lsat: track pending payments, keep old tokens

pull/101/head
Oliver Gugger 4 years ago
parent 31bb18255e
commit a23dfe36ab
No known key found for this signature in database
GPG Key ID: 8E4256593F177720

@ -6,8 +6,10 @@ import (
"fmt"
"regexp"
"sync"
"time"
"github.com/lightninglabs/loop/lndclient"
"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/macaroons"
"github.com/lightningnetwork/lnd/zpay32"
@ -35,6 +37,15 @@ const (
// going to pay to acquire an LSAT token.
// TODO(guggero): make this configurable
MaxRoutingFeeSats = 10
// PaymentTimeout is the maximum time we allow a payment to take before
// we stop waiting for it.
PaymentTimeout = 60 * time.Second
// manualRetryHint is the error text we return to tell the user how a
// token payment can be retried if the payment fails.
manualRetryHint = "consider removing pending token file if error " +
"persists. use 'listauth' command to find out token file name"
)
var (
@ -91,36 +102,49 @@ func (i *Interceptor) UnaryInterceptor(ctx context.Context, method string,
return nil
}
// If we already have a token, let's append it.
if i.store.HasToken() {
lsat, err := i.store.Token()
if err != nil {
return err
}
if err = addLsatCredentials(lsat); err != nil {
return err
// Let's see if the store already contains a token and what state it
// might be in. If a previous call was aborted, we might have a pending
// token that needs to be handled separately.
token, err := i.store.CurrentToken()
switch {
// If there is no token yet, nothing to do at this point.
case err == ErrNoToken:
// Some other error happened that we have to surface.
case err != nil:
log.Errorf("Failed to get token from store: %v", err)
return fmt.Errorf("getting token from store failed: %v", err)
// Only if we have a paid token append it. We don't resume a pending
// payment just yet, since we don't even know if a token is required for
// this call. We also never send a pending payment to the server since
// we know it's not valid.
case !token.isPending():
if err = addLsatCredentials(token); err != nil {
log.Errorf("Adding macaroon to request failed: %v", err)
return fmt.Errorf("adding macaroon failed: %v", err)
}
}
// We need a way to extract the response headers sent by the
// server. This can only be done through the experimental
// grpc.Trailer call option.
// We execute the request and inspect the error. If it's the
// LSAT specific payment required error, we might execute the
// same method again later with the paid LSAT token.
// We need a way to extract the response headers sent by the server.
// This can only be done through the experimental grpc.Trailer call
// option. We execute the request and inspect the error. If it's the
// LSAT specific payment required error, we might execute the same
// method again later with the paid LSAT token.
trailerMetadata := &metadata.MD{}
opts = append(opts, grpc.Trailer(trailerMetadata))
err := invoker(ctx, method, req, reply, cc, opts...)
err = invoker(ctx, method, req, reply, cc, opts...)
// Only handle the LSAT error message that comes in the form of
// a gRPC status error.
if isPaymentRequired(err) {
lsat, err := i.payLsatToken(ctx, trailerMetadata)
paidToken, err := i.handlePayment(ctx, token, trailerMetadata)
if err != nil {
return err
}
if err = addLsatCredentials(lsat); err != nil {
return err
if err = addLsatCredentials(paidToken); err != nil {
log.Errorf("Adding macaroon to request failed: %v", err)
return fmt.Errorf("adding macaroon failed: %v", err)
}
// Execute the same request again, now with the LSAT
@ -130,6 +154,35 @@ func (i *Interceptor) UnaryInterceptor(ctx context.Context, method string,
return err
}
// handlePayment tries to obtain a valid token by either tracking the payment
// status of a pending token or paying for a new one.
func (i *Interceptor) handlePayment(ctx context.Context, token *Token,
md *metadata.MD) (*Token, error) {
switch {
// Resume/track a pending payment if it was interrupted for some reason.
