Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

[input/size] Check tx size constants #4775

Merged
merged 4 commits into from
Mar 10, 2021
Merged

[input/size] Check tx size constants #4775

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
fe71c90
input/size: split constants into confirmed/non-confirmed
halseth Nov 17, 2020
3a30763
input/size: fix comments for constants
halseth Nov 17, 2020
2bc37db
lnwallet: export HTLC generating methods
halseth Nov 17, 2020
d30aae4
input/size: add txSize test
halseth Feb 1, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
74 changes: 49 additions & 25 deletions input/size.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -115,6 +115,7 @@ const (
// - Sequence: 4 bytes
InputSize = 32 + 4 + 1 + 4

// FundingInputSize 41 bytes
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Where's the script that was run? Should we consider adding it to the repo, or instead extending our tests to craft the actual transaction to compare to the estimate?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It was a pretty rough script I wrote, not sure if worth adding it since we shouldn't be changing these very often.

Posting for reference: halseth@d86684c

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

my vote would be to add the script and have it generate a test suite that verifies the actual size. we can fail the build if the tests are not properly committed in git or fail the size checks. I'd be okay with making that a follow up as well

// FundingInputSize represents the size of an input to a funding
// transaction, and is equivalent to the size of a standard segwit input
// as calculated above.
Expand Down Expand Up @@ -204,31 +205,37 @@ const (
// HTLCWeight 172 weight
HTLCWeight = witnessScaleFactor * HTLCSize

// HtlcTimeoutWeight 663 weight
// HtlcTimeoutWeight is the weight of the HTLC timeout transaction
// which will transition an outgoing HTLC to the delay-and-claim state.
HtlcTimeoutWeight = 663

// HtlcSuccessWeight 703 weight
// HtlcSuccessWeight is the weight of the HTLC success transaction
// which will transition an incoming HTLC to the delay-and-claim state.
HtlcSuccessWeight = 703

// HtlcConfirmedScriptOverhead 3 bytes
// HtlcConfirmedScriptOverhead is the extra length of an HTLC script
// that requires confirmation before it can be spent. These extra bytes
// is a result of the extra CSV check.
HtlcConfirmedScriptOverhead = 3

// HtlcTimeoutWeightConfirmed 666 weight
// HtlcTimeoutWeightConfirmed is the weight of the HTLC timeout
// transaction which will transition an outgoing HTLC to the
// delay-and-claim state, for the confirmed HTLC outputs. It is 3 bytes
// larger because of the additional CSV check in the input script.
HtlcTimeoutWeightConfirmed = HtlcTimeoutWeight + HtlcConfirmedScriptOverhead

// HtlcSuccessWeightCOnfirmed is the weight of the HTLC success
// HtlcSuccessWeightConfirmed 706 weight
// HtlcSuccessWeightConfirmed is the weight of the HTLC success
// transaction which will transition an incoming HTLC to the
// delay-and-claim state, for the confirmed HTLC outputs. It is 3 bytes
// larger because of the cdditional CSV check in the input script.
HtlcSuccessWeightConfirmed = HtlcSuccessWeight + HtlcConfirmedScriptOverhead

// MaxHTLCNumber 966
// MaxHTLCNumber is the maximum number HTLCs which can be included in a
// commitment transaction. This limit was chosen such that, in the case
// of a contract breach, the punishment transaction is able to sweep
Expand Down Expand Up @@ -286,7 +293,7 @@ const (
// - witness_script (to_remote_delayed_script)
ToRemoteConfirmedWitnessSize = 1 + 1 + 73 + 1 + ToRemoteConfirmedScriptSize

