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

lnwallet: fix bug that makes commitment transaction unspendable

Browse Source 
Introduce TimelockShift which is used to make sure the commitment
transaction is spendable by setting the locktime with it so that
it is larger than 500,000,000, thus interpreting it as Unix epoch
timestamp and not a block height. It is also smaller than the current
timestamp which has bit (1 << 30) set, so there is no risk of having
the commitment transaction be rejected. This way we can safely use
the lower 24 bits of the locktime field for part of the obscured
commitment transaction number.
This commit is contained in:
Christopher Jämthagen 2017-01-13 15:29:56 +01:00 committed by Olaoluwa Osuntokun
parent 0410ea7374
commit bdb38cafcc
1 changed files with 11 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
lnwallet/script_utils.go
View File

@ -23,6 +23,16 @@ var (
SequenceLockTimeSeconds = uint32(1 << 22)
SequenceLockTimeMask = uint32(0x0000ffff)
OP_CHECKSEQUENCEVERIFY byte = txscript.OP_NOP3
// TimelockShift is used to make sure the commitment transaction is
// spendable by setting the locktime with it so that it is larger than
// 500,000,000, thus interpreting it as Unix epoch timestamp and not
// a block height. It is also smaller than the current timestamp which
// has bit (1 << 30) set, so there is no risk of having the commitment
// transaction be rejected. This way we can safely use the lower 24 bits
// of the locktime field for part of the obscured commitment transaction
// number.
TimelockShift = uint32(1 << 29)
)
const (
@ -807,7 +817,7 @@ func SetStateNumHint(commitTx *wire.MsgTx, stateNum uint64,
// Set the height bit of the sequence number in order to disable any
// sequence locks semantics.
commitTx.TxIn[0].Sequence = uint32(stateNum>>24) | wire.SequenceLockTimeDisabled
commitTx.LockTime = uint32(stateNum & 0xFFFFFF)
commitTx.LockTime = uint32(stateNum&0xFFFFFF) | TimelockShift
return nil
}