akovalenko/lnd.xprv
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Htlcswitch: rename Deobfuscator and Obfuscator interfaces

Browse Source 
This commit renames the Deobfuscator interface to ErrorDecrypter and
the Obfuscator interface to ErrorEncrypter. With this rename, the
purpose of these two interfaces are a bit clearer.

Additionally, DecryptError (which was formerly Deobfuscate) now
directly returns an ForwardingError type instead of the
lnwire.FailureMessage.
This commit is contained in:
Olaoluwa Osuntokun 2017-10-10 19:36:52 -07:00
parent 30a46291f8
commit 12ae63101d
No known key found for this signature in database
GPG Key ID: 964EA263DD637C21
9 changed files with 109 additions and 93 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
htlcswitch/circuit.go
View File

@ -38,9 +38,9 @@ type paymentCircuit struct {
// request back.
Dest lnwire.ShortChannelID
// Obfuscator is used to re-encrypt the onion failure before sending it
// back to the originator of the payment.
Obfuscator Obfuscator
// ErrorEncrypter is used to re-encrypt the onion failure before
// sending it back to the originator of the payment.
ErrorEncrypter ErrorEncrypter
// RefCount is used to count the circuits with the same circuit key.
RefCount int
@ -48,13 +48,14 @@ type paymentCircuit struct {
// newPaymentCircuit creates new payment circuit instance.
func newPaymentCircuit(src, dest lnwire.ShortChannelID, key circuitKey,
obfuscator Obfuscator) *paymentCircuit {
e ErrorEncrypter) *paymentCircuit {
return &paymentCircuit{
Src: src,
Dest: dest,
PaymentHash: key,
RefCount: 1,
Obfuscator: obfuscator,
Src: src,
Dest: dest,
PaymentHash: key,
RefCount: 1,
ErrorEncrypter: e,
}
}

