// Check kernel hash target and coinstake signature
public static bool CheckProofOfStake(IBlockRepository blockStore, ITransactionRepository trasnactionStore, IBlockTransactionMapStore mapStore,
ChainedBlock pindexPrev, BlockStake prevBlockStake, Transaction tx, uint nBits, out uint256 hashProofOfStake, out uint256 targetProofOfStake)
{
targetProofOfStake = null; hashProofOfStake = null;
// todo: Comments on this mehtod:
// the store objects (IBlockRepository and ITransactionRepository) should be a singleton instance of
// the BlockValidator and would be initiated as part of a Dependency Injection freamwork
if (!tx.IsCoinStake)
{
return(false); // error("CheckProofOfStake() : called on non-coinstake %s", tx.GetHash().ToString());
}
// Kernel (input 0) must match the stake hash target per coin age (nBits)
var txIn = tx.Inputs[0];
// First try finding the previous transaction in database
var txPrev = trasnactionStore.Get(txIn.PrevOut.Hash);
if (txPrev == null)
{
return(false); // tx.DoS(1, error("CheckProofOfStake() : INFO: read txPrev failed")); // previous transaction not in main chain, may occur during initial download
}
// Verify signature
if (!VerifySignature(txPrev, tx, 0, ScriptVerify.None))
{
return(false); // tx.DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", tx.GetHash().ToString()));
}
// Read block header
var blockHashPrev = mapStore.GetBlockHash(txIn.PrevOut.Hash);
var block = blockHashPrev == null ? null : blockStore.GetBlock(blockHashPrev);
if (block == null)
{
return(false); //fDebug? error("CheckProofOfStake() : read block failed") : false; // unable to read block of previous transaction
}
// Min age requirement
if (IsProtocolV3((int)tx.Time))
{
int nDepth = 0;
if (IsConfirmedInNPrevBlocks(blockStore, txPrev, pindexPrev, StakeMinConfirmations - 1, ref nDepth))
{
return(false); // tx.DoS(100, error("CheckProofOfStake() : tried to stake at depth %d", nDepth + 1));
}
}
else
{
var nTimeBlockFrom = block.Header.Time;
if (nTimeBlockFrom + StakeMinAge > tx.Time)
{
return(false); // error("CheckProofOfStake() : min age violation");
}
}
if (!CheckStakeKernelHash(pindexPrev, nBits, block, txPrev, prevBlockStake, txIn.PrevOut, tx.Time, out hashProofOfStake, out targetProofOfStake, false))
{
return(false); // tx.DoS(1, error("CheckProofOfStake() : INFO: check kernel failed on coinstake %s, hashProof=%s", tx.GetHash().ToString(), hashProofOfStake.ToString())); // may occur during initial download or if behind on block chain sync
}
return(true);
}
public static bool CheckKernel(IBlockRepository blockStore, ITransactionRepository trasnactionStore,
IBlockTransactionMapStore mapStore, StakeChain stakeChain,
ChainedBlock pindexPrev, uint nBits, long nTime, OutPoint prevout, ref long pBlockTime)
{
uint256 hashProofOfStake = null, targetProofOfStake = null;
var txPrev = trasnactionStore.Get(prevout.Hash);
if (txPrev == null)
{
return(false);
}
// Read block header
var blockHashPrev = mapStore.GetBlockHash(prevout.Hash);
var block = blockHashPrev == null ? null : blockStore.GetBlock(blockHashPrev);
if (block == null)
{
return(false);
}
if (IsProtocolV3((int)nTime))
{
int nDepth = 0;
if (IsConfirmedInNPrevBlocks(blockStore, txPrev, pindexPrev, StakeMinConfirmations - 1, ref nDepth))
{
return(false); // tx.DoS(100, error("CheckProofOfStake() : tried to stake at depth %d", nDepth + 1));
}
}
else
{
var nTimeBlockFrom = block.Header.Time;
if (nTimeBlockFrom + StakeMinAge > nTime)
{
return(false); // error("CheckProofOfStake() : min age violation");
}
}
var prevBlockStake = stakeChain.Get(pindexPrev.HashBlock);
if (prevBlockStake == null)
{
return(false); // the stake proof of the previous block is not set
}
// todo: check this unclear logic
//if (pBlockTime)
// pBlockTime = block.Header.Time;
return(CheckStakeKernelHash(pindexPrev, nBits, block, txPrev, prevBlockStake, prevout, (uint)nTime, out hashProofOfStake, out targetProofOfStake, false));
}