lnwallet: move latest SignDescriptor + serialization

lnwallet/interface.go

@@ -224,66 +224,6 @@ type BlockChainIO interface {
 	GetBlock(blockHash *chainhash.Hash) (*wire.MsgBlock, error)
 }
 
-// SignDescriptor houses the necessary information required to successfully sign
-// a given output. This struct is used by the Signer interface in order to gain
-// access to critical data needed to generate a valid signature.
-type SignDescriptor struct {
-	// Pubkey is the public key to which the signature should be generated
-	// over. The Signer should then generate a signature with the private
-	// key corresponding to this public key.
-	PubKey *btcec.PublicKey
-
-	// 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. 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
-	// output is being signed.
-	WitnessScript []byte
-
-	// Output is the target output which should be signed. The PkScript and
-	// Value fields within the output should be properly populated,
-	// otherwise an invalid signature may be generated.
-	Output *wire.TxOut
-
-	// HashType is the target sighash type that should be used when
-	// generating the final sighash, and signature.
-	HashType txscript.SigHashType
-
-	// SigHashes is the pre-computed sighash midstate to be used when
-	// generating the final sighash for signing.
-	SigHashes *txscript.TxSigHashes
-
-	// InputIndex is the target input within the transaction that should be
-	// signed.
-	InputIndex int
-}
-
 // Signer represents an abstract object capable of generating raw signatures as
 // well as full complete input scripts given a valid SignDescriptor and
 // transaction. This interface fully abstracts away signing paving the way for