104
htlcswitch/failure.go
View File

@ -5,6 +5,7 @@ import (
"github.com/lightningnetwork/lightning-onion"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/roasbeef/btcd/btcec"
)
// ForwardingError wraps an lnwire.FailureMessage in a struct that also
@ -17,45 +18,48 @@ type ForwardingError struct {
lnwire.FailureMessage
}
// ErrorDecrypter is an interface that is used to decrypt the onion encrypted
// failure reason an extra out a well formed error.
type Deobfuscator interface {
// Deobfuscate peels off each layer of onion encryption from the first
type ErrorDecrypter interface {
// DecryptError peels off each layer of onion encryption from the first
// hop, to the source of the error. A fully populated
// lnwire.FailureMessage is returned.
Deobfuscate(lnwire.OpaqueReason) (lnwire.FailureMessage, error)
// lnwire.FailureMessage is returned along with the source of the
// error.
DecryptError(lnwire.OpaqueReason) (*ForwardingError, error)
}
// Obfuscator is an interface that is used to encrypt HTLC related errors at
// the source of the error, and also at each intermediate hop all the way back
// to the source of the payment.
type Obfuscator interface {
// InitialObfuscate is used to convert the failure into opaque
// reason.
// InitialObfuscate transforms a concrete failure message into an
// ErrorEncrypter is an interface that is used to encrypt HTLC related errors
// at the source of the error, and also at each intermediate hop all the way
// back to the source of the payment.
type ErrorEncrypter interface {
// EncryptFirstHop transforms a concrete failure message into an
// encrypted opaque failure reason. This method will be used at the
// source that the error occurs. It differs from BackwardObfuscate
// source that the error occurs. It differs from IntermediateEncrypt
// slightly, in that it computes a proper MAC over the error.
InitialObfuscate(lnwire.FailureMessage) (lnwire.OpaqueReason, error)
EncryptFirstHop(lnwire.FailureMessage) (lnwire.OpaqueReason, error)
// BackwardObfuscate wraps an already encrypted opaque reason error in
// an additional layer of onion encryption. This process repeats until
// the error arrives at the source of the payment.
BackwardObfuscate(lnwire.OpaqueReason) lnwire.OpaqueReason
// IntermediateEncrypt wraps an already encrypted opaque reason error
// in an additional layer of onion encryption. This process repeats
// until the error arrives at the source of the payment.
IntermediateEncrypt(lnwire.OpaqueReason) lnwire.OpaqueReason
}
// FailureObfuscator is used to obfuscate the onion failure.
type FailureObfuscator struct {
*sphinx.OnionObfuscator
// SphinxErrorEncrypter is a concrete implementation of both the ErrorEncrypter
// interface backed by an implementation of the Sphinx packet format. As a
// result, all errors handled are themselves wrapped in layers of onion
// encryption and must be treated as such accordingly.
type SphinxErrorEncrypter struct {
*sphinx.OnionErrorEncrypter
}
// InitialObfuscate transforms a concrete failure message into an encrypted
// EncryptFirstHop transforms a concrete failure message into an encrypted
// opaque failure reason. This method will be used at the source that the error
// occurs. It differs from BackwardObfuscate slightly, in that it computes a
// proper MAC over the error.
//
// NOTE: Part of the Obfuscator interface.
func (o *FailureObfuscator) InitialObfuscate(failure lnwire.FailureMessage) (lnwire.OpaqueReason, error) {
// NOTE: Part of the ErrorEncrypter interface.
func (o *SphinxErrorEncrypter) EncryptFirstHop(failure lnwire.FailureMessage) (lnwire.OpaqueReason, error) {
var b bytes.Buffer
if err := lnwire.EncodeFailure(&b, failure, 0); err != nil {
return nil, err
@ -63,46 +67,54 @@ func (o *FailureObfuscator) InitialObfuscate(failure lnwire.FailureMessage) (lnw
// We pass a true as the first parameter to indicate that a MAC should
// be added.
return o.OnionObfuscator.Obfuscate(true, b.Bytes()), nil
return o.EncryptError(true, b.Bytes()), nil
}
// BackwardObfuscate wraps an already encrypted opaque reason error in an
// IntermediateEncrypt wraps an already encrypted opaque reason error in an
// additional layer of onion encryption. This process repeats until the error
// arrives at the source of the payment. We re-encrypt the message on the
// backwards path to ensure that the error is indistinguishable from any other
// error seen.
//
// NOTE: Part of the Obfuscator interface.
func (o *FailureObfuscator) BackwardObfuscate(reason lnwire.OpaqueReason) lnwire.OpaqueReason {
return o.OnionObfuscator.Obfuscate(false, reason)
// NOTE: Part of the ErrorEncrypter interface.
func (s *SphinxErrorEncrypter) IntermediateEncrypt(reason lnwire.OpaqueReason) lnwire.OpaqueReason {
return s.EncryptError(false, reason)
}
// A compile time check to ensure FailureObfuscator implements the Obfuscator
// interface.
var _ Obfuscator = (*FailureObfuscator)(nil)
// A compile time check to ensure SphinxErrorEncrypter implements the
// ErrorEncrypter interface.
var _ ErrorEncrypter = (*SphinxErrorEncrypter)(nil)
// FailureDeobfuscator wraps the sphinx data obfuscator and adds awareness of
// the lnwire onion failure messages to it.
type FailureDeobfuscator struct {
*sphinx.OnionDeobfuscator
// SphinxErrorDecrypter wraps the sphinx data SphinxErrorDecrypter and maps the
// returned errors to concrete lnwire.FailureMessage instances.
type SphinxErrorDecrypter struct {
*sphinx.OnionErrorDecrypter
}
// Deobfuscate peels off each layer of onion encryption from the first hop, to
// the source of the error. A fully populated lnwire.FailureMessage is
// returned.
// DecryptError peels off each layer of onion encryption from the first hop, to
// the source of the error. A fully populated lnwire.FailureMessage is returned
// along with the source of the error.
//
// NOTE: Part of the Obfuscator interface.
func (o *FailureDeobfuscator) Deobfuscate(reason lnwire.OpaqueReason) (lnwire.FailureMessage, error) {
// NOTE: Part of the ErrorDecrypter interface.
func (s *SphinxErrorDecrypter) DecryptError(reason lnwire.OpaqueReason) (*ForwardingError, error) {
_, failureData, err := o.OnionDeobfuscator.Deobfuscate(reason)
source, failureData, err := s.OnionErrorDecrypter.DecryptError(reason)
if err != nil {
return nil, err
}
r := bytes.NewReader(failureData)
return lnwire.DecodeFailure(r, 0)
failureMsg, err := lnwire.DecodeFailure(r, 0)
if err != nil {
return nil, err
}
return &ForwardingError{
ErrorSource: source,
FailureMessage: failureMsg,
}, nil
}
// A compile time check to ensure FailureDeobfuscator implements the
// Deobfuscator interface.
var _ Deobfuscator = (*FailureDeobfuscator)(nil)
// A compile time check to ensure ErrorDecrypter implements the Deobfuscator
// interface.
var _ ErrorDecrypter = (*SphinxErrorDecrypter)(nil)

