lnd/routing/blindedpath/blinded_path_test.go
Elle Mouton b490deefdf
routing/blindedpath: dont error out unless all paths fail
In this commit, we adjust BuildBlindedPaymentPaths to only error out
completely if none of the paths it received from FindRoutes resulted in
a usable blinded path.
2024-08-07 17:02:56 +02:00

1061 lines
29 KiB
Go

package blindedpath
import (
"bytes"
"encoding/hex"
"fmt"
"math/rand"
"reflect"
"testing"
"testing/quick"
"github.com/btcsuite/btcd/btcec/v2"
sphinx "github.com/lightningnetwork/lightning-onion"
"github.com/lightningnetwork/lnd/channeldb/models"
"github.com/lightningnetwork/lnd/keychain"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/record"
"github.com/lightningnetwork/lnd/routing/route"
"github.com/lightningnetwork/lnd/tlv"
"github.com/stretchr/testify/require"
)
var (
pubkeyBytes, _ = hex.DecodeString(
"598ec453728e0ffe0ae2f5e174243cf58f2" +
"a3f2c83d2457b43036db568b11093",
)
pubKeyY = new(btcec.FieldVal)
_ = pubKeyY.SetByteSlice(pubkeyBytes)
pubkey = btcec.NewPublicKey(new(btcec.FieldVal).SetInt(4), pubKeyY)
)
// TestApplyBlindedPathPolicyBuffer tests blinded policy adjustments.
func TestApplyBlindedPathPolicyBuffer(t *testing.T) {
tests := []struct {
name string
policyIn *BlindedHopPolicy
expectedOut *BlindedHopPolicy
incMultiplier float64
decMultiplier float64
expectedError string
}{
{
name: "invalid increase multiplier",
incMultiplier: 0,
expectedError: "blinded path policy increase " +
"multiplier must be greater than or equal to 1",
},
{
name: "decrease multiplier too small",
incMultiplier: 1,
decMultiplier: -1,
expectedError: "blinded path policy decrease " +
"multiplier must be in the range [0;1]",
},
{
name: "decrease multiplier too big",
incMultiplier: 1,
decMultiplier: 2,
expectedError: "blinded path policy decrease " +
"multiplier must be in the range [0;1]",
},
{
name: "no change",
incMultiplier: 1,
decMultiplier: 1,
policyIn: &BlindedHopPolicy{
CLTVExpiryDelta: 1,
MinHTLCMsat: 2,
MaxHTLCMsat: 3,
BaseFee: 4,
FeeRate: 5,
},
expectedOut: &BlindedHopPolicy{
CLTVExpiryDelta: 1,
MinHTLCMsat: 2,
MaxHTLCMsat: 3,
BaseFee: 4,
FeeRate: 5,
},
},
{
name: "buffer up by 100% and down by 50%",
incMultiplier: 2,
decMultiplier: 0.5,
policyIn: &BlindedHopPolicy{
CLTVExpiryDelta: 10,
MinHTLCMsat: 20,
MaxHTLCMsat: 300,
BaseFee: 40,
FeeRate: 50,
},
expectedOut: &BlindedHopPolicy{
CLTVExpiryDelta: 20,
MinHTLCMsat: 40,
MaxHTLCMsat: 150,
BaseFee: 80,
FeeRate: 100,
},
},
{
name: "new HTLC minimum larger than OG " +
"maximum",
incMultiplier: 2,
decMultiplier: 1,
policyIn: &BlindedHopPolicy{
CLTVExpiryDelta: 10,
MinHTLCMsat: 20,
MaxHTLCMsat: 30,
BaseFee: 40,
FeeRate: 50,
},
expectedOut: &BlindedHopPolicy{
CLTVExpiryDelta: 20,
MinHTLCMsat: 20,
MaxHTLCMsat: 30,
BaseFee: 80,
FeeRate: 100,
},
},
{
name: "new HTLC maximum smaller than OG " +
"minimum",
incMultiplier: 1,
decMultiplier: 0.5,
policyIn: &BlindedHopPolicy{
CLTVExpiryDelta: 10,
MinHTLCMsat: 20,
MaxHTLCMsat: 30,
BaseFee: 40,
FeeRate: 50,
},
expectedOut: &BlindedHopPolicy{
CLTVExpiryDelta: 10,
MinHTLCMsat: 20,
MaxHTLCMsat: 30,
BaseFee: 40,
FeeRate: 50,
},
},
{
name: "new HTLC minimum and maximums are not " +
"compatible",
incMultiplier: 2,
decMultiplier: 0.5,
policyIn: &BlindedHopPolicy{
CLTVExpiryDelta: 10,
MinHTLCMsat: 30,
MaxHTLCMsat: 100,
