The current `prevector` size of 28 bytes (chosen to fill the `sizeof(CScript)` aligned size) was introduced in 2015 (https://github.com/bitcoin/bitcoin/pull/6914) before SegWit and TapRoot.
However, the increasingly common `P2WSH` and `P2TR` scripts are both 34 bytes, and are forced to use heap (re)allocation rather than efficient inline storage.
The core trade-off of this change is to eliminate heap allocations for common 34-36 byte scripts at the cost of increasing the base memory footprint of all `CScript` objects by 8 bytes (while still respecting peak memory usage defined by `-dbcache`).
Increasing the `prevector` size allows these scripts to be stored inline, avoiding extra heap allocations, reducing potential memory fragmentation, and improving performance during cache flushes. Massif analysis confirms a lower stable memory usage after flushing, suggesting the elimination of heap allocations outweighs the larger base size for common workloads.
Due to memory alignment, increasing the `prevector` size to 36 bytes doesn't change the overall `sizeof(CScript)` compared to an increase to 34 bytes, allowing us to include `P2PK` scripts as well at no additional memory cost.
Performance benchmarks for AssumeUTXO load and flush show:
* Small dbcache (450MB): ~1-3% performance improvement (despite more frequent flushes)
* Large dbcache (4500MB): ~6-8% performance improvement due to fewer heap allocations (and basically the number of flushes)
* Very large dbcache (4500MB): ~5-6% performance improvement due to fewer heap allocations (and memory limit not being reached, so there's no memory penalty)
Full IBD and reindex-chainstate with larger `dbcache` values also show an overall ~3-4% speedup.
Co-authored-by: Ava Chow <github@achow101.com>
Co-authored-by: Andrew Toth <andrewstoth@gmail.com>
Co-authored-by: maflcko <6399679+maflcko@users.noreply.github.com>
When parsing a descriptor, it is useful to be able to check whether a
string begins with a substring without consuming that substring as
another function such as Func() will be used later which requires that
substring to be present at the beginning.
Specifically, for MuSig2, this modified Const will be used to determine
whether a an expression begins with "musig(" before a subsequent
Func("musig", ...) is used.
Instead of GetPrivKey returning a key and having the caller fill the
FlatSigningProvider, have GetPrivKey take the FlatSigningProvider and
fill it by itself. This will be necessary for descriptors such as
musig() where there are private keys that need to be added to the
FlatSigningProvider but do not directly appear in any resulting scripts.
GetPrivKey is now changed to void as the caller no longer cares whether
it succeeds or fails.
Instead of having ExpandHelper fill in the origins in the
FlatSigningProvider output, have GetPubKey do it by itself. This reduces
the extra variables needed in order to track and set origins in
ExpandHelper.
Also changes GetPubKey to return a std::optional<CPubKey> rather than
using a bool and output parameters.
Legacy wallets should only import keys to the keypool if they came in a
single key descriptor. Instead of relying on assumptions about the
descriptor based on how many pubkeys show up after expanding the
descriptor, explicitly mark descriptors as being single key type and use
that for the check.
ff0194a7ce miniscript: convert non-critical asserts to CHECK_NONFATAL (Antoine Poinsot)
Pull request description:
The Miniscript code contains assertions to prevent ending up in an insane state or prevent UB, but also to enforce logical invariants. For the latter it is not necessary to crash the program if they are broken. Raising an exception suffices, especially as this code is often called through the RPC interface which can in turn handle the exception and the user can report it to developers.
This revives #28678 from Pieter Wuille.
ACKs for top commit:
hodlinator:
ACK ff0194a7ce
TheCharlatan:
ACK ff0194a7ce
brunoerg:
code review ACK ff0194a7ce
Tree-SHA512: 8ed8f7b494e46ecf7cdebe75120cd0ffe543b6bc289bf882dac631fe2ec2cae590d5f7bc2316e52db085791694b136dffbc71c40c1e16886fa53ab00bd8cabd0
* Range-for avoids ++i/i++ debate and decreases linecount.
* seen_multipath is only used if multipath_segment_index hasn't already been set. Rename it to seen_substitutes to better describe what it does, now that the context implies its involved in multipath.
ffff4a293a bench: Update span-serialize comment (MarcoFalke)
fa4d6ec97b refactor: Avoid false-positive gcc warning (MarcoFalke)
fa942332b4 scripted-diff: Bump copyright headers after std::span changes (MarcoFalke)
fa0c6b7179 refactor: Remove unused Span alias (MarcoFalke)
fade0b5e5e scripted-diff: Use std::span over Span (MarcoFalke)
fadccc26c0 refactor: Make Span an alias of std::span (MarcoFalke)
fa27e36717 test: Fix broken span_tests (MarcoFalke)
fadf02ef8b refactor: Return std::span from MakeUCharSpan (MarcoFalke)
fa720b94be refactor: Return std::span from MakeByteSpan (MarcoFalke)
Pull request description:
`Span` has some issues:
* It does not support fixed-size spans, which are available through `std::span`.
