Do not verify certificate when using --insecure-registry on an HTTPS registry

Signed-off-by: Tibor Vass <teabee89@gmail.com>

Conflicts:
	registry/registry.go
	registry/registry_test.go
	registry/service.go
	registry/session.go

daemon/config.go

@@ -56,7 +56,7 @@ func (config *Config) InstallFlags() {
 	flag.StringVar(&config.BridgeIP, []string{"#bip", "-bip"}, "", "Use this CIDR notation address for the network bridge's IP, not compatible with -b")
 	flag.StringVar(&config.BridgeIface, []string{"b", "-bridge"}, "", "Attach containers to a pre-existing network bridge\nuse 'none' to disable container networking")
 	flag.StringVar(&config.FixedCIDR, []string{"-fixed-cidr"}, "", "IPv4 subnet for fixed IPs (ex: 10.20.0.0/16)\nthis subnet must be nested in the bridge subnet (which is defined by -b or --bip)")
-	opts.ListVar(&config.InsecureRegistries, []string{"-insecure-registry"}, "Make these registries use http")
+	opts.ListVar(&config.InsecureRegistries, []string{"-insecure-registry"}, "Enable insecure communication with specified registries (no certificate verification for HTTPS and enable HTTP fallback)")
 	flag.BoolVar(&config.InterContainerCommunication, []string{"#icc", "-icc"}, true, "Enable inter-container communication")
 	flag.StringVar(&config.GraphDriver, []string{"s", "-storage-driver"}, "", "Force the Docker runtime to use a specific storage driver")
 	flag.StringVar(&config.ExecDriver, []string{"e", "-exec-driver"}, "native", "Force the Docker runtime to use a specific exec driver")

docs/sources/reference/commandline/cli.md

@@ -70,7 +70,7 @@ expect an integer, and they can only be specified once.
       -g, --graph="/var/lib/docker"              Path to use as the root of the Docker runtime
       -H, --host=[]                              The socket(s) to bind to in daemon mode or connect to in client mode, specified using one or more tcp://host:port, unix:///path/to/socket, fd://* or fd://socketfd.
       --icc=true                                 Enable inter-container communication
-      --insecure-registry=[]                     Make these registries use http
+      --insecure-registry=[]                     Enable insecure communication with specified registries (no certificate verification for HTTPS and enable HTTP fallback)
       --ip=0.0.0.0                               Default IP address to use when binding container ports
       --ip-forward=true                          Enable net.ipv4.ip_forward
       --ip-masq=true                             Enable IP masquerading for bridge's IP range
@@ -195,16 +195,16 @@ to other machines on the Internet. This may interfere with some network topologi
 can be disabled with --ip-masq=false.
 
 
+By default, Docker will assume all registries are secured via TLS with certificate verification
+enabled. Prior versions of Docker used an auto fallback if a registry did not support TLS
+(or if the TLS connection failed). This introduced the opportunity for Man In The Middle (MITM)
+attacks, so as of Docker 1.3.1, the user must now specify the `--insecure-registry` daemon flag
+for each insecure registry. An insecure registry is either not using TLS (i.e. plain text HTTP),
+or is using TLS with a CA certificate not known by the Docker daemon (i.e. certification
+verification disabled). For example, if there is a registry listening for HTTP at 127.0.0.1:5000,
+as of Docker 1.3.1 you are required to specify `--insecure-registry 127.0.0.1:5000` when starting
+the Docker daemon.
 
-By default docker will assume all registries are securied via TLS.  Prior versions
-of docker used an auto fallback if a registry did not support TLS.  This introduces
-the opportunity for MITM attacks so in Docker 1.2 the user must specify `--insecure-registries` 
-when starting the Docker daemon to state which registries are not using TLS and to communicate
-with these registries via plain text.  If you are running a local registry over plain text
-on `127.0.0.1:5000` you will be required to specify `--insecure-registries 127.0.0.1:500` 
-when starting the docker daemon to be able to push and pull images to that registry.
-No automatic fallback will happen after Docker 1.2 to detect if a registry is using
-HTTP or HTTPS.
 
