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Do not trigger a DoS ban if SCRIPT_VERIFY_NULLDUMMY fails

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Peter Todd 2014-03-10 22:36:46 -04:00
parent 6380180821
commit f80cffa213
2 changed files with 24 additions and 6 deletions
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24
src/main.cpp
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@ -1588,14 +1588,26 @@ bool CheckInputs(const CTransaction& tx, CValidationState &state, CCoinsViewCach
pvChecks->push_back(CScriptCheck()); pvChecks->push_back(CScriptCheck());
check.swap(pvChecks->back()); check.swap(pvChecks->back());
} else if (!check()) { } else if (!check()) {
if (flags & SCRIPT_VERIFY_STRICTENC) { if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) {
// For now, check whether the failure was caused by non-canonical // Check whether the failure was caused by a
// encodings or not; if so, don't trigger DoS protection. // non-mandatory script verification check, such as
CScriptCheck check(coins, tx, i, flags & (~SCRIPT_VERIFY_STRICTENC), 0); // non-standard DER encodings or non-null dummy
// arguments; if so, don't trigger DoS protection to
// avoid splitting the network between upgraded and
// non-upgraded nodes.
CScriptCheck check(coins, tx, i,
flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, 0);
if (check()) if (check())
return state.Invalid(false, REJECT_NONSTANDARD, "non-canonical"); return state.Invalid(false, REJECT_NONSTANDARD, "non-mandatory-script-verify-flag");
} }
return state.DoS(100,false, REJECT_NONSTANDARD, "non-canonical"); // Failures of other flags indicate a transaction that is
// invalid in new blocks, e.g. a invalid P2SH. We DoS ban
// such nodes as they are not following the protocol. That
// said during an upgrade careful thought should be taken
// as to the correct behavior - we may want to continue
// peering with non-upgraded nodes even after a soft-fork
// super-majority vote has passed.
return state.DoS(100,false, REJECT_INVALID, "mandatory-script-verify-flag-failed");
} }
} }
} }

6
src/script.h
View file

@ -49,6 +49,9 @@ enum
// them to be valid. (but old blocks may not comply with) Currently just P2SH, // them to be valid. (but old blocks may not comply with) Currently just P2SH,
// but in the future other flags may be added, such as a soft-fork to enforce // but in the future other flags may be added, such as a soft-fork to enforce
// strict DER encoding. // strict DER encoding.
//
// Failing one of these tests may trigger a DoS ban - see CheckInputs() for
// details.
static const unsigned int MANDATORY_SCRIPT_VERIFY_FLAGS = SCRIPT_VERIFY_P2SH; static const unsigned int MANDATORY_SCRIPT_VERIFY_FLAGS = SCRIPT_VERIFY_P2SH;
// Standard script verification flags that standard transactions will comply // Standard script verification flags that standard transactions will comply
@ -58,6 +61,9 @@ static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY
SCRIPT_VERIFY_STRICTENC | SCRIPT_VERIFY_STRICTENC |
SCRIPT_VERIFY_NULLDUMMY; SCRIPT_VERIFY_NULLDUMMY;
// For convenience, standard but not mandatory verify flags.
static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
enum txnouttype enum txnouttype
{ {
TX_NONSTANDARD, TX_NONSTANDARD,