highperfocused/bitcoin
1
0
Fork 0
mirror of https://github.com/bitcoin/bitcoin.git synced 2025-12-12 13:43:43 +01:00
Code Issues Packages Projects Releases Wiki Activity

Merge bitcoin/bitcoin#28651: Make miniscript GetWitnessSize accurate for tapscript

Browse Source 
b22810887b miniscript: make GetWitnessSize accurate for tapscript (Pieter Wuille)
8be9851408 test: add tests for miniscript GetWitnessSize (Pieter Wuille)
7ed2b2d430 test: remove mutable global contexts in miniscript fuzzer/test (Pieter Wuille)

Pull request description:

  So far, the same algorithm is used to compute an (upper bound on) the maximum witness size for both P2WSH and P2TR miniscript. That's unfortunate, because it means fee estimations for P2TR miniscript will miss out on the generic savings brought by P2TR witnesses (smaller signatures and public keys, specifically).

  Fix this by making the algorithm use script context specification calculations, and add tests for it. Also included is a cleanup for the tests to avoid mutable globals, as I found it hard to reason about what exactly was being tested.

ACKs for top commit:
  achow101:
    ACK b22810887b
  darosior:
    ACK b22810887b

Tree-SHA512: e4bda7376628f3e91cfc74917cefc554ca16eb5f2a0e1adddc33eb8717c4aaa071e56a40f85a2041ae74ec445a7bd0129bba48994c203e0e6e4d25af65954d9e
This commit is contained in:
Andrew Chow
2023-10-17 18:22:29 -04:00
parent 9c30f5ef9d b22810887b
commit c2d4e40e45
3 changed files with 124 additions and 101 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
src/script/miniscript.h
View File

@@ -1105,13 +1105,15 @@ private:
}
internal::WitnessSize CalcWitnessSize() const {
const uint32_t sig_size = IsTapscript(m_script_ctx) ? 1 + 65 : 1 + 72;
const uint32_t pubkey_size = IsTapscript(m_script_ctx) ? 1 + 32 : 1 + 33;
switch (fragment) {
case Fragment::JUST_0: return {{}, 0};
case Fragment::JUST_1:
case Fragment::OLDER:
case Fragment::AFTER: return {0, {}};
case Fragment::PK_K: return {1 + 72, 1};
case Fragment::PK_H: return {1 + 72 + 1 + 33, 1 + 1 + 33};
case Fragment::PK_K: return {sig_size, 1};
case Fragment::PK_H: return {sig_size + pubkey_size, 1 + pubkey_size};
case Fragment::SHA256:
case Fragment::RIPEMD160:
case Fragment::HASH256:
@@ -1131,8 +1133,8 @@ private:
case Fragment::OR_C: return {subs[0]->ws.sat | (subs[0]->ws.dsat + subs[1]->ws.sat), {}};
case Fragment::OR_D: return {subs[0]->ws.sat | (subs[0]->ws.dsat + subs[1]->ws.sat), subs[0]->ws.dsat + subs[1]->ws.dsat};
case Fragment::OR_I: return {(subs[0]->ws.sat + 1 + 1) | (subs[1]->ws.sat + 1), (subs[0]->ws.dsat + 1 + 1) | (subs[1]->ws.dsat + 1)};
case Fragment::MULTI: return {k * (1 + 72) + 1, k + 1};
case Fragment::MULTI_A: return {k * (1 + 65) + static_cast<uint32_t>(keys.size()) - k, static_cast<uint32_t>(keys.size())};
case Fragment::MULTI: return {k * sig_size + 1, k + 1};
case Fragment::MULTI_A: return {k * sig_size + static_cast<uint32_t>(keys.size()) - k, static_cast<uint32_t>(keys.size())};
case Fragment::WRAP_A:
case Fragment::WRAP_N:
case Fragment::WRAP_S: