01960c53c7 fuzz: make FuzzedDataProvider usage deterministic (Martin Leitner-Ankerl)
Pull request description:
There exist many usages of `fuzzed_data_provider` where it is evaluated directly in the function call.
Unfortunately, [the order of evaluation of function arguments is unspecified](https://en.cppreference.com/w/cpp/language/eval_order), and a simple example shows that it can differ e.g. between clang++ and g++: https://godbolt.org/z/jooMezWWY
When the evaluation order is not consistent, the same fuzzing/random input will produce different output, which is bad for coverage/reproducibility. This PR fixes all these cases I have found where unspecified evaluation order could be a problem.
Finding these has been manual work; I grepped the sourcecode for these patterns, and looked at each usage individually. So there is a chance I missed some.
* `fuzzed_data_provider`
* `.Consume`
* `>Consume`
* `.rand`
I first discovered this in https://github.com/bitcoin/bitcoin/pull/29013#discussion_r1420236394. Note that there is a possibility that due to this fix the evaluation order is now different in many cases than when the fuzzing corpus has been created. If that is the case, the fuzzing corpus will have worse coverage than before.
Update: In list-initialization the order of evaluation is well defined, so e.g. usages in `initializer_list` or constructors that use `{...}` is ok.
ACKs for top commit:
achow101:
ACK 01960c53c7
vasild:
ACK 01960c53c7
ismaelsadeeq:
ACK 01960c53c7
Tree-SHA512: e56d087f6f4bf79c90b972a5f0c6908d1784b3cfbb8130b6b450d5ca7d116c5a791df506b869a23bce930b2a6977558e1fb5115bb4e061969cc40f568077a1ad
Beyond renaming it also adjusts whitespace and adds braces to conform to current doc/developer-notes.md.
TestEncrypt: Change iterator type to auto in ahead of vector -> span conversion.
Only touches functions that will be modified in next commit.
a0abcbd382 doc: Mention multipath specifier (Ava Chow)
0019f61fc5 tests: Test importing of multipath descriptors (Ava Chow)
f97d5c137d wallet, rpc: Allow importdescriptors to import multipath descriptors (Ava Chow)
32dcbca3fb rpc: Allow importmulti to import multipath descriptors correctly (Ava Chow)
64dfe3ce4b wallet: Move internal to be per key when importing (Ava Chow)
1692245525 tests: Multipath descriptors for scantxoutset and deriveaddresses (Ava Chow)
cddc0ba9a9 rpc: Have deriveaddresses derive receiving and change (Ava Chow)
360456cd22 tests: Multipath descriptors for getdescriptorinfo (Ava Chow)
a90eee444c tests: Add unit tests for multipath descriptors (Ava Chow)
1bbf46e2da descriptors: Change Parse to return vector of descriptors (Ava Chow)
0d640c6f02 descriptors: Have ParseKeypath handle multipath specifiers (Ava Chow)
a5f39b1034 descriptors: Change ParseScript to return vector of descriptors (Ava Chow)
0d55deae15 descriptors: Add DescriptorImpl::Clone (Ava Chow)
7e86541f72 descriptors: Add PubkeyProvider::Clone (Ava Chow)
Pull request description:
It is convenient to have a descriptor which specifies both receiving and change addresses in a single string. However, as discussed in https://github.com/bitcoin/bitcoin/issues/17190#issuecomment-895515768, it is not feasible to use a generic multipath specification like BIP 88 due to combinatorial blow up and that it would result in unexpected descriptors.
To resolve that problem, this PR proposes a targeted solution which allows only a single pair of 2 derivation indexes to be inserted in the place of a single derivation index. So instead of two descriptor `wpkh(xpub.../0/0/*)` and `wpkh(xpub.../0/1/*)` to represent receive and change addresses, this could be written as `wpkh(xpub.../0/<0;1>/*)`. The multipath specifier is of the form `<NUM;NUM>`. Each `NUM` can have its own hardened specifier, e.g. `<0;1h>` is valid. The multipath specifier can also only appear in one path index in the derivation path.
