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author | Andrew Chow <achow101-github@achow101.com> | 2022-03-04 07:12:16 -0500 |
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committer | Andrew Chow <achow101-github@achow101.com> | 2022-03-04 07:28:23 -0500 |
commit | bada9636d7f2efbc620fd89107baa2bf3e64a6b8 (patch) | |
tree | 89bb23c7472e0c52330c0ef809ddd138dbb0b802 /src/script/script.h | |
parent | 4fae737f4b749b0e2e3cf3fd4dc28db7a1a93b19 (diff) | |
parent | 4828d53eccd52a67631c64cef0ba7df90dff138d (diff) | |
download | bitcoin-bada9636d7f2efbc620fd89107baa2bf3e64a6b8.tar.xz |
Merge bitcoin/bitcoin#24043: Add (sorted)multi_a descriptor for k-of-n multisig inside tr
4828d53eccd52a67631c64cef0ba7df90dff138d Add (sorted)multi_a descriptors to doc/descriptors.md (Pieter Wuille)
b5f33ac1f82aea290b4653af36ac2ad1bf1cce7b Simplify wallet_taproot.py functional test (Pieter Wuille)
eb0667ea96d52db9135514a5e95ab943f6abd8a6 Add tests for (sorted)multi_a derivation/signing (Pieter Wuille)
c17c6aa08df81aa0086d80b50187c8cd60ecc222 Add signing support for (sorted)multi_a scripts (Pieter Wuille)
3eed6fca57d1fa7544f372e6e7de0a9ae1b5715a Add multi_a descriptor inference (Pieter Wuille)
79728c4a3d8a74f276daf1e72abbdecdab85a5d8 Add (sorted)multi_a descriptor and script derivation (Pieter Wuille)
25e95f9ff89a97b87ce218f28274c3c821b2d54d Merge/generalize IsValidMultisigKeyCount/GetMultisigKeyCount (Pieter Wuille)
Pull request description:
This adds a new `multi_a(k,key_1,key_2,...,key_n)` (and corresponding `sortedmulti_a`) descriptor for k-of-n policies inside `tr()`. Semantically it is very similar to the existing `multi()` descriptor, but with the following changes:
* The corresponding script is `<key1> OP_CHECKSIG <key2> OP_CHECKSIGADD <key3> OP_CHECKSIGADD ... <key_n> OP_CHECKSIGADD <k> OP_NUMEQUAL`, rather than the traditional `OP_CHECKMULTISIG`-based script, making it usable inside the `tr()` descriptor.
* The keys can optionally be specified in x-only notation.
* Both the number of keys and the threshold can be as high as 999; this is the limit due to the consensus stacksize=1000 limit
I expect that this functionality will later be replaced with a miniscript-based implementation, but I don't think it's necessary to wait for that.
Limitations:
* The wallet code will for not estimate witness size incorrectly for script path spends, which may result in a (dramatic) fee underpayment with large multi_a scripts.
* The multi_a script construction is (slightly) suboptimal for n-of-n (where a `<key1> OP_CHECKSIGVERIFY ... <key_n-1> OP_CHECKSIGVERIFY <key_n> OP_CHECKSIG` would be better). Such a construction is not included here.
ACKs for top commit:
achow101:
ACK 4828d53eccd52a67631c64cef0ba7df90dff138d
gruve-p:
ACK https://github.com/bitcoin/bitcoin/pull/24043/commits/4828d53eccd52a67631c64cef0ba7df90dff138d
sanket1729:
code review ACK 4828d53eccd52a67631c64cef0ba7df90dff138d
darosior:
Code review ACK 4828d53eccd52a67631c64cef0ba7df90dff138d
Tree-SHA512: 5dcd434b79585f0ff830f7d501d27df5e346f5749f47a3109ec309ebf2cbbad0e1da541eec654026d911ab67fd7cf7793fab0f765628d68d81b96ef2a4d234ce
Diffstat (limited to 'src/script/script.h')
-rw-r--r-- | src/script/script.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/script/script.h b/src/script/script.h index 8b7a7bb7b3..a89c987306 100644 --- a/src/script/script.h +++ b/src/script/script.h @@ -29,6 +29,9 @@ static const int MAX_OPS_PER_SCRIPT = 201; // Maximum number of public keys per multisig static const int MAX_PUBKEYS_PER_MULTISIG = 20; +/** The limit of keys in OP_CHECKSIGADD-based scripts. It is due to the stack limit in BIP342. */ +static constexpr unsigned int MAX_PUBKEYS_PER_MULTI_A = 999; + // Maximum script length in bytes static const int MAX_SCRIPT_SIZE = 10000; |