Merge pull request #767 from sangaman/master

zpay32: handle segwit prefixes > 2 chars

rpcserver.go

@@ -1693,7 +1693,8 @@ func (r *rpcServer) SendPayment(paymentStream lnrpc.Lightning_SendPaymentServer)
 				// attempt to decode it, populating the
 				// payment accordingly.
 				if nextPayment.PaymentRequest != "" {
-					payReq, err := zpay32.Decode(nextPayment.PaymentRequest)
+					payReq, err := zpay32.Decode(nextPayment.PaymentRequest,
+						activeNetParams.Params)
 					if err != nil {
 						select {
 						case errChan <- err:
@@ -1882,7 +1883,8 @@ func (r *rpcServer) SendPaymentSync(ctx context.Context,
 	// If the proto request has an encoded payment request, then we we'll
 	// use that solely to dispatch the payment.
 	if nextPayment.PaymentRequest != "" {
-		payReq, err := zpay32.Decode(nextPayment.PaymentRequest)
+		payReq, err := zpay32.Decode(nextPayment.PaymentRequest,
+			activeNetParams.Params)
 		if err != nil {
 			return nil, err
 		}
@@ -2150,7 +2152,7 @@ func (r *rpcServer) AddInvoice(ctx context.Context,
 // createRPCInvoice creates an *lnrpc.Invoice from the *channeldb.Invoice.
 func createRPCInvoice(invoice *channeldb.Invoice) (*lnrpc.Invoice, error) {
 	paymentRequest := string(invoice.PaymentRequest)
-	decoded, err := zpay32.Decode(paymentRequest)
+	decoded, err := zpay32.Decode(paymentRequest, activeNetParams.Params)
 	if err != nil {
 		return nil, fmt.Errorf("unable to decode payment request: %v",
 			err)
@@ -2978,7 +2980,7 @@ func (r *rpcServer) DecodePayReq(ctx context.Context,
 	// Fist we'll attempt to decode the payment request string, if the
 	// request is invalid or the checksum doesn't match, then we'll exit
 	// here with an error.
-	payReq, err := zpay32.Decode(req.PayReq)
+	payReq, err := zpay32.Decode(req.PayReq, activeNetParams.Params)
 	if err != nil {
 		return nil, err
 	}

zpay32/invoice.go

@@ -265,9 +265,9 @@ func NewInvoice(net *chaincfg.Params, paymentHash [32]byte,
 	return invoice, nil
 }
 
-// Decode parses the provided encoded invoice, and returns a decoded Invoice in
+// Decode parses the provided encoded invoice and returns a decoded Invoice if
-// case it is valid by BOLT-0011.
+// it is valid by BOLT-0011 and matches the provided active network.
-func Decode(invoice string) (*Invoice, error) {
+func Decode(invoice string, net *chaincfg.Params) (*Invoice, error) {
 	decodedInvoice := Invoice{}
 
 	// Decode the invoice using the modified bech32 decoder.
@@ -276,9 +276,9 @@ func Decode(invoice string) (*Invoice, error) {
 		return nil, err
 	}
 
-	// We expect the human-readable part to at least have ln + two chars
+	// We expect the human-readable part to at least have ln + one char
 	// encoding the network.
-	if len(hrp) < 4 {
+	if len(hrp) < 3 {
 		return nil, fmt.Errorf("hrp too short")
 	}
 
@@ -288,24 +288,17 @@ func Decode(invoice string) (*Invoice, error) {
 	}
 
 	// The next characters should be a valid prefix for a segwit BIP173
-	// address. This will also determine which network this invoice is
+	// address that match the active network.
-	// meant for.
+	if !strings.HasPrefix(hrp[2:], net.Bech32HRPSegwit) {
-	var net *chaincfg.Params
-	if strings.HasPrefix(hrp[2:], chaincfg.MainNetParams.Bech32HRPSegwit) {
-		net = &chaincfg.MainNetParams
-	} else if strings.HasPrefix(hrp[2:], chaincfg.TestNet3Params.Bech32HRPSegwit) {
-		net = &chaincfg.TestNet3Params
-	} else if strings.HasPrefix(hrp[2:], chaincfg.SimNetParams.Bech32HRPSegwit) {
-		net = &chaincfg.SimNetParams
-	} else {
 		return nil, fmt.Errorf("unknown network")
 	}
 	decodedInvoice.Net = net
 
-	// Optionally, if there's anything left of the HRP, it encodes the
+	// Optionally, if there's anything left of the HRP after ln + the segwit
-	// payment amount.
+	// prefix, we try to decode this as the payment amount.
-	if len(hrp) > 4 {
+	var netPrefixLength = len(net.Bech32HRPSegwit) + 2
-		amount, err := decodeAmount(hrp[4:])
+	if len(hrp) > netPrefixLength {
+		amount, err := decodeAmount(hrp[netPrefixLength:])
 		if err != nil {
 			return nil, err
 		}
@@ -573,11 +566,7 @@ func parseData(invoice *Invoice, data []byte, net *chaincfg.Params) error {
 