case token != nil && token.isPending():
log.Infof("Payment of LSAT token is required, resuming/" +
"tracking previous payment from pending LSAT token")
err := i.trackPayment(ctx, token)
if err != nil {
return nil, err
}
return token, nil
// We don't have a token yet, try to get a new one.
case token == nil:
// We don't have a token yet, get a new one.
log.Infof("Payment of LSAT token is required, paying invoice")
return i.payLsatToken(ctx, md)
// We have a token and it's valid, nothing more to do here.
default:
log.Debugf("Found valid LSAT token to add to request")
return token, nil
}
}
// payLsatToken reads the payment challenge from the response metadata and tries
// to pay the invoice encoded in them, returning a paid LSAT token if
// successful.
@ -161,31 +214,100 @@ func (i *Interceptor) payLsatToken(ctx context.Context, md *metadata.MD) (
return nil, fmt.Errorf("unable to decode invoice: %v", err)
}
// Create and store the pending token so we can resume the payment in
// case the payment is interrupted somehow.
token, err := tokenFromChallenge(macBytes, invoice.PaymentHash)
if err != nil {
return nil, fmt.Errorf("unable to create token: %v", err)
}
err = i.store.StoreToken(token)
if err != nil {
return nil, fmt.Errorf("unable to store pending token: %v", err)
}
// Pay invoice now and wait for the result to arrive or the main context
// being canceled.
// TODO(guggero): Store payment information so we can track the payment
// later in case the client shuts down while the payment is in flight.
payCtx, cancel := context.WithTimeout(ctx, PaymentTimeout)
defer cancel()
respChan := i.lnd.Client.PayInvoice(
ctx, invoiceStr, MaxRoutingFeeSats, nil,
payCtx, invoiceStr, MaxRoutingFeeSats, nil,
)
select {
case result := <-respChan:
if result.Err != nil {
return nil, result.Err
}
token, err := NewToken(
macBytes, invoice.PaymentHash, result.Preimage,
lnwire.NewMSatFromSatoshis(result.PaidAmt),
lnwire.NewMSatFromSatoshis(result.PaidFee),
token.Preimage = result.Preimage
token.AmountPaid = lnwire.NewMSatFromSatoshis(result.PaidAmt)
token.RoutingFeePaid = lnwire.NewMSatFromSatoshis(
result.PaidFee,
)
if err != nil {
return nil, fmt.Errorf("unable to create token: %v",
err)
}
return token, i.store.StoreToken(token)
case <-payCtx.Done():
return nil, fmt.Errorf("payment timed out. try again to track "+
"payment. %s", manualRetryHint)
case <-ctx.Done():
return nil, fmt.Errorf("context canceled")
return nil, fmt.Errorf("parent context canceled. try again to"+
"track payment. %s", manualRetryHint)
}
}
// trackPayment tries to resume a pending payment by tracking its state and
// waiting for a conclusive result.
func (i *Interceptor) trackPayment(ctx context.Context, token *Token) error {
// Lookup state of the payment.
paymentStateCtx, cancel := context.WithCancel(ctx)
defer cancel()
payStatusChan, payErrChan, err := i.lnd.Router.TrackPayment(
paymentStateCtx, token.PaymentHash,
)
if err != nil {
log.Errorf("Could not call TrackPayment on lnd: %v", err)
return fmt.Errorf("track payment call to lnd failed: %v", err)
}
// We can't wait forever, so we give the payment tracking the same
// timeout as the original payment.
payCtx, cancel := context.WithTimeout(ctx, PaymentTimeout)
defer cancel()
// We'll consume status updates until we reach a conclusive state or
// reach the timeout.
for {
select {
// If we receive a state without an error, the payment has been
// initiated. Loop until the payment
case result := <-payStatusChan:
switch result.State {
// If the payment was successful, we have all the
// information we need and we can return the fully paid
// token.
case routerrpc.PaymentState_SUCCEEDED:
extractPaymentDetails(token, result)
return i.store.StoreToken(token)
// The payment is still in transit, we'll give it more
// time to complete.
