/// <summary>
/// Create HigherLevelBlock
/// </summary>
/// <param name="period"></param>
/// <param name="hashPrev"></param>
/// <param name="txset"></param>
/// <param name="privateKey">PrivateKey of the bank.</param>
/// <returns></returns>
public static HigherLevelBlock CreateHigherLevelBlock(long period, string hashPrev, List<PaymentTransaction> txset, string privateKey)
{
string hash = CryptoHelper.Hash(hashPrev + JsonHelper.Serialize(txset));
List<LowerLevelBlock> lowerLevelBlockSet = new List<LowerLevelBlock>();
LowerLevelBlock lowerLevelBlock = new LowerLevelBlock(txset);
lowerLevelBlockSet.Add(lowerLevelBlock);
return new HigherLevelBlock
{
Period = period,
Hash = hash,
LowerLevelBlockSet = lowerLevelBlockSet,
Signature = CryptoHelper.Sign(privateKey, hash)
};
}
public LowerLevelBlock AddLowerLevelBlock(LowerLevelBlock newLowerLevelBlock)
{
var result = QueryStoreProcedure("AddLowerLevelBlock", new Dictionary<string, object>
{
{"@blockSize", newLowerLevelBlock.blockSize },
{"@blockHeader", newLowerLevelBlock.blockHeader },
{"@transactionCounter", newLowerLevelBlock.TransactionCounter },
{"@transactions", newLowerLevelBlock.TransactionSet },
{"@period", newLowerLevelBlock.Period },
{"@hash", newLowerLevelBlock.Hash },
{"@signature", newLowerLevelBlock.Signature },
{"@signatureToCertifyIssuer", newLowerLevelBlock.SignatureToCertifyIssuer },
});
if (result.Tables[0].Rows.Count > 0)
{
var llb = new LowerLevelBlock().FromRow(result.Tables[0].Rows[0]);
return llb;
}
return null;
}
public void CreateLowerLevelBlockForIssuer1()
{
if (issuer1.s_PaymentPool.Count == 0)
return;
//Construct low level block
LowerLevelBlock block = new LowerLevelBlock();
block.TransactionCounter = 0;
//Construct the block header
block.blockHeader.hashPrevBlock = GetPreviousTransactionHash();
block.blockHeader.Issuer = issuer1.Id.ToString();
block.blockHeader.Time = GetTime(DateTime.Now);
block.blockHeader.Version = issuer1.version;
while(issuer1.s_PaymentPool.Count != 0 && block.TransactionCounter < MAX_TRANSACTION)
{
PaymentTransaction transaction = issuer1.s_PaymentPool.Dequeue();
if(VerifyTransaction(transaction) == true)
{
block.TransactionSet.Add(transaction);
block.TransactionCounter++;
}
}
//Add the Merkle root
block.blockHeader.hashMerkleRoot = ConstructMerkleTree(block);
//Add the hash & size of this block
block.Hash = CryptoHelper.Hash(JsonHelper.Serialize(block));
block.blockSize = Marshal.SizeOf(block);
//Call api to post the lowerlevelblock to Bank
string requestUri = string.Format("certifier/api/postLowerLevelBlock");
HttpContent content = new StringContent(JsonHelper.Serialize(block));
content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
HttpResponseMessage response = RestApiHelper.HttpClient.PostAsync(requestUri, content).Result;
response.EnsureSuccessStatusCode();
}
/// <summary>
/// Verify LowerLevelBlock
/// </summary>
/// <param name="block"></param>
/// <param name="hashPrev"></param>
/// <param name="publicKey"></param>
/// <returns></returns>
public static bool VerifyLowerLevelBlock(LowerLevelBlock block, string hashPrev, string publicKey, string issuerPublicKey)
{
string hash = CryptoHelper.Hash(JsonHelper.Serialize(block.TransactionSet));
if (block.Hash == hash)
{
if (CryptoHelper.Verify(issuerPublicKey, hash, block.Signature))
{
if (CryptoHelper.Verify(publicKey, issuerPublicKey, block.SignatureToCertifyIssuer))
{
return true;
}
}
}
return false;
}
public void ReceiveLowerLevelBlock(LowerLevelBlock block)
{
bankService.bank.s_LowerLevelBlockPool.Enqueue(block);
bankService.bank.prevBlockHash = block.Hash;
//TODO: write the received block into database
}
private bool CheckingLedger(LowerLevelBlock llb)
{
//TODO:check ledger
throw new NotImplementedException();
}
private string ConstructMerkleTree(LowerLevelBlock block)
{
int numberofPayment = block.TransactionCounter;
int counter = 0;
Queue<string> MerkleTree = new Queue<string>();
foreach (var transaction in block.TransactionSet)
{
MerkleTree.Enqueue(CryptoHelper.Hash(JsonHelper.Serialize(transaction)));
}
if (numberofPayment % 2 == 1)
{
MerkleTree.Enqueue(CryptoHelper.Hash(JsonHelper.Serialize(block.TransactionSet[numberofPayment - 1])));
numberofPayment++;
}
while (MerkleTree.Count != 1)
{
string hash = MerkleTree.Dequeue();
hash += MerkleTree.Dequeue();
MerkleTree.Enqueue(CryptoHelper.Hash(JsonHelper.Serialize(hash)));
counter += 2;
if(counter + 1 == numberofPayment)
{
hash = MerkleTree.Dequeue();
hash += hash;
MerkleTree.Enqueue(CryptoHelper.Hash(JsonHelper.Serialize(hash)));
counter++;
}
if(counter == numberofPayment)
{
counter = 0;
numberofPayment /= 2;
}
}
string result = MerkleTree.Dequeue();
MerkleTree = null;
return result;
}