1. Reorder the PoW fields in the 'Filter' proto by field index, instead
of contextually.
2. Deduplicate expression for 'pow' & replace if-block with boolean op
to simplify 'FilterManager::isProofOfWorkValid'.
3. Avoid slightly confusing use of null char as a separator to prevent
hashing collisions in 'EquihashProofOfWorkService::getChallenge'. Use
comma separator and escape the 'itemId' & 'ownerId' arguments instead.
(based on PR #5858 review comments)
Remove all the 'challengeValidation', 'difficultyValidation' and
'testDifficulty' BiPredicate method params from 'HashCashService' &
'ProofOfWorkService', to simplify the API. These were originally
included to aid testing, but turned out to be unnecessary.
Patches committed on behalf of @chimp1984.
Change the type of the 'difficulty' field in the Filter & ProofOfWork
proto objects from int32/bytes to double and make it use a linear scale,
in place of the original logarithmic scale which counts the (effective)
number of required zeros.
This allows fine-grained difficulty control for Equihash, though for
Hashcash it simply rounds up to the nearest power of 2 internally.
NOTE: This is a breaking change to PoW & filter serialisation (unlike
the earlier PR commits), as the proto field version nums aren't updated.
Add an abstract base class, 'ProofOfWorkService', for the existing PoW
implementation 'HashCashService' and a new 'EquihashProofOfWorkService'
PoW implementation based on Equihash-90-5 (which has 72 byte solutions &
5-10 MB peak memory usage). Since the current 'ProofOfWork' protobuf
object only provides a 64-bit counter field to hold the puzzle solution
(as that is all Hashcash requires), repurpose the 'payload' field to
hold the Equihash puzzle solution bytes, with the 'challenge' field
equal to the puzzle seed: the SHA256 hash of the offerId & makerAddress.
Use a difficulty scale factor of 3e-5 (derived from benchmarking) to try
to make the average Hashcash & Equihash puzzle solution times roughly
equal for any given log-difficulty/numLeadingZeros integer chosen in the
filter.
NOTE: An empty enabled-version-list in the filter defaults to Hashcash
(= version 0) only. The new Equihash-90-5 PoW scheme is version 1.
Add a numeric version field to the 'ProofOfWork' protobuf object, along
with a list of allowed version numbers, 'enabled_pow_versions', to the
filter. The versions are taken to be in order of preference from most to
least preferred when creating a PoW, with an empty list signifying use
of the default algorithm only (that is, version 0: Hashcash).
An explicit list is used instead of an upper & lower version bound, in
case a new PoW algorithm (or changed algorithm params) turns out to
provide worse resistance than an earlier version.
(The fields are unused for now, to be enabled in a later commit.)
Replace 'BiFunction<T, U, Boolean>' with the primitive specialisation
'BiPredicate<T, U>' in HashCashService & FilterManager.
As part of this, replace similar predicate constructs found elsewhere.
NOTE: This touches the DAO packages (trivially @ VoteResultService).
When doing a resync from genesis the number of blocks is limited to 6000
so that requires lots of requests and with that increases risk of broken
connections. Giving more tolerance for retries avoids that the user has
to restart the app.
When syncing from genesis the number of blocks are limited so we get the
`onParseBlockCompleteAfterBatchProcessing` called each time when the received
blocks are processed, and as we are not at wallet height we repeat requesting
blocks. But the new check for the BTC recipient triggers a resync from resource call.
We add now a check that we do this check only once the wallet is synced and our
block height from dao state matches wallet blockheight.
- At genesis we use the genesis height for request (not height+1)
- If wallet is not synced yet we do not call onParseBlockChainComplete (as it was before)
We added 1 as with the lite monitor mode we persist the most recent block,
thus we request with the start height for the next block.
But that cause a problem at a DAO full mode which has lite monitor mode set
as then the block parsing would not be triggered.
We refactor it so that we take the chainHeight from the dao state
directly and add 1 at the requests.
We add a check if we are at chain tip, and if so we skip requests
and call the onParseBlockChainComplete directly.
Add a check of 'scriptTypeId' field, against the output of the spending
tx, to the 'RawTransactionInput::validate' method. Also make the seller
as well as the buyer validate each raw BSQ/BTC input received from the
peer. This prevents either peer from claiming that any of their
non-segwit inputs are segwit in order to underpay the tx fee.
Prevent the seller from stealing the combined tx fee as change by lying
about the value of one or more of his BTC inputs, which are passed to
the buyer as raw inputs in the 'BsqSwapFinalizeTxRequest' message.
To this end, add a 'RawTransactionInput::validate' method to check the
'value' field against the output value of the respective spending tx and
run it on every seller input in 'ProcessBsqSwapFinalizeTxRequest', so
that the buyer is no longer just trusting those numbers.
Additionally, check that the spending txIds from the raw BTC inputs
supplied by the seller actually match those of his signed inputs in the
accompanying partially signed tx, thus tying the raw input values to the
seller's tx.
PaymentMethod use an instance of TradeLimits and expect that it
has been injected, which is the case for desktop but not for
headless apps, so we enforce injection in the app base classes
used for headless apps.
The validation of trade statistics use a method in PaymentMethod
where that dependency is required.
Tha hack how the PaymentMethod use TradeLimits is not nice, but
would require more effort for refactoring.
We had historically higher trade limits and assets which are not in the
currency list anymore, so we apply the filter only for data after
Nov 1st 2021.
found in the active list. Otherwise the 2 BTC default is used.
We get TradeStatistics3 objects from old retired PaymentMethods
which are not found in the active list.
That check is done if:
- If we are after activation time
- If filter is available
- If value in filter is > 0
The check compares the paid fee and the fee value from filter
and requires that paid fee is > 70% of filter value.
See comments in code for more background.
