cnct+lnwl+hswc: use lntypes.Preimage for witness beacon

htlcswitch/link.go

@@ -1417,7 +1417,7 @@ func (l *channelLink) handleUpstreamMsg(msg lnwire.Message) {
 		// any contested contracts watched by any on-chain arbitrators
 		// can now sweep this HTLC on-chain.
 		go func() {
-			err := l.cfg.PreimageCache.AddPreimages(pre[:])
+			err := l.cfg.PreimageCache.AddPreimages(pre)
 			if err != nil {
 				l.errorf("unable to add preimage=%x to "+
 					"cache", pre[:])

htlcswitch/link_test.go

@@ -1532,10 +1532,7 @@ func newSingleLinkTestHarness(chanAmt, chanReserve btcutil.Amount) (
 		invoiceRegistry = newMockRegistry(globalPolicy.TimeLockDelta)
 	)
 
-	pCache := &mockPreimageCache{
-		// hash -> preimage
-		preimageMap: make(map[[32]byte][]byte),
-	}
+	pCache := newMockPreimageCache()
 
 	aliceDb := aliceChannel.State().Db
 	aliceSwitch, err := initSwitchWithDB(testStartingHeight, aliceDb)
@@ -4042,10 +4039,7 @@ func restartLink(aliceChannel *lnwallet.LightningChannel, aliceSwitch *Switch,
 
 		invoiceRegistry = newMockRegistry(globalPolicy.TimeLockDelta)
 
-		pCache = &mockPreimageCache{
-			// hash -> preimage
-			preimageMap: make(map[[32]byte][]byte),
-		}
+		pCache = newMockPreimageCache()
 	)
 
 	aliceDb := aliceChannel.State().Db

htlcswitch/mock.go

@@ -32,26 +32,31 @@ import (
 
 type mockPreimageCache struct {
 	sync.Mutex
-	preimageMap map[[32]byte][]byte
+	preimageMap map[lntypes.Hash]lntypes.Preimage
 }
 
-func (m *mockPreimageCache) LookupPreimage(hash []byte) ([]byte, bool) {
+func newMockPreimageCache() *mockPreimageCache {
+	return &mockPreimageCache{
+		preimageMap: make(map[lntypes.Hash]lntypes.Preimage),
+	}
+}
+
+func (m *mockPreimageCache) LookupPreimage(
+	hash lntypes.Hash) (lntypes.Preimage, bool) {
+
 	m.Lock()
 	defer m.Unlock()
 
-	var h [32]byte
-	copy(h[:], hash)
-
-	p, ok := m.preimageMap[h]
+	p, ok := m.preimageMap[hash]
 	return p, ok
 }
 
-func (m *mockPreimageCache) AddPreimages(preimages ...[]byte) error {
+func (m *mockPreimageCache) AddPreimages(preimages ...lntypes.Preimage) error {
 	m.Lock()
 	defer m.Unlock()
 
 	for _, preimage := range preimages {
-		m.preimageMap[sha256.Sum256(preimage)] = preimage
+		m.preimageMap[preimage.Hash()] = preimage
 	}
 
 	return nil

htlcswitch/test_utils.go

@@ -367,10 +367,7 @@ func createTestChannel(alicePrivKey, bobPrivKey []byte,
 	aliceSigner := &mockSigner{aliceKeyPriv}
 	bobSigner := &mockSigner{bobKeyPriv}
 
-	pCache := &mockPreimageCache{
-		// hash -> preimage
-		preimageMap: make(map[[32]byte][]byte),
-	}
+	pCache := newMockPreimageCache()
 
 	alicePool := lnwallet.NewSigPool(runtime.NumCPU(), aliceSigner)
 	channelAlice, err := lnwallet.NewLightningChannel(
@@ -982,10 +979,7 @@ type hopNetwork struct {
 func newHopNetwork() *hopNetwork {
 	defaultDelta := uint32(6)
 
-	pCache := &mockPreimageCache{
-		// hash -> preimage
-		preimageMap: make(map[[32]byte][]byte),
-	}
+	pCache := newMockPreimageCache()
 
 	globalPolicy := ForwardingPolicy{
 		MinHTLC:       lnwire.NewMSatFromSatoshis(5),