lnwallet: drop some comments upon script_utils.go

This commit is contained in:
Olaoluwa Osuntokun 2015-12-28 23:55:36 -06:00
parent 7648fee903
commit 1c4887e746

@ -9,11 +9,12 @@ import (
"github.com/btcsuite/btcutil"
)
// scriptHashPkScript...
func scriptHashPkScript(scriptBytes []byte) ([]byte, error) {
// scriptHashPkScript generates a pay-to-script-hash public key script paying
// to the hash160 of the passed redeem script.
func scriptHashPkScript(redeemScript []byte) ([]byte, error) {
bldr := txscript.NewScriptBuilder()
bldr.AddOp(txscript.OP_HASH160)
bldr.AddData(btcutil.Hash160(scriptBytes))
bldr.AddData(btcutil.Hash160(redeemScript))
bldr.AddOp(txscript.OP_EQUAL)
return bldr.Script()
}
@ -25,31 +26,31 @@ func genFundingPkScript(aPub, bPub []byte) ([]byte, error) {
return nil, fmt.Errorf("Pubkey size error. Compressed pubkeys only")
}
if bytes.Compare(aPub, bPub) == -1 { // swap to sort pubkeys if needed
// Swap to sort pubkeys if needed. Keys are sorted in lexicographical
// order. The signatures within the scriptSig must also adhere to the
// order, ensuring that the signatures for each public key appears
// in the proper order on the stack.
if bytes.Compare(aPub, bPub) == -1 {
aPub, bPub = bPub, aPub
}
bldr := txscript.NewScriptBuilder()
// Require 2 signatures, so from both of the pubkeys
bldr.AddOp(txscript.OP_2)
// add both pubkeys (sorted)
bldr.AddData(aPub)
bldr.AddData(aPub) // Add both pubkeys (sorted).
bldr.AddData(bPub)
// 2 keys total. In case that wasn't obvious.
bldr.AddOp(txscript.OP_2)
// Good ol OP_CHECKMULTISIG. Don't forget the zero!
bldr.AddOp(txscript.OP_CHECKMULTISIG)
// get byte slice
return bldr.Script()
}
// fundMultiSigOut creates a TxOut for the funding transaction.
// Give it the two pubkeys and it'll give you the p2sh'd txout.
// You don't have to remember the p2sh preimage, as long as you remember the
// pubkeys involved.
// fundMultiSigOut create the redeemScript for the funding transaction, and
// also a TxOut paying to the p2sh of the multi-sig redeemScript. Give it the
// two pubkeys and it'll give you the p2sh'd txout. You don't have to remember
// the p2sh preimage, as long as you remember the pubkeys involved.
func fundMultiSigOut(aPub, bPub []byte, amt int64) ([]byte, *wire.TxOut, error) {
if amt < 0 {
return nil, nil, fmt.Errorf("Can't create FundTx script with negative coins")
return nil, nil, fmt.Errorf("can't create FundTx script with " +
"negative coins")
}
// p2shify
@ -65,7 +66,8 @@ func fundMultiSigOut(aPub, bPub []byte, amt int64) ([]byte, *wire.TxOut, error)
return redeemScript, wire.NewTxOut(amt, pkScript), nil
}
// the scriptsig to put on a P2SH input
// spendMultiSig generates the scriptSig required to redeem the 2-of-2 p2sh
// multi-sig output.
func spendMultiSig(redeemScript, sigA, sigB []byte) ([]byte, error) {
bldr := txscript.NewScriptBuilder()
@ -84,8 +86,10 @@ func spendMultiSig(redeemScript, sigA, sigB []byte) ([]byte, error) {
return bldr.Script()
}
// findScriptOutputIndex...
// only finds first matchin, assumes unique pkScripts
// findScriptOutputIndex finds the index of the public key script output
// matching 'script'. Additionally, a boolean is returned indicating if
// a matching output was found at all.
// NOTE: The search stops after the first matching script is found.
func findScriptOutputIndex(tx *wire.MsgTx, script []byte) (bool, uint32) {
found := false
index := uint32(0)