18
htlcswitch/iterator.go
View File

@ -198,11 +198,13 @@ func (p *OnionProcessor) DecodeHopIterator(r io.Reader, rHash []byte) (HopIterat
}, lnwire.CodeNone
}
// DecodeOnionObfuscator takes an io.Reader which should contain the onion
// packet as original received by a forwarding node and creates an Obfuscator
// instance using the derived shared secret. In the case that en error occurs,
// a lnwire failure code detailing the parsing failure will be returned.
func (p *OnionProcessor) DecodeOnionObfuscator(r io.Reader) (Obfuscator, lnwire.FailCode) {
// ExtractErrorEncrypter takes an io.Reader which should contain the onion
// packet as original received by a forwarding node and creates an
// ErrorEncrypter instance using the derived shared secret. In the case that en
// error occurs, a lnwire failure code detailing the parsing failure will be
// returned.
func (p *OnionProcessor) ExtractErrorEncrypter(r io.Reader) (ErrorEncrypter, lnwire.FailCode) {
onionPkt := &sphinx.OnionPacket{}
if err := onionPkt.Decode(r); err != nil {
switch err {
@ -215,7 +217,7 @@ func (p *OnionProcessor) DecodeOnionObfuscator(r io.Reader) (Obfuscator, lnwire.
}
}
onionObfuscator, err := sphinx.NewOnionObfuscator(p.router,
onionObfuscator, err := sphinx.NewOnionErrorEncrypter(p.router,
onionPkt.EphemeralKey)
if err != nil {
switch err {
@ -230,7 +232,7 @@ func (p *OnionProcessor) DecodeOnionObfuscator(r io.Reader) (Obfuscator, lnwire.
}
}
return &FailureObfuscator{
OnionObfuscator: onionObfuscator,
return &SphinxErrorEncrypter{
OnionErrorEncrypter: onionObfuscator,
}, lnwire.CodeNone
}

9
htlcswitch/link.go
View File

@ -103,7 +103,7 @@ type ChannelLinkConfig struct {
// DecodeOnionObfuscator function is responsible for decoding HTLC
// Sphinx onion blob, and creating onion failure obfuscator.
DecodeOnionObfuscator func(r io.Reader) (Obfuscator, lnwire.FailCode)
DecodeOnionObfuscator func(r io.Reader) (ErrorEncrypter, lnwire.FailCode)
// GetLastChannelUpdate retrieves the latest routing policy for this
// particular channel. This will be used to provide payment senders our
@ -570,7 +570,7 @@ func (l *channelLink) handleDownStreamPkt(pkt *htlcPacket, isReProcess bool) {
// Otherwise, we'll send back a proper failure
// message.
default:
reason, err = obfuscator.InitialObfuscate(failure)
reason, err = obfuscator.EncryptFirstHop(failure)
if err != nil {
log.Errorf("unable to obfuscate error: %v", err)
return
@ -1461,8 +1461,9 @@ func (l *channelLink) processLockedInHtlcs(
// sendHTLCError functions cancels HTLC and send cancel message back to the
// peer from which HTLC was received.
func (l *channelLink) sendHTLCError(rHash [32]byte, failure lnwire.FailureMessage,
obfuscator Obfuscator) {
reason, err := obfuscator.InitialObfuscate(failure)
e ErrorEncrypter) {
reason, err := e.EncryptFirstHop(failure)
if err != nil {
log.Errorf("unable to obfuscate error: %v", err)
return

