public string CalculateHash()
{
string inputStr = fromAccount + toAccount + timestamp + amount;
string hash = ChainHelper.CalculateHash(inputStr);
return(hash);
}
/**
* Loops over all the blocks in the chain and verify if they are properly
* linked together and nobody has tampered with the hashes. By checking
* the blocks it also verifies the (signed) transactions inside of them.
*
* @returns {boolean}
*/
public bool IsChainValid(out string error)
{
// Check if the Genesis block hasn't been tampered with by comparing
// the output of createGenesisBlock with the first block on our chain
//var realGenesis = JsonConvert.SerializeObject(this.createGenesisBlock(), Formatting.Indented);
//if (realGenesis != JsonConvert.SerializeObject(this.chain[0], Formatting.Indented))
//{
// return false;
//}
// Check the remaining blocks on the chain to see if there hashes and
// signatures are correct
for (int i = 1; i < this.blocks.Count; i++)
{
var currentBlock = this.blocks[i];
if (!currentBlock.HasValidTransactions())
{
error = "Invalid transaction signature(s)";
return(false);
}
string hashStartWith = string.Empty;
for (int k = 0; k < ChainHelper.NUMBER_ZEROES; k++)
{
hashStartWith += "0";
}
if (!currentBlock.hash.StartsWith(hashStartWith))
{
error = "Tampered block hash values";
return(false);
}
var rawData = currentBlock.index + currentBlock.previousHash + currentBlock.timestamp.ToString() + currentBlock.nonce + ChainHelper.FindMerkleRootHash(currentBlock.transactions);
if (currentBlock.hash != ChainHelper.CalculateHash(ChainHelper.CalculateHash(rawData)))
{
error = "Tampered block hash values";
return(false);
}
}
error = null;
return(true);
}
private void MineBlock(Block block)
{
if (block.transactions == null)
{
return;
}
var merkleRootHash = ChainHelper.FindMerkleRootHash(block.transactions);
long nonce = -1;
var hash = string.Empty;
do
{
nonce++;
var rowData = block.index + block.previousHash + block.timestamp.ToString() + nonce + merkleRootHash;
hash = ChainHelper.CalculateHash(ChainHelper.CalculateHash(rowData));
}while (!hash.StartsWith(hashStartWith));
block.hash = hash;
block.nonce = nonce;
}
/**
* Returns the SHA256 of this block (by processing all the data stored
* inside this block)
*
* @returns {string}
*/
public string CalculateHash()
{
string inputStr = this.previousHash + this.timestamp.ToString() + JsonConvert.SerializeObject(this.transactions, Formatting.Indented) + this.nonce;
return(ChainHelper.CalculateHash(inputStr));
}