case routerrpc.PaymentState_IN_FLIGHT:
// Any other state means either error or timeout.
default:
return fmt.Errorf("payment tracking failed "+
"with state %s. %s",
result.State.String(), manualRetryHint)
}
// Abort the payment execution for any error.
case err := <-payErrChan:
return fmt.Errorf("payment tracking failed: %v. %s",
err, manualRetryHint)
case <-payCtx.Done():
return fmt.Errorf("payment tracking timed out. %s",
manualRetryHint)
}
}
}
@ -198,3 +320,13 @@ func isPaymentRequired(err error) bool {
statusErr.Message() == GRPCErrMessage &&
statusErr.Code() == GRPCErrCode
}
// extractPaymentDetails extracts the preimage and amounts paid for a payment
// from the payment status and stores them in the token.
func extractPaymentDetails(token *Token, status lndclient.PaymentStatus) {
token.Preimage = status.Preimage
total := status.Route.TotalAmount
fees := status.Route.TotalFees()
token.AmountPaid = total - fees
token.RoutingFeePaid = fees
}

@ -0,0 +1,327 @@
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/routerrpc"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/lightningnetwork/lnd/routing/route"
"google.golang.org/grpc"
"google.golang.org/grpc/status"
"gopkg.in/macaroon.v2"
)
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
}
// TestInterceptor tests that the interceptor can handle LSAT protocol responses
// and pay the token.
func TestInterceptor(t *testing.T) {
t.Parallel()
var (
lnd = test.NewMockLnd()
store = &mockStore{}
testTimeout = 5 * time.Second
interceptor = NewInterceptor(&lnd.LndServices, store)
testMac = makeMac(t)
testMacBytes = serializeMac(t, testMac)
testMacHex = hex.EncodeToString(testMacBytes)
paidPreimage = lntypes.Preimage{1, 2, 3, 4, 5}
paidToken = &Token{
Preimage: paidPreimage,
baseMac: testMac,
}
pendingToken = &Token{
Preimage: zeroPreimage,
baseMac: testMac,
}
backendWg sync.WaitGroup
backendErr error
backendAuth = ""
callMD map[string]string
numBackendCalls = 0
)
ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
defer cancel()
// resetBackend is used by the test cases to define the behaviour of the
// simulated backend and reset its starting conditions.
resetBackend := func(expectedErr error, expectedAuth string) {
backendErr = expectedErr
backendAuth = expectedAuth
callMD = nil
}
testCases := []struct {
name string
initialToken *Token
resetCb func()
expectLndCall bool
sendPaymentCb func(msg test.PaymentChannelMessage)
trackPaymentCb func(msg test.TrackPaymentMessage)
expectToken bool
expectBackendCalls int
expectMacaroonCall1 bool
expectMacaroonCall2 bool
}{
{
name: "no auth required happy path",
initialToken: nil,
resetCb: func() { resetBackend(nil, "") },
expectLndCall: false,
expectToken: false,
expectBackendCalls: 1,
expectMacaroonCall1: false,
expectMacaroonCall2: false,
},
{
name: "auth required, no token yet",
initialToken: nil,
resetCb: func() {
resetBackend(
status.New(
GRPCErrCode, GRPCErrMessage,
).Err(),
makeAuthHeader(testMacBytes),
)
},
expectLndCall: true,
sendPaymentCb: func(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(msg test.TrackPaymentMessage) {
t.Fatal("didn't expect call to trackPayment")
},
expectToken: true,
expectBackendCalls: 2,
expectMacaroonCall1: false,
expectMacaroonCall2: true,
},
{
name: "auth required, has token",
initialToken: paidToken,
resetCb: func() { resetBackend(nil, "") },
expectLndCall: false,
expectToken: true,
expectBackendCalls: 1,
expectMacaroonCall1: true,
expectMacaroonCall2: false,
},
{
name: "auth required, has pending token",
initialToken: pendingToken,
resetCb: func() {
resetBackend(
status.New(
GRPCErrCode, GRPCErrMessage,
).Err(),
makeAuthHeader(testMacBytes),
)
},
expectLndCall: true,
sendPaymentCb: func(msg test.PaymentChannelMessage) {
t.Fatal("didn't expect call to sendPayment")
},
trackPaymentCb: func(msg test.TrackPaymentMessage) {
// The next call to the "backend" shouldn't
// return an error.
