public virtual Block CreateValidBlockAndAddToChain(string privateKey, Blockchain blockchain, uint protocolVersion, IEnumerable <AbstractTransaction> transactions, BigDecimal difficulty, BigDecimal maximumTarget, CancellationToken ct)
{
if (difficulty < 1)
{
throw new DifficultyCalculationException("Difficulty cannot be zero.");
}
bool targetMet = false;
var currentTarget = maximumTarget / difficulty;
Block b = PrepareBlock(blockchain, protocolVersion, transactions, currentTarget);
// Keep on mining
while (targetMet == false)
{
ct.ThrowIfCancellationRequested();
if (hotRestart)
{
b = PrepareBlock(blockchain, protocolVersion, transactions, currentTarget);
hotRestart = false;
}
if (b.Header.Nonce == ulong.MaxValue)
{
throw new NonceLimitReachedException();
}
b.Header.IncrementNonce();
var hash = _blockFinalizer.CalculateHash(b);
_blockFinalizer.FinalizeBlock(b, hash, privateKey);
try
{
_validator.ValidateBlock(b, currentTarget, blockchain, true, true);
targetMet = true;
}
catch (BlockRejectedException ex)
{
if (ex.Message != "Hash has no leading zero" && ex.Message != "Hash value is equal or higher than the current target")
{
throw;
}
}
}
return(b);
}
public virtual void ValidateBlockHeader(Block block, BigDecimal hashValue, BigDecimal currentTarget, bool checkTimestamp, string netId)
{
// The block must be in the same network as our node
if (block.Header.MagicNumber != netId)
{
throw new BlockRejectedException("Block comes from a different network", block);
}
if (!block.Header.IsFinalized())
{
throw new BlockRejectedException("Block is not hashed or signed or hashed properly", block);
}
else if (block.Header.Hash != _blockFinalizer.CalculateHash(block))
{
throw new BlockRejectedException("The hash property of the block is not equal to the calculated hash", block);
}
// Hash value must be lower than the target and the first byte must be zero
// because the first byte indidates if the hashValue is a positive or negative number,
// negative numbers are not allowed.
if (!block.Header.Hash.StartsWith("0"))
{
throw new BlockRejectedException("Hash has no leading zero", block);
}
// The hash value must be lower than the given target
if (hashValue >= currentTarget)
{
throw new BlockRejectedException("Hash value is equal or higher than the current target", block);
}
if (!checkTimestamp)
{
return;
}
// Timestamp must not be lower than UTC - 2 min and not higher than UTC + 2 min
if (_timestamper.GetCurrentUtcTimestamp() - block.Header.Timestamp > BlockchainConstants.MaximumTimestampOffset || _timestamper.GetCurrentUtcTimestamp() - block.Header.Timestamp < (BlockchainConstants.MaximumTimestampOffset * -1))
{
throw new BlockRejectedException("Block timestamp differs too much");
}
}