BaseFee: 40,
FeeRate: 50,
},
expectedOut: &BlindedHopPolicy{
CLTVExpiryDelta: 20,
MinHTLCMsat: 30,
MaxHTLCMsat: 100,
BaseFee: 80,
FeeRate: 100,
},
},
}
for _, test := range tests {
test := test
t.Run(test.name, func(t *testing.T) {
t.Parallel()
bufferedPolicy, err := AddPolicyBuffer(
test.policyIn, test.incMultiplier,
test.decMultiplier,
)
if test.expectedError != "" {
require.ErrorContains(
t, err, test.expectedError,
)
return
}
require.Equal(t, test.expectedOut, bufferedPolicy)
})
}
}
// TestBlindedPathAccumulatedPolicyCalc tests the logic for calculating the
// accumulated routing policies of a blinded route against an example mentioned
// in the spec document:
// https://github.com/lightning/bolts/blob/master/proposals/route-blinding.md
func TestBlindedPathAccumulatedPolicyCalc(t *testing.T) {
t.Parallel()
// In the spec example, the blinded route is:
// Carol -> Bob -> Alice
// And Alice chooses the following buffered policy for both the C->B
// and B->A edges.
nodePolicy := &record.PaymentRelayInfo{
FeeRate: 500,
BaseFee: 100,
CltvExpiryDelta: 144,
}
hopPolicies := []*record.PaymentRelayInfo{
nodePolicy,
nodePolicy,
}
// Alice's minimum final expiry delta is chosen to be 12.
aliceMinFinalExpDelta := uint16(12)
totalBase, totalRate, totalCLTVDelta := calcBlindedPathPolicies(
hopPolicies, aliceMinFinalExpDelta,
)
require.Equal(t, lnwire.MilliSatoshi(201), totalBase)
require.EqualValues(t, 1001, totalRate)
require.EqualValues(t, 300, totalCLTVDelta)
}
// TestPadBlindedHopInfo asserts that the padding of blinded hop data is done
// correctly and that it takes the expected number of iterations.
func TestPadBlindedHopInfo(t *testing.T) {
tests := []struct {
name string
expectedIterations int
expectedFinalSize int
// We will use the PathID field of BlindedRouteData to set an
// initial payload size. The ints in this list represent the
// size of each PathID.
pathIDs []int
// existingPadding is a map from entry index (based on the
// pathIDs set) to the number of pre-existing padding bytes to
// add.
existingPadding map[int]int
// prePad is true if all the hop payloads should be pre-padded
// with a zero length TLV Padding field.
prePad bool
// minPayloadSize can be used to set the minimum number of bytes
// that the resulting records should be.
minPayloadSize int
}{
{
// If there is only one entry, then no padding is
// expected.
name: "single entry",
expectedIterations: 1,
pathIDs: []int{10},
// The final size will be 12 since the path ID is 10
// bytes, and it will be prefixed by type and value
// bytes.
expectedFinalSize: 12,
},
{
// Same as the above example but with a minimum final
// size specified.
name: "single entry with min size",
expectedIterations: 2,
pathIDs: []int{10},
minPayloadSize: 500,
expectedFinalSize: 504,
},
{
// All the payloads are the same size from the get go
// meaning that no padding is expected.
name: "all start equal",
expectedIterations: 1,
pathIDs: []int{10, 10, 10},
// The final size will be 12 since the path ID is 10
// bytes, and it will be prefixed by type and value
// bytes.
expectedFinalSize: 12,
},
{
// If the blobs differ by 1 byte it will take 4
// iterations:
// 1) padding of 1 is added to entry 2 which will
// increase its size by 3 bytes since padding does
// not yet exist for it.