This results in the parser returning two descriptors. The first descriptor uses the first `NUM` in all pairs present, and the second uses the second `NUM`. In our implementation, if a multipath descriptor is not provided, a pair is still returned, but the second element is just `nullptr`.
The wallet will not output the multipath descriptors (yet). Furthermore, when a multipath descriptor is imported, it is expanded to the two descriptors and each imported on its own, with the second descriptor being implicitly for internal (change) addresses. There is no change to how the wallet stores or outputs descriptors (yet).
Note that the path specifier is different from what was proposed. It uses angle brackets and the semicolon because these are unused characters available in the character set and I wanted to avoid conflicts with characters already in use in descriptors.
Closes#17190
ACKs for top commit:
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mjdietzx:
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pythcoiner:
reACK a0abcbd
furszy:
Code review ACK a0abcbd
glozow:
light code review ACK a0abcbd382
Tree-SHA512: 84ea40b3fd1b762194acd021cae018c2f09b98e595f5e87de5c832c265cfe8a6d0bc4dae25785392fa90db0f6301ddf9aea787980a29c74f81d04b711ac446c2
401cc4ec70 fuzz: improve scriptpubkeyman target (brunoerg)
Pull request description:
Fixes#30541
This PR aims to improve `scriptpubkeyman` target to avoid timeouts. The input provided in #30541 takes too much time to run because it basically calls only `MarkUnusedAddresses` (300 times * number of spks). The following changes were made to improve it:
- Reduce keypool size.
- When calling `MarkUnusedAddresses`, do it with one of the spks per iteration.
- Remove the specific `AddDescriptorKey` call since it is already covered with `AddWalletDescriptor`.
- Limit number of iterations to a reasonable value.
ACKs for top commit:
maflcko:
lgtm ACK 401cc4ec70
achow101:
ACK 401cc4ec70
Tree-SHA512: 941812bc6d991dd03675a2974ce1b839494ca7f6e6d8a22c689d4bf4fed2dac5491246998f19cb15dbff516fdd8eeda27e7628c3206d45f57dc292bc05624a5c
Move `SetKeyFromPassphrase` to out of LIMITED_WHILE,
remove `SetKey` calls since it is already called
internally by other functions and reduce the number
of iterations.
734076c6de [wallet, rpc]: add `max_tx_weight` to tx funding options (ismaelsadeeq)
b6fc5043c1 [wallet]: update the data type of `change_output_size`, `change_spend_size` and `tx_noinputs_size` to `int` (ismaelsadeeq)
baab0d2d43 [doc]: update reason for deducting change output weight (ismaelsadeeq)
7f61d31a5c [refactor]: update coin selection algorithms input parameter `max_weight` name (ismaelsadeeq)
Pull request description:
This PR taken over from #29264
The PR added an option `max_tx_weight` to transaction funding RPC's that ensures the resulting transaction weight does not exceed the specified `max_tx_weight` limit.
If `max_tx_weight` is not given `MAX_STANDARD_TX_WEIGHT` is used as the max threshold.
This PR addressed outstanding review comments in #29264
For more context and rationale behind this PR see https://delvingbitcoin.org/t/lightning-transactions-with-v3-and-ephemeral-anchors/418/11?u=instagibbs
ACKs for top commit:
achow101:
ACK 734076c6de
furszy:
utACK 734076c6de
rkrux:
reACK [734076c](734076c6de)
Tree-SHA512: 013501aa443d239ee2ac01bccfc5296490c27b4edebe5cfca6b96c842375e895e5cfeb5424e82e359be581460f8be92095855763a62779a18ccd5bdfdd7ddce7
This allows a transaction's weight to be bound under a certain
weight if possible and desired. This can be beneficial for future
RBF attempts, or whenever a more restricted spend topology is
desired.
