//
// Check transaction inputs, and make sure any
// pay-to-script-hash transactions are evaluating IsStandard scripts
//
// Why bother? To avoid denial-of-service attacks; an attacker
// can submit a standard HASH... OP_EQUAL transaction,
// which will get accepted into blocks. The redemption
// script can be anything; an attacker could use a very
// expensive-to-check-upon-redemption script like:
// DUP CHECKSIG DROP ... repeated 100 times... OP_1
//
public static bool AreInputsStandard(Transaction tx, TxOutRepository mapInputs)
{
if(tx.IsCoinBase)
return true; // Coinbases don't use vin normally
for(int i = 0 ; i < tx.Inputs.Count ; i++)
{
TxOut prev = mapInputs.GetOutputFor(tx.Inputs[i]);
if(prev == null)
return false;
if(!IsStandardScriptSig(tx.Inputs[i].ScriptSig, prev.ScriptPubKey))
return false;
}
return true;
}
//
// Check transaction inputs, and make sure any
// pay-to-script-hash transactions are evaluating IsStandard scripts
//
// Why bother? To avoid denial-of-service attacks; an attacker
// can submit a standard HASH... OP_EQUAL transaction,
// which will get accepted into blocks. The redemption
// script can be anything; an attacker could use a very
// expensive-to-check-upon-redemption script like:
// DUP CHECKSIG DROP ... repeated 100 times... OP_1
//
public static bool AreInputsStandard(Transaction tx, TxOutRepository mapInputs)
{
if (tx.IsCoinBase)
{
return(true); // Coinbases don't use vin normally
}
for (int i = 0; i < tx.Inputs.Count; i++)
{
TxOut prev = mapInputs.GetOutputFor(tx.Inputs[i]);
if (prev == null)
{
return(false);
}
if (!IsStandardScriptSig(tx.Inputs[i].ScriptSig, prev.ScriptPubKey))
{
return(false);
}
}
return(true);
}
