Support for type hints was introduced in Python 3.5. Type hints make it easier to read and review code in my opinion. Also an IDE may discover a potential bug sooner. Yet, as PEP 484 says: "It should also be emphasized that Python will remain a dynamically typed language, and the authors have no desire to ever make type hints mandatory, even by convention."
Mypy is used in lint-python.sh to do the type checking. The package is standard so there is little chance that it will be abandoned. Mypy checks that type hints in source code are correct when they are not, it fails with an error.
Useful resources:
* https://docs.python.org/3.5/library/typing.html
* https://www.python.org/dev/peps/pep-0484/
9743432034 Fix bug where duplicate PSBT keys are accepted (John L. Jegutanis)
Pull request description:
As per the BIP 174 spec a PSBT key cannot be duplicated,
however the current code accepts key duplication.
The PSBT key/value entries can be duplicated when the value
is `empty()` or `IsNull()` for `CScript` or `CTxOut` respectively
and if those key/value entries are serialized before the non-empty ones.
For example, the following PSBT, included in the test vectors,
contains a duplicate field:
```
// magic
70736274ff
// global tx
//// key
0100
//// value
2a02000000000140420f000000000017a9146e91b72d5593e7d4391e2ff44e91e985c31641f08700000000
//// separator
00
// no inputs
// outputs
//// key PSBT_OUT_WITNESSSCRIPT
0101
//// value (empty script)
00
//// key PSBT_OUT_WITNESSSCRIPT (same as the above)
0101
//// value (an OP_RETURN script)
016a
//// separator
00
```
ACKs for top commit:
achow101:
ACK 9743432034
instagibbs:
code review ACK 9743432034
Tree-SHA512: 34f4b34c8e6561c6a6ab745cdd319f6687eac6f7cecc735c94035eeca8c5157e17a27f2ae853dbaa6634fcd5a8f4e1c6cc13d1ebd7e563459665d72bb147cc1e
As per the BIP 174 spec a PSBT key cannot be duplicated,
however the current code accepts key duplication.
The PSBT key/value entries can be duplicated when the value
is `empty()` or `IsNull()` for `CScript` or `CTxOut` respectively
and if those key/value entries are serialized before the non-empty ones.
For example, the following PSBT, included in the test vectors,
contains a duplicate field:
```
// magic
70736274ff
// global tx
//// key
0100
//// value
2a02000000000140420f000000000017a9146e91b72d5593e7d4391e2ff44e91e985c31641f08700000000
//// separator
00
// no inputs
// outputs
//// key PSBT_OUT_WITNESSSCRIPT
0101
//// value (empty script)
00
//// key PSBT_OUT_WITNESSSCRIPT (same as the above)
0101
//// value (an OP_RETURN script)
016a
//// separator
00
```
c4b0c08f7c Update tx-size-small comment with relevant CVE disclosure (Gregory Sanders)
Pull request description:
Code first introduced under https://github.com/bitcoin/bitcoin/pull/11423 with essentially no description and no discussion.
ACKs for top commit:
MarcoFalke:
ACK c4b0c08f7c
fanquake:
ACK c4b0c08f7c
Tree-SHA512: 95d5c92998b8b1e944c477dbaee265b62612b6e815099ab31d9ff580b4dff777abaf7f326a284644709f918aa1510412d62310689b1250ef6e64de7b19ca9f71
0c62e3aa73 New regression testing for CVE-2018-17144, CVE-2012-2459, and CVE-2010-5137. (lucash-dev)
38bfca6bb2 Added comments referencing multiple CVEs in tests and production code. (lucash-dev)
Pull request description:
This functional test includes two scenarios that test for regressions of vulnerabilities, but they are only briefly described. There are freely available documents explaining in detail the issues, but without explicit mentions, the developer trying to maintain the code needs an additional step of digging in commit history and PR conversations to figure it out.
Added comments to explicitly mention CVE-2018-17144 and CVE-2012-2459, for more complete documentation.
This improves developer experience by making understanding the tests easier.
ACKs for top commit:
laanwj:
ACK 0c62e3aa73, checked the CVE numbers, thanks for adding documentation
Tree-SHA512: 3ee05351745193b8b959e4a25d50f25a693b2d24b0732ed53cf7d5882df40b5dd0f1877bd5c69cffb921d4a7acf9deb3cc1160b96dc730d9b5984151ad06b7c9
2222c96dee test: Add notes on how to generate data/wallets/high_minversion (MarcoFalke)
Pull request description:
I forgot to do this in #16796
ACKs for top commit:
ryanofsky:
ACK 2222c96dee
Tree-SHA512: 5f24ffa641b97eac4febad42ade7228b14fa72335c918a10880c5dec86a3ecc3075a31526f275188e07fea95b8e2c6320c64f716099f604b00e13d5366fcee37
333317ce6b test: Test that low difficulty chain fork is rejected (MarcoFalke)
fa31dc1bf4 test: Pass down correct chain name in tests (MarcoFalke)
Pull request description:
To prevent OOM, Bitcoin Core will reject chain forks at low difficulty by default. This is the only use-case of checkpoints, so add a test for it to make sure the feature works as expected. If it didn't work, checkpoints would have no use-case and we might as well remove them
ACKs for top commit:
Sjors:
Thanks for adding the node 1 example. Code review ACK 333317c
Tree-SHA512: 90dffa540d0904f3cffb61d2382b1a26f84fe9560b7013e4461546383add31a8757b350616a6d43217c59ef7b8b2a1b62bb3bab582c679cbb2c660a782ce7be1
CVE-2018-17144 and CVE-2012-2459 are only partially tested for regression.
- CVE-2018-17144 is not tested for the inflation bug.
- CVE-2012-2459 is only tested for the mutated block being rejected, not
for the original block being accepted afterwards.
This commit fixes that limitation.
Also added functional test for CVE-2010-5137.
d20d756752 rpc: faster getblockstats using BlockUndo data (Felix Weis)
Pull request description:
Using undo data for a block (rev?????.dat) we can retrieve value information about prevouts and calculate the final transaction fee (rate). This approach is about 80x faster, drops the requirement for `-txindex`, and works for all non-pruned blocks.
```
# 2018-11-25T16:36:19Z Bitcoin Core version v0.17.99.0-edc715240-dirty (release build)
seq 550100 550200 0.00s user 0.00s system 62% cpu 0.004 total
xargs -n1 src/bitcoin-cli getblockstats 0.21s user 0.19s system 17% cpu 2.302 total
# 2018-11-25T16:39:17Z Bitcoin Core version v0.17.0 (release build)
seq 550100 550200 0.00s user 0.00s system 87% cpu 0.002 total
xargs -n1 src/bitcoin-cli getblockstats 0.24s user 0.22s system 0% cpu 3:19.42 total
```
ACKs for commit d20d75:
MarcoFalke:
re-utACK d20d756752
Tree-SHA512: 5babc3eb8d2fee2cb23dc12f522656b80737a540cbf2b13390a8f388304c46c064cca76f896b46a6e2abae8cc582d28e1ab20dd4bb17ad6142f20630c2d30c54
Using undo data for a block (rev?????.dat) we can retrieve value information about prevouts and calculate the final transaction fee (rate). This approach is about 80x faster, drops the requirement for -txindex, and works for all non-pruned blocks.