Co-authored-by: Greg Sanders <gsanders87@gmail.com>
- This commit renames the coin selection algorithms input parameter `max_weight`
to `max_selection_weight` for clarity.
The parameter represent the maximum weight of the UTXOs the coin selection algorithm
should select, not the transaction maximum weight.
- The commit updates the parameter docstring to provide correct description.
- Also updates coin selection unit and fuzzing test variables to match the new name.
d7290d662f fuzz: wallet, add target for Crypter (Ayush Singh)
Pull request description:
This PR adds fuzz coverage for `wallet/crypter`.
Motivation: Issue [27272](https://github.com/bitcoin/bitcoin/issues/27272#issue-1628327906)
I ran this for a long time with Sanitizers on and had no crashes; the average `exec/sec` also looks good to me. However, I would really appreciate it if some of the reviewers could try it on their machines too, and give their feedback.
ACKs for top commit:
maflcko:
utACK d7290d662f
achow101:
ACK d7290d662f
brunoerg:
utACK d7290d662f
Tree-SHA512: f5c496cabdd3263a7e1ad49eeff702725336f76bf19a82e5dbbead082e990889dd43c851d0d2d6ab740f44b8ec2aa06defd9ff6b02be68b5f8b4eaf963f88599
bd34dd85e7 Use `exact_target` shorthand in coinselector_tests (Murch)
7aa7e30441 Fold GetSelectionWaste() into ComputeAndSetWaste() (Murch)
Pull request description:
PR #26152 moved waste calculation into SelectionResult to be able to correct the waste score on basis of the bump_fee_group_discount for overlapping ancestries. This left two functions with largely overlapping purpose, where one was simply a wrapper of the other. This PR cleans up the overlap, and fixes the double-meaning of `change_cost` where the `GetChange()` function assumed that no change was created when `change_cost` was set to 0. This behavior was exploited in a bunch of tests, but is problematic, because a `change_cost` of 0 is permitted with custom settings for feerate and discard_feerate (i.e. when they’re both 0).
ACKs for top commit:
achow101:
ACK bd34dd85e7
furszy:
Code ACK bd34dd85e7
ismaelsadeeq:
Code Review ACK bd34dd85e7
Tree-SHA512: 83a2688d45d719dc61a64b5180fe136107faccf401a59df65245c05d701748a03e85ed56fde8c9b7ef39a3ab54374dd3718c559bda5b3f55dafedfd7fed25161
e3249f2111 fuzz: add more coverage for `ScriptPubKeyMan` (brunoerg)
Pull request description:
This PR adds more coverage for `ScriptPubKeyMan`:
- Check `GetKey` and `HasPrivKey` after adding descriptor key.
- Cover `GetEndRange` and `GetKeyPoolSize`.
- Cover `MarkUnusedAddresses` with the scripts from ScriptPubKeys and `GetMetadata` with the destinations from them.
ACKs for top commit:
marcofleon:
Tested ACK e3249f2111. I ran the updated harness for ~9 hours on an empty corpus, generated a coverage report, and checked that the new functions mentioned were hit. Coverage of `scriptpubkeyman.cpp` increased.
murchandamus:
Tested ACK e3249f2111
Tree-SHA512: cfab91f6c8401174842e79209c0e9225c08f011fe9b41d0a58bcec716ae4545eaf803867f899ed7b5fbcefea45711f91894e36df082ba19732dd310cd9e61a79
Both `GetSelectionWaste()` and `ComputeAndSetWaste()` now are part of
`SelectionResult`. Instead of `ComputeAndSetWaste()` being a wrapper for
`GetSelectionWaste()`, we combine them to a new function
`RecalculateWaste()`.
As I was combining the logic of the two functions, I noticed that
`GetSelectionWaste()` was making the odd assumption that the
`change_cost` being set to zero means that no change is created.
However, if we build transactions at a feerate of zero with the
`discard_feerate` also set to zero, we'd organically have a
`change_cost` of zero, even when we create change on a transaction.
