google.golang.org/grpc@v1.74.2/internal/xds/bootstrap/tlscreds/bundle_ext_test.go (about)

     1  /*
     2   *
     3   * Copyright 2023 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  package tlscreds_test
    20  
    21  import (
    22  	"context"
    23  	"crypto/tls"
    24  	"encoding/json"
    25  	"fmt"
    26  	"os"
    27  	"strings"
    28  	"testing"
    29  	"time"
    30  
    31  	"google.golang.org/grpc"
    32  	"google.golang.org/grpc/codes"
    33  	"google.golang.org/grpc/internal/envconfig"
    34  	"google.golang.org/grpc/internal/grpctest"
    35  	"google.golang.org/grpc/internal/stubserver"
    36  	"google.golang.org/grpc/internal/testutils"
    37  	"google.golang.org/grpc/internal/xds/bootstrap/tlscreds"
    38  	testgrpc "google.golang.org/grpc/interop/grpc_testing"
    39  	testpb "google.golang.org/grpc/interop/grpc_testing"
    40  	"google.golang.org/grpc/status"
    41  	"google.golang.org/grpc/testdata"
    42  )
    43  
    44  const defaultTestTimeout = 5 * time.Second
    45  
    46  type s struct {
    47  	grpctest.Tester
    48  }
    49  
    50  func Test(t *testing.T) {
    51  	grpctest.RunSubTests(t, s{})
    52  }
    53  
    54  type Closable interface {
    55  	Close()
    56  }
    57  
    58  func (s) TestValidTlsBuilder(t *testing.T) {
    59  	caCert := testdata.Path("x509/server_ca_cert.pem")
    60  	clientCert := testdata.Path("x509/client1_cert.pem")
    61  	clientKey := testdata.Path("x509/client1_key.pem")
    62  	clientSpiffeBundle := testdata.Path("spiffe_end2end/client_spiffebundle.json")
    63  	tests := []struct {
    64  		name string
    65  		jd   string
    66  	}{
    67  		{
    68  			name: "Absent configuration",
    69  			jd:   `null`,
    70  		},
    71  		{
    72  			name: "Empty configuration",
    73  			jd:   `{}`,
    74  		},
    75  		{
    76  			name: "Only CA certificate chain",
    77  			jd:   fmt.Sprintf(`{"ca_certificate_file": "%s"}`, caCert),
    78  		},
    79  		{
    80  			name: "Only private key and certificate chain",
    81  			jd:   fmt.Sprintf(`{"certificate_file":"%s","private_key_file":"%s"}`, clientCert, clientKey),
    82  		},
    83  		{
    84  			name: "CA chain, private key and certificate chain",
    85  			jd:   fmt.Sprintf(`{"ca_certificate_file":"%s","certificate_file":"%s","private_key_file":"%s"}`, caCert, clientCert, clientKey),
    86  		},
    87  		{
    88  			name: "Only refresh interval", jd: `{"refresh_interval": "1s"}`,
    89  		},
    90  		{
    91  			name: "Refresh interval and CA certificate chain",
    92  			jd:   fmt.Sprintf(`{"refresh_interval": "1s","ca_certificate_file": "%s"}`, caCert),
    93  		},
    94  		{
    95  			name: "Refresh interval, private key and certificate chain",
    96  			jd:   fmt.Sprintf(`{"refresh_interval": "1s","certificate_file":"%s","private_key_file":"%s"}`, clientCert, clientKey),
    97  		},
    98  		{
    99  			name: "Refresh interval, CA chain, private key and certificate chain",
   100  			jd:   fmt.Sprintf(`{"refresh_interval": "1s","ca_certificate_file":"%s","certificate_file":"%s","private_key_file":"%s"}`, caCert, clientCert, clientKey),
   101  		},
   102  		{
   103  			name: "Refresh interval, CA chain, private key, certificate chain, spiffe bundle",
   104  			jd:   fmt.Sprintf(`{"refresh_interval": "1s","ca_certificate_file":"%s","certificate_file":"%s","private_key_file":"%s","spiffe_trust_bundle_map_file":"%s"}`, caCert, clientCert, clientKey, clientSpiffeBundle),