19
htlcswitch/mock.go
View File

@ -153,11 +153,11 @@ var _ HopIterator = (*mockHopIterator)(nil)
// encodes the failure and do not makes any onion obfuscation.
type mockObfuscator struct{}
func newMockObfuscator() Obfuscator {
func newMockObfuscator() ErrorEncrypter {
return &mockObfuscator{}
}
func (o *mockObfuscator) InitialObfuscate(failure lnwire.FailureMessage) (
func (o *mockObfuscator) EncryptFirstHop(failure lnwire.FailureMessage) (
lnwire.OpaqueReason, error) {
var b bytes.Buffer
@ -167,7 +167,7 @@ func (o *mockObfuscator) InitialObfuscate(failure lnwire.FailureMessage) (
return b.Bytes(), nil
}
func (o *mockObfuscator) BackwardObfuscate(reason lnwire.OpaqueReason) lnwire.OpaqueReason {
func (o *mockObfuscator) IntermediateEncrypt(reason lnwire.OpaqueReason) lnwire.OpaqueReason {
return reason
}
@ -176,21 +176,24 @@ func (o *mockObfuscator) BackwardObfuscate(reason lnwire.OpaqueReason) lnwire.Op
// only decodes the failure do not makes any onion obfuscation.
type mockDeobfuscator struct{}
func newMockDeobfuscator() Deobfuscator {
func newMockDeobfuscator() ErrorDecrypter {
return &mockDeobfuscator{}
}
func (o *mockDeobfuscator) Deobfuscate(reason lnwire.OpaqueReason) (lnwire.FailureMessage,
error) {
func (o *mockDeobfuscator) DecryptError(reason lnwire.OpaqueReason) (*ForwardingError, error) {
r := bytes.NewReader(reason)
failure, err := lnwire.DecodeFailure(r, 0)
if err != nil {
return nil, err
}
return failure, nil
return &ForwardingError{
FailureMessage: failure,
}, nil
}
var _ Deobfuscator = (*mockDeobfuscator)(nil)
var _ ErrorDecrypter = (*mockDeobfuscator)(nil)
// mockIteratorDecoder test version of hop iterator decoder which decodes the
// encoded array of hops.

9
htlcswitch/packet.go
View File

@ -35,10 +35,7 @@ type htlcPacket struct {
// obfuscator contains the necessary state to allow the switch to wrap
// any forwarded errors in an additional layer of encryption.
//
// TODO(andrew.shvv) revisit after refactoring the way of returning
// errors inside the htlcswitch packet.
obfuscator Obfuscator
obfuscator ErrorEncrypter
// isObfuscated is set to true if an error occurs as soon as the switch
// forwards a packet to the link. If so, and this is an error packet,
@ -61,13 +58,13 @@ func newInitPacket(destNode [33]byte, htlc *lnwire.UpdateAddHTLC) *htlcPacket {
// newAddPacket creates htlc switch add packet which encapsulates the add htlc
// request and additional information for proper forwarding over htlc switch.
func newAddPacket(src, dest lnwire.ShortChannelID,
htlc *lnwire.UpdateAddHTLC, obfuscator Obfuscator) *htlcPacket {
htlc *lnwire.UpdateAddHTLC, e ErrorEncrypter) *htlcPacket {
return &htlcPacket{
dest: dest,
src: src,
htlc: htlc,
obfuscator: obfuscator,
obfuscator: e,
}
}