0ff1c2a838 Separate reason for premature spends (coinbase/locktime) (Suhas Daftuar)
54470e767b Assert validation reasons are contextually correct (Suhas Daftuar)
2120c31521 [refactor] Update some comments in validation.cpp as we arent doing DoS there (Matt Corallo)
12dbdd7a41 [refactor] Drop unused state.DoS(), state.GetDoS(), state.CorruptionPossible() (Matt Corallo)
aa502b88d1 scripted-diff: Remove DoS calls to CValidationState (Matt Corallo)
7721ad64f4 [refactor] Prep for scripted-diff by removing some \ns which annoy sed. (Matt Corallo)
5e78c5734b Allow use of state.Invalid() for all reasons (Matt Corallo)
6b34bc6b6f Fix handling of invalid headers (Suhas Daftuar)
ef54b486d5 [refactor] Use Reasons directly instead of DoS codes (Matt Corallo)
9ab2a0412e CorruptionPossible -> BLOCK_MUTATED (Matt Corallo)
6e55b292b0 CorruptionPossible -> TX_WITNESS_MUTATED (Matt Corallo)
7df16e70e6 LookupBlockIndex -> CACHED_INVALID (Matt Corallo)
c8b0d22698 [refactor] Drop redundant nDoS, corruptionPossible, SetCorruptionPossible (Matt Corallo)
34477ccd39 [refactor] Add useful-for-dos "reason" field to CValidationState (Matt Corallo)
6a7f8777a0 Ban all peers for all block script failures (Suhas Daftuar)
7b999103e2 Clean up banning levels (Matt Corallo)
b8b4c80146 [refactor] drop IsInvalid(nDoSOut) (Matt Corallo)
8818729013 [refactor] Refactor misbehavior ban decisions to MaybePunishNode() (Matt Corallo)
00e11e61c0 [refactor] rename stateDummy -> orphan_state (Matt Corallo)
f34fa719cf Drop obsolete sigops comment (Matt Corallo)
Pull request description:
This is a rebase of #11639 with some fixes for the last few comments which were not yet addressed.
The original PR text, with some strikethroughs of text that is no longer correct:
> This cleans up an old main-carryover - it made sense that main could decide what DoS scores to assign things because the DoS scores were handled in a different part of main, but now validation is telling net_processing what DoS scores to assign to different things, which is utter nonsense. Instead, we replace CValidationState's nDoS and CorruptionPossible with a general ValidationInvalidReason, which net_processing can handle as it sees fit. I keep the behavior changes here to a minimum, but in the future we can utilize these changes for other smarter behavior, such as disconnecting/preferring to rotate outbound peers based on them providing things which are invalid due to SOFT_FORK because we shouldn't ban for such cases.
>
> This is somewhat complementary with, though obviously conflicts heavily with #11523, which added enums in place of DoS scores, as well as a few other cleanups (which are still relevant).
>
> Compared with previous bans, the following changes are made:
>
> Txn with empty vin/vout or null prevouts move from 10 DoS
> points to 100.
> Loose transactions with a dependency loop now result in a ban
> instead of 10 DoS points.
> ~~BIP68-violation no longer results in a ban as it is SOFT_FORK.~~
> ~~Non-SegWit SigOp violation no longer results in a ban as it
> considers P2SH sigops and is thus SOFT_FORK.~~
> ~~Any script violation in a block no longer results in a ban as
> it may be the result of a SOFT_FORK. This should likely be
> fixed in the future by differentiating between them.~~
> Proof of work failure moves from 50 DoS points to a ban.
> Blocks with timestamps under MTP now result in a ban, blocks
> too far in the future continue to not result in a ban.
> Inclusion of non-final transactions in a block now results in a
> ban instead of 10 DoS points.
Note: The change to ban all peers for consensus violations is actually NOT the change I'd like to make -- I'd prefer to only ban outbound peers in those situations. The current behavior is a bit of a mess, however, and so in the interests of advancing this PR I tried to keep the changes to a minimum. I plan to revisit the behavior in a followup PR.
EDIT: One reviewer suggested I add some additional context for this PR:
> The goal of this work was to make net_processing aware of the actual reasons for validation failures, rather than just deal with opaque numbers instructing it to do something.
>
> In the future, I'd like to make it so that we use more context to decide how to punish a peer. One example is to differentiate inbound and outbound peer misbehaviors. Another potential example is if we'd treat RECENT_CONSENSUS_CHANGE failures differently (ie after the next consensus change is implemented), and perhaps again we'd want to treat some peers differently than others.