   105  		},
   106  		{
   107  			name: "Unknown field",
   108  			jd:   `{"unknown_field": "foo"}`,
   109  		},
   110  	}
   111  
   112  	for _, test := range tests {
   113  		t.Run(test.name, func(t *testing.T) {
   114  			msg := json.RawMessage(test.jd)
   115  			_, stop, err := tlscreds.NewBundle(msg)
   116  			if err != nil {
   117  				t.Fatalf("NewBundle(%s) returned error %s when expected to succeed", test.jd, err)
   118  			}
   119  			stop()
   120  		})
   121  	}
   122  }
   123  
   124  func (s) TestInvalidTlsBuilder(t *testing.T) {
   125  	tests := []struct {
   126  		name, jd, wantErrPrefix string
   127  	}{
   128  		{
   129  			name:          "Wrong type in json",
   130  			jd:            `{"ca_certificate_file": 1}`,
   131  			wantErrPrefix: "failed to unmarshal config:"},
   132  		{
   133  			name:          "Missing private key",
   134  			jd:            fmt.Sprintf(`{"certificate_file":"%s"}`, testdata.Path("x509/server_cert.pem")),
   135  			wantErrPrefix: "pemfile: private key file and identity cert file should be both specified or not specified",
   136  		},
   137  	}
   138  
   139  	for _, test := range tests {
   140  		t.Run(test.name, func(t *testing.T) {
   141  			msg := json.RawMessage(test.jd)
   142  			_, stop, err := tlscreds.NewBundle(msg)
   143  			if err == nil || !strings.HasPrefix(err.Error(), test.wantErrPrefix) {
   144  				if stop != nil {
   145  					stop()
   146  				}
   147  				t.Fatalf("NewBundle(%s): got error %s, want an error with prefix %s", msg, err, test.wantErrPrefix)
   148  			}
   149  		})
   150  	}
   151  }
   152  
   153  func (s) TestCaReloading(t *testing.T) {
   154  	serverCa, err := os.ReadFile(testdata.Path("x509/server_ca_cert.pem"))
   155  	if err != nil {
   156  		t.Fatalf("Failed to read test CA cert: %s", err)
   157  	}
   158  
   159  	// Write CA certs to a temporary file so that we can modify it later.
   160  	caPath := t.TempDir() + "/ca.pem"
   161  	if err = os.WriteFile(caPath, serverCa, 0644); err != nil {
   162  		t.Fatalf("Failed to write test CA cert: %v", err)
   163  	}
   164  	cfg := fmt.Sprintf(`{
   165  		"ca_certificate_file": "%s",
   166  		"refresh_interval": ".01s"
   167  	}`, caPath)
   168  	tlsBundle, stop, err := tlscreds.NewBundle([]byte(cfg))
   169  	if err != nil {
   170  		t.Fatalf("Failed to create TLS bundle: %v", err)
   171  	}
   172  	defer stop()
   173  
   174  	serverCredentials := grpc.Creds(testutils.CreateServerTLSCredentials(t, tls.NoClientCert))
   175  	server := stubserver.StartTestService(t, nil, serverCredentials)
   176  
   177  	conn, err := grpc.NewClient(
   178  		server.Address,
   179  		grpc.WithCredentialsBundle(tlsBundle),
   180  		grpc.WithAuthority("x.test.example.com"),
   181  	)
   182  	if err != nil {
   183  		t.Fatalf("Error dialing: %v", err)
   184  	}
   185  	defer conn.Close()
   186  
   187  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   188  	defer cancel()
   189  
   190  	client := testgrpc.NewTestServiceClient(conn)
   191  	if _, err = client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
   192  		t.Errorf("Error calling EmptyCall: %v", err)
   193  	}
   194  	// close the server and create a new one to force client to do a new
   195  	// handshake.
