lnwire: all hashes within the protocol are now 32-bytes

We now enforce that the site of all revocation pre-images+hashes (used
for HTLC’s) are now 32-bytes.

Additionally, all payment pre-images are now required to be 32-bytes
not he wire. There also exists a Script level enforcement of the
payment pre-image size at a lower level.

This commit serves to unify the sizes of all hashes/pre-images across
the codebase.

lnwire/funding_request.go

@@ -46,7 +46,7 @@ type FundingRequest struct {
 	// 2: channel responder
 	FeePayer uint8
 
-	RevocationHash   [20]byte
+	RevocationHash   [32]byte
 	Pubkey           *btcec.PublicKey
 	DeliveryPkScript PkScript // *MUST* be either P2PKH or P2SH
 	ChangePkScript   PkScript // *MUST* be either P2PKH or P2SH

lnwire/funding_request_test.go

@@ -9,8 +9,6 @@ import (
 )
 
 func TestFundingRequestEncodeDecode(t *testing.T) {
-	copy(revocationHash[:], revocationHashBytes)
-
 	// funding request
 	fr := &FundingRequest{
 		ReservationID:          uint64(12345678),
@@ -23,7 +21,7 @@ func TestFundingRequestEncodeDecode(t *testing.T) {
 		FeePayer:               uint8(0),
 		PaymentAmount:          btcutil.Amount(1234567),
 		MinDepth:               uint32(6),
-		RevocationHash:         revocationHash,
+		RevocationHash:         revHash,
 		Pubkey:                 pubKey,
 		DeliveryPkScript:       deliveryPkScript,
 		ChangePkScript:         changePkScript,

lnwire/funding_response.go

@@ -30,7 +30,7 @@ type FundingResponse struct {
 	// 2: channel responder
 	FeePayer uint8
 
-	RevocationHash   [20]byte
+	RevocationHash   [32]byte
 	Pubkey           *btcec.PublicKey
 	CommitSig        *btcec.Signature // Requester's Commitment
 	DeliveryPkScript PkScript         // *MUST* be either P2PKH or P2SH

lnwire/funding_response_test.go

@@ -21,7 +21,7 @@ func TestFundingResponseEncodeDecode(t *testing.T) {
 		MinDepth:               uint32(6),
 		LockTime:               uint32(4320), // 30 block-days
 		FeePayer:               uint8(1),
-		RevocationHash:         revocationHash,
+		RevocationHash:         revHash,
 		Pubkey:                 pubKey,
 		CommitSig:              commitSig,
 		DeliveryPkScript:       deliveryPkScript,

lnwire/htlc_addrequest.go

@@ -45,7 +45,7 @@ type HTLCAddRequest struct {
 	// number of pre-images for each of the listed hashes. For regular HTLC's
 	// this slice only has one hash. However, for "multi-sig" HTLC's, the
 	// length of this slice should be N.
-	RedemptionHashes [][20]byte
+	RedemptionHashes [][32]byte
 
 	// OnionBlob is the raw serialized mix header used to route an HTLC in
 	// a privacy-preserving manner. The mix header is defined currently to
@@ -78,7 +78,7 @@ func (c *HTLCAddRequest) Decode(r io.Reader, pver uint32) error {
 	// Expiry(4)
 	// Amount(4)
 	// ContractType(1)
-	// RedemptionHashes (numOfHashes * 20 + numOfHashes)
+	// RedemptionHashes (numOfHashes * 32 + numOfHashes)
 	// OnionBlog
 	err := readElements(r,
 		&c.ChannelPoint,

lnwire/htlc_addrequest_test.go

@@ -7,8 +7,8 @@ import (
 )
 
 func TestHTLCAddRequestEncodeDecode(t *testing.T) {
-	redemptionHashes := make([][20]byte, 1)
+	redemptionHashes := make([][32]byte, 1)
-	copy(redemptionHashes[0][:], bytes.Repeat([]byte{0x09}, 20))
+	redemptionHashes[0] = revHash
 
 	// First create a new HTLCAR message.
 	addReq := &HTLCAddRequest{

lnwire/htlc_settlerequest.go

@@ -21,17 +21,18 @@ type HTLCSettleRequest struct {
 
 	// HTLCKey denotes the exact HTLC stage within the receiving node's
 	// commitment transaction to be removed.
+	// TODO(roasbeef): rename to LogIndex
 	HTLCKey HTLCKey
 
 	// RedemptionProofs are the R-value preimages required to fully settle
 	// an HTLC. The number of preimages in the slice will depend on the
 	// specific ContractType of the referenced HTLC.
-	RedemptionProofs [][20]byte
+	RedemptionProofs [][32]byte
 }
 
