Extend Docker authorization with TLS user information

Currently Docker authorization framework does not use any user
information, which already available in the Docker context for TLS
connection.
The purpose of this CR is to complete the existing authz work by adding
the basic client certificate details (SUBJECT_NAME) and authentication
method (TLS) to the authz request.

We think this should be the default behavior when no extended
authorization module is specified (currently WIP under #20883).

Signed-off-by: Liron Levin <liron@twistlock.com>

api/server/middleware/authorization.go

@@ -13,11 +13,19 @@ import (
 func NewAuthorizationMiddleware(plugins []authorization.Plugin) Middleware {
 	return func(handler httputils.APIFunc) httputils.APIFunc {
 		return func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
-			// FIXME: fill when authN gets in
-			// User and UserAuthNMethod are taken from AuthN plugins
-			// Currently tracked in https://github.com/docker/docker/pull/13994
+
 			user := ""
 			userAuthNMethod := ""
+
+			// Default authorization using existing TLS connection credentials
+			// FIXME: Non trivial authorization mechanisms (such as advanced certificate validations, kerberos support
+			// and ldap) will be extracted using AuthN feature, which is tracked under:
+			// https://github.com/docker/docker/pull/20883
+			if r.TLS != nil && len(r.TLS.PeerCertificates) > 0 {
+				user = r.TLS.PeerCertificates[0].Subject.CommonName
+				userAuthNMethod = "TLS"
+			}
+
 			authCtx := authorization.NewCtx(plugins, user, userAuthNMethod, r.Method, r.RequestURI)
 
 			if err := authCtx.AuthZRequest(w, r); err != nil {

integration-cli/docker_cli_authz_unix_test.go

@@ -53,6 +53,8 @@ type authorizationController struct {
 	psRequestCnt  int                    // psRequestCnt counts the number of calls to list container request api
 	psResponseCnt int                    // psResponseCnt counts the number of calls to list containers response API
 	requestsURIs  []string               // requestsURIs stores all request URIs that are sent to the authorization controller
+	reqUser       string
+	resUser       string
 }
 
 func (s *DockerAuthzSuite) SetUpTest(c *check.C) {
@@ -104,6 +106,7 @@ func (s *DockerAuthzSuite) SetUpSuite(c *check.C) {
 		}
 		b, err := json.Marshal(reqRes)
 		c.Assert(err, check.IsNil)
+		s.ctrl.reqUser = authReq.User
 		w.Write(b)
 	})
 
@@ -131,6 +134,7 @@ func (s *DockerAuthzSuite) SetUpSuite(c *check.C) {
 		}
 		b, err := json.Marshal(resRes)
 		c.Assert(err, check.IsNil)
+		s.ctrl.resUser = authReq.User
 		w.Write(b)
 	})
 
@@ -213,6 +217,45 @@ func (s *DockerAuthzSuite) TestAuthZPluginAllowRequest(c *check.C) {
 	c.Assert(s.ctrl.psResponseCnt, check.Equals, 1)
 }
 
+func (s *DockerAuthzSuite) TestAuthZPluginTls(c *check.C) {
+
+	const testDaemonHTTPSAddr = "tcp://localhost:4271"
+	// start the daemon and load busybox, --net=none build fails otherwise
+	// cause it needs to pull busybox
+	if err := s.d.Start(
+		"--authorization-plugin="+testAuthZPlugin,
+		"--tlsverify",
+		"--tlscacert",
+		"fixtures/https/ca.pem",
+		"--tlscert",
+		"fixtures/https/server-cert.pem",
+		"--tlskey",
+		"fixtures/https/server-key.pem",
+		"-H", testDaemonHTTPSAddr); err != nil {
+		c.Fatalf("Could not start daemon with busybox: %v", err)
+	}
+
+	s.ctrl.reqRes.Allow = true
+	s.ctrl.resRes.Allow = true
+
+	out, _ := dockerCmd(
+		c,
+		"--tlsverify",
+		"--tlscacert", "fixtures/https/ca.pem",
+		"--tlscert", "fixtures/https/client-cert.pem",
+		"--tlskey", "fixtures/https/client-key.pem",
+		"-H",
+		testDaemonHTTPSAddr,
+		"version",
+	)
+	if !strings.Contains(out, "Server") {
+		c.Fatalf("docker version should return information of server side")
+	}
+
+	c.Assert(s.ctrl.reqUser, check.Equals, "client")
+	c.Assert(s.ctrl.resUser, check.Equals, "client")
+}
+
 func (s *DockerAuthzSuite) TestAuthZPluginDenyRequest(c *check.C) {
 	err := s.d.Start("--authorization-plugin=" + testAuthZPlugin)
 	c.Assert(err, check.IsNil)