// 2) Now entry 1 will be short 2 bytes. It will be
// padded by 2 bytes but again since it is a new
// padding field, 4 bytes are added.
// 3) Finally, entry 2 is padded by 1 extra. Since it
// already does have a padding field, this does end
// up adding only 1 extra byte.
// 4) The fourth iteration determines that all are now
// the same size.
name: "differ by 1 - no pre-padding",
expectedIterations: 4,
pathIDs: []int{4, 3},
expectedFinalSize: 10,
},
{
// By pre-padding the payloads with a zero byte padding,
// we can reduce the number of iterations quite a bit.
name: "differ by 1 - with pre-padding",
expectedIterations: 2,
pathIDs: []int{4, 3},
expectedFinalSize: 8,
prePad: true,
},
{
name: "existing padding and diff of 1",
expectedIterations: 2,
pathIDs: []int{10, 11},
// By adding some existing padding, the type and length
// field for the padding are already accounted for in
// the first iteration, and so we only expect two
// iterations to get the payloads to match size here:
// one for adding a single extra byte to the smaller
// payload and another for confirming the sizes match.
existingPadding: map[int]int{0: 1, 1: 1},
expectedFinalSize: 16,
},
{
// In this test, we test a BigSize bucket shift. We do
// this by setting the initial path ID's of both entries
// to a 0 size which means the total encoding of those
// will be 2 bytes (to encode the type and length). Then
// for the initial padding, we let the first entry be
// 253 bytes long which is just long enough to be in
// the second BigSize bucket which uses 3 bytes to
// encode the value length. We make the second entry
// 252 bytes which still puts it in the first bucket
// which uses 1 byte for the length. The difference in
// overall packet size will be 3 bytes (the first entry
// has 2 more length bytes and 1 more value byte). So
// the function will try to pad the second entry by 3
// bytes (iteration 1). This will however result in the
// second entry shifting to the second BigSize bucket
// meaning it will gain an additional 2 bytes for the
// new length encoding meaning that overall it gains 5
// bytes in size. This will result in another iteration
// which will result in padding the first entry with an
// extra 2 bytes to meet the second entry's new size
// (iteration 2). One more iteration (3) is then done
// to confirm that all entries are now the same size.
name: "big size bucket shift",
expectedIterations: 3,
// We make the path IDs large enough so that
pathIDs: []int{0, 0},
existingPadding: map[int]int{0: 253, 1: 252},
expectedFinalSize: 261,
},
}
for _, test := range tests {
test := test
t.Run(test.name, func(t *testing.T) {
t.Parallel()
// If the test includes existing padding, then make sure
// that the number of existing padding entries is equal
// to the number of PathID entries.
if test.existingPadding != nil {
require.Len(t, test.existingPadding,
len(test.pathIDs))
}
hopDataSet := make([]*hopData, len(test.pathIDs))
for i, l := range test.pathIDs {
pathID := tlv.SomeRecordT(
tlv.NewPrimitiveRecord[tlv.TlvType6](
make([]byte, l),
),
)
data := &record.BlindedRouteData{
PathID: pathID,
}
if test.existingPadding != nil {
//nolint:lll
padding := tlv.SomeRecordT(
tlv.NewPrimitiveRecord[tlv.TlvType1](
make([]byte, test.existingPadding[i]),
),
)
data.Padding = padding
}
hopDataSet[i] = &hopData{data: data}
}
hopInfo, stats, err := padHopInfo(
hopDataSet, test.prePad, test.minPayloadSize,
)
require.NoError(t, err)
require.Equal(t, test.expectedIterations,
stats.numIterations)
require.Equal(t, test.expectedFinalSize,
stats.finalPaddedSize)
// We expect all resulting blobs to be the same size.
for _, info := range hopInfo {
require.Len(
t, info.PlainText,
test.expectedFinalSize,
)
}
})
}
}
// TestPadBlindedHopInfoBlackBox tests the padHopInfo function via the
// quick.Check testing function. It generates a random set of hopData and
// asserts that the resulting padded set always has the same encoded length.
func TestPadBlindedHopInfoBlackBox(t *testing.T) {
fn := func(data hopDataList) bool {
resultList, _, err := padHopInfo(data, true, 0)
require.NoError(t, err)
// There should be a resulting sphinx.HopInfo struct for each
// hopData passed to the padHopInfo function.
if len(resultList) != len(data) {
return false
}
// There is nothing left to check if input set was empty to
// start with.
if len(data) == 0 {
return true
}
// Now, assert that the encoded size of each item is the same.
