Now that signing is deterministic, we can require exact correspondence between the
automatically generated tests and the ones read from JSON. Do this, and update
the tests to those deterministic versions. Note that some flag changes weren't
correctly applied before.
Based on an earlier patch by Peter Todd, though the rules here are different
(P2SH scripts should not have a CLEANSTACK check before the P2SH evaluation).
Add a sanity check to prevent cosmic rays from flipping a bit in the
generated public key, or bugs in the elliptic curve code. This is
simply done by signing a (randomized) message, and verifying the
result.
This turns STRICTENC turn into a softforking-safe change (even though it
is not intended as a consensus rule), and as a result guarantee that using
it for mempool validation only results in consensus-valid transactions in
the mempool.
NOP1 to NOP10 are reserved for future soft-fork upgrades. In the event
of an upgrade such NOPs have *VERIFY behavior, meaning that if their
arguments are not correct the script fails. Discouraging these NOPs by
rejecting transactions containing them from the mempool ensures that
we'll never accept transactions, nor mine blocks, with scripts that are
now invalid according to the majority of hashing power even if we're not
yet upgraded. Previously this wasn't an issue as the IsStandard() rules
didn't allow upgradable NOPs anyway, but 7f3b4e95 relaxed the
IsStandard() rules for P2SH redemptions allowing any redeemScript to be
spent.
We *do* allow upgradable NOPs in scripts so long as they are not
executed. This is harmless as there is no opportunity for the script to
be invalid post-upgrade.
This allows for a reversal of the current behavior.
This:
CScript foo;
CScriptID bar(foo.GetID());
Becomes:
CScript foo;
CScriptID bar(foo);
This way, CScript is no longer dependent on CScriptID or Hash();
* Delete canonical_tests.cpp, and move the tests to script_tests.cpp.
* Split off SCRIPT_VERIFY_DERSIG from SCRIPT_VERIFY_STRICTENC (the BIP62 part of it).
* Change signature STRICTENC/DERSIG semantics to fail the script entirely rather than the CHECKSIG result (softfork safety, and BIP62 requirement).
* Add many autogenerated tests for several odd cases.
* Mention specific BIP62 rules in the script verification flags.
Pieter Wuille