 	// The rest are tagged parts.
 	tagData := data[7:]
-	if err := parseTaggedFields(invoice, tagData, net); err != nil {
+	return parseTaggedFields(invoice, tagData, net)
-		return err
-	}
-
-	return nil
 }
 
 // parseTimestamp converts a 35-bit timestamp (encoded in base32) to uint64.

zpay32/invoice_test.go

@@ -15,7 +15,10 @@ import (
 	"github.com/roasbeef/btcd/btcec"
 	"github.com/roasbeef/btcd/chaincfg"
 	"github.com/roasbeef/btcd/chaincfg/chainhash"
+	"github.com/roasbeef/btcd/wire"
 	"github.com/roasbeef/btcutil"
+
+	litecoinCfg "github.com/ltcsuite/ltcd/chaincfg"
 )
 
 var (
@@ -90,11 +93,24 @@ var (
 	// Must be initialized in init().
 	testPaymentHash     [32]byte
 	testDescriptionHash [32]byte
+
+	ltcTestNetParams chaincfg.Params
+	ltcMainNetParams chaincfg.Params
 )
 
 func init() {
 	copy(testPaymentHash[:], testPaymentHashSlice[:])
 	copy(testDescriptionHash[:], testDescriptionHashSlice[:])
+
+	// Initialize litecoin testnet and mainnet params by applying key fields
+	// to copies of bitcoin params.
+	// TODO(sangaman): create an interface for chaincfg.params
+	ltcTestNetParams = chaincfg.TestNet3Params
+	ltcTestNetParams.Net = wire.BitcoinNet(litecoinCfg.TestNet4Params.Net)
+	ltcTestNetParams.Bech32HRPSegwit = litecoinCfg.TestNet4Params.Bech32HRPSegwit
+	ltcMainNetParams = chaincfg.MainNetParams
+	ltcMainNetParams.Net = wire.BitcoinNet(litecoinCfg.MainNetParams.Net)
+	ltcMainNetParams.Bech32HRPSegwit = litecoinCfg.MainNetParams.Bech32HRPSegwit
 }
 
 // TestDecodeEncode tests that an encoded invoice gets decoded into the expected
@@ -123,7 +139,7 @@ func TestDecodeEncode(t *testing.T) {
 			valid:          false,
 		},
 		{
-			encodedInvoice: "lnb1asdsaddnv4wudz", // hrp too short
+			encodedInvoice: "ln1asdsaddnv4wudz", // hrp too short
 			valid:          false,
 		},
 		{
@@ -515,10 +531,64 @@ func TestDecodeEncode(t *testing.T) {
 				return i
 			},
 		},
+		{
+			// Decode a mainnet invoice while expecting active net to be testnet
+			encodedInvoice: "lnbc241pveeq09pp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdqqnp4q0n326hr8v9zprg8gsvezcch06gfaqqhde2aj730yg0durunfhv66jd3m5klcwhq68vdsmx2rjgxeay5v0tkt2v5sjaky4eqahe4fx3k9sqavvce3capfuwv8rvjng57jrtfajn5dkpqv8yelsewtljwmmycq62k443",
+			valid:          false,
+			decodedInvoice: func() *Invoice {
+				return &Invoice{
+					Net:         &chaincfg.TestNet3Params,
+					MilliSat:    &testMillisat24BTC,
+					Timestamp:   time.Unix(1503429093, 0),
+					PaymentHash: &testPaymentHash,
+					Destination: testPubKey,
+					Description: &testEmptyString,
+				}
+			},
+			skipEncoding: true, // Skip encoding since we were given the wrong net
+		},
+		{
+			// Decode a litecoin testnet invoice
+			encodedInvoice: "lntltc241pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsnp4q0n326hr8v9zprg8gsvezcch06gfaqqhde2aj730yg0durunfhv66m2eq2fx9uctzkmj30meaghyskkgsd6geap5qg9j2ae444z24a4p8xg3a6g73p8l7d689vtrlgzj0wyx2h6atq8dfty7wmkt4frx9g9sp730h5a",
+			valid:          true,
+			decodedInvoice: func() *Invoice {
+				return &Invoice{
+					// TODO(sangaman): create an interface for chaincfg.params
+					Net:             &ltcTestNetParams,
+					MilliSat:        &testMillisat24BTC,
+					Timestamp:       time.Unix(1496314658, 0),
+					PaymentHash:     &testPaymentHash,
+					DescriptionHash: &testDescriptionHash,
+					Destination:     testPubKey,
+				}
+			},
+		},
+		{
+			// Decode a litecoin mainnet invoice
+			encodedInvoice: "lnltc241pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsnp4q0n326hr8v9zprg8gsvezcch06gfaqqhde2aj730yg0durunfhv66859t2d55efrxdlgqg9hdqskfstdmyssdw4fjc8qdl522ct885pqk7acn2aczh0jeht0xhuhnkmm3h0qsrxedlwm9x86787zzn4qwwwcpjkl3t2",
+			valid:          true,
+			decodedInvoice: func() *Invoice {
+				return &Invoice{
+					Net:             &ltcMainNetParams,
+					MilliSat:        &testMillisat24BTC,
+					Timestamp:       time.Unix(1496314658, 0),
+					PaymentHash:     &testPaymentHash,
+					DescriptionHash: &testDescriptionHash,
+					Destination:     testPubKey,
+				}
+			},
+		},
 	}
 
