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

lnwallet: modify the Signer interface to reflect new key derivation scheme

Browse Source 
This commit modifies the Signer interface to reflect the new key
derivation defined within BOLT-0003. This entails removing the prior
PrivateTweak field all together in favor of two new fields: SingleTweak
and DoubleTweak.

These two fields are mutually exclusive. The SingleTweak field is now
required in order to sign all regular non-delay, and also must be used
to generate signatures for the localKey, or delayKey. The DoubleTweak
field is used to generate the private key that corresponds to the
revoked revocation key.
This commit is contained in:
Olaoluwa Osuntokun 2017-07-29 18:47:06 -07:00
parent 7b002175f4
commit 9c0261206d
No known key found for this signature in database
GPG Key ID: 9CC5B105D03521A2
1 changed files with 29 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
lnwallet/interface.go
View File

@ -234,14 +234,33 @@ type SignDescriptor struct {
// key corresponding to this public key.
PubKey *btcec.PublicKey
// PrivateTweak is a scalar value that should be added to the private
// key corresponding to the above public key to obtain the private key
// to be used to sign this input. This value is typically a leaf node
// from the revocation tree.
// SingleTweak is a scalar value that will be added to the private key
// corresponding to the above public key to obtain the private key to
// be used to sign this input. This value is typically derived via the
// following computation:
//
// * derivedKey = privkey + sha256(perCommitmentPoint || pubKey) mod N
//
// NOTE: If this value is nil, then the input can be signed using only
// the above public key.
PrivateTweak []byte
// the above public key. Either a SingleTweak should be set or a
// DoubleTweak, not both.
SingleTweak []byte
// DoubleTweak is a private key that will be used in combination with
// its corresponding private key to derive the private key that is to
// be used to sign the target input. Within the Lightning protocol,
// this value is typically the commitment secret from a previously
// revoked commitment transaction. This value is in combination with
// two hash values, and the original private key to derive the private
// key to be used when signing.
//
// * k = (privKey*sha256(pubKey || tweakPub) +
// tweakPriv*sha256(tweakPub || pubKey)) mod N
//
// NOTE: If this value is nil, then the input can be signed using only
// the above public key. Either a SingleTweak should be set or a
// DoubleTweak, not both.
DoubleTweak *btcec.PrivateKey
// WitnessScript is the full script required to properly redeem the
// output. This field will only be populated if a p2wsh or a p2sh
@ -283,6 +302,10 @@ type Signer interface {
// SignDescriptor. This method should be capable of generating the
// proper input script for both regular p2wkh output and p2wkh outputs
// nested within a regular p2sh output.
//
// NOTE: This method will ignore any tweak parameters set within the
// passed SignDescriptor as it assumes a set of typical script
// templates (p2wkh, np2wkh, etc).
ComputeInputScript(tx *wire.MsgTx, signDesc *SignDescriptor) (*InputScript, error)
}