// AcceptedHtlcScriptSize 143 bytes
// AcceptedHtlcScriptSize 140 bytes
// - OP_DUP: 1 byte
// - OP_HASH160: 1 byte
// - OP_DATA: 1 byte (RIPEMD160(SHA256(revocationkey)) length)
Expand Down Expand Up @@ -321,20 +328,18 @@ const (
// - OP_DROP: 1 byte
// - OP_CHECKSIG: 1 byte
// - OP_ENDIF: 1 byte
// - OP_1: 1 byte // These 3 extra bytes are used for both confirmed and regular
// - OP_CSV: 1 byte // HTLC script types. The size won't be correct in all cases,
// - OP_DROP: 1 byte // but it is just an upper bound used for fee estimation in any case.
// - OP_1: 1 byte // These 3 extra bytes are only
// - OP_CSV: 1 byte // present for the confirmed
// - OP_DROP: 1 byte // HTLC script types.
// - OP_ENDIF: 1 byte
AcceptedHtlcScriptSize = 3*1 + 20 + 5*1 + 33 + 8*1 + 20 + 4*1 +
33 + 5*1 + 4 + 8*1
33 + 5*1 + 4 + 5*1

// AcceptedHtlcScriptSizeConfirmed 143 bytes
//
// TODO(halseth): the non-confirmed version currently includes the
// overhead.
AcceptedHtlcScriptSizeConfirmed = AcceptedHtlcScriptSize // + HtlcConfirmedScriptOverhead
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Why was this commented out in the past again?

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ah nvm, I see the TODO now

AcceptedHtlcScriptSizeConfirmed = AcceptedHtlcScriptSize +
HtlcConfirmedScriptOverhead

// AcceptedHtlcTimeoutWitnessSize 219
// AcceptedHtlcTimeoutWitnessSize 217 bytes
// - number_of_witness_elements: 1 byte
// - sender_sig_length: 1 byte
// - sender_sig: 73 bytes
Expand All @@ -343,7 +348,11 @@ const (
// - witness_script: (accepted_htlc_script)
AcceptedHtlcTimeoutWitnessSize = 1 + 1 + 73 + 1 + 1 + AcceptedHtlcScriptSize

// AcceptedHtlcPenaltyWitnessSize 252 bytes
// AcceptedHtlcTimeoutWitnessSizeConfirmed 220 bytes
AcceptedHtlcTimeoutWitnessSizeConfirmed = 1 + 1 + 73 + 1 + 1 +
AcceptedHtlcScriptSizeConfirmed

// AcceptedHtlcPenaltyWitnessSize 250 bytes
// - number_of_witness_elements: 1 byte
// - revocation_sig_length: 1 byte
// - revocation_sig: 73 bytes
Expand All @@ -353,7 +362,11 @@ const (
// - witness_script (accepted_htlc_script)
AcceptedHtlcPenaltyWitnessSize = 1 + 1 + 73 + 1 + 33 + 1 + AcceptedHtlcScriptSize

// AcceptedHtlcSuccessWitnessSize 322 bytes
// AcceptedHtlcPenaltyWitnessSizeConfirmed 253 bytes
AcceptedHtlcPenaltyWitnessSizeConfirmed = 1 + 1 + 73 + 1 + 33 + 1 +
AcceptedHtlcScriptSizeConfirmed

// AcceptedHtlcSuccessWitnessSize 324 bytes
// - number_of_witness_elements: 1 byte
// - nil_length: 1 byte
// - sig_alice_length: 1 byte
Expand All @@ -364,6 +377,8 @@ const (
// - preimage: 32 bytes
// - witness_script_length: 1 byte
// - witness_script (accepted_htlc_script)
//
// Input to second level success tx, spending non-delayed HTLC output.
AcceptedHtlcSuccessWitnessSize = 1 + 1 + 1 + 73 + 1 + 73 + 1 + 32 + 1 +
AcceptedHtlcScriptSize

Expand All @@ -373,7 +388,7 @@ const (
AcceptedHtlcSuccessWitnessSizeConfirmed = 1 + 1 + 1 + 73 + 1 + 73 + 1 + 32 + 1 +
AcceptedHtlcScriptSizeConfirmed