* It is confusing to have it available and in use at the same time with `std::span`.
* It does not obey the standard library iterator build hardening flags. See https://github.com/bitcoin/bitcoin/issues/31272 for a discussion. For example, this allows to catch issues like the one fixed in commit fabeca3458.
Both types are type-safe and can even implicitly convert into each other in most contexts.
However, exclusively using `std::span` seems less confusing, so do it here with a scripted-diff.
ACKs for top commit:
l0rinc:
reACK ffff4a293a
theuni:
ACK ffff4a293a.
Tree-SHA512: 9cc2f1f43551e2c07cc09f38b1f27d11e57e9e9bc0c6138c8fddd0cef54b91acd8b14711205ff949be874294a121910d0aceffe0e8914c4cff07f1e0e87ad5b8
21e9d39a37 docs: add release notes for 31603 (brunoerg)
a8b548d75d test: `getdescriptorinfo`/`importdescriptors` with whitespace in pubkeys (brunoerg)
c7afca3d62 test: descriptor: check whitespace into keys (brunoerg)
cb722a3cea descriptor: check whitespace in ParsePubkeyInner (brunoerg)
50856695ef test: fix descriptors in `ismine_tests` (brunoerg)
Pull request description:
Currently, we successfully parse descriptors which contains spaces in the beginning or end of the public/private key within a fragment (e.g. `pk( KEY)`, `pk(KEY )` or `pk( KEY )`). I have noticed that one of the reasons is that the `DecodeBase58` function simply ignore these whitespaces.
This PR changes the `ParsePubkeyInner ` to reject pubkeys that contain a whitespace at the beginning and/or at the end. We will only check the whitespace in some RPCs (e.g. `importdescriptors`), but an already imported descriptor won't be affected by this check, especially because we store descriptors from `ToString`.
For context: https://github.com/brunoerg/bitcoinfuzz/issues/72
ACKs for top commit:
rkrux:
tACK 21e9d39a37
darosior:
re-ACK 21e9d39a37
sipa:
utACK 21e9d39a37
Tree-SHA512: 54f48a89a235517e5cdc29a46dceeb7dabbee93c7616a166288ff3f90131808eb0ece43b0797a11fe827a5f7bd51d65e3e75c16789b0a42020934cabb684cc8f
Historically, the headers have been bumped some time after a file has
been touched. Do it now to avoid having to touch them again in the
future for that reason.
-BEGIN VERIFY SCRIPT-
sed -i --regexp-extended 's;( 20[0-2][0-9])(-20[0-2][0-9])? The Bitcoin Core developers;\1-present The Bitcoin Core developers;g' $( git show --pretty="" --name-only HEAD~1 )
-END VERIFY SCRIPT-
Due to Base58, keys with whitespace at the beginning or
at the end are successfully parsed. This commit adds a
check into `ParsePubkeyInner` to verify whether if the
first or last char of the key is a space.
The Miniscript code contains assertions to prevent ending up in an insane state or prevent UB, but
also to enforce logical invariants. For the latter it is not necessary to crash the program if they
are broken. Raising an exception suffices, especially as this code is often called through the RPC
interface which can in turn handle the exception and the user can report it to developers.
This is based on previous work from Pieter Wuille.
Multipath descriptors requires performing a deep copy, so a Clone
function that does that is added to miniscript::Node instead of the
current shallow copy.
Co-Authored-By: Antoine Poinsot <darosior@protonmail.com>
c0045e6cee Add test for multipath miniscript expression (David Gumberg)
b4ac48090f descriptor: Use InferXOnlyPubkey for miniscript XOnly pubkey from script (Ava Chow)
4c50c21f6b tests: Check ExpandPrivate matches for both parsed descriptors (Ava Chow)
092569e858 descriptor: Try the other parity in ConstPubkeyProvider::GetPrivKey() (Ava Chow)
Pull request description:
When a `ConstPubkeyProvider` is xonly, the stored pubkey does not necessarily have the correct parity bit. `ToPrivateString()` is correctly handling this by looking up the keys for both parity bits, but `GetPrivKey` does not. This results in not finding the private key when it is actually available if its pubkey has the other parity bit value.
To fix this, this key finding is refactored into `GetPrivKey()` so that its behavior is corrected, and `ToPrivateString()` is changed to use `GetPrivKey()` as well.