 Docker supports softlinks for the Docker data directory
 (`/var/lib/docker`) and for `/var/lib/docker/tmp`. The `DOCKER_TMPDIR` and the data directory can be set like this:

graph/tags_unit_test.go

@@ -53,7 +53,7 @@ func mkTestTagStore(root string, t *testing.T) *TagStore {
 	if err != nil {
 		t.Fatal(err)
 	}
-	store, err := NewTagStore(path.Join(root, "tags"), graph, nil)
+	store, err := NewTagStore(path.Join(root, "tags"), graph, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}

registry/endpoint.go

@@ -2,7 +2,6 @@ package registry
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -34,9 +33,9 @@ func scanForApiVersion(hostname string) (string, APIVersion) {
 	return hostname, DefaultAPIVersion
 }
 
-func NewEndpoint(hostname string) (*Endpoint, error) {
+func NewEndpoint(hostname string, secure bool) (*Endpoint, error) {
 	var (
-		endpoint        Endpoint
+		endpoint        = Endpoint{secure: secure}
 		trimmedHostname string
 		err             error
 	)
@@ -49,14 +48,27 @@ func NewEndpoint(hostname string) (*Endpoint, error) {
 		return nil, err
 	}
 
+	// Try HTTPS ping to registry
 	endpoint.URL.Scheme = "https"
 	if _, err := endpoint.Ping(); err != nil {
-		log.Debugf("Registry %s does not work (%s), falling back to http", endpoint, err)
-		// TODO: Check if http fallback is enabled
-		endpoint.URL.Scheme = "http"
-		if _, err = endpoint.Ping(); err != nil {
-			return nil, errors.New("Invalid Registry endpoint: " + err.Error())
+
+		//TODO: triggering highland build can be done there without "failing"
+
+		if secure {
+			// If registry is secure and HTTPS failed, show user the error and tell them about `--insecure-registry`
+			// in case that's what they need. DO NOT accept unknown CA certificates, and DO NOT fallback to HTTP.
+			return nil, fmt.Errorf("Invalid registry endpoint %s: %v. If this private registry supports only HTTP or HTTPS with an unknown CA certificate, please add `--insecure-registry %s` to the daemon's arguments. In the case of HTTPS, if you have access to the registry's CA certificate, no need for the flag; simply place the CA certificate at /etc/docker/certs.d/%s/ca.crt", endpoint, err, endpoint.URL.Host, endpoint.URL.Host)
 		}
+
+		// If registry is insecure and HTTPS failed, fallback to HTTP.
+		log.Debugf("Error from registry %q marked as insecure: %v. Insecurely falling back to HTTP", endpoint, err)
+		endpoint.URL.Scheme = "http"
+		_, err2 := endpoint.Ping()
+		if err2 == nil {
+			return &endpoint, nil
+		}
+
+		return nil, fmt.Errorf("Invalid registry endpoint %q. HTTPS attempt: %v. HTTP attempt: %v", endpoint, err, err2)
 	}
 
 	return &endpoint, nil
@@ -65,6 +77,7 @@ func NewEndpoint(hostname string) (*Endpoint, error) {
 type Endpoint struct {
 	URL     *url.URL
 	Version APIVersion
+	secure  bool
 }
 
 // Get the formated URL for the root of this registry Endpoint
@@ -88,7 +101,7 @@ func (e Endpoint) Ping() (RegistryInfo, error) {
 		return RegistryInfo{Standalone: false}, err
 	}
 
-	resp, _, err := doRequest(req, nil, ConnectTimeout)
+	resp, _, err := doRequest(req, nil, ConnectTimeout, e.secure)
 	if err != nil {
 		return RegistryInfo{Standalone: false}, err
 	}
@@ -127,3 +140,19 @@ func (e Endpoint) Ping() (RegistryInfo, error) {
 	log.Debugf("RegistryInfo.Standalone: %t", info.Standalone)
 	return info, nil
 }
+
+// IsSecure returns false if the provided hostname is part of the list of insecure registries.
+// Insecure registries accept HTTP and/or accept HTTPS with certificates from unknown CAs.
+func IsSecure(hostname string, insecureRegistries []string) bool {
+	if hostname == IndexServerAddress() {
+		return true
+	}
+
+	for _, h := range insecureRegistries {
+		if hostname == h {
+			return false
+		}
+	}
+
+	return true
+}

registry/registry.go

@@ -14,6 +14,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/docker/docker/pkg/log"
 	"github.com/docker/docker/utils"
 )
 
@@ -35,13 +36,17 @@ const (
 	ConnectTimeout
 )
 