 	for i, test := range tests {
-		invoice, err := Decode(test.encodedInvoice)
+		var decodedInvoice *Invoice
+		net := &chaincfg.MainNetParams
+		if test.decodedInvoice != nil {
+			decodedInvoice = test.decodedInvoice()
+			net = decodedInvoice.Net
+		}
+
+		invoice, err := Decode(test.encodedInvoice, net)
 		if (err == nil) != test.valid {
 			t.Errorf("Decoding test %d failed: %v", i, err)
 			return
@@ -535,11 +605,6 @@ func TestDecodeEncode(t *testing.T) {
 			continue
 		}
 
-		var decodedInvoice *Invoice
-		if test.decodedInvoice != nil {
-			decodedInvoice = test.decodedInvoice()
-		}
-
 		if test.beforeEncoding != nil {
 			test.beforeEncoding(decodedInvoice)
 		}
@@ -621,6 +686,30 @@ func TestNewInvoice(t *testing.T) {
 			valid:          true,
 			encodedInvoice: "lnbc20m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsfpp3qjmp7lwpagxun9pygexvgpjdc4jdj85fr9yq20q82gphp2nflc7jtzrcazrra7wwgzxqc8u7754cdlpfrmccae92qgzqvzq2ps8pqqqqqqpqqqqq9qqqvpeuqafqxu92d8lr6fvg0r5gv0heeeqgcrqlnm6jhphu9y00rrhy4grqszsvpcgpy9qqqqqqgqqqqq7qqzqj9n4evl6mr5aj9f58zp6fyjzup6ywn3x6sk8akg5v4tgn2q8g4fhx05wf6juaxu9760yp46454gpg5mtzgerlzezqcqvjnhjh8z3g2qqdhhwkj",
 		},
+		{
+			// Create a litecoin testnet invoice
+			newInvoice: func() (*Invoice, error) {
+				return NewInvoice(&ltcTestNetParams,
+					testPaymentHash, time.Unix(1496314658, 0),
+					Amount(testMillisat24BTC),
+					DescriptionHash(testDescriptionHash),
+					Destination(testPubKey))
+			},
+			valid:          true,
+			encodedInvoice: "lntltc241pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsnp4q0n326hr8v9zprg8gsvezcch06gfaqqhde2aj730yg0durunfhv66m2eq2fx9uctzkmj30meaghyskkgsd6geap5qg9j2ae444z24a4p8xg3a6g73p8l7d689vtrlgzj0wyx2h6atq8dfty7wmkt4frx9g9sp730h5a",
+		},
+		{
+			// Create a litecoin mainnet invoice
+			newInvoice: func() (*Invoice, error) {
+				return NewInvoice(&ltcMainNetParams,
+					testPaymentHash, time.Unix(1496314658, 0),
+					Amount(testMillisat24BTC),
+					DescriptionHash(testDescriptionHash),
+					Destination(testPubKey))
+			},
+			valid:          true,
+			encodedInvoice: "lnltc241pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsnp4q0n326hr8v9zprg8gsvezcch06gfaqqhde2aj730yg0durunfhv66859t2d55efrxdlgqg9hdqskfstdmyssdw4fjc8qdl522ct885pqk7acn2aczh0jeht0xhuhnkmm3h0qsrxedlwm9x86787zzn4qwwwcpjkl3t2",
+		},
 	}
 
 	for i, test := range tests {
@@ -689,11 +778,7 @@ func compareInvoices(expected, actual *Invoice) error {
 			expected.FallbackAddr, actual.FallbackAddr)
 	}
 
-	if err := compareRoutingInfos(expected.RoutingInfo, actual.RoutingInfo); err != nil {
+	return compareRoutingInfos(expected.RoutingInfo, actual.RoutingInfo)
-		return err
-	}
-
-	return nil
 }
 
 func comparePubkeys(a, b *btcec.PublicKey) bool {