Test the usage of cert metadata in ACL policies

Signed-off-by: Peter Verraedt <peter@verraedt.be>

builtin/credential/cert/backend_test.go

@@ -458,6 +458,168 @@ func TestBackend_PermittedDNSDomainsIntermediateCA(t *testing.T) {
 	}
 }
 
+func TestBackend_MetadataBasedACLPolicy(t *testing.T) {
+	// Start cluster with cert auth method enabled
+	coreConfig := &vault.CoreConfig{
+		DisableMlock: true,
+		DisableCache: true,
+		Logger:       log.NewNullLogger(),
+		CredentialBackends: map[string]logical.Factory{
+			"cert": Factory,
+		},
+	}
+	cluster := vault.NewTestCluster(t, coreConfig, &vault.TestClusterOptions{
+		HandlerFunc: vaulthttp.Handler,
+	})
+	cluster.Start()
+	defer cluster.Cleanup()
+	cores := cluster.Cores
+	vault.TestWaitActive(t, cores[0].Core)
+	client := cores[0].Client
+
+	var err error
+
+	// Enable the cert auth method
+	err = client.Sys().EnableAuthWithOptions("cert", &api.EnableAuthOptions{
+		Type: "cert",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Enable metadata in aliases
+	_, err = client.Logical().Write("auth/cert/config", map[string]interface{}{
+		"enable_identity_alias_metadata": true,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Retrieve its accessor id
+	auths, err := client.Sys().ListAuth()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var accessor string
+
+	for _, auth := range auths {
+		if auth.Type == "cert" {
+			accessor = auth.Accessor
+		}
+	}
+
+	if accessor == "" {
+		t.Fatal("failed to find cert auth accessor")
+	}
+
+	// Write ACL policy
+	err = client.Sys().PutPolicy("metadata-based", fmt.Sprintf(`
+path "kv/cn/{{identity.entity.aliases.%s.metadata.common_name}}" {
+	capabilities = ["read"]
+}
+path "kv/ext/{{identity.entity.aliases.%s.metadata.2-1-1-1}}" {
+	capabilities = ["read"]
+}
+`, accessor, accessor))
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	ca, err := ioutil.ReadFile("test-fixtures/root/rootcacert.pem")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Set the trusted certificate in the backend
+	_, err = client.Logical().Write("auth/cert/certs/test", map[string]interface{}{
+		"display_name":                "test",
+		"policies":                    "metadata-based",
+		"certificate":                 string(ca),
+		"allowed_metadata_extensions": "2.1.1.1,1.2.3.45",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// This function is a copy-paste from the NewTestCluster, with the
+	// modification to reconfigure the TLS on the api client with a
+	// specific client certificate.
+	getAPIClient := func(port int, tlsConfig *tls.Config) *api.Client {
+		transport := cleanhttp.DefaultPooledTransport()
+		transport.TLSClientConfig = tlsConfig.Clone()
+		if err := http2.ConfigureTransport(transport); err != nil {
+			t.Fatal(err)
+		}
+		client := &http.Client{
+			Transport: transport,
+			CheckRedirect: func(*http.Request, []*http.Request) error {
+				// This can of course be overridden per-test by using its own client
+				return fmt.Errorf("redirects not allowed in these tests")
+			},
+		}
+		config := api.DefaultConfig()
+		if config.Error != nil {
+			t.Fatal(config.Error)
+		}
+		config.Address = fmt.Sprintf("https://127.0.0.1:%d", port)
+		config.HttpClient = client
+
+		// Set the client certificates
+		config.ConfigureTLS(&api.TLSConfig{
+			CACertBytes: cluster.CACertPEM,
+			ClientCert:  "test-fixtures/root/rootcawextcert.pem",
+			ClientKey:   "test-fixtures/root/rootcawextkey.pem",
+		})
+
+		apiClient, err := api.NewClient(config)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return apiClient
+	}
+
+	// Create a new api client with the desired TLS configuration
+	newClient := getAPIClient(cores[0].Listeners[0].Address.Port, cores[0].TLSConfig)
+
+	var secret *api.Secret
+
+	secret, err = newClient.Logical().Write("auth/cert/login", map[string]interface{}{
+		"name": "test",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if secret.Auth == nil || secret.Auth.ClientToken == "" {
+		t.Fatalf("expected a successful authentication")
+	}
+
+	// Check paths guarded by ACL policy
+	newClient.SetToken(secret.Auth.ClientToken)
+
+	fmt.Printf("%#v\n", secret.Auth)
+
+	_, err = newClient.Logical().Read("kv/cn/example.com")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = newClient.Logical().Read("kv/cn/not.example.com")
+	if err == nil {
+		t.Fatal("expected access denied")
+	}
+
+	_, err = newClient.Logical().Read("kv/ext/A UTF8String Extension")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = newClient.Logical().Read("kv/ext/bar")
+	if err == nil {
+		t.Fatal("expected access denied")
+	}
+}
+
 func TestBackend_NonCAExpiry(t *testing.T) {
 	var resp *logical.Response
 	var err error