   196  	server.Stop()
   197  
   198  	invalidCa, err := os.ReadFile(testdata.Path("ca.pem"))
   199  	if err != nil {
   200  		t.Fatalf("Failed to read test CA cert: %v", err)
   201  	}
   202  	// unload root cert
   203  	err = os.WriteFile(caPath, invalidCa, 0644)
   204  	if err != nil {
   205  		t.Fatalf("Failed to write test CA cert: %v", err)
   206  	}
   207  	for ; ctx.Err() == nil; <-time.After(10 * time.Millisecond) {
   208  		ss := stubserver.StubServer{
   209  			Address:    server.Address,
   210  			EmptyCallF: func(context.Context, *testpb.Empty) (*testpb.Empty, error) { return &testpb.Empty{}, nil },
   211  		}
   212  		server = stubserver.StartTestService(t, &ss, serverCredentials)
   213  
   214  		// Client handshake should eventually fail because the client CA was
   215  		// reloaded, and thus the server cert is signed by an unknown CA.
   216  		t.Log(server)
   217  		_, err = client.EmptyCall(ctx, &testpb.Empty{})
   218  		const wantErr = "certificate signed by unknown authority"
   219  		if status.Code(err) == codes.Unavailable && strings.Contains(err.Error(), wantErr) {
   220  			// Certs have reloaded.
   221  			server.Stop()
   222  			break
   223  		}
   224  		t.Logf("EmptyCall() got err: %s, want code: %s, want err: %s", err, codes.Unavailable, wantErr)
   225  		server.Stop()
   226  	}
   227  	if ctx.Err() != nil {
   228  		t.Errorf("Timed out waiting for CA certs reloading")
   229  	}
   230  }
   231  
   232  // Test_SPIFFE_Reloading sets up a client and server. The client is configured
   233  // to use a SPIFFE bundle map, and the server is configured to use TLS creds
   234  // compatible with this bundle. A handshake is performed and connection is
   235  // expected to be successful. Then we change the client's SPIFFE Bundle Map file
   236  // on disk to one that should fail with the server's credentials. This change
   237  // should be picked up by the client via our file reloading. Another handshake
   238  // is performed and checked for failure, ensuring that gRPC is correctly using
   239  // the changed-on-disk bundle map.
   240  func (s) Test_SPIFFE_Reloading(t *testing.T) {
   241  	testutils.SetEnvConfig(t, &envconfig.XDSSPIFFEEnabled, true)
   242  	clientSPIFFEBundle, err := os.ReadFile(testdata.Path("spiffe_end2end/client_spiffebundle.json"))
   243  	if err != nil {
   244  		t.Fatalf("Failed to read test SPIFFE bundle: %v", err)
   245  	}
   246  
   247  	// Write CA certs to a temporary file so that we can modify it later.
   248  	spiffePath := t.TempDir() + "/client_spiffe.json"
   249  	if err = os.WriteFile(spiffePath, clientSPIFFEBundle, 0644); err != nil {
   250  		t.Fatalf("Failed to write test SPIFFE Bundle %v: %v", clientSPIFFEBundle, err)
   251  	}
   252  	cfg := fmt.Sprintf(`{
   253  		"spiffe_trust_bundle_map_file": "%s",
   254  		"refresh_interval": ".01s"
   255  	}`, spiffePath)
   256  	tlsBundle, stop, err := tlscreds.NewBundle([]byte(cfg))
   257  	if err != nil {
   258  		t.Fatalf("Failed to create TLS bundle: %v", err)
   259  	}
   260  	defer stop()
   261  
   262  	l, err := testutils.LocalTCPListener()
   263  	if err != nil {
   264  		t.Fatalf("testutils.LocalTCPListener() failed: %v", err)
   265  	}
   266  	lis := testutils.NewRestartableListener(l)
   267  	defer lis.Close()
   268  	ss := stubserver.StubServer{
   269  		Listener:   lis,
   270  		EmptyCallF: func(context.Context, *testpb.Empty) (*testpb.Empty, error) { return &testpb.Empty{}, nil },
   271  	}
   272  
   273  	serverCredentials := grpc.Creds(testutils.CreateServerTLSCredentialsCompatibleWithSPIFFE(t, tls.NoClientCert))
   274  	server := stubserver.StartTestService(t, &ss, serverCredentials)