This commit cleans up this duplicate meaning of `change_cost` and relies
on `GetChange()` to figure out whether there is change on basis of the
`min_viable_change` and whatever is left after deducting fees.
Since this broke a bunch of tests that relied on the double-meaning of
`change_cost` a bunch of tests had to be fixed.
d51fbab4b3 wallet, test: Be able to always swap BDB endianness (Ava Chow)
0b753156ce test: Test bdb_ro dump of wallet without reset LSNs (Ava Chow)
c1984f1282 test: Test dumping dbs with overflow pages (Ava Chow)
fd7b16e391 test: Test dumps of other endian BDB files (Ava Chow)
6ace3e953f bdb: Be able to make byteswapped databases (Ava Chow)
d9878903fb Error if LSNs are not reset (Ava Chow)
4d7a3ae78e Berkeley RO Database fuzz test (TheCharlatan)
3568dce9e9 tests: Add BerkeleyRO to db prefix tests (Ava Chow)
70cfbfdadf wallettool: Optionally use BERKELEY_RO as format when dumping BDB wallets (Ava Chow)
dd57713f6e Add MakeBerkeleyRODatabase (Ava Chow)
6e50bee67d Implement handling of other endianness in BerkeleyRODatabase (Ava Chow)
cdd61c9cc1 wallet: implement independent BDB deserializer in BerkeleyRODatabase (Ava Chow)
ecba230979 wallet: implement BerkeleyRODatabase::Backup (Ava Chow)
0c8e728476 wallet: implement BerkeleyROBatch (Ava Chow)
756ff9b478 wallet: add dummy BerkeleyRODatabase and BerkeleyROBatch classes (Ava Chow)
ca18aea5c4 Add AutoFile::seek and tell (Ava Chow)
Pull request description:
Split from #26596
This PR adds `BerkeleyRODatabase` which is an independent implementation of a BDB file parser. It provides read only access to a BDB file, and can therefore be used as a read only database backend for wallets. This will be used for dumping legacy wallet records and migrating legacy wallets without the need for BDB itself.
Wallettool's `dump` command is changed to use `BerkeleyRODatabase` instead of `BerkeleyDatabase` (and `CWallet` itself) to demonstrate that this parser works and to test it against the existing wallettool functional tests.
ACKs for top commit:
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TheCharlatan:
Re-ACK d51fbab4b3
furszy:
reACK d51fbab4b3
laanwj:
re-ACK d51fbab4b3
theStack:
ACK d51fbab4b3
Tree-SHA512: 1e7b97edf223b2974eed2e9eac1179fc82bb6359e0a66b7d2a0c8b9fa515eae9ea036f1edf7c76cdab2e75ad994962b134b41056ccfbc33b8d54f0859e86657b
Copying util::Result values is less efficient than moving them because they
allocate memory and contain strings. Also this is needed to avoid compile
errors in https://github.com/bitcoin/bitcoin/pull/25722 which adds a
std::unique_ptr member to util::Result which implicity disables copying.
`util::Result` objects are aggregates that can hold multiple fields with
different information. Currently Result objects can only hold a success value
of an arbitrary type or a single bilingual_str error message. In followup PR
https://github.com/bitcoin/bitcoin/pull/25722, Result objects may be able to
hold both success and failure values of different types, plus error and warning
messages.
Having a Result::operator= assignment operator that completely erases all
existing Result information before assigning new information is potentially
dangerous in this case. For example, code that looks like it is assigning a
warning value could erase previously-assigned success or failure values.
Conversely, code that looks like it is just assigning a success or failure
value could erase previously assigned error and warning messages.
To prevent potential bugs like this, disable Result::operator= assignment
operator.
It is possible in the future we may want to re-enable operator= in limited
cases (such as when implicit conversions are not used) or add a Replace() or
Reset() method that mimicks default operator= behavior. Followup PR
https://github.com/bitcoin/bitcoin/pull/25722 also adds a Result::Update()
method providing another way to update an existing Result object.