14
htlcswitch/switch.go
View File

@ -40,7 +40,7 @@ type pendingPayment struct {
// deobfuscator is an serializable entity which is used if we received
// an error, it deobfuscates the onion failure blob, and extracts the
// exact error from it.
deobfuscator Deobfuscator
deobfuscator ErrorDecrypter
}
// plexPacket encapsulates switch packet and adds error channel to receive
@ -170,7 +170,7 @@ func New(cfg Config) *Switch {
// SendHTLC is used by other subsystems which aren't belong to htlc switch
// package in order to send the htlc update.
func (s *Switch) SendHTLC(nextNode [33]byte, htlc *lnwire.UpdateAddHTLC,
deobfuscator Deobfuscator) ([sha256.Size]byte, error) {
deobfuscator ErrorDecrypter) ([sha256.Size]byte, error) {
// Create payment and add to the map of payment in order later to be
// able to retrieve it and return response to the user.
@ -391,7 +391,7 @@ func (s *Switch) handleLocalDispatch(payment *pendingPayment, packet *htlcPacket
// We'll attempt to fully decrypt the onion encrypted error. If
// we're unable to then we'll bail early.
failure, err := payment.deobfuscator.Deobfuscate(htlc.Reason)
failure, err := payment.deobfuscator.DecryptError(htlc.Reason)
if err != nil {
// TODO(roasbeef): can happen in case of local error in
// link pkt handling
@ -442,7 +442,7 @@ func (s *Switch) handlePacketForward(packet *htlcPacket) error {
// than we should notify this link that some error
// occurred.
failure := lnwire.FailUnknownNextPeer{}
reason, err := packet.obfuscator.InitialObfuscate(failure)
reason, err := packet.obfuscator.EncryptFirstHop(failure)
if err != nil {
err := errors.Errorf("unable to obfuscate "+
"error: %v", err)
@ -482,7 +482,7 @@ func (s *Switch) handlePacketForward(packet *htlcPacket) error {
// channel link than we should notify this
// link that some error occurred.
failure := lnwire.NewTemporaryChannelFailure(nil)
reason, err := packet.obfuscator.InitialObfuscate(failure)
reason, err := packet.obfuscator.EncryptFirstHop(failure)
if err != nil {
err := errors.Errorf("unable to obfuscate "+
"error: %v", err)
@ -516,7 +516,7 @@ func (s *Switch) handlePacketForward(packet *htlcPacket) error {
packet.obfuscator,
)); err != nil {
failure := lnwire.NewTemporaryChannelFailure(nil)
reason, err := packet.obfuscator.InitialObfuscate(failure)
reason, err := packet.obfuscator.EncryptFirstHop(failure)
if err != nil {
err := errors.Errorf("unable to obfuscate "+
"error: %v", err)
@ -558,7 +558,7 @@ func (s *Switch) handlePacketForward(packet *htlcPacket) error {
// If this is failure than we need to obfuscate the error.
if htlc, ok := htlc.(*lnwire.UpdateFailHTLC); ok && !packet.isObfuscated {
htlc.Reason = circuit.Obfuscator.BackwardObfuscate(
htlc.Reason = circuit.ErrorEncrypter.IntermediateEncrypt(
htlc.Reason,
)
}

2
htlcswitch/switch_test.go
View File

@ -352,7 +352,7 @@ func TestSwitchSendPayment(t *testing.T) {
// back. This request should be forwarded back to alice channel link.
obfuscator := newMockObfuscator()
failure := lnwire.FailIncorrectPaymentAmount{}
reason, err := obfuscator.InitialObfuscate(failure)
reason, err := obfuscator.EncryptFirstHop(failure)
if err != nil {
t.Fatalf("unable obfuscate failure: %v", err)
}

8
htlcswitch/test_utils.go
View File

@ -556,7 +556,7 @@ func newThreeHopNetwork(t *testing.T, aliceToBob,
Peer: bobServer,
Switch: aliceServer.htlcSwitch,
DecodeHopIterator: decoder.DecodeHopIterator,
DecodeOnionObfuscator: func(io.Reader) (Obfuscator,
DecodeOnionObfuscator: func(io.Reader) (ErrorEncrypter,
lnwire.FailCode) {
return obfuscator, lnwire.CodeNone
},
@ -577,7 +577,7 @@ func newThreeHopNetwork(t *testing.T, aliceToBob,
Peer: aliceServer,
Switch: bobServer.htlcSwitch,
DecodeHopIterator: decoder.DecodeHopIterator,
DecodeOnionObfuscator: func(io.Reader) (Obfuscator,
DecodeOnionObfuscator: func(io.Reader) (ErrorEncrypter,
lnwire.FailCode) {
return obfuscator, lnwire.CodeNone
},
@ -598,7 +598,7 @@ func newThreeHopNetwork(t *testing.T, aliceToBob,
Peer: carolServer,
Switch: bobServer.htlcSwitch,
DecodeHopIterator: decoder.DecodeHopIterator,
DecodeOnionObfuscator: func(io.Reader) (Obfuscator,
DecodeOnionObfuscator: func(io.Reader) (ErrorEncrypter,
lnwire.FailCode) {
return obfuscator, lnwire.CodeNone
},
@ -619,7 +619,7 @@ func newThreeHopNetwork(t *testing.T, aliceToBob,
Peer: bobServer,
Switch: carolServer.htlcSwitch,
DecodeHopIterator: decoder.DecodeHopIterator,
DecodeOnionObfuscator: func(io.Reader) (Obfuscator,
DecodeOnionObfuscator: func(io.Reader) (ErrorEncrypter,
lnwire.FailCode) {
return obfuscator, lnwire.CodeNone
},