// Get the size of the first item as a base point.
payloadSize := len(resultList[0].PlainText)
// All the other entries should have the same encoded size.
for i := 1; i < len(resultList); i++ {
if len(resultList[i].PlainText) != payloadSize {
return false
}
}
return true
}
require.NoError(t, quick.Check(fn, nil))
}
type hopDataList []*hopData
// Generate returns a random instance of the hopDataList type.
//
// NOTE: this is part of the quick.Generate interface.
func (h hopDataList) Generate(rand *rand.Rand, size int) reflect.Value {
data := make(hopDataList, rand.Intn(size))
for i := 0; i < len(data); i++ {
data[i] = &hopData{
data: genBlindedRouteData(rand),
nodeID: pubkey,
}
}
return reflect.ValueOf(data)
}
// A compile-time check to ensure that hopDataList implements the
// quick.Generator interface.
var _ quick.Generator = (*hopDataList)(nil)
// sometimesDo calls the given function with a 50% probability.
func sometimesDo(fn func(), rand *rand.Rand) {
if rand.Intn(1) == 0 {
return
}
fn()
}
// genBlindedRouteData generates a random record.BlindedRouteData object.
func genBlindedRouteData(rand *rand.Rand) *record.BlindedRouteData {
var data record.BlindedRouteData
sometimesDo(func() {
data.Padding = tlv.SomeRecordT(
tlv.NewPrimitiveRecord[tlv.TlvType1](
make([]byte, rand.Intn(1000000)),
),
)
}, rand)
sometimesDo(func() {
data.ShortChannelID = tlv.SomeRecordT(
tlv.NewRecordT[tlv.TlvType2](lnwire.ShortChannelID{
BlockHeight: rand.Uint32(),
TxIndex: rand.Uint32(),
TxPosition: uint16(rand.Uint32()),
}),
)
}, rand)
sometimesDo(func() {
data.NextNodeID = tlv.SomeRecordT(
tlv.NewPrimitiveRecord[tlv.TlvType4](pubkey),
)
}, rand)
sometimesDo(func() {
data.PathID = tlv.SomeRecordT(
tlv.NewPrimitiveRecord[tlv.TlvType6](
make([]byte, rand.Intn(100)),
),
)
}, rand)
sometimesDo(func() {
data.NextBlindingOverride = tlv.SomeRecordT(
tlv.NewPrimitiveRecord[tlv.TlvType8](pubkey),
)
}, rand)
sometimesDo(func() {
data.RelayInfo = tlv.SomeRecordT(
tlv.NewRecordT[tlv.TlvType10](record.PaymentRelayInfo{
CltvExpiryDelta: uint16(rand.Uint32()),
FeeRate: rand.Uint32(),
BaseFee: lnwire.MilliSatoshi(
rand.Uint32(),
),
}),
)
}, rand)
sometimesDo(func() {
data.Constraints = tlv.SomeRecordT(
tlv.NewRecordT[tlv.TlvType12](record.PaymentConstraints{
MaxCltvExpiry: rand.Uint32(),
HtlcMinimumMsat: lnwire.MilliSatoshi(
rand.Uint32(),
),
}),
)
}, rand)
return &data
}
// TestBuildBlindedPath tests the logic for constructing a blinded path against
// an example mentioned in this spec document:
// https://github.com/lightning/bolts/blob/master/proposals/route-blinding.md
// This example does not use any dummy hops.
func TestBuildBlindedPath(t *testing.T) {
// Alice chooses the following path to herself for blinded path
// construction:
// Carol -> Bob -> Alice.