Co-authored-by: stickies-v <stickies-v@protonmail.com>
13161ecf03 opt: Skip over barren combinations of tiny UTXOs (Murch)
b7672c7cdd opt: Skip checking max_weight separately (Murch)
1edd2baa37 opt: Cut if last addition was minimal weight (Murch)
5248e2a60d opt: Skip heavier UTXOs with same effective value (Murch)
9124c73742 opt: Tiebreak UTXOs by weight for CoinGrinder (Murch)
451be19dc1 opt: Skip evaluation of equivalent input sets (Murch)
407b1e3432 opt: Track remaining effective_value in lookahead (Murch)
5f84f3cc04 opt: Skip branches with worse weight (Murch)
d68bc74fb2 fuzz: Test optimality of CoinGrinder (Murch)
67df6c629a fuzz: Add CoinGrinder fuzz target (Murch)
1502231229 coinselection: Track whether CG completed (Murch)
7488acc646 test: Add coin_grinder_tests (Murch)
6cc9a46cd0 coinselection: Add CoinGrinder algorithm (Murch)
89d0956643 opt: Tie-break UTXO sort by waste for BnB (Murch)
aaee65823c doc: Document max_weight on BnB (Murch)
Pull request description:
***Please refer to the [topic on Delving Bitcoin](https://delvingbitcoin.org/t/gutterguard-and-coingrinder-simulation-results/279) discussing Gutter Guard/Coingrinder simulation results.***
Adds a coin selection algorithm that minimizes the weight of the input set while creating change.
Motivations
---
- At high feerates, using unnecessary inputs can significantly increase the fees
- Users are upset when fees are relatively large compared to the amount sent
- Some users struggle to maintain a sufficient count of UTXOs in their wallet
Approach
---
So far, Bitcoin Core has used a balanced approach to coin selection, where it will generate multiple input set candidates using various coin selection algorithms and pick the least wasteful among their results, but not explicitly minimize the input set weight. Under some circumstances, we _do_ want to minimize the weight of the input set. Sometimes changeless solutions require many or heavy inputs, and there is not always a changeless solution for Branch and Bound to find in the first place. This can cause expensive transactions unnecessarily. Given a wallet with sufficient funds, `CoinGrinder` will pick the minimal-waste input set for a transaction with a change output. The current implementation only runs `CoinGrinder` at feerates over 3×long-term-feerate-estimate (by default 30 ṩ/vB), which may be a decent compromise between our goal to reduce costs for the users, but still permit transactions at lower feerates to naturally reduce the wallet’s UTXO pool to curb bloat.
Trade-offs
---
Simulations for my thesis on coin selection ([see Section 6.3.2.1 [PDF]](https://murch.one/erhardt2016coinselection.pdf)) suggest that minimizing the input set for all transactions tends to grind a wallet’s UTXO pool to dust (pun intended): an approach selecting inputs per coin-age-priority (in effect similar to “largest first selection”) on average produced a UTXO pool with 15× the UTXO count as Bitcoin Core’s Knapsack-based Coin Selection then (in 2016). Therefore, I do not recommend running `CoinGrinder` under all circumstances, but only at extreme feerates or when we have another good reason to minimize the input set for other reasons. In the long-term, we should introduce additional metrics to score different input set candidates, e.g. on basis of their privacy and wallet health impact, to pick from all our coin selection results, but until then, we may want to limit use of `CoinGrinder` in other ways.
ACKs for top commit:
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sr-gi:
ACK [13161ec](13161ecf03)
sipa:
ACK 13161ecf03
Tree-SHA512: 895b08b2ebfd0b71127949b7dba27146a6d10700bf8590402b14f261e7b937f4e2e1b24ca46de440c35f19349043ed2eba4159dc2aa3edae57721384186dae40
Instead turning tx.vout into a vector of `CRecipient`, make `FundTransaction`
take a `CRecipient` vector directly. This allows us to remove SFFO logic from
the wrapper RPC `FundTransaction` since the `CRecipient` objects have already
been created with the correct SFFO values. This also allows us to remove
SFFO from both `FundTransaction` function signatures.