   275  
   276  	defer server.Stop()
   277  
   278  	conn, err := grpc.NewClient(
   279  		server.Address,
   280  		grpc.WithCredentialsBundle(tlsBundle),
   281  		grpc.WithAuthority("x.test.example.com"),
   282  	)
   283  	if err != nil {
   284  		t.Fatalf("grpc.NewClient(%q) failed: %v", server.Address, err)
   285  	}
   286  	defer conn.Close()
   287  
   288  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   289  	defer cancel()
   290  
   291  	client := testgrpc.NewTestServiceClient(conn)
   292  	if _, err = client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
   293  		t.Errorf("Error calling EmptyCall: %v", err)
   294  	}
   295  
   296  	// Setup the wrong bundle to be reloaded
   297  	wrongBundle, err := os.ReadFile(testdata.Path("spiffe_end2end/server_spiffebundle.json"))
   298  	if err != nil {
   299  		t.Fatalf("Failed to read test spiffe bundle %v: %v", "spiffe_end2end/server_spiffebundle.json", err)
   300  	}
   301  	// Write the bundle that will fail to the tmp file path to be reloaded
   302  	err = os.WriteFile(spiffePath, wrongBundle, 0644)
   303  	if err != nil {
   304  		t.Fatalf("Failed to write test spiffe bundle %v: %v", "spiffe_end2end/server_spiffebundle.json", err)
   305  	}
   306  
   307  	for ; ctx.Err() == nil; <-time.After(10 * time.Millisecond) {
   308  		// Stop and restart the listener to force new handshakes
   309  		lis.Stop()
   310  		lis.Restart()
   311  		// Client handshake should eventually fail because the client CA was
   312  		// reloaded, and thus the server cert is signed by an unknown CA.
   313  		t.Log(server)
   314  		_, err = client.EmptyCall(ctx, &testpb.Empty{})
   315  		const wantErr = "no bundle found for peer certificates trust domain"
   316  		if status.Code(err) == codes.Unavailable && strings.Contains(err.Error(), wantErr) {
   317  			// Certs have reloaded.
   318  			server.Stop()
   319  			break
   320  		}
   321  		t.Logf("EmptyCall() got err: %s, want code: %s, want err: %s", err, codes.Unavailable, wantErr)
   322  	}
   323  	if ctx.Err() != nil {
   324  		t.Errorf("Timed out waiting for CA certs reloading")
   325  	}
   326  }
   327  
   328  func (s) TestMTLS(t *testing.T) {
   329  	s := stubserver.StartTestService(t, nil, grpc.Creds(testutils.CreateServerTLSCredentials(t, tls.RequireAndVerifyClientCert)))
   330  	defer s.Stop()
   331  
   332  	cfg := fmt.Sprintf(`{
   333  		"ca_certificate_file": "%s",
   334  		"certificate_file": "%s",
   335  		"private_key_file": "%s"
   336  	}`,
   337  		testdata.Path("x509/server_ca_cert.pem"),
   338  		testdata.Path("x509/client1_cert.pem"),
   339  		testdata.Path("x509/client1_key.pem"))
   340  	tlsBundle, stop, err := tlscreds.NewBundle([]byte(cfg))
   341  	if err != nil {
   342  		t.Fatalf("Failed to create TLS bundle: %v", err)
   343  	}
   344  	defer stop()
   345  	conn, err := grpc.NewClient(s.Address, grpc.WithCredentialsBundle(tlsBundle), grpc.WithAuthority("x.test.example.com"))
   346  	if err != nil {
   347  		t.Fatalf("Error dialing: %v", err)
   348  	}
   349  	defer conn.Close()
   350  	client := testgrpc.NewTestServiceClient(conn)
   351  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   352  	defer cancel()
   353  	if _, err = client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
   354  		t.Errorf("EmptyCall(): got error %v when expected to succeed", err)
   355  	}
   356  }
   357  
   358  // Test_MTLS_SPIFFE configures a client and server. The server has a certificate
   359  // chain that is compatible with the client's configured SPIFFE bundle map. An
   360  // MTLS connection is attempted between the two and checked for success.
