diff options
| author | Peter Todd <pete@petertodd.org> | 2014-09-28 21:17:36 -0400 |
|---|---|---|
| committer | Peter Todd <pete@petertodd.org> | 2014-11-17 22:22:33 -0500 |
| commit | 03914234b3c9c35d66b51d580fe727a0707394ca (patch) | |
| tree | 7b8bb1ddba7c75adefa5241bc97d3b5f0a5d2608 /src/script/interpreter.cpp | |
| parent | 8adf457047677df1d58da070bae5629526bb5b74 (diff) | |
Discourage NOPs reserved for soft-fork upgrades
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.
Diffstat (limited to 'src/script/interpreter.cpp')
| -rw-r--r-- | src/script/interpreter.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp index cf81fe30a2..760086eaba 100644 --- a/src/script/interpreter.cpp +++ b/src/script/interpreter.cpp @@ -329,8 +329,14 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un // Control // case OP_NOP: + break; + case OP_NOP1: case OP_NOP2: case OP_NOP3: case OP_NOP4: case OP_NOP5: case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10: + { + if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) + return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS); + } break; case OP_IF: |