resetBackend(nil, "")
msg.Updates <- lndclient.PaymentStatus{
State: routerrpc.PaymentState_SUCCEEDED,
Preimage: paidPreimage,
Route: &route.Route{},
}
},
expectToken: true,
expectBackendCalls: 2,
expectMacaroonCall1: false,
expectMacaroonCall2: true,
},
}
// 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.
invoker := func(_ context.Context, _ string, _ interface{},
_ interface{}, _ *grpc.ClientConn,
opts ...grpc.CallOption) error {
defer backendWg.Done()
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
}
// Run through the test cases.
for _, tc := range testCases {
// Initial condition and simulated backend call.
store.token = tc.initialToken
tc.resetCb()
numBackendCalls = 0
var overallWg sync.WaitGroup
backendWg.Add(1)
overallWg.Add(1)
go func() {
err := interceptor.UnaryInterceptor(
ctx, "", nil, nil, nil, invoker, nil,
)
if err != nil {
panic(err)
}
overallWg.Done()
}()
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(payment)
case track := <-lnd.TrackPaymentChannel:
tc.trackPaymentCb(track)
case <-time.After(testTimeout):
t.Fatalf("[%s]: no payment request received",
tc.name)
}
}
backendWg.Wait()
overallWg.Wait()
// Interpret result/expectations.
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 makeMac(t *testing.T) *macaroon.Macaroon {
dummyMac, err := macaroon.New(
[]byte("aabbccddeeff00112233445566778899"), []byte("AA=="),
"LSAT", macaroon.LatestVersion,
)
if err != nil {
t.Fatalf("unable to create macaroon: %v", err)
return nil
}
return dummyMac
}
func serializeMac(t *testing.T, mac *macaroon.Macaroon) []byte {
macBytes, err := mac.MarshalBinary()
if err != nil {
t.Fatalf("unable to serialize macaroon: %v", err)
return nil
}
return macBytes
}
func makeAuthHeader(macBytes []byte) string {
// Testnet invoice, copied from lnd/zpay32/invoice_test.go
invoice := "lntb20m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqc" +
"yq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy04" +
"3l2ahrqsfpp3x9et2e20v6pu37c5d9vax37wxq72un98k6vcx9fz94w0qf23" +
"7cm2rqv9pmn5lnexfvf5579slr4zq3u8kmczecytdx0xg9rwzngp7e6guwqp" +
"qlhssu04sucpnz4axcv2dstmknqq6jsk2l"
return fmt.Sprintf("LSAT macaroon='%s' invoice='%s'",
base64.StdEncoding.EncodeToString(macBytes), invoice)
}

@ -1,38 +1,55 @@
package lsat
import (
"errors"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"strings"
)
var (
// ErrNoToken is the error returned when the store doesn't contain a
// token yet.
ErrNoToken = fmt.Errorf("no token in store")
ErrNoToken = errors.New("no token in store")
// storeFileName is the name of the file where we store the final,
// valid, token to.
storeFileName = "lsat.token"
// storeFileNamePending is the name of the file where we store a pending
// token until it was successfully paid for.
storeFileNamePending = "lsat.token.pending"
// errNoReplace is the error that is returned if a new token is
// being written to a store that already contains a paid token.
errNoReplace = errors.New("won't replace existing paid token with " +
"new token. " + manualRetryHint)
)
// Store is an interface that allows users to store and retrieve an LSAT token.
type Store interface {
// HasToken returns true if the store contains a token.
HasToken() bool
// CurrentToken returns the token that is currently contained in the
// store or an error if there is none.