   361  func (s) Test_MTLS_SPIFFE(t *testing.T) {
   362  	testutils.SetEnvConfig(t, &envconfig.XDSSPIFFEEnabled, true)
   363  	tests := []struct {
   364  		name         string
   365  		serverOption grpc.ServerOption
   366  	}{
   367  		{
   368  			name:         "MTLS SPIFFE",
   369  			serverOption: grpc.Creds(testutils.CreateServerTLSCredentialsCompatibleWithSPIFFE(t, tls.RequireAndVerifyClientCert)),
   370  		},
   371  		{
   372  			name:         "MTLS SPIFFE Chain",
   373  			serverOption: grpc.Creds(testutils.CreateServerTLSCredentialsCompatibleWithSPIFFEChain(t, tls.RequireAndVerifyClientCert)),
   374  		},
   375  	}
   376  	for _, tc := range tests {
   377  		t.Run(tc.name, func(t *testing.T) {
   378  			s := stubserver.StartTestService(t, nil, tc.serverOption)
   379  			defer s.Stop()
   380  
   381  			cfg := fmt.Sprintf(`{
   382  	"certificate_file": "%s",
   383  	"private_key_file": "%s",
   384  	"spiffe_trust_bundle_map_file": "%s"
   385  }`,
   386  				testdata.Path("spiffe_end2end/client_spiffe.pem"),
   387  				testdata.Path("spiffe_end2end/client.key"),
   388  				testdata.Path("spiffe_end2end/client_spiffebundle.json"))
   389  			tlsBundle, stop, err := tlscreds.NewBundle([]byte(cfg))
   390  			if err != nil {
   391  				t.Fatalf("Failed to create TLS bundle: %v", err)
   392  			}
   393  			defer stop()
   394  			conn, err := grpc.NewClient(s.Address, grpc.WithCredentialsBundle(tlsBundle), grpc.WithAuthority("x.test.example.com"))
   395  			if err != nil {
   396  				t.Fatalf("Error dialing: %v", err)
   397  			}
   398  			defer conn.Close()
   399  			client := testgrpc.NewTestServiceClient(conn)
   400  			ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   401  			defer cancel()
   402  			if _, err = client.EmptyCall(ctx, &testpb.Empty{}); err != nil {
   403  				t.Errorf("EmptyCall(): got error %v when expected to succeed", err)
   404  			}
   405  		})
   406  	}
   407  }
   408  
   409  // Test_MTLS_SPIFFE_FlagDisabled configures a client and server. The server has
   410  // a certificate chain that is compatible with the client's configured SPIFFE
   411  // bundle map. However, the XDS flag that enabled SPIFFE usage is disabled. An
   412  // MTLS connection is attempted between the two and checked for failure.
   413  func (s) Test_MTLS_SPIFFE_FlagDisabled(t *testing.T) {
   414  	testutils.SetEnvConfig(t, &envconfig.XDSSPIFFEEnabled, false)
   415  	serverOption := grpc.Creds(testutils.CreateServerTLSCredentialsCompatibleWithSPIFFE(t, tls.RequireAndVerifyClientCert))
   416  	s := stubserver.StartTestService(t, nil, serverOption)
   417  	defer s.Stop()
   418  
   419  	cfg := fmt.Sprintf(`{
   420  "certificate_file": "%s",
   421  "private_key_file": "%s",
   422  "spiffe_trust_bundle_map_file": "%s"
   423  }`,
   424  		testdata.Path("spiffe_end2end/client_spiffe.pem"),
   425  		testdata.Path("spiffe_end2end/client.key"),
   426  		testdata.Path("spiffe_end2end/client_spiffebundle.json"))
   427  	tlsBundle, stop, err := tlscreds.NewBundle([]byte(cfg))
   428  	if err != nil {
   429  		t.Fatalf("Failed to create TLS bundle: %v", err)
   430  	}
   431  	defer stop()
   432  	conn, err := grpc.NewClient(s.Address, grpc.WithCredentialsBundle(tlsBundle), grpc.WithAuthority("x.test.example.com"))
   433  	if err != nil {
   434  		t.Fatalf("Error dialing: %v", err)
   435  	}
   436  	defer conn.Close()
   437  	client := testgrpc.NewTestServiceClient(conn)
   438  	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   439  	defer cancel()
   440  	if _, err = client.EmptyCall(ctx, &testpb.Empty{}); err == nil {
   441  		t.Errorf("EmptyCall(): got success want failure")
   442  	}
   443  }
   444  