// Let's construct the corresponding route.Route for this which will be
// returned from the `FindRoutes` config callback.
var (
privC, pkC = btcec.PrivKeyFromBytes([]byte{1})
privB, pkB = btcec.PrivKeyFromBytes([]byte{2})
privA, pkA = btcec.PrivKeyFromBytes([]byte{3})
carol = route.NewVertex(pkC)
bob = route.NewVertex(pkB)
alice = route.NewVertex(pkA)
chanCB = uint64(1)
chanBA = uint64(2)
)
realRoute := &route.Route{
SourcePubKey: carol,
Hops: []*route.Hop{
{
PubKeyBytes: bob,
ChannelID: chanCB,
},
{
PubKeyBytes: alice,
ChannelID: chanBA,
},
},
}
realPolicies := map[uint64]*models.ChannelEdgePolicy{
chanCB: {
ChannelID: chanCB,
ToNode: bob,
},
chanBA: {
ChannelID: chanBA,
ToNode: alice,
},
}
paths, err := BuildBlindedPaymentPaths(&BuildBlindedPathCfg{
FindRoutes: func(_ lnwire.MilliSatoshi) ([]*route.Route,
error) {
return []*route.Route{realRoute}, nil
},
FetchChannelEdgesByID: func(chanID uint64) (
*models.ChannelEdgeInfo, *models.ChannelEdgePolicy,
*models.ChannelEdgePolicy, error) {
return nil, realPolicies[chanID], nil, nil
},
BestHeight: func() (uint32, error) {
return 1000, nil
},
// In the spec example, all the policies get replaced with
// the same static values.
AddPolicyBuffer: func(_ *BlindedHopPolicy) (
*BlindedHopPolicy, error) {
return &BlindedHopPolicy{
FeeRate: 500,
BaseFee: 100,
CLTVExpiryDelta: 144,
MinHTLCMsat: 1000,
MaxHTLCMsat: lnwire.MaxMilliSatoshi,
}, nil
},
PathID: []byte{1, 2, 3},
ValueMsat: 1000,
MinFinalCLTVExpiryDelta: 12,
BlocksUntilExpiry: 200,
})
require.NoError(t, err)
require.Len(t, paths, 1)
path := paths[0]
// Check that all the accumulated policy values are correct.
require.EqualValues(t, 201, path.FeeBaseMsat)
require.EqualValues(t, 1001, path.FeeRate)
require.EqualValues(t, 300, path.CltvExpiryDelta)
require.EqualValues(t, 1000, path.HTLCMinMsat)
require.EqualValues(t, lnwire.MaxMilliSatoshi, path.HTLCMaxMsat)
// Now we check the hops.
require.Len(t, path.Hops, 3)
// Assert that all the encrypted recipient blobs have been padded such
// that they are all the same size.
require.Len(t, path.Hops[0].CipherText, len(path.Hops[1].CipherText))
require.Len(t, path.Hops[1].CipherText, len(path.Hops[2].CipherText))
// The first hop, should have the real pub key of the introduction
// node: Carol.
hop := path.Hops[0]
require.True(t, hop.BlindedNodePub.IsEqual(pkC))
// As Carol, let's decode the hop data and assert that all expected
// values have been included.
var (
blindingPoint = path.FirstEphemeralBlindingPoint
data *record.BlindedRouteData
)
// Check that Carol's info is correct.
data, blindingPoint = decryptAndDecodeHopData(
t, privC, blindingPoint, hop.CipherText,
)
require.Equal(
t, lnwire.NewShortChanIDFromInt(chanCB),
data.ShortChannelID.UnwrapOrFail(t).Val,
)
require.Equal(t, record.PaymentRelayInfo{
CltvExpiryDelta: 144,
FeeRate: 500,
BaseFee: 100,
}, data.RelayInfo.UnwrapOrFail(t).Val)
require.Equal(t, record.PaymentConstraints{
MaxCltvExpiry: 1500,
HtlcMinimumMsat: 1000,
}, data.Constraints.UnwrapOrFail(t).Val)
// Check that all Bob's info is correct.
hop = path.Hops[1]
data, blindingPoint = decryptAndDecodeHopData(
t, privB, blindingPoint, hop.CipherText,
)
require.Equal(
t, lnwire.NewShortChanIDFromInt(chanBA),
data.ShortChannelID.UnwrapOrFail(t).Val,
)
require.Equal(t, record.PaymentRelayInfo{
CltvExpiryDelta: 144,
FeeRate: 500,
BaseFee: 100,
}, data.RelayInfo.UnwrapOrFail(t).Val)
require.Equal(t, record.PaymentConstraints{
MaxCltvExpiry: 1356,
HtlcMinimumMsat: 1000,
}, data.Constraints.UnwrapOrFail(t).Val)
// Check that all Alice's info is correct.