CurrentToken() (*Token, error)
// Token returns the token that is contained in the store or an error
// if there is none.
Token() (*Token, error)
// AllTokens returns all tokens that the store has knowledge of, even
// if they might be expired. The tokens are mapped by their identifying
// attribute like file name or storage key.
AllTokens() (map[string]*Token, error)
// StoreToken saves a token to the store, overwriting any old token if
// there is one.
// StoreToken saves a token to the store. Old tokens should be kept for
// accounting purposes but marked as invalid somehow.
StoreToken(*Token) error
}
// FileStore is an implementation of the Store interface that uses a single file
// to save the serialized token.
// FileStore is an implementation of the Store interface that files to save the
// serialized tokens. There is always just one current token that is either
// pending or fully paid.
type FileStore struct {
fileName string
fileName string
fileNamePending string
}
// A compile-time flag to ensure that FileStore implements the Store interface.
@ -50,42 +67,136 @@ func NewFileStore(storeDir string) (*FileStore, error) {
}
return &FileStore{
fileName: filepath.Join(storeDir, storeFileName),
fileName: filepath.Join(storeDir, storeFileName),
fileNamePending: filepath.Join(storeDir, storeFileNamePending),
}, nil
}
// HasToken returns true if the store contains a token.
// CurrentToken returns the token that is currently contained in the store or an
// error if there is none.
//
// NOTE: This is part of the Store interface.
func (f *FileStore) HasToken() bool {
return fileExists(f.fileName)
func (f *FileStore) CurrentToken() (*Token, error) {
// As this is only a wrapper for external users to make sure the store
// is locked, the actual implementation is in the non-exported method.
return f.currentToken()
}
// Token returns the token that is contained in the store or an error if there
// is none.
//
// NOTE: This is part of the Store interface.
func (f *FileStore) Token() (*Token, error) {
if !f.HasToken() {
// currentToken returns the current token without locking the store.
func (f *FileStore) currentToken() (*Token, error) {
switch {
case fileExists(f.fileName):
return readTokenFile(f.fileName)
case fileExists(f.fileNamePending):
return readTokenFile(f.fileNamePending)
default:
return nil, ErrNoToken
}
bytes, err := ioutil.ReadFile(f.fileName)
}
// AllTokens returns all tokens that the store has knowledge of, even if they
// might be expired. The tokens are mapped by their identifying attribute like
// file name or storage key.
//
// NOTE: This is part of the Store interface.
func (f *FileStore) AllTokens() (map[string]*Token, error) {
tokens := make(map[string]*Token)
// All tokens start with the same name so we can get them by the prefix.
// As the tokens don't expire yet, there currently can't be more than
// just one token, either pending or paid.
// TODO(guggero): Update comment once tokens expire and we keep backups.
tokenDir := filepath.Dir(f.fileName)
files, err := ioutil.ReadDir(tokenDir)
if err != nil {
return nil, err
}
return deserializeToken(bytes)
for _, file := range files {
name := file.Name()
if !strings.HasPrefix(name, storeFileName) {
continue
}
fileName := filepath.Join(tokenDir, name)
token, err := readTokenFile(fileName)
if err != nil {
return nil, err
}
tokens[fileName] = token
}
return tokens, nil
}
// StoreToken saves a token to the store, overwriting any old token if there is
// one.
//
// NOTE: This is part of the Store interface.
func (f *FileStore) StoreToken(token *Token) error {
bytes, err := serializeToken(token)
func (f *FileStore) StoreToken(newToken *Token) error {
// Serialize the token first, before we rename anything.
bytes, err := serializeToken(newToken)
if err != nil {
return err
}
return ioutil.WriteFile(f.fileName, bytes, 0600)
// We'll need to know if there is any other token already in place,
// either pending or not, that we need to delete or overwrite.
currentToken, err := f.currentToken()
switch {
// No token in the store yet, just write it to the corresponding file.