-func newClient(jar http.CookieJar, roots *x509.CertPool, cert *tls.Certificate, timeout TimeoutType) *http.Client {
+func newClient(jar http.CookieJar, roots *x509.CertPool, cert *tls.Certificate, timeout TimeoutType, secure bool) *http.Client {
 	tlsConfig := tls.Config{RootCAs: roots}
 
 	if cert != nil {
 		tlsConfig.Certificates = append(tlsConfig.Certificates, *cert)
 	}
 
+	if !secure {
+		tlsConfig.InsecureSkipVerify = true
+	}
+
 	httpTransport := &http.Transport{
 		DisableKeepAlives: true,
 		Proxy:             http.ProxyFromEnvironment,
@@ -78,69 +83,76 @@ func newClient(jar http.CookieJar, roots *x509.CertPool, cert *tls.Certificate,
 	}
 }
 
-func doRequest(req *http.Request, jar http.CookieJar, timeout TimeoutType) (*http.Response, *http.Client, error) {
-	hasFile := func(files []os.FileInfo, name string) bool {
-		for _, f := range files {
-			if f.Name() == name {
-				return true
-			}
-		}
-		return false
-	}
-
-	hostDir := path.Join("/etc/docker/certs.d", req.URL.Host)
-	fs, err := ioutil.ReadDir(hostDir)
-	if err != nil && !os.IsNotExist(err) {
-		return nil, nil, err
-	}
-
+func doRequest(req *http.Request, jar http.CookieJar, timeout TimeoutType, secure bool) (*http.Response, *http.Client, error) {
 	var (
 		pool  *x509.CertPool
 		certs []*tls.Certificate
 	)
 
-	for _, f := range fs {
-		if strings.HasSuffix(f.Name(), ".crt") {
-			if pool == nil {
-				pool = x509.NewCertPool()
+	if secure && req.URL.Scheme == "https" {
+		hasFile := func(files []os.FileInfo, name string) bool {
+			for _, f := range files {
+				if f.Name() == name {
+					return true
+				}
 			}
-			data, err := ioutil.ReadFile(path.Join(hostDir, f.Name()))
-			if err != nil {
-				return nil, nil, err
-			}
-			pool.AppendCertsFromPEM(data)
+			return false
 		}
-		if strings.HasSuffix(f.Name(), ".cert") {
-			certName := f.Name()
-			keyName := certName[:len(certName)-5] + ".key"
-			if !hasFile(fs, keyName) {
-				return nil, nil, fmt.Errorf("Missing key %s for certificate %s", keyName, certName)
-			}
-			cert, err := tls.LoadX509KeyPair(path.Join(hostDir, certName), path.Join(hostDir, keyName))
-			if err != nil {
-				return nil, nil, err
-			}
-			certs = append(certs, &cert)
+
+		hostDir := path.Join("/etc/docker/certs.d", req.URL.Host)
+		log.Debugf("hostDir: %s", hostDir)
+		fs, err := ioutil.ReadDir(hostDir)
+		if err != nil && !os.IsNotExist(err) {
+			return nil, nil, err
 		}
-		if strings.HasSuffix(f.Name(), ".key") {
-			keyName := f.Name()
-			certName := keyName[:len(keyName)-4] + ".cert"
-			if !hasFile(fs, certName) {
-				return nil, nil, fmt.Errorf("Missing certificate %s for key %s", certName, keyName)
+
+		for _, f := range fs {
+			if strings.HasSuffix(f.Name(), ".crt") {
+				if pool == nil {
+					pool = x509.NewCertPool()
+				}
+				log.Debugf("crt: %s", hostDir+"/"+f.Name())
+				data, err := ioutil.ReadFile(path.Join(hostDir, f.Name()))
+				if err != nil {
+					return nil, nil, err
+				}
+				pool.AppendCertsFromPEM(data)
+			}
+			if strings.HasSuffix(f.Name(), ".cert") {
+				certName := f.Name()
+				keyName := certName[:len(certName)-5] + ".key"
+				log.Debugf("cert: %s", hostDir+"/"+f.Name())
+				if !hasFile(fs, keyName) {
+					return nil, nil, fmt.Errorf("Missing key %s for certificate %s", keyName, certName)
+				}
+				cert, err := tls.LoadX509KeyPair(path.Join(hostDir, certName), path.Join(hostDir, keyName))
+				if err != nil {
+					return nil, nil, err
+				}
+				certs = append(certs, &cert)
+			}
+			if strings.HasSuffix(f.Name(), ".key") {
+				keyName := f.Name()
+				certName := keyName[:len(keyName)-4] + ".cert"
+				log.Debugf("key: %s", hostDir+"/"+f.Name())
+				if !hasFile(fs, certName) {
+					return nil, nil, fmt.Errorf("Missing certificate %s for key %s", certName, keyName)
+				}
 			}
 		}
 	}
 