hop = path.Hops[2]
data, _ = decryptAndDecodeHopData(
t, privA, blindingPoint, hop.CipherText,
)
require.True(t, data.ShortChannelID.IsNone())
require.True(t, data.RelayInfo.IsNone())
require.Equal(t, record.PaymentConstraints{
MaxCltvExpiry: 1212,
HtlcMinimumMsat: 1000,
}, data.Constraints.UnwrapOrFail(t).Val)
require.Equal(t, []byte{1, 2, 3}, data.PathID.UnwrapOrFail(t).Val)
}
// TestBuildBlindedPathWithDummyHops tests the construction of a blinded path
// which includes dummy hops.
func TestBuildBlindedPathWithDummyHops(t *testing.T) {
// Alice chooses the following path to herself for blinded path
// construction:
// Carol -> Bob -> Alice.
// Let's construct the corresponding route.Route for this which will be
// returned from the `FindRoutes` config callback.
var (
privC, pkC = btcec.PrivKeyFromBytes([]byte{1})
privB, pkB = btcec.PrivKeyFromBytes([]byte{2})
privA, pkA = btcec.PrivKeyFromBytes([]byte{3})
carol = route.NewVertex(pkC)
bob = route.NewVertex(pkB)
alice = route.NewVertex(pkA)
chanCB = uint64(1)
chanBA = uint64(2)
)
realRoute := &route.Route{
SourcePubKey: carol,
Hops: []*route.Hop{
{
PubKeyBytes: bob,
ChannelID: chanCB,
},
{
PubKeyBytes: alice,
ChannelID: chanBA,
},
},
}
realPolicies := map[uint64]*models.ChannelEdgePolicy{
chanCB: {
ChannelID: chanCB,
ToNode: bob,
},
chanBA: {
ChannelID: chanBA,
ToNode: alice,
},
}
paths, err := BuildBlindedPaymentPaths(&BuildBlindedPathCfg{
FindRoutes: func(_ lnwire.MilliSatoshi) ([]*route.Route,
error) {
return []*route.Route{realRoute}, nil
},
FetchChannelEdgesByID: func(chanID uint64) (
*models.ChannelEdgeInfo, *models.ChannelEdgePolicy,
*models.ChannelEdgePolicy, error) {
policy, ok := realPolicies[chanID]
if !ok {
return nil, nil, nil,
fmt.Errorf("edge not found")
}
return nil, policy, nil, nil
},
BestHeight: func() (uint32, error) {
return 1000, nil
},
// In the spec example, all the policies get replaced with
// the same static values.
AddPolicyBuffer: func(_ *BlindedHopPolicy) (
*BlindedHopPolicy, error) {
return &BlindedHopPolicy{
FeeRate: 500,
BaseFee: 100,
CLTVExpiryDelta: 144,
MinHTLCMsat: 1000,
MaxHTLCMsat: lnwire.MaxMilliSatoshi,
}, nil
},
PathID: []byte{1, 2, 3},
ValueMsat: 1000,
MinFinalCLTVExpiryDelta: 12,
BlocksUntilExpiry: 200,
// By setting the minimum number of hops to 4, we force 2 dummy
// hops to be added to the real route.
MinNumHops: 4,
DefaultDummyHopPolicy: &BlindedHopPolicy{
CLTVExpiryDelta: 50,
FeeRate: 100,
BaseFee: 100,
MinHTLCMsat: 1000,
MaxHTLCMsat: lnwire.MaxMilliSatoshi,
},
})
require.NoError(t, err)
require.Len(t, paths, 1)
path := paths[0]
// Check that all the accumulated policy values are correct.
require.EqualValues(t, 403, path.FeeBaseMsat)
require.EqualValues(t, 2003, path.FeeRate)
require.EqualValues(t, 588, path.CltvExpiryDelta)
require.EqualValues(t, 1000, path.HTLCMinMsat)
require.EqualValues(t, lnwire.MaxMilliSatoshi, path.HTLCMaxMsat)
// Now we check the hops.