case err == ErrNoToken:
// What's the target file name we are going to write?
newFileName := f.fileName
if newToken.isPending() {
newFileName = f.fileNamePending
}
return ioutil.WriteFile(newFileName, bytes, 0600)
// Fail on any other error.
case err != nil:
return err
// Replace a pending token with a paid one.
case currentToken.isPending() && !newToken.isPending():
// Make sure we replace the the same token, just with a
// different state.
if currentToken.PaymentHash != newToken.PaymentHash {
return fmt.Errorf("new paid token doesn't match " +
"existing pending token")
}
// Write the new token first, so we still have the pending
// around if something goes wrong.
err := ioutil.WriteFile(f.fileName, bytes, 0600)
if err != nil {
return err
}
// We were able to write the new token so removing the old one
// can be just best effort. By default, the valid one will be
// read by the store if both exist.
_ = os.Remove(f.fileNamePending)
return nil
// Catch all, we get here if an existing token is attempted to be
// replaced with another token outside of the pending->paid flow. The
// user should manually remove the token in that case.
// TODO(guggero): Once tokens expire, this logic has to be adapted
// accordingly.
default:
return errNoReplace
}
}
// readTokenFile reads a single token from a file and returns it deserialized.
func readTokenFile(tokenFile string) (*Token, error) {
bytes, err := ioutil.ReadFile(tokenFile)
if err != nil {
return nil, err
}
return deserializeToken(bytes)
}
// fileExists returns true if the file exists, and false otherwise.

@ -0,0 +1,131 @@
package lsat
import (
"io/ioutil"
"os"
"path/filepath"
"testing"
"github.com/lightningnetwork/lnd/lntypes"
)
// TestStore tests the basic functionality of the file based store.
func TestFileStore(t *testing.T) {
t.Parallel()
tempDirName, err := ioutil.TempDir("", "lsatstore")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(tempDirName)
var (
paidPreimage = lntypes.Preimage{1, 2, 3, 4, 5}
paidToken = &Token{
Preimage: paidPreimage,
baseMac: makeMac(t),
}
pendingToken = &Token{
Preimage: zeroPreimage,
baseMac: makeMac(t),
}
)
store, err := NewFileStore(tempDirName)
if err != nil {
t.Fatalf("could not create test store: %v", err)
}
// Make sure the current store is empty.
_, err = store.CurrentToken()
if err != ErrNoToken {
t.Fatalf("expected store to be empty but error was: %v", err)
}
tokens, err := store.AllTokens()
if err != nil {
t.Fatalf("unexpected error listing all tokens: %v", err)
}
if len(tokens) != 0 {
t.Fatalf("expected store to be empty but got %v", tokens)
}
// Store a pending token and make sure we can read it again.
err = store.StoreToken(pendingToken)
if err != nil {
t.Fatalf("could not save pending token: %v", err)
}
if !fileExists(filepath.Join(tempDirName, storeFileNamePending)) {
t.Fatalf("expected file %s/%s to exist but it didn't",
tempDirName, storeFileNamePending)
}
token, err := store.CurrentToken()
if err != nil {
t.Fatalf("could not read pending token: %v", err)
}
if !token.baseMac.Equal(pendingToken.baseMac) {
t.Fatalf("expected macaroon to match")
}
tokens, err = store.AllTokens()
if err != nil {
t.Fatalf("unexpected error listing all tokens: %v", err)
}
if len(tokens) != 1 {
t.Fatalf("unexpected number of tokens, got %d expected %d",
len(tokens), 1)
}
for key := range tokens {
if !tokens[key].baseMac.Equal(pendingToken.baseMac) {
t.Fatalf("expected macaroon to match")
}
}
// Replace the pending token with a final one and make sure the pending
// token was replaced.