 	if len(certs) == 0 {
-		client := newClient(jar, pool, nil, timeout)
+		client := newClient(jar, pool, nil, timeout, secure)
 		res, err := client.Do(req)
 		if err != nil {
 			return nil, nil, err
 		}
 		return res, client, nil
 	}
+
 	for i, cert := range certs {
-		client := newClient(jar, pool, cert, timeout)
+		client := newClient(jar, pool, cert, timeout, secure)
 		res, err := client.Do(req)
 		// If this is the last cert, otherwise, continue to next cert if 403 or 5xx
 		if i == len(certs)-1 || err == nil && res.StatusCode != 403 && res.StatusCode < 500 {
@@ -202,49 +214,6 @@ func ResolveRepositoryName(reposName string) (string, string, error) {
 	return hostname, reposName, nil
 }
 
-// this method expands the registry name as used in the prefix of a repo
-// to a full url. if it already is a url, there will be no change.
-func ExpandAndVerifyRegistryUrl(hostname string, secure bool) (string, error) {
-	if hostname == IndexServerAddress() {
-		return hostname, nil
-	}
-
-	endpoint := fmt.Sprintf("http://%s/v1/", hostname)
-
-	if secure {
-		endpoint = fmt.Sprintf("https://%s/v1/", hostname)
-	}
-
-	if _, oerr := pingRegistryEndpoint(endpoint); oerr != nil {
-		//TODO: triggering highland build can be done there without "failing"
-		err := fmt.Errorf("Invalid registry endpoint '%s': %s ", endpoint, oerr)
-
-		if secure {
-			err = fmt.Errorf("%s. If this private registry supports only HTTP, please add `--insecure-registry %s` to the daemon's arguments.", oerr, hostname)
-		}
-
-		return "", err
-	}
-
-	return endpoint, nil
-}
-
-// this method verifies if the provided hostname is part of the list of
-// insecure registries and returns false if HTTP should be used
-func IsSecure(hostname string, insecureRegistries []string) bool {
-	if hostname == IndexServerAddress() {
-		return true
-	}
-
-	for _, h := range insecureRegistries {
-		if hostname == h {
-			return false
-		}
-	}
-
-	return true
-}
-
 func trustedLocation(req *http.Request) bool {
 	var (
 		trusteds = []string{"docker.com", "docker.io"}

registry/registry_test.go

@@ -18,7 +18,7 @@ var (
 
 func spawnTestRegistrySession(t *testing.T) *Session {
 	authConfig := &AuthConfig{}
-	endpoint, err := NewEndpoint(makeURL("/v1/"))
+	endpoint, err := NewEndpoint(makeURL("/v1/"), false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -30,7 +30,7 @@ func spawnTestRegistrySession(t *testing.T) *Session {
 }
 
 func TestPingRegistryEndpoint(t *testing.T) {
-	ep, err := NewEndpoint(makeURL("/v1/"))
+	ep, err := NewEndpoint(makeURL("/v1/"), false)
 	if err != nil {
 		t.Fatal(err)
 	}

registry/service.go

@@ -89,7 +89,10 @@ func (s *Service) Search(job *engine.Job) engine.Status {
 	if err != nil {
 		return job.Error(err)
 	}
-	endpoint, err := NewEndpoint(hostname)
+
+	secure := IsSecure(hostname, s.insecureRegistries)
+
+	endpoint, err := NewEndpoint(hostname, secure)
 	if err != nil {
 		return job.Error(err)
 	}

registry/session.go

@@ -64,7 +64,7 @@ func NewSession(authConfig *AuthConfig, factory *utils.HTTPRequestFactory, endpo
 }
 
 func (r *Session) doRequest(req *http.Request) (*http.Response, *http.Client, error) {
-	return doRequest(req, r.jar, r.timeout)
+	return doRequest(req, r.jar, r.timeout, r.indexEndpoint.secure)
 }
 
 // Retrieve the history of a given image from the Registry.