require.Len(t, path.Hops, 5)
// Assert that all the encrypted recipient blobs have been padded such
// that they are all the same size.
require.Len(t, path.Hops[0].CipherText, len(path.Hops[1].CipherText))
require.Len(t, path.Hops[1].CipherText, len(path.Hops[2].CipherText))
require.Len(t, path.Hops[2].CipherText, len(path.Hops[3].CipherText))
require.Len(t, path.Hops[3].CipherText, len(path.Hops[4].CipherText))
// The first hop, should have the real pub key of the introduction
// node: Carol.
hop := path.Hops[0]
require.True(t, hop.BlindedNodePub.IsEqual(pkC))
// As Carol, let's decode the hop data and assert that all expected
// values have been included.
var (
blindingPoint = path.FirstEphemeralBlindingPoint
data *record.BlindedRouteData
)
// Check that Carol's info is correct.
data, blindingPoint = decryptAndDecodeHopData(
t, privC, blindingPoint, hop.CipherText,
)
require.Equal(
t, lnwire.NewShortChanIDFromInt(chanCB),
data.ShortChannelID.UnwrapOrFail(t).Val,
)
require.Equal(t, record.PaymentRelayInfo{
CltvExpiryDelta: 144,
FeeRate: 500,
BaseFee: 100,
}, data.RelayInfo.UnwrapOrFail(t).Val)
require.Equal(t, record.PaymentConstraints{
MaxCltvExpiry: 1788,
HtlcMinimumMsat: 1000,
}, data.Constraints.UnwrapOrFail(t).Val)
// Check that all Bob's info is correct.
hop = path.Hops[1]
data, blindingPoint = decryptAndDecodeHopData(
t, privB, blindingPoint, hop.CipherText,
)
require.Equal(
t, lnwire.NewShortChanIDFromInt(chanBA),
data.ShortChannelID.UnwrapOrFail(t).Val,
)
require.Equal(t, record.PaymentRelayInfo{
CltvExpiryDelta: 144,
FeeRate: 500,
BaseFee: 100,
}, data.RelayInfo.UnwrapOrFail(t).Val)
require.Equal(t, record.PaymentConstraints{
MaxCltvExpiry: 1644,
HtlcMinimumMsat: 1000,
}, data.Constraints.UnwrapOrFail(t).Val)
// Check that all Alice's info is correct. The payload should contain
// a next_node_id field that is equal to Alice's public key. This
// indicates to Alice that she should continue peeling the onion.
hop = path.Hops[2]
data, blindingPoint = decryptAndDecodeHopData(
t, privA, blindingPoint, hop.CipherText,
)
require.True(t, data.ShortChannelID.IsNone())
require.True(t, data.RelayInfo.IsSome())
require.True(t, data.Constraints.IsSome())
require.Equal(t, pkA, data.NextNodeID.UnwrapOrFail(t).Val)
// Alice should be able to decrypt the next payload with her private
// key. This next payload is yet another dummy hop.
hop = path.Hops[3]
data, blindingPoint = decryptAndDecodeHopData(
t, privA, blindingPoint, hop.CipherText,
)
require.True(t, data.ShortChannelID.IsNone())
require.True(t, data.RelayInfo.IsSome())
require.True(t, data.Constraints.IsSome())
require.Equal(t, pkA, data.NextNodeID.UnwrapOrFail(t).Val)
// Unwrapping one more time should reveal the final hop info for Alice.
hop = path.Hops[4]
data, _ = decryptAndDecodeHopData(
t, privA, blindingPoint, hop.CipherText,
)
require.True(t, data.ShortChannelID.IsNone())
require.True(t, data.RelayInfo.IsNone())
require.Equal(t, record.PaymentConstraints{
MaxCltvExpiry: 1212,
HtlcMinimumMsat: 1000,
}, data.Constraints.UnwrapOrFail(t).Val)
require.Equal(t, []byte{1, 2, 3}, data.PathID.UnwrapOrFail(t).Val)
// Demonstrate that BuildBlindedPaymentPaths continues to use any
// functioning paths even if some routes cant be used to build a blinded
// path. We do this by forcing FetchChannelEdgesByID to error out for
// the first 2 calls. FindRoutes returns 3 routes and so by the end, we
// still get 1 valid path.
