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authorJohnson Lau <jl2012@users.noreply.github.com>2016-09-22 15:06:54 +0800
committerJohnson Lau <jl2012@xbt.hk>2016-09-27 23:40:59 +0800
commite41bd449ab2b8d01260795383af2c40b659d8587 (patch)
treeec0bc7f8b5624774199b09072fdcee0ed66f6122 /src/script/interpreter.cpp
parent5a4f6d72e6154d21eb34fbbc8d7c099532569966 (diff)
Add policy: null signature for failed CHECK(MULTI)SIG
Diffstat (limited to 'src/script/interpreter.cpp')
-rw-r--r--src/script/interpreter.cpp14
1 files changed, 13 insertions, 1 deletions
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index fd356fed0a..41756ea711 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -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.