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Add policy: null signature for failed CHECK(MULTI)SIG

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Johnson Lau 2016-09-22 15:06:54 +08:00 • committed by Johnson Lau
parent 5a4f6d72e6
commit e41bd449ab
8 changed files with 55 additions and 2 deletions
src/script
interpreter.cpp

14
src/script/interpreter.cpp
View file

@ -885,6 +885,9 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
}
bool fSuccess = checker.CheckSig(vchSig, vchPubKey, scriptCode, sigversion);
if (!fSuccess && (flags & SCRIPT_VERIFY_NULLFAIL) && vchSig.size())
return set_error(serror, SCRIPT_ERR_SIG_NULLFAIL);
popstack(stack);
popstack(stack);
stack.push_back(fSuccess ? vchTrue : vchFalse);
@ -914,6 +917,9 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
if (nOpCount > MAX_OPS_PER_SCRIPT)
return set_error(serror, SCRIPT_ERR_OP_COUNT);
int ikey = ++i;
// ikey2 is the position of last non-signature item in the stack. Top stack item = 1.
// With SCRIPT_VERIFY_NULLFAIL, this is used for cleanup if operation fails.
int ikey2 = nKeysCount + 2;
i += nKeysCount;
if ((int)stack.size() < i)
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
@ -970,8 +976,14 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
}
// Clean up stack of actual arguments
while (i-- > 1)
while (i-- > 1) {
// If the operation failed, we require that all signatures must be empty vector
if (!fSuccess && (flags & SCRIPT_VERIFY_NULLFAIL) && !ikey2 && stacktop(-1).size())
return set_error(serror, SCRIPT_ERR_SIG_NULLFAIL);
if (ikey2 > 0)
ikey2--;
popstack(stack);
}
// A bug causes CHECKMULTISIG to consume one extra argument
// whose contents were not checked in any way.