ACKs for commit 0ff1c2:
jnewbery:
utACK 0ff1c2a838
ryanofsky:
utACK 0ff1c2a838. Only change is dropping the first commit (f3883a321bf4ab289edcd9754b12cae3a648b175), and dropping the temporary `assert(level == GetDoS())` that was in 35ee77f2832eaffce30042e00785c310c5540cdc (now c8b0d22698)
Tree-SHA512: e915a411100876398af5463d0a885920e44d473467bb6af991ef2e8f2681db6c1209bb60f848bd154be72d460f039b5653df20a6840352c5f7ea5486d9f777a3
Compared with previous bans, the following changes are made:
* Txn with empty vin/vout or null prevouts move from 10 DoS
points to 100.
* Loose transactions with a dependency loop now result in a ban
instead of 10 DoS points.
* Many pre-segwit soft-fork errors now result in a ban.
Note: Transactions that violate soft-fork script flags since P2SH do not generally
result in a ban. Also, banning behavior for invalid blocks is dependent on
whether the node is validating with multiple script check threads, due to a long-
standing bug. That inconsistency is still present after this commit.
* Proof of work failure moves from 50 DoS points to a ban.
* Blocks with timestamps under MTP now result in a ban, blocks
too far in the future continue to *not* result in a ban.
* Inclusion of non-final transactions in a block now results in a
ban instead of 10 DoS points.
Co-authored-by: Anthony Towns <aj@erisian.com.au>
5df6f089b5 More tests of signer checks (Andrew Chow)
7c8bffdc24 Test that a non-witness script as witness utxo is not signed (Andrew Chow)
8254e9950f Additional sanity checks in SignPSBTInput (Pieter Wuille)
c05712cb59 Only wipe wrong UTXO type data if overwritten by wallet (Pieter Wuille)
Pull request description:
The current PSBT signing code can end up producing a non-segwit signature, while only the UTXO being spent is provided in the PSBT (as opposed to the entire transaction being spent). This may be used to trick a user to incorrectly decide a transaction has the semantics he intends to sign.
Fix this by refusing to sign if there is any mismatch between the provided data and what is being signed.
Tree-SHA512: b55790d79d8166e05513fc4c603a982a33710e79dc3c045060cddac6b48a1be3a28ebf8db63f988b6567b15dd27fd09bbaf48846e323c8635376ac20178956f4
0-input transactions can be ambiguously deserialized as being witness
transactions. Since the unsigned transaction is never serialized as
a witness transaction as it has no witnesses, we should always
deserialize it as a non-witness transaction and set the serialization
flags as such.
Also always serialize the unsigned transaction as a non-witness transaction.
4b7091a842 Replace median fee rate with feerate percentiles (Marcin Jachymiak)
Pull request description:
Currently, the `medianfeerate` statistic is calculated from the feerate of the middle transaction of a list of transactions sorted by feerate.
This PR instead uses the value of the 50th percentile weight unit in the block, and also calculates the feerate at the 10th, 25th, 75th, and 90th percentiles. This more accurately corresponds with what is generally meant by median feerate.
Tree-SHA512: 59255e243df90d7afbe69839408c58c9723884b8ab82c66dc24a769e89c6d539db1905374a3f025ff28272fb25a0b90e92d8101103e39a6d9c0d60423a596714
Removes medianfeerate result from getblockstats.
Adds feerate_percentiles which give the feerate of the 10th, 25th, 50th,
75th, and 90th percentile weight unit in the block.
When extra entropy is not specified by the caller, CKey::Sign will
now always create a signature that has a low R value and is at most
70 bytes. The resulting signature on the stack will be 71 bytes when
the sighash byte is included.
Using low R signatures means that the resulting DER encoded signature
will never need to have additional padding to account for high R
values.
Checks that all of the one byte type keys are actually one byte and
throw an error if they are not.
Add tests for each type to check for this behavior.
Added functional tests for PSBT that test the RPCs. Also added all
of the BIP 174 test vectors (except for the updater tests) in the
functional tests.
Added a Unit test for the BIP 174 updater test vector.
