontext.GetLogger(registry.app).Infof("restricting TLS version to %s or higher", config.HTTP.TLS.MinimumTLS)
+
+		tlsCipherSuites, err := getCipherSuites(config.HTTP.TLS.CipherSuites)
+		if err != nil {
+			return err
+		}
+		dcontext.GetLogger(registry.app).Infof("restricting TLS cipher suites to: %s", strings.Join(getCipherSuiteNames(tlsCipherSuites), ","))
+
 		tlsConf := &tls.Config{
 			ClientAuth:               tls.NoClientCert,
 			NextProtos:               nextProtos(config),
-			MinVersion:               tls.VersionTLS10,
+			MinVersion:               tlsMinVersion,
 			PreferServerCipherSuites: true,
-			CipherSuites: []uint16{
+			CipherSuites:             tlsCipherSuites,
-				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
-				tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
-				tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
-				tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
-				tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
-				tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
-			},
 		}
 
 		if config.HTTP.TLS.LetsEncrypt.CacheFile != "" {

registry/registry_test.go

@@ -3,12 +3,24 @@ package registry
 import (
 	"bufio"
 	"context"
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
 	"fmt"
 	"io/ioutil"
+	"math/big"
 	"net"
 	"net/http"
 	"os"
+	"path"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 
@@ -38,18 +50,30 @@ func TestNextProtos(t *testing.T) {
 	}
 }
 
-func setupRegistry() (*Registry, error) {
+type registryTLSConfig struct {
+	cipherSuites    []string
+	certificatePath string
+	privateKeyPath  string
+	certificate     *tls.Certificate
+}
+
+func setupRegistry(tlsCfg *registryTLSConfig, addr string) (*Registry, error) {
 	config := &configuration.Configuration{}
 	// TODO: this needs to change to something ephemeral as the test will fail if there is any server
 	// already listening on port 5000
-	config.HTTP.Addr = ":5000"
+	config.HTTP.Addr = addr
 	config.HTTP.DrainTimeout = time.Duration(10) * time.Second
+	if tlsCfg != nil {
+		config.HTTP.TLS.CipherSuites = tlsCfg.cipherSuites
+		config.HTTP.TLS.Certificate = tlsCfg.certificatePath
+		config.HTTP.TLS.Key = tlsCfg.privateKeyPath
+	}
 	config.Storage = map[string]configuration.Parameters{"inmemory": map[string]interface{}{}}
 	return NewRegistry(context.Background(), config)
 }
 