var errCount int
paths, err = BuildBlindedPaymentPaths(&BuildBlindedPathCfg{
FindRoutes: func(_ lnwire.MilliSatoshi) ([]*route.Route,
error) {
return []*route.Route{realRoute, realRoute, realRoute},
nil
},
FetchChannelEdgesByID: func(chanID uint64) (
*models.ChannelEdgeInfo, *models.ChannelEdgePolicy,
*models.ChannelEdgePolicy, error) {
// Force the call to error for the first 2 channels.
if errCount < 2 {
errCount++
return nil, nil, nil,
fmt.Errorf("edge not found")
}
policy, ok := realPolicies[chanID]
if !ok {
return nil, nil, nil,
fmt.Errorf("edge not found")
}
return nil, policy, nil, nil
},
BestHeight: func() (uint32, error) {
return 1000, nil
},
// In the spec example, all the policies get replaced with
// the same static values.
AddPolicyBuffer: func(_ *BlindedHopPolicy) (
*BlindedHopPolicy, error) {
return &BlindedHopPolicy{
FeeRate: 500,
BaseFee: 100,
CLTVExpiryDelta: 144,
MinHTLCMsat: 1000,
MaxHTLCMsat: lnwire.MaxMilliSatoshi,
}, nil
},
PathID: []byte{1, 2, 3},
ValueMsat: 1000,
MinFinalCLTVExpiryDelta: 12,
BlocksUntilExpiry: 200,
// By setting the minimum number of hops to 4, we force 2 dummy
// hops to be added to the real route.
MinNumHops: 4,
DefaultDummyHopPolicy: &BlindedHopPolicy{
CLTVExpiryDelta: 50,
FeeRate: 100,
BaseFee: 100,
MinHTLCMsat: 1000,
MaxHTLCMsat: lnwire.MaxMilliSatoshi,
},
})
require.NoError(t, err)
require.Len(t, paths, 1)
}
// TestSingleHopBlindedPath tests that blinded path construction is done
// correctly for the case where the destination node is also the introduction
// node.
func TestSingleHopBlindedPath(t *testing.T) {
var (
_, pkC = btcec.PrivKeyFromBytes([]byte{1})
carol = route.NewVertex(pkC)
)
realRoute := &route.Route{
SourcePubKey: carol,
// No hops since Carol is both the introduction node and the
// final destination node.
Hops: []*route.Hop{},
}
paths, err := BuildBlindedPaymentPaths(&BuildBlindedPathCfg{
FindRoutes: func(_ lnwire.MilliSatoshi) ([]*route.Route,
error) {
return []*route.Route{realRoute}, nil
},
BestHeight: func() (uint32, error) {
return 1000, nil
},
PathID: []byte{1, 2, 3},
ValueMsat: 1000,
MinFinalCLTVExpiryDelta: 12,
BlocksUntilExpiry: 200,
})
require.NoError(t, err)
require.Len(t, paths, 1)
path := paths[0]
// Check that all the accumulated policy values are correct. Since this
// is a unique case where the destination node is also the introduction
// node, the accumulated fee and HTLC values should be zero and the
// CLTV expiry delta should be equal to Carol's MinFinalCLTVExpiryDelta.
require.EqualValues(t, 0, path.FeeBaseMsat)
require.EqualValues(t, 0, path.FeeRate)
require.EqualValues(t, 0, path.HTLCMinMsat)
require.EqualValues(t, 0, path.HTLCMaxMsat)
require.EqualValues(t, 12, path.CltvExpiryDelta)
}
func decryptAndDecodeHopData(t *testing.T, priv *btcec.PrivateKey,
ephem *btcec.PublicKey, cipherText []byte) (*record.BlindedRouteData,
*btcec.PublicKey) {
router := sphinx.NewRouter(
&keychain.PrivKeyECDH{PrivKey: priv}, nil,
)
decrypted, err := router.DecryptBlindedHopData(ephem, cipherText)
require.NoError(t, err)
buf := bytes.NewBuffer(decrypted)
routeData, err := record.DecodeBlindedRouteData(buf)
require.NoError(t, err)
nextEphem, err := router.NextEphemeral(ephem)
require.NoError(t, err)
return routeData, nextEphem
}