Additionally, the descriptor test checks are updated to include a check for `ExpandPrivate()` to verify that both the parsed public and private descriptors produce `SigningProvider`s with the same contents.
Fixes#31589
ACKs for top commit:
Pttn:
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davidgumberg:
utACK c0045e6cee
kevkevinpal:
Concept and Code review ACK [c0045e6](c0045e6cee)
furszy:
ACK c0045e6cee
theStack:
re-ACK c0045e6cee
rkrux:
Concept ACK c0045e6cee
Tree-SHA512: 3dcf2a802b996e0680a3f819075e5a689eb22e484c81ea79b40ec04197ee4ba3f6b9c87c45dfe8a847c9b805b2fd0fad77ffb92a93e65dc3aad74d69d9e3d97f
f6a6d91205 test: add check for getting SigningProvider for a CPubKey (Sebastian Falbesoner)
62a95f5af9 test: refactor: move `CreateDescriptor` helper to wallet test util module (Sebastian Falbesoner)
493656763f desc spkm: Return SigningProvider only if we have the privkey (Ava Chow)
Pull request description:
If we know about a pubkey that's in our descriptor, but we don't have the private key, don't return a SigningProvider for that pubkey.
This is specifically an issue for Taproot outputs that use the H point as the resulting PSBTs may end up containing irrelevant information because the H point was detected as a pubkey each unrelated descriptor knew about.
Split from #29675
ACKs for top commit:
fjahr:
ACK f6a6d91205
theStack:
re-ACK f6a6d91205
furszy:
utACK f6a6d91205. Only reviewed the actual change in detail, not the test commit.
Tree-SHA512: 30a196e611a0c5d9ebe5baf6d896caaa6af66f1615463dbb0c31e52604d53cf342922bb9967b3c697b47083d76b0485c77a5f545bd6381247c8bc44321c70f97
GetPrivKey() needs the same handling of all keyids for xonly keys that
ToPrivateString() does. Refactor that into GetPrivKey() and reuse it in
ToPrivateString() to resolve this.
366ae00b77 descriptor: Assume `ParseScript` is not being called with a P2WPKH context (brunoerg)
e366408590 descriptor: remove unreachable verification for `pkh` (brunoerg)
Pull request description:
This PR removes an unreachable verification in the `ParseScript` function. It returns an error if `pkh` is not being used at top level, sh, wsh or tr. However, any usage of `pkh` without these contexts will not reach this verification but other ones like "invalid keys" (e.g. `wpkh(pkh(L4gM1FBdyHNpkzsFh9ipnofLhpZRp2mwobpeULy1a6dBTvw8Ywtd))`).
ACKs for top commit:
davidgumberg:
crACK 366ae00b77
achow101:
ACK 366ae00b77
tdb3:
cr ACK 366ae00b77
sipa:
crACK 366ae00b77
Tree-SHA512: b954221a77eed623aeed5eb54f14e82c49540a151d3388831924caa7a784e48a2a975e418af1e13d491e4f8cded3b1797aa39e0e4e39e302a991105df09cdec0
For Span, iterators are just raw data pointers. However, for std::span
they are not.
This change makes it explicit where data pointers are expected.
Otherwise, there could be a compile error later on:
No known conversion from 'iterator' (aka '__normal_iterator<const std::byte *, std::span<const std::byte, 18446744073709551615>>') to 'std::byte *'.
This was missed during the original PR switching the nHashType argument
to int32_t in SignatureHash in bc52cda1f3.
The problem was discovered after running into a linker error when
attempting to link this code as a static library using the header as a
declaration with a riscv32 bare metal toolchain. The compiler would
error with:
/opt/riscv-ilp32/lib/gcc/riscv32-unknown-elf/13.2.0/../../../../riscv32-unknown-elf/bin/ld: build_kernel_riscv/src/libbitcoin_consensus.a(interpreter.cpp.o): in function `GenericTransactionSignatureChecker<CTransaction>::CheckECDSASignature(std::vector<unsigned char, std::allocator<unsigned char> > const&, std::vector<unsigned char, std::allocator<unsigned char> > const&, CScript const&, SigVersion) const':
/home/user/bitcoin/build_kernel_riscv/./script/interpreter.cpp:2043:(.text._ZNK34GenericTransactionSignatureCheckerI12CTransactionE19CheckECDSASignatureERKSt6vectorIhSaIhEES6_RK7CScript10SigVersion[_ZNK34GenericTransactionSignatureCheckerI12CTransactionE19CheckECDSASignatureERKSt6vectorIhSaIhEES6_RK7CScript10SigVersion]+0xee): undefined reference to `uint256 SignatureHash<CTransaction>(CScript const&, CTransaction const&, unsigned int, int, long long const&, SigVersion, PrecomputedTransactionData const*)'
