lnwallet: reject duplicate settles for the same HTLC

This commit is contained in:
Olaoluwa Osuntokun 2018-05-25 18:39:55 -07:00
parent b6d046ad84
commit 28f37def7c
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GPG Key ID: 964EA263DD637C21

@ -4380,6 +4380,14 @@ func (lc *LightningChannel) SettleHTLC(preimage [32]byte,
lc.ShortChanID()) lc.ShortChanID())
} }
// Now that we know the HTLC exists, before checking to see if the
// preimage matches, we'll ensure that we haven't already attempted to
// modify the HTLC.
if lc.remoteUpdateLog.htlcHasModification(htlcIndex) {
return fmt.Errorf("HTLC with ID %d has already been settled",
htlcIndex)
}
if htlc.RHash != sha256.Sum256(preimage[:]) { if htlc.RHash != sha256.Sum256(preimage[:]) {
return fmt.Errorf("Invalid payment preimage %x for hash %x", return fmt.Errorf("Invalid payment preimage %x for hash %x",
preimage[:], htlc.RHash[:]) preimage[:], htlc.RHash[:])
@ -4398,6 +4406,11 @@ func (lc *LightningChannel) SettleHTLC(preimage [32]byte,
lc.localUpdateLog.appendUpdate(pd) lc.localUpdateLog.appendUpdate(pd)
// With the settle added to our local log, we'll now mark the HTLC as
// modified to prevent ourselves from accidentally attempting a
// duplicate settle.
lc.remoteUpdateLog.markHtlcModified(htlcIndex)
return nil return nil
} }
@ -4415,6 +4428,14 @@ func (lc *LightningChannel) ReceiveHTLCSettle(preimage [32]byte, htlcIndex uint6
lc.ShortChanID()) lc.ShortChanID())
} }
// Now that we know the HTLC exists, before checking to see if the
// preimage matches, we'll ensure that they haven't already attempted
// to modify the HTLC.
if lc.localUpdateLog.htlcHasModification(htlcIndex) {
return fmt.Errorf("HTLC with ID %d has already been settled",
htlcIndex)
}
if htlc.RHash != sha256.Sum256(preimage[:]) { if htlc.RHash != sha256.Sum256(preimage[:]) {
return fmt.Errorf("Invalid payment preimage %x for hash %x", return fmt.Errorf("Invalid payment preimage %x for hash %x",
preimage[:], htlc.RHash[:]) preimage[:], htlc.RHash[:])
@ -4430,6 +4451,12 @@ func (lc *LightningChannel) ReceiveHTLCSettle(preimage [32]byte, htlcIndex uint6
} }
lc.remoteUpdateLog.appendUpdate(pd) lc.remoteUpdateLog.appendUpdate(pd)
// With the settle added to the remote log, we'll now mark the HTLC as
// modified to prevent the remote party from accidentally attempting a
// duplicate settle.
lc.localUpdateLog.markHtlcModified(htlcIndex)
return nil return nil
} }