@ -114,16 +114,16 @@ var (
// QuoteHtlcP2WSH is a template script just used for sweep fee
// estimation.
QuoteHtlcP2WSH , _ = NewHtlc (
HtlcV2 , ^ int32 ( 0 ) , dummyPubKey , dummyPubKey , quoteHash ,
HtlcP2WSH , & chaincfg . MainNetParams ,
QuoteHtlcP2WSH , _ = NewHtlc V2 (
^ int32 ( 0 ) , dummyPubKey , dummyPubKey , quoteHash ,
& chaincfg . MainNetParams ,
)
// QuoteHtlcP2TR is a template script just used for sweep fee
// estimation.
QuoteHtlcP2TR , _ = NewHtlc (
HtlcV3 , ^ int32 ( 0 ) , dummyPubKey , dummyPubKey , quoteHash ,
HtlcP2TR , & chaincfg . MainNetParams ,
QuoteHtlcP2TR , _ = NewHtlc V3 (
^ int32 ( 0 ) , dummyPubKey , dummyPubKey , dummyPubKey, dummyPubKey ,
quoteHash , & chaincfg . MainNetParams ,
)
// ErrInvalidScriptVersion is returned when an unknown htlc version
@ -135,6 +135,10 @@ var (
// selected for a v2 script.
ErrInvalidOutputSelected = fmt . Errorf ( "taproot output selected for " +
"non taproot htlc" )
// ErrInvalidOutputType is returned when an unknown output type is
// associated with a certain swap htlc.
ErrInvalidOutputType = fmt . Errorf ( "invalid htlc output type" )
)
// String returns the string value of HtlcOutputType.
@ -151,38 +155,54 @@ func (h HtlcOutputType) String() string {
}
}
// NewHtlc returns a new instance. For v3 scripts, an internal pubkey generated
// by both participants must be provided.
func NewHtlc ( version ScriptVersion , cltvExpiry int32 ,
senderKey , receiverKey [ 33 ] byte , hash lntypes . Hash ,
outputType HtlcOutputType , chainParams * chaincfg . Params ) ( * Htlc , error ) {
// NewHtlcV2 returns a new V2 (P2WSH) HTLC instance.
func NewHtlcV2 ( cltvExpiry int32 , senderKey , receiverKey [ 33 ] byte ,
hash lntypes . Hash , chainParams * chaincfg . Params ) ( * Htlc , error ) {
var (
err error
htlc HtlcScript
htlc , err := newHTLCScriptV2 (
cltvExpiry , senderKey , receiverKey , hash ,
)
switch version {
case HtlcV2 :
htlc , err = newHTLCScriptV2 (
cltvExpiry , senderKey , receiverKey , hash ,
)
case HtlcV3 :
htlc , err = newHTLCScriptV3 (
cltvExpiry , senderKey , receiverKey , hash ,
)
if err != nil {
return nil , err
}
default :
return nil , ErrInvalidScriptVersion
address , pkScript , sigScript , err := htlc . lockingConditions (
HtlcP2WSH , chainParams ,
)
if err != nil {
return nil , fmt . Errorf ( "could not get address: %w" , err )
}
return & Htlc {
HtlcScript : htlc ,
Hash : hash ,
Version : HtlcV2 ,
PkScript : pkScript ,
OutputType : HtlcP2WSH ,
ChainParams : chainParams ,
Address : address ,
SigScript : sigScript ,
} , nil
}
// NewHtlcV3 returns a new V3 HTLC (P2TR) instance. Internal pubkey generated
// by both participants must be provided.
func NewHtlcV3 ( cltvExpiry int32 , senderInternalKey , receiverInternalKey ,
senderKey , receiverKey [ 33 ] byte , hash lntypes . Hash ,
chainParams * chaincfg . Params ) ( * Htlc , error ) {
htlc , err := newHTLCScriptV3 (
cltvExpiry , senderInternalKey , receiverInternalKey ,
senderKey , receiverKey , hash ,
)
if err != nil {
return nil , err
}
address , pkScript , sigScript , err := htlc . lockingConditions (
outputType , chainParams ,
HtlcP2TR , chainParams ,
)
if err != nil {
return nil , fmt . Errorf ( "could not get address: %w" , err )
@ -191,9 +211,9 @@ func NewHtlc(version ScriptVersion, cltvExpiry int32,
return & Htlc {
HtlcScript : htlc ,
Hash : hash ,
Version : version ,
Version : HtlcV3 ,
PkScript : pkScript ,
OutputType : outputType ,
OutputType : HtlcP2TR ,
ChainParams : chainParams ,
Address : address ,
SigScript : sigScript ,
@ -481,7 +501,8 @@ type HtlcScriptV3 struct {
}
// newHTLCScriptV3 constructs a HtlcScipt with the HTLC V3 taproot script.
func newHTLCScriptV3 ( cltvExpiry int32 , senderHtlcKey , receiverHtlcKey [ 33 ] byte ,
func newHTLCScriptV3 ( cltvExpiry int32 , senderInternalKey , receiverInternalKey ,
senderHtlcKey , receiverHtlcKey [ 33 ] byte ,
swapHash lntypes . Hash ) ( * HtlcScriptV3 , error ) {
senderPubKey , err := schnorr . ParsePubKey ( senderHtlcKey [ 1 : ] )
@ -494,13 +515,6 @@ func newHTLCScriptV3(cltvExpiry int32, senderHtlcKey, receiverHtlcKey [33]byte,
return nil , err
}
aggregateKey , _ , _ , err := musig2 . AggregateKeys (
[ ] * btcec . PublicKey { senderPubKey , receiverPubKey } , true ,
)
if err != nil {
return nil , err
}
// Create our success path script, we'll use this separately
// to generate the success path leaf.
successPathScript , err := GenSuccessPathScript (
@ -527,6 +541,31 @@ func newHTLCScriptV3(cltvExpiry int32, senderHtlcKey, receiverHtlcKey [33]byte,
rootHash := tree . RootNode . TapHash ( )
// Parse the pub keys used in the internal aggregate key. They are
// optional and may just be the same keys that are used for the script
// paths.
senderInternalPubKey , err := schnorr . ParsePubKey ( senderInternalKey [ 1 : ] )
if err != nil {
return nil , err
}
receiverInternalPubKey , err := schnorr . ParsePubKey (
receiverInternalKey [ 1 : ] ,
)
if err != nil {
return nil , err
}
// Calculate the internal aggregate key.
aggregateKey , _ , _ , err := musig2 . AggregateKeys (
[ ] * btcec . PublicKey {
senderInternalPubKey , receiverInternalPubKey ,
} , true ,
)
if err != nil {
return nil , err
}
// Calculate top level taproot key.
taprootKey := txscript . ComputeTaprootOutputKey (
aggregateKey . PreTweakedKey , rootHash [ : ] ,
Andras Banki-Horvath
1 year ago