err = store.StoreToken(paidToken)
if err != nil {
t.Fatalf("could not save pending token: %v", err)
}
if !fileExists(filepath.Join(tempDirName, storeFileName)) {
t.Fatalf("expected file %s/%s to exist but it didn't",
tempDirName, storeFileName)
}
if fileExists(filepath.Join(tempDirName, storeFileNamePending)) {
t.Fatalf("expected file %s/%s to be removed but it wasn't",
tempDirName, storeFileNamePending)
}
token, err = store.CurrentToken()
if err != nil {
t.Fatalf("could not read pending token: %v", err)
}
if !token.baseMac.Equal(paidToken.baseMac) {
t.Fatalf("expected macaroon to match")
}
tokens, err = store.AllTokens()
if err != nil {
t.Fatalf("unexpected error listing all tokens: %v", err)
}
if len(tokens) != 1 {
t.Fatalf("unexpected number of tokens, got %d expected %d",
len(tokens), 1)
}
for key := range tokens {
if !tokens[key].baseMac.Equal(paidToken.baseMac) {
t.Fatalf("expected macaroon to match")
}
}
// Make sure we can't replace the existing paid token with a pending.
err = store.StoreToken(pendingToken)
if err != errNoReplace {
t.Fatalf("unexpected error. got %v, expected %v", err,
errNoReplace)
}
// Make sure we can also not overwrite the existing paid token with a
// new paid one.
err = store.StoreToken(paidToken)
if err != errNoReplace {
t.Fatalf("unexpected error. got %v, expected %v", err,
errNoReplace)
}
}

@ -11,6 +11,12 @@ import (
"gopkg.in/macaroon.v2"
)
var (
// zeroPreimage is an empty, invalid payment preimage that is used to
// initialize pending tokens with.
zeroPreimage lntypes.Preimage
)
// Token is the main type to store an LSAT token in.
type Token struct {
// PaymentHash is the hash of the LSAT invoice that needs to be paid.
@ -19,7 +25,8 @@ type Token struct {
PaymentHash lntypes.Hash
// Preimage is the proof of payment indicating that the token has been
// paid for if set.
// paid for if set. If the preimage is empty, the payment might still
// be in transit.
Preimage lntypes.Preimage
// AmountPaid is the total amount in msat that the user paid to get the
@ -39,21 +46,6 @@ type Token struct {
baseMac *macaroon.Macaroon
}
// NewToken creates a new token from the given base macaroon and payment
// information.
func NewToken(baseMac []byte, paymentHash *[32]byte, preimage lntypes.Preimage,
amountPaid, routingFeePaid lnwire.MilliSatoshi) (*Token, error) {
token, err := tokenFromChallenge(baseMac, paymentHash)
if err != nil {
return nil, err
}
token.Preimage = preimage
token.AmountPaid = amountPaid
token.RoutingFeePaid = routingFeePaid
return token, nil
}
// tokenFromChallenge parses the parts that are present in the challenge part
// of the LSAT auth protocol which is the macaroon and the payment hash.
func tokenFromChallenge(baseMac []byte, paymentHash *[32]byte) (*Token, error) {
@ -67,6 +59,7 @@ func tokenFromChallenge(baseMac []byte, paymentHash *[32]byte) (*Token, error) {
token := &Token{
TimeCreated: time.Now(),
baseMac: mac,
Preimage: zeroPreimage,
}
hash, err := lntypes.MakeHash(paymentHash[:])
if err != nil {
@ -95,6 +88,20 @@ func (t *Token) PaidMacaroon() (*macaroon.Macaroon, error) {
return mac, nil
}
// IsValid returns true if the timestamp contained in the base macaroon is not
// yet expired.
func (t *Token) IsValid() bool {
// TODO(guggero): Extract and validate from caveat once we add an
// expiration date to the LSAT.
return true
}
// isPending returns true if the payment for the LSAT is still in flight and we
// haven't received the preimage yet.
func (t *Token) isPending() bool {
return t.Preimage == zeroPreimage
}
// serializeToken returns a byte-serialized representation of the token.
func serializeToken(t *Token) ([]byte, error) {
var b bytes.Buffer

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