This removes the P2SH script verify flag from the various reference test
data since it is now a noop due to the corresponding flag being removed
from the script engine.
This removes the ScriptVerifyStrictEncoding flag from the txscript
package, changes the default semantics to always enforce its behavior
and updates all callers in the repository accordingly.
This change is being made to simplify the script engine code since the
flag has always been active and required by consensus in Decred, so
there is no need to require a flag to conditionally toggle it.
It should be noted that the tests removed from script_valid.json
specifically dealt with ensuring signatures not compliant with DER
encoding did not cause execution to halt early on invalid signatures
when neither of the ScriptVerifyStrictEncoding or
ScriptVerifyDERSignatures flags were set. Therefore, they are no longer
necessary.
For nearly the same reason, the tx test related to the empty pubkey
tx_valid.json was moved to tx_invalid.json. In particular, an empty
pubkey without ScriptVerifyStrictEncoding simply failed the signature
check and continued execution, while the same condition with the flag
halts execution. Thus, without the flag the final NOT in the script
would allow the script to succeed, while it does not under the strict
encoding rules.
Finally, the STRICTENC indicator to enable the flag in the test data has
been retained for now in order to keep the logic changes separate.
This modifies the script engine to replace OP_NOP3 with
OP_CHECKSEQUENCEVERIFY and adds a flag to selectively enable its
enforcement.
The new opcode examines the top item on the stack and compares it
against the sequence number of the associated transaction input in order
to allow scripts to conditionally enforce the inclusion of relative time
locks to the transaction.
The following is an overview of the changes:
- Introduce a new flag named ScriptVerifyCheckSequenceVerify to
provide conditional enforcement of the new opcode
- Introduce a constant named OP_CHECKSEQUENCEVERIFY which has the same
value as OP_NOP3 since it is replacing it
- Update opcode to name mappings accordingly
- Abstract the logic that deals with time lock verification since it is
the same for both the new opcode and OP_CHECKLOCKTIMEVERIFY
- Implement the required opcode semantics
- Add tests to ensure the opcode works as expected including when used
both correctly and incorrectly
This reverts the changes related to the CheckSequenceVerify opcode that
were merged from upstream since additional changes are needed and it's
much cleaner to implement all of code related to the sequence locks in
the same PR which will be referenced by the DCP as opposed to being
split up in multiple.
Upstream commit a6bf1d9850.
The merge commit modifies all of the encoded transactions in the test
data to use Decred native format and contains some other minor
modifications necessary to integrate with Decred.
This modifies the signatures of all the transactions in the invalid
transaction data which involve checking signatures to ensure that they
are not failing for the wrong reason.
In order to make it easier for future updates, it introduces three
well-known private keys, 1, 2, and 3, that are used for signing all of
the transactions and adds them to the comments in the test data. The
first one is used for regular CHECKSIG while all three are used for
CHECKMULTISIG.
This removes the tests related to max money checks since txscript does
not do sanity checking on the monetary amounts as that is done by the
consensus rules in blockchain.
While here, update dcrscript -> txscript in the comments to reflect
reality.
As an aside, the existing tests were invalid anyways since the
signatures were invalid and thus the tests were failing for the wrong
reason.
This removes the test for the original Bitcoin bug in CHECKMULTISIG that
required an additional argument since that has been fixed in Decred and
the test therefore no longer applies.
As an aside, the existing test was invalid anyways since the signature
was invalid and thus the test would've failed for the wrong reason.
This replaces the tests for CODESEPARATOR in the invalid transaction
JSON data to be correct for Decred. It is always invalid to pass over
the CODESEPARATOR opcode in Decred as opposed to the Bitcoin behavior
where it changes what is hashed for the signature hash calculation.
As an aside, the previous tests were invalid anyways since they included
a signature that was invalid so the test would've failed for the wrong
reason. For all of these tests it's important for them to pass other
than the specific failure condition they are intended to trigger.
This corrects the hashes for the p2sh scripts in the invalid transaction
JSON data. This helps ensure the transactions are failing for the
intended reason as opposed to the p2sh script never being run because
the script hashes don't match.
See https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki for
more information.
This commit mimics Bitcoin Core commit bc60b2b4b401f0adff5b8b9678903ff8feb5867b
and includes additional tests from Bitcoin Core commit
cb54d17355864fa08826d6511a0d7692b21ef2c9
This commit contains fixes from the results of a thorough audit of
txscript to find any cases of script evaluation which doesn't match the
required consensus behavior. These conditions are fairly obscure and
highly unlikely to happen in any real scripts, but they could have
nevertheless been used by a clever attacker with malicious intent to
cause a fork.
Test cases which exercise these conditions have been added to the
reference tests and will contributed upstream to improve the quality for
the entire ecosystem.
This commit adds two new verification flags to txscript named
ScriptVerifyStrictEncoding and ScriptVerifyDerSignatures.
The ScriptVerifyStrictEncoding flag enforces signature scripts
and public keys to follow the strict encoding requirements.
The ScriptVerifyDerSignatures flag enforces signature scripts
to follow the strict encoding requirements.
These flags mimic Bitcoin Core's SCRIPT_VERIFY_STRICTENC and
SCRIPT_VERIFY_DERSIG flags and brings the Bitcoin Core test scripts up
to date.
This commit contains the entire btcscript repository along with several
changes needed to move all of the files into the txscript directory in
order to prepare it for merging. This does NOT update btcd or any of the
other packages to use the new location as that will be done separately.
- All import paths in the old btcscript test files have been changed to the
new location
- All references to btcscript as the package name have been chagned to
txscript
This is ongoing work toward #214.