   445  func (s) Test_MTLS_SPIFFE_Failure(t *testing.T) {
   446  	testutils.SetEnvConfig(t, &envconfig.XDSSPIFFEEnabled, true)
   447  	tests := []struct {
   448  		name             string
   449  		certFile         string
   450  		keyFile          string
   451  		spiffeBundleFile string
   452  		serverOption     grpc.ServerOption
   453  		wantErrContains  string
   454  		wantErrCode      codes.Code
   455  	}{
   456  		{
   457  			name:             "No matching trust domain in bundle",
   458  			certFile:         "spiffe_end2end/client_spiffe.pem",
   459  			keyFile:          "spiffe_end2end/client.key",
   460  			spiffeBundleFile: "spiffe_end2end/server_spiffebundle.json",
   461  			serverOption:     grpc.Creds(testutils.CreateServerTLSCredentialsCompatibleWithSPIFFE(t, tls.RequireAndVerifyClientCert)),
   462  			wantErrContains:  "spiffe: no bundle found for peer certificates",
   463  			wantErrCode:      codes.Unavailable,
   464  		},
   465  		{
   466  			name:             "Server cert has no valid SPIFFE URIs",
   467  			certFile:         "spiffe_end2end/client_spiffe.pem",
   468  			keyFile:          "spiffe_end2end/client.key",
   469  			spiffeBundleFile: "spiffe_end2end/client_spiffebundle.json",
   470  			serverOption:     grpc.Creds(testutils.CreateServerTLSCredentials(t, tls.RequireAndVerifyClientCert)),
   471  			wantErrContains:  "spiffe: could not get spiffe ID from peer leaf cert",
   472  			wantErrCode:      codes.Unavailable,
   473  		},
   474  		{
   475  			name:             "Server cert has valid spiffe ID but doesn't chain to the root CA",
   476  			certFile:         "spiffe_end2end/client_spiffe.pem",
   477  			keyFile:          "spiffe_end2end/client.key",
   478  			spiffeBundleFile: "spiffe_end2end/client_spiffebundle.json",
   479  			serverOption:     grpc.Creds(testutils.CreateServerTLSCredentialsValidSPIFFEButWrongCA(t, tls.RequireAndVerifyClientCert)),
   480  			wantErrContains:  "spiffe: x509 certificate Verify failed: x509: certificate signed by unknown authority",
   481  			wantErrCode:      codes.Unavailable,
   482  		},
   483  	}
   484  	for _, tc := range tests {
   485  		t.Run(tc.name, func(t *testing.T) {
   486  			s := stubserver.StartTestService(t, nil, tc.serverOption)
   487  			defer s.Stop()
   488  			cfg := fmt.Sprintf(`{
   489  "certificate_file": "%s",
   490  "private_key_file": "%s",
   491  "spiffe_trust_bundle_map_file": "%s"
   492  }`,
   493  				testdata.Path(tc.certFile),
   494  				testdata.Path(tc.keyFile),
   495  				testdata.Path(tc.spiffeBundleFile))
   496  			tlsBundle, stop, err := tlscreds.NewBundle([]byte(cfg))
   497  			if err != nil {
   498  				t.Fatalf("Failed to create TLS bundle: %v", err)
   499  			}
   500  			defer stop()
   501  			conn, err := grpc.NewClient(s.Address, grpc.WithCredentialsBundle(tlsBundle), grpc.WithAuthority("x.test.example.com"))
   502  			if err != nil {
   503  				t.Fatalf("grpc.NewClient(%q) failed: %v", s.Address, err)
   504  			}
   505  			defer conn.Close()
   506  			client := testgrpc.NewTestServiceClient(conn)
   507  			ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
   508  			defer cancel()
   509  			if _, err = client.EmptyCall(ctx, &testpb.Empty{}); err == nil {
   510  				t.Errorf("EmptyCall(): got success. want failure")
   511  			}
   512  			if status.Code(err) != tc.wantErrCode {
   513  				t.Errorf("EmptyCall(): failed with wrong error. got code %v. want code: %v", status.Code(err), tc.wantErrCode)
   514  			}
   515  			if !strings.Contains(err.Error(), tc.wantErrContains) {
   516  				t.Errorf("EmptyCall(): failed with wrong error. got %v. want contains: %v", err, tc.wantErrContains)
   517  			}
   518  		})
   519  	}
   520  }