This sets us up in a future PR to be able to use these RPCs with BIP352
static payment codes.
a44808fb43 fuzz: rule-out too deep derivation paths in descriptor parsing targets (Antoine Poinsot)
Pull request description:
This fixes the `mocked_descriptor_parse` timeout reported in #28812 and direct the targets more toward what they are intended to fuzz: the descriptor syntax.
ACKs for top commit:
sipa:
utACK a44808fb43
achow101:
ACK a44808fb43
dergoegge:
ACK a44808fb43 - Not running into timeouts anymore
TheCharlatan:
ACK a44808fb43
Tree-SHA512: a5dd1dbe9adf8f088bdc435addab88b56f435e6d7d2065bd6d5c6d80a32e3f1f97d3d2323131ab233618cd6dcc477c458abe3c4c865ab569449b8bc176231e93
e03d6f7ed5 fuzz: set `m_fallback_fee`/`m_fee_mode` in `wallet_fees` target (brunoerg)
Pull request description:
`m_fallback_fee` and `m_fee_mode` are used in `GetMinimumFeeRate` but we're not setting any value for them in `wallet_fees` target. That's the reason fuzzing is never reaching the following code:

This PR fixes it.
ACKs for top commit:
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review ACK e03d6f7ed5
achow101:
ACK e03d6f7ed5
murchandamus:
ACK e03d6f7ed5
Tree-SHA512: 5d364f5351d65762a3ddf88e3abb7bda401b7e4955285e083031d216fb50082b1ea98e2c065aff75a5a8a3d1bc4c2e5e3ca9f9478d902ee8f8d4347b6cbe53af
576bee88fd fuzz: disable BnB when SFFO is enabled (furszy)
05e5ff194c test: add coverage for BnB-SFFO restriction (furszy)
0c5755761c wallet: create tx, log resulting coin selection info (furszy)
5cea25ba79 wallet: skip BnB when SFFO is active (Murch)
Pull request description:
Solves #28918. Coming from https://github.com/bitcoin/bitcoin/issues/28918#issuecomment-1838626406 discussion.
The intention is to decouple only the bugfix relevant commits from #28985, allowing them to be included in the 26.x release. This way, we can avoid disabling the coin selection fuzzing test for an entire release.
Note:
Have introduced few changes to the bug fix commit so that the unit tests pass without the additional burden introduced in #28985.
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ACK 576bee88fd
achow101:
ACK 576bee88fd
Tree-SHA512: f5d90eb3f3f524265afe4719495c9bf30f98b9af26cf039f7df5a7db977abae72caa7a3478cdd0ab10cd143bc1662e8fc5286b5bc10fc10f0dd582a45b45c31a
There exist many usages of `fuzzed_data_provider` where it is evaluated directly in the function call.
Unfortunately, the order of evaluation of function arguments is unspecified. This means it can differ
between compilers/version/optimization levels etc. But when the evaluation order changes, the same
fuzzing input will produce different output, which is bad for coverage/reproducibility.
This PR fixes all these cases where by moving multiple calls to `fuzzed_data_provider` out of the
function arguments.
Instead of using the output parameters, return CreatedTransactionResult
from FundTransaction in the same way that CreateTransaction does.
Additionally, instead of modifying the original CMutableTransaction, the
result from CreateTransactionInternal is used.
Instead of having a separate CCoinControl::SelectExternal function, we
can use the normal CCoinControl::Select function and explicitly use
PreselectedInput::SetTxOut in the caller. The semantics of what an
external input is remains.
Also, add missing includes to scriptpubkeyman.
Also, export dependecies of the BasicTestingSetup from setup_common.h,
to avoid having to include them when setup_common.h is already included.