 func TestGracefulShutdown(t *testing.T) {
-	registry, err := setupRegistry()
+	registry, err := setupRegistry(nil, ":5000")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -98,3 +122,227 @@ func TestGracefulShutdown(t *testing.T) {
 		t.Error("Body is not {}; ", string(body))
 	}
 }
+
+func TestGetCipherSuite(t *testing.T) {
+	resp, err := getCipherSuites([]string{"TLS_RSA_WITH_AES_128_CBC_SHA"})
+	if err != nil || len(resp) != 1 || resp[0] != tls.TLS_RSA_WITH_AES_128_CBC_SHA {
+		t.Errorf("expected cipher suite %q, got %q",
+			"TLS_RSA_WITH_AES_128_CBC_SHA",
+			strings.Join(getCipherSuiteNames(resp), ","),
+		)
+	}
+
+	resp, err = getCipherSuites([]string{"TLS_RSA_WITH_AES_128_CBC_SHA", "TLS_AES_128_GCM_SHA256"})
+	if err != nil || len(resp) != 2 ||
+		resp[0] != tls.TLS_RSA_WITH_AES_128_CBC_SHA || resp[1] != tls.TLS_AES_128_GCM_SHA256 {
+		t.Errorf("expected cipher suites %q, got %q",
+			"TLS_RSA_WITH_AES_128_CBC_SHA,TLS_AES_128_GCM_SHA256",
+			strings.Join(getCipherSuiteNames(resp), ","),
+		)
+	}
+
+	_, err = getCipherSuites([]string{"TLS_RSA_WITH_AES_128_CBC_SHA", "bad_input"})
+	if err == nil {
+		t.Error("did not return expected error about unknown cipher suite")
+	}
+}
+
+func buildRegistryTLSConfig(name, keyType string, cipherSuites []string) (*registryTLSConfig, error) {
+	var priv interface{}
+	var pub crypto.PublicKey
+	var err error
+	switch keyType {
+	case "rsa":
+		priv, err = rsa.GenerateKey(rand.Reader, 2048)
+		if err != nil {
+			return nil, fmt.Errorf("failed to create rsa private key: %v", err)
+		}
+		rsaKey := priv.(*rsa.PrivateKey)
+		pub = rsaKey.Public()
+	case "ecdsa":
+		priv, err = ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
+		if err != nil {
+			return nil, fmt.Errorf("failed to create ecdsa private key: %v", err)
+		}
+		ecdsaKey := priv.(*ecdsa.PrivateKey)
+		pub = ecdsaKey.Public()
+	default:
+		return nil, fmt.Errorf("unsupported key type: %v", keyType)
+	}
+
+	notBefore := time.Now()
+	notAfter := notBefore.Add(time.Minute)
+	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
+	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create serial number: %v", err)
+	}
+	cert := x509.Certificate{
+		SerialNumber: serialNumber,
+		Subject: pkix.Name{
+			Organization: []string{"registry_test"},
+		},
+		NotBefore:             notBefore,
+		NotAfter:              notAfter,
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		BasicConstraintsValid: true,
+		IPAddresses:           []net.IP{net.ParseIP("127.0.0.1")},
+		DNSNames:              []string{"localhost"},
+		IsCA:                  true,
+	}
+	derBytes, err := x509.CreateCertificate(rand.Reader, &cert, &cert, pub, priv)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create certificate: %v", err)
+	}
+	if _, err := os.Stat(os.TempDir()); os.IsNotExist(err) {
+		os.Mkdir(os.TempDir(), 1777)
+	}
+
+	certPath := path.Join(os.TempDir(), name+".pem")
+	certOut, err := os.Create(certPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create pem: %v", err)
+	}
+	if err := pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes}); err != nil {
+		return nil, fmt.Errorf("failed to write data to %s: %v", certPath, err)
+	}
+	if err := certOut.Close(); err != nil {
+		return nil, fmt.Errorf("error closing %s: %v", certPath, err)
+	}
+
+	keyPath := path.Join(os.TempDir(), name+".key")
+	keyOut, err := os.OpenFile(keyPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open %s for writing: %v", keyPath, err)
+	}
+	privBytes, err := x509.MarshalPKCS8PrivateKey(priv)
+	if err != nil {
+		return nil, fmt.Errorf("unable to marshal private key: %v", err)
+	}
+	if err := pem.Encode(keyOut, &pem.Block{Type: "PRIVATE KEY", Bytes: privBytes}); err != nil {
+		return nil, fmt.Errorf("failed to write data to key.pem: %v", err)
+	}
+	if err := keyOut.Close(); err != nil {
+		return nil, fmt.Errorf("error closing %s: %v", keyPath, err)
+	}
+
+	tlsCert := tls.Certificate{
+		Certificate: [][]byte{derBytes},
+		PrivateKey:  priv,
+	}
+
+	tlsTestCfg := registryTLSConfig{
+		cipherSuites:    cipherSuites,
+		certificatePath: certPath,
+		privateKeyPath:  keyPath,
+		certificate:     &tlsCert,
+	}
+
+	return &tlsTestCfg, nil
+}
+
+func TestRegistrySupportedCipherSuite(t *testing.T) {
+	name := "registry_test_server_supported_cipher"
+	cipherSuites := []string{"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256"}
+	serverTLS, err := buildRegistryTLSConfig(name, "rsa", cipherSuites)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	registry, err := setupRegistry(serverTLS, ":5001")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// run registry server
+	var errchan chan error
+	go func() {
+		errchan <- registry.ListenAndServe()
+	}()
+	select {
+	case err = <-errchan:
+		t.Fatalf("Error listening: %v", err)
+	default:
+	}
+
+	// Wait for some unknown random time for server to start listening
+	time.Sleep(3 * time.Second)
+
+	// send tls request with server supported cipher suite
+	clientCipherSuites, err := getCipherSuites(cipherSuites)
+	if err != nil {
+		t.Fatal(err)
+	}
+	clientTLS := tls.Config{
+		InsecureSkipVerify: true,
+		CipherSuites:       clientCipherSuites,
+	}
+	dialer := net.Dialer{
+		Timeout: time.Second * 5,
+	}
+	conn, err := tls.DialWithDialer(&dialer, "tcp", "127.0.0.1:5001", &clientTLS)
+	if err != nil {
+		t.Fatal(err)
+	}
+	fmt.Fprintf(conn, "GET /v2/ HTTP/1.1\r\nHost: 127.0.0.1\r\n\r\n")
+
+	resp, err := http.ReadResponse(bufio.NewReader(conn), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if resp.Status != "200 OK" {
+		t.Error("response status is not 200 OK: ", resp.Status)
+	}
+	if body, err := ioutil.ReadAll(resp.Body); err != nil || string(body) != "{}" {
+		t.Error("Body is not {}; ", string(body))
+	}
+
+	// send stop signal
+	quit <- os.Interrupt
+	time.Sleep(100 * time.Millisecond)
+}
+
+func TestRegistryUnsupportedCipherSuite(t *testing.T) {
+	name := "registry_test_server_unsupported_cipher"
+	serverTLS, err := buildRegistryTLSConfig(name, "rsa", []string{"TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA358"})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	registry, err := setupRegistry(serverTLS, ":5002")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// run registry server
+	var errchan chan error
+	go func() {
+		errchan <- registry.ListenAndServe()
+	}()
+	select {
+	case err = <-errchan:
+		t.Fatalf("Error listening: %v", err)
+	default:
+	}
+
+	// Wait for some unknown random time for server to start listening
+	time.Sleep(3 * time.Second)
+
+	// send tls request with server unsupported cipher suite
+	clientTLS := tls.Config{
+		InsecureSkipVerify: true,
+		CipherSuites:       []uint16{tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256},
+	}
+	dialer := net.Dialer{
+		Timeout: time.Second * 5,
+	}
+	_, err = tls.DialWithDialer(&dialer, "tcp", "127.0.0.1:5002", &clientTLS)
+	if err == nil {
+		t.Error("expected TLS connection to timeout")
+	}
+
+	// send stop signal
+	quit <- os.Interrupt
+	time.Sleep(100 * time.Millisecond)
+}