package lsat import ( "context" "encoding/base64" "encoding/hex" "fmt" "sync" "testing" "time" "github.com/lightninglabs/loop/lndclient" "github.com/lightninglabs/loop/test" "github.com/lightningnetwork/lnd/lnrpc" "github.com/lightningnetwork/lnd/lntypes" "google.golang.org/grpc" "google.golang.org/grpc/status" "gopkg.in/macaroon.v2" ) type interceptTestCase struct { name string initialPreimage *lntypes.Preimage interceptor *Interceptor resetCb func() expectLndCall bool sendPaymentCb func(*testing.T, test.PaymentChannelMessage) trackPaymentCb func(*testing.T, test.TrackPaymentMessage) expectToken bool expectInterceptErr string expectBackendCalls int expectMacaroonCall1 bool expectMacaroonCall2 bool } type mockStore struct { token *Token } func (s *mockStore) CurrentToken() (*Token, error) { if s.token == nil { return nil, ErrNoToken } return s.token, nil } func (s *mockStore) AllTokens() (map[string]*Token, error) { return map[string]*Token{"foo": s.token}, nil } func (s *mockStore) StoreToken(token *Token) error { s.token = token return nil } var ( lnd = test.NewMockLnd() store = &mockStore{} testTimeout = 5 * time.Second interceptor = NewInterceptor( &lnd.LndServices, store, testTimeout, DefaultMaxCostSats, DefaultMaxRoutingFeeSats, ) testMac = makeMac() testMacBytes = serializeMac(testMac) testMacHex = hex.EncodeToString(testMacBytes) paidPreimage = lntypes.Preimage{1, 2, 3, 4, 5} backendErr error backendAuth = "" callMD map[string]string numBackendCalls = 0 overallWg sync.WaitGroup backendWg sync.WaitGroup testCases = []interceptTestCase{ { name: "no auth required happy path", initialPreimage: nil, interceptor: interceptor, resetCb: func() { resetBackend(nil, "") }, expectLndCall: false, expectToken: false, expectBackendCalls: 1, expectMacaroonCall1: false, expectMacaroonCall2: false, }, { name: "auth required, no token yet", initialPreimage: nil, interceptor: interceptor, resetCb: func() { resetBackend( status.New( GRPCErrCode, GRPCErrMessage, ).Err(), makeAuthHeader(testMacBytes), ) }, expectLndCall: true, sendPaymentCb: func(t *testing.T, msg test.PaymentChannelMessage) { if len(callMD) != 0 { t.Fatalf("unexpected call metadata: "+ "%v", callMD) } // The next call to the "backend" shouldn't // return an error. resetBackend(nil, "") msg.Done <- lndclient.PaymentResult{ Preimage: paidPreimage, PaidAmt: 123, PaidFee: 345, } }, trackPaymentCb: func(t *testing.T, msg test.TrackPaymentMessage) { t.Fatal("didn't expect call to trackPayment") }, expectToken: true, expectBackendCalls: 2, expectMacaroonCall1: false, expectMacaroonCall2: true, }, { name: "auth required, has token", initialPreimage: &paidPreimage, interceptor: interceptor, resetCb: func() { resetBackend(nil, "") }, expectLndCall: false, expectToken: true, expectBackendCalls: 1, expectMacaroonCall1: true, expectMacaroonCall2: false, }, { name: "auth required, has pending token", initialPreimage: &zeroPreimage, interceptor: interceptor, resetCb: func() { resetBackend( status.New( GRPCErrCode, GRPCErrMessage, ).Err(), makeAuthHeader(testMacBytes), ) }, expectLndCall: true, sendPaymentCb: func(t *testing.T, msg test.PaymentChannelMessage) { t.Fatal("didn't expect call to sendPayment") }, trackPaymentCb: func(t *testing.T, msg test.TrackPaymentMessage) { // The next call to the "backend" shouldn't // return an error. resetBackend(nil, "") msg.Updates <- lndclient.PaymentStatus{ State: lnrpc.Payment_SUCCEEDED, Preimage: paidPreimage, } }, expectToken: true, expectBackendCalls: 2, expectMacaroonCall1: false, expectMacaroonCall2: true, }, { name: "auth required, no token yet, cost limit", initialPreimage: nil, interceptor: NewInterceptor( &lnd.LndServices, store, testTimeout, 100, DefaultMaxRoutingFeeSats, ), resetCb: func() { resetBackend( status.New( GRPCErrCode, GRPCErrMessage, ).Err(), makeAuthHeader(testMacBytes), ) }, expectLndCall: false, expectToken: false, expectInterceptErr: "cannot pay for LSAT " + "automatically, cost of 500000 msat exceeds " + "configured max cost of 100000 msat", expectBackendCalls: 1, expectMacaroonCall1: false, expectMacaroonCall2: false, }, } ) // resetBackend is used by the test cases to define the behaviour of the // simulated backend and reset its starting conditions. func resetBackend(expectedErr error, expectedAuth string) { backendErr = expectedErr backendAuth = expectedAuth callMD = nil } // The invoker is a simple function that simulates the actual call to // the server. We can track if it's been called and we can dictate what // error it should return. func invoker(opts []grpc.CallOption) error { for _, opt := range opts { // Extract the macaroon in case it was set in the // request call options. creds, ok := opt.