// OfferedHtlcScriptSize 136 bytes
// OfferedHtlcScriptSize 133 bytes
// - OP_DUP: 1 byte
// - OP_HASH160: 1 byte
// - OP_DATA: 1 byte (RIPEMD160(SHA256(revocationkey)) length)
Expand Down Expand Up @@ -404,19 +419,17 @@ const (
// - OP_EQUALVERIFY: 1 byte
// - OP_CHECKSIG: 1 byte
// - OP_ENDIF: 1 byte
// - OP_1: 1 byte
// - OP_CSV: 1 byte
// - OP_DROP: 1 byte
// - OP_1: 1 byte // These 3 extra bytes are only
// - OP_CSV: 1 byte // present for the confirmed
// - OP_DROP: 1 byte // HTLC script types.
// - OP_ENDIF: 1 byte
OfferedHtlcScriptSize = 3*1 + 20 + 5*1 + 33 + 10*1 + 33 + 5*1 + 20 + 7*1
OfferedHtlcScriptSize = 3*1 + 20 + 5*1 + 33 + 10*1 + 33 + 5*1 + 20 + 4*1

// OfferedHtlcScriptSizeConfirmed 136 bytes
//
// TODO(halseth): the non-confirmed version currently includes the
// overhead.
OfferedHtlcScriptSizeConfirmed = OfferedHtlcScriptSize // + HtlcConfirmedScriptOverhead
OfferedHtlcScriptSizeConfirmed = OfferedHtlcScriptSize +
HtlcConfirmedScriptOverhead

// OfferedHtlcSuccessWitnessSize 245 bytes
// OfferedHtlcSuccessWitnessSize 242 bytes
// - number_of_witness_elements: 1 byte
// - receiver_sig_length: 1 byte
// - receiver_sig: 73 bytes
Expand All @@ -426,6 +439,10 @@ const (
// - witness_script (offered_htlc_script)
OfferedHtlcSuccessWitnessSize = 1 + 1 + 73 + 1 + 32 + 1 + OfferedHtlcScriptSize

// OfferedHtlcSuccessWitnessSizeConfirmed 245 bytes
OfferedHtlcSuccessWitnessSizeConfirmed = 1 + 1 + 73 + 1 + 32 + 1 +
OfferedHtlcScriptSizeConfirmed

// OfferedHtlcTimeoutWitnessSize 285 bytes
// - number_of_witness_elements: 1 byte
// - nil_length: 1 byte
Expand All @@ -436,15 +453,18 @@ const (
// - nil_length: 1 byte
// - witness_script_length: 1 byte
// - witness_script (offered_htlc_script)
OfferedHtlcTimeoutWitnessSize = 1 + 1 + 1 + 73 + 1 + 73 + 1 + 1 + OfferedHtlcScriptSize
//
// Input to second level timeout tx, spending non-delayed HTLC output.
OfferedHtlcTimeoutWitnessSize = 1 + 1 + 1 + 73 + 1 + 73 + 1 + 1 +
OfferedHtlcScriptSize

// OfferedHtlcTimeoutWitnessSizeConfirmed 288 bytes
//
// Input to second level timeout tx, spending 1 CSV delayed HTLC output.
OfferedHtlcTimeoutWitnessSizeConfirmed = 1 + 1 + 1 + 73 + 1 + 73 + 1 + 1 +
OfferedHtlcScriptSizeConfirmed

// OfferedHtlcPenaltyWitnessSize 246 bytes
// OfferedHtlcPenaltyWitnessSize 243 bytes
// - number_of_witness_elements: 1 byte
// - revocation_sig_length: 1 byte
// - revocation_sig: 73 bytes
Expand All @@ -454,6 +474,10 @@ const (
// - witness_script (offered_htlc_script)
OfferedHtlcPenaltyWitnessSize = 1 + 1 + 73 + 1 + 33 + 1 + OfferedHtlcScriptSize

// OfferedHtlcPenaltyWitnessSizeConfirmed 246 bytes
OfferedHtlcPenaltyWitnessSizeConfirmed = 1 + 1 + 73 + 1 + 33 + 1 +
OfferedHtlcScriptSizeConfirmed

// AnchorScriptSize 40 bytes
// - pubkey_length: 1 byte
// - pubkey: 33 bytes
Expand Down
Loading