This change improves usability across network upgrades, by informing
users when their new transactions are being created with the consensus
branch ID from the previous epoch.
We only check failing signatures against the previous epoch to minimise
the extra computational load on nodes.
Refactor experimental feature handling
Adds new rpc call `getexperimentalfeatures` and also adds experimental features to `getblockchaininfo` output.
Closes#2671.
Remove time adjustment; instead warn if peer clocks are too different
The policy is: warn if we have seen at least 8 (TIMEDATA_WARNING_SAMPLES) peer times, in the version messages of the first 20 (TIMEDATA_MAX_SAMPLES) unique (by IP address) peers that connect, that are more than 10 minutes (TIMEDATA_WARNING_THRESHOLD seconds) but less than 10 days (TIMEDATA_IGNORE_THRESHOLD seconds) away from local time.
fixes#4338
This moves all access to these datastructures through accessor functions
and protects them with a lock.
Relative to the upstream commit, we also add GetMiscWarning() to make this accessible to tests.
Signed-off-by: Daira Hopwood <daira@jacaranda.org>
This is a first step in avoiding racy accesses to strMiscWarning.
By itself this commit causes a link error because global variables relating to alerts
are only accessible in the zcashd server, but util is used in other binaries.
Signed-off-by: Daira Hopwood <daira@jacaranda.org>
Note that the MTP of a block is the median timestamp of the preceding 11 blocks, i.e. it is
typically (with no or only moderate timestamp manipulation) expected to be 6 block intervals
behind that block's timestamp, which *on average* is 450 seconds behind (after Blossom activation).
So the effective limit on future dating of timestamps is ~82.5 minutes. This makes it
exceptionally unlikely --even taking into account feasible timestamp manipulation of this
and previous blocks-- that the chain will stall because no block is found before the limit.
(This may rely on assumptions that do not hold for testnet.)
If an adversary were to have a sufficient fraction of mining power to engineer this situation
then there would be something seriously wrong, and arguably the chain should stall in that
case, pending manual intervention.
Co-authored-by: Jack Grigg <jack@z.cash>
Signed-off-by: Daira Hopwood <daira@jacaranda.org>
There are only a few uses of `insecure_random` outside the tests.
This PR replaces uses of insecure_random (and its accompanying global
state) in the core code with an FastRandomContext that is automatically
seeded on creation.
This is meant to be used for inner loops. The FastRandomContext
can be in the outer scope, or the class itself, then rand32() is used
inside the loop. Useful e.g. for pushing addresses in CNode or the fee
rounding, or randomization for coin selection.
As a context is created per purpose, thus it gets rid of
cross-thread unprotected shared usage of a single set of globals, this
should also get rid of the potential race conditions.
- I'd say TxMempool::check is not called enough to warrant using a special
fast random context, this is switched to GetRand() (open for
discussion...)
- The use of `insecure_rand` in ConnectThroughProxy has been replaced by
an atomic integer counter. The only goal here is to have a different
credentials pair for each connection to go on a different Tor circuit,
it does not need to be random nor unpredictable.
- To avoid having a FastRandomContext on every CNode, the context is
passed into PushAddress as appropriate.
There remains an insecure_random for test usage in `test_random.h`.
Zcash: Resolved conflicts with the following files
src/addrman.cpp
src/main.cpp
src/net.cpp
src/net.h
src/policy/fees.cpp
src/policy/fees.h
src/random.cpp
src/test/merkle_tests.cpp
src/test/net_tests.cpp
src/test/prevector_tests.cpp
src/test/sighash_tests.cpp
src/test/skiplist_tests.cpp
src/test/test_bitcoin.cpp
src/test/versionbits_tests.cpp
src/wallet/test/crypto_tests.cpp
Wallet interface refactor
This refactors the logic introduced in #4144 to improve the separation between the node and wallet. The notifier thread now lives next in `src/validationinterface.cpp` directly next to the existing `CMainSignals` node-wallet interface.
Part of #3877.
Bitcoin script PRs 1
Cherry-picked from the following upstream PRs:
- bitcoin/bitcoin#6335
- bitcoin/bitcoin#6424
- bitcoin/bitcoin#11058
- bitcoin/bitcoin#12460
- bitcoin/bitcoin#13194
Part of #2074.
Jack Grigg
Homu
MeshCollider
Alfredo Garcia
Daira Hopwood
Gregory Maxwell
ebfull
Wladimir J. van der Laan
Luke Dashjr
MarcoFalke
Dimitris Apostolou
Jorge Timón
Dagur Valberg Johannsson
Eirik Ogilvie-Wigley