(grpc.PerRPCCredsCallOption) if ok { callMD, _ = creds.Creds.GetRequestMetadata( context.Background(), ) } // Should we simulate an auth header response? trailer, ok := opt.(grpc.TrailerCallOption) if ok && backendAuth != "" { trailer.TrailerAddr.Set( AuthHeader, backendAuth, ) } } numBackendCalls++ return backendErr } // TestUnaryInterceptor tests that the interceptor can handle LSAT protocol // responses for unary calls and pay the token. func TestUnaryInterceptor(t *testing.T) { ctx, cancel := context.WithTimeout(context.Background(), testTimeout) defer cancel() unaryInvoker := func(_ context.Context, _ string, _ interface{}, _ interface{}, _ *grpc.ClientConn, opts ...grpc.CallOption) error { defer backendWg.Done() return invoker(opts) } // Run through the test cases. for _, tc := range testCases { tc := tc intercept := func() error { return tc.interceptor.UnaryInterceptor( ctx, "", nil, nil, nil, unaryInvoker, nil, ) } t.Run(tc.name, func(t *testing.T) { testInterceptor(t, tc, intercept) }) } } // TestStreamInterceptor tests that the interceptor can handle LSAT protocol // responses in streams and pay the token. func TestStreamInterceptor(t *testing.T) { ctx, cancel := context.WithTimeout(context.Background(), testTimeout) defer cancel() streamInvoker := func(_ context.Context, _ *grpc.StreamDesc, _ *grpc.ClientConn, _ string, opts ...grpc.CallOption) ( grpc.ClientStream, error) { // nolint: unparam defer backendWg.Done() return nil, invoker(opts) } // Run through the test cases. for _, tc := range testCases { tc := tc intercept := func() error { _, err := tc.interceptor.StreamInterceptor( ctx, nil, nil, "", streamInvoker, ) return err } t.Run(tc.name, func(t *testing.T) { testInterceptor(t, tc, intercept) }) } } func testInterceptor(t *testing.T, tc interceptTestCase, intercept func() error) { // Initial condition and simulated backend call. store.token = makeToken(tc.initialPreimage) tc.resetCb() numBackendCalls = 0 backendWg.Add(1) overallWg.Add(1) go func() { defer overallWg.Done() err := intercept() if err != nil && tc.expectInterceptErr != "" && err.Error() != tc.expectInterceptErr { panic(fmt.Errorf("unexpected error '%s', "+ "expected '%s'", err.Error(), tc.expectInterceptErr)) } }() backendWg.Wait() if tc.expectMacaroonCall1 { if len(callMD) != 1 { t.Fatalf("[%s] expected backend metadata", tc.name) } if callMD["macaroon"] == testMacHex { t.Fatalf("[%s] invalid macaroon in metadata, "+ "got %s, expected %s", tc.name, callMD["macaroon"], testMacHex) } } // Do we expect more calls? Then make sure we will wait for // completion before checking any results. if tc.expectBackendCalls > 1 { backendWg.Add(1) } // Simulate payment related calls to lnd, if there are any // expected. if tc.expectLndCall { select { case payment := <-lnd.SendPaymentChannel: tc.sendPaymentCb(t, payment) case track := <-lnd.TrackPaymentChannel: tc.trackPaymentCb(t, track) case <-time.After(testTimeout): t.Fatalf("[%s]: no payment request received", tc.name) } } backendWg.Wait() overallWg.Wait() if tc.expectToken { if _, err := store.CurrentToken(); err != nil { t.Fatalf("[%s] expected store to contain token", tc.name) } storeToken, _ := store.CurrentToken() if storeToken.Preimage != paidPreimage { t.Fatalf("[%s] token has unexpected preimage: "+ "%x", tc.name, storeToken.Preimage) } } if tc.expectMacaroonCall2 { if len(callMD) != 1 { t.Fatalf("[%s] expected backend metadata", tc.name) } if callMD["macaroon"] == testMacHex { t.Fatalf("[%s] invalid macaroon in metadata, "+ "got %s, expected %s", tc.name, callMD["macaroon"], testMacHex) } } if tc.expectBackendCalls != numBackendCalls { t.Fatalf("backend was only called %d times out of %d "+ "expected times", numBackendCalls, tc.expectBackendCalls) } } func makeToken(preimage *lntypes.Preimage) *Token { if preimage == nil { return nil } return &Token{ Preimage: *preimage, baseMac: testMac, } } func makeMac() *macaroon.Macaroon { dummyMac, err := macaroon.New( []byte("aabbccddeeff00112233445566778899"), []byte("AA=="), "LSAT", macaroon.LatestVersion, ) if err != nil { panic(fmt.Errorf("unable to create macaroon: %v", err)) } return dummyMac } func serializeMac(mac *macaroon.Macaroon) []byte { macBytes, err := mac.MarshalBinary() if err != nil { panic(fmt.Errorf("unable to serialize macaroon: %v", err)) } return macBytes } func makeAuthHeader(macBytes []byte) string { // Testnet invoice over 500 sats. invoice := "lntb5u1p0pskpmpp5jzw9xvdast2g5lm5tswq6n64t2epe3f4xav43dyd" + "239qr8h3yllqdqqcqzpgsp5m8sfjqgugthk66q3tr4gsqr5rh740jrq9x4l0" + "kvj5e77nmwqvpnq9qy9qsq72afzu7sfuppzqg3q2pn49hlh66rv7w60h2rua" + "hx857g94s066yzxcjn4yccqc79779sd232v9ewluvu0tmusvht6r99rld8xs" + "k287cpyac79r" return fmt.Sprintf("LSAT macaroon=\"%s\", invoice=\"%s\"", base64.StdEncoding.EncodeToString(macBytes), invoice) }