 // NewHTLCSettleRequest returns a new empty HTLCSettleRequest.
 func NewHTLCSettleRequest(chanPoint *wire.OutPoint, key HTLCKey,
-	redemptionProofs [][20]byte) *HTLCSettleRequest {
+	redemptionProofs [][32]byte) *HTLCSettleRequest {
 
 	return &HTLCSettleRequest{
 		ChannelPoint:     chanPoint,
@@ -51,7 +52,7 @@ var _ Message = (*HTLCSettleRequest)(nil)
 func (c *HTLCSettleRequest) Decode(r io.Reader, pver uint32) error {
 	// ChannelPoint(8)
 	// HTLCKey(8)
-	// RedemptionProofs(N*20)
+	// RedemptionProofs(N*32)
 	err := readElements(r,
 		&c.ChannelPoint,
 		&c.HTLCKey,
@@ -94,8 +95,8 @@ func (c *HTLCSettleRequest) Command() uint32 {
 //
 // This is part of the lnwire.Message interface.
 func (c *HTLCSettleRequest) MaxPayloadLength(uint32) uint32 {
-	// 36 + 8 + (21 * 15)
+	// 36 + 8 + (32 * 15)
-	return 359
+	return 524
 }
 
 // Validate performs any necessary sanity checks to ensure all fields present

lnwire/htlc_settlerequest_test.go

@@ -7,8 +7,8 @@ import (
 )
 
 func TestHTLCSettleRequestEncodeDecode(t *testing.T) {
-	redemptionProofs := make([][20]byte, 1)
+	redemptionProofs := make([][32]byte, 1)
-	copy(redemptionProofs[0][:], bytes.Repeat([]byte{0x09}, 20))
+	redemptionProofs[0] = revHash
 
 	// First create a new HTLCSR message.
 	settleReq := NewHTLCSettleRequest(outpoint1, HTLCKey(23), redemptionProofs)

lnwire/lnwire.go

@@ -169,7 +169,7 @@ func writeElement(w io.Writer, element interface{}) error {
 		if _, err := w.Write(e[:]); err != nil {
 			return err
 		}
-	case [][20]byte:
+	case [][32]byte:
 		// First write out the number of elements in the slice.
 		sliceSize := len(e)
 		if err := writeElement(w, uint16(sliceSize)); err != nil {
@@ -182,7 +182,7 @@ func writeElement(w io.Writer, element interface{}) error {
 				return err
 			}
 		}
-	case [20]byte:
+	case [32]byte:
 		// TODO(roasbeef): should be factor out to caller logic...
 		if _, err := w.Write(e[:]); err != nil {
 			return err
@@ -408,7 +408,7 @@ func readElement(r io.Reader, element interface{}) error {
 			return err
 		}
 		*e = sig
-	case *[][20]byte:
+	case *[][32]byte:
 		// How many to read
 		var sliceSize uint16
 		err = readElement(r, &sliceSize)
@@ -416,10 +416,10 @@ func readElement(r io.Reader, element interface{}) error {
 			return err
 		}
 
-		data := make([][20]byte, 0, sliceSize)
+		data := make([][32]byte, 0, sliceSize)
 		// Append the actual
 		for i := uint16(0); i < sliceSize; i++ {
-			var element [20]byte
+			var element [32]byte
 			err = readElement(r, &element)
 			if err != nil {
 				return err
@@ -427,7 +427,7 @@ func readElement(r io.Reader, element interface{}) error {
 			data = append(data, element)
 		}
 		*e = data
-	case *[20]byte:
+	case *[32]byte:
 		if _, err = io.ReadFull(r, e[:]); err != nil {
 			return err
 		}

lnwire/lnwire_test.go

@@ -15,6 +15,13 @@ import (
 // Common variables and functions for the message tests
 
 var (
+	revHash = [32]byte{
+		0xb7, 0x94, 0x38, 0x5f, 0x2d, 0x1e, 0xf7, 0xab,
+		0x4d, 0x92, 0x73, 0xd1, 0x90, 0x63, 0x81, 0xb4,
+		0x4f, 0x2f, 0x6f, 0x25, 0x88, 0xa3, 0xef, 0xb9,
+		0x6a, 0x49, 0x18, 0x83, 0x31, 0x98, 0x47, 0x53,
+	}
+
 	// For debugging, writes to /dev/shm/
 	// Maybe in the future do it if you do "go test -v"
 	WRITE_FILE = false