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

Correct htlc witness size calculations #815

Merged
merged 4 commits into from
Dec 7, 2020
Merged

Correct htlc witness size calculations #815

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
dcb50b5
BOLT#3: use 4 bytes for cltv_expiry in accepted_htlc_script
halseth Nov 11, 2020
a9e064d
BOLT#3: correct success_witness size
halseth Nov 11, 2020
9fdee1e
BOLT#3: note HTLC tx wieghts differ a bit from actual weights
halseth Nov 11, 2020
2a8da1a
bolt3: remove double 'with'
halseth Nov 27, 2020
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
13 changes: 7 additions & 6 deletions 03-transactions.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -829,7 +829,7 @@ Multiplying non-witness data by 4 results in a weight of:

The *expected weight* of an HTLC transaction is calculated as follows:

accepted_htlc_script: 139 bytes (142 bytes with option_anchor_outputs)
accepted_htlc_script: 140 bytes (143 bytes with option_anchor_outputs)
- OP_DUP: 1 byte
- OP_HASH160: 1 byte
- OP_DATA: 1 byte (RIPEMD160(SHA256(revocationpubkey)) length)
Expand Down Expand Up @@ -859,7 +859,7 @@ The *expected weight* of an HTLC transaction is calculated as follows:
- OP_ELSE: 1 byte
- OP_DROP: 1 byte
- OP_DATA: 1 byte (cltv_expiry length)
- cltv_expiry: 3 bytes
- cltv_expiry: 4 bytes
- OP_CHECKLOCKTIMEVERIFY: 1 byte
- OP_DROP: 1 byte
- OP_CHECKSIG: 1 byte
Expand Down Expand Up @@ -916,7 +916,7 @@ The *expected weight* of an HTLC transaction is calculated as follows:
- witness_script_length: 1 byte
- witness_script (offered_htlc_script)

success_witness: 325 bytes (328 bytes with option_anchor_outputs)
success_witness: 324 bytes (327 bytes with option_anchor_outputs)
- number_of_witness_elements: 1 byte
- nil_length: 1 byte
- sig_alice_length: 1 byte
Expand Down Expand Up @@ -954,11 +954,12 @@ The *expected weight* of an HTLC transaction is calculated as follows:
- lock_time: 4 bytes

Multiplying non-witness data by 4 results in a weight of 376. Adding
the witness data for each case (285 or 288 + 2 for HTLC-timeout, 325 or 328 + 2 for
the witness data for each case (285 or 288 + 2 for HTLC-timeout, 324 or 327 + 2 for
HTLC-success) results in weights of:

663 (HTLC-timeout) (666 with with option_anchor_outputs))
703 (HTLC-success) (706 with with option_anchor_outputs))
663 (HTLC-timeout) (666 with option_anchor_outputs))
703 (HTLC-success) (706 with option_anchor_outputs))
- (really 702 and 705, but we use these numbers for historical reasons)

# Appendix B: Funding Transaction Test Vectors

Expand Down