/// <summary>
/// Requests PIT for the specified block from a random connected neighbor node.
/// Nominally, only the transactions included in `txids` need to be verifiable with the PIT, but
/// due to how Cuckoo filtering works, some false positives will also be included. This helps with anonymization, if the false positive rate is high enough.
/// </summary>
/// <param name="block_num">Block number for which the PIT should be included.</param>
/// <param name="txids">List of interesting transactions, which we wish to verify.</param>
private void requestPITForBlock(ulong block_num, List <string> txids)
{
lock (pitCache)
{
long currentTime = Clock.getTimestamp();
// Request might already have been sent. In that case, we re-send it we have been waiting for too long.
if (!pitCache.ContainsKey(block_num) || currentTime - pitCache[block_num].requestSent > pitRequestTimeout)
{
Cuckoo filter = new Cuckoo(txids.Count);
foreach (var tx in txids)
{
filter.Add(Encoding.UTF8.GetBytes(tx));
}
byte[] filter_bytes = filter.getFilterBytes();
MemoryStream m = new MemoryStream(filter_bytes.Length + 12);
using (BinaryWriter w = new BinaryWriter(m, Encoding.UTF8, true))
{
w.Write(block_num);
w.Write(filter_bytes.Length);
w.Write(filter_bytes);
}
CoreProtocolMessage.broadcastProtocolMessageToSingleRandomNode(new char[] { 'M' }, ProtocolMessageCode.getPIT, m.ToArray(), 0);
PITCacheItem ci = new PITCacheItem()
{
pit = null,
requestedForTXIDs = txids,
requestSent = Clock.getTimestamp()
};
pitCache.AddOrReplace(block_num, ci);
}
}
}
/// <summary>
/// Verifies that the given remote endpoint is reachable by connecting to it and sending a short message.
/// </summary>
/// <remarks>
/// This function is used to ensure that the remote endpoing has listed the correct IP and port information for their `PresenceList` entry.
/// </remarks>
/// <param name="endpoint">Target endpoint to verify for connectivity.</param>
/// <returns>True, if the endpoing is connectable.</returns>
public static bool checkNodeConnectivity(RemoteEndpoint endpoint)
{
// TODO TODO TODO TODO we should put this in a separate thread
string hostname = endpoint.getFullAddress(true);
if (CoreNetworkUtils.PingAddressReachable(hostname) == false)
{
Logging.warn("Node {0} was not reachable on the advertised address.", hostname);
CoreProtocolMessage.sendBye(endpoint, ProtocolByeCode.notConnectable, "External " + hostname + " not reachable!", "");
return(false);
}
return(true);
}
private void requestBlockHeaders(ulong from, ulong to)
{
Logging.info("Requesting block headers from {0} to {1}", from, to);
using (MemoryStream mOut = new MemoryStream())
{
using (BinaryWriter writer = new BinaryWriter(mOut))
{
writer.Write(from);
writer.Write(to);
}
// Request from all nodes
//NetworkClientManager.broadcastData(new char[] { 'M', 'H' }, ProtocolMessageCode.getBlockHeaders, mOut.ToArray(), null);
// Request from a single random node
CoreProtocolMessage.broadcastProtocolMessageToSingleRandomNode(new char[] { 'M' }, ProtocolMessageCode.getBlockHeaders, mOut.ToArray(), 0);
}
}
// Called when receiving a keepalive network message. The PresenceList will update the appropriate entry based on the timestamp.
// Returns TRUE if it updated an entry in the PL
// Sets the out address parameter to be the KA wallet's address or null if an error occured
public static bool receiveKeepAlive(byte[] bytes, out byte[] address, RemoteEndpoint endpoint)
{
address = null;
// Get the current timestamp
long currentTime = Clock.getNetworkTimestamp();
try
{
using (MemoryStream m = new MemoryStream(bytes))
{
using (BinaryReader reader = new BinaryReader(m))
{
int keepAliveVersion = reader.ReadInt32();
int walletLen = reader.ReadInt32();
byte[] wallet = reader.ReadBytes(walletLen);
// Assign the out address parameter
address = wallet;
string deviceid = reader.ReadString();
long timestamp = reader.ReadInt64();
string hostname = reader.ReadString();
char node_type = '0';
node_type = reader.ReadChar();
int sigLen = reader.ReadInt32();
byte[] signature = reader.ReadBytes(sigLen);
//Logging.info(String.Format("[PL] KEEPALIVE request from {0}", hostname));
if (node_type == 'C' || node_type == 'R')
{
// all good, continue
}
else if (node_type == 'M' || node_type == 'H')
{
if (myPresenceType == 'M' || myPresenceType == 'H')
{
// check balance
if (IxianHandler.getWalletBalance(wallet) < ConsensusConfig.minimumMasterNodeFunds)
{
return(false);
}
}
}
else
{
// reject everything else
return(false);
}
lock (presences)
{
Presence listEntry = presences.Find(x => x.wallet.SequenceEqual(wallet));
if (listEntry == null && wallet.SequenceEqual(IxianHandler.getWalletStorage().getPrimaryAddress()))
{
Logging.warn("My entry was removed from local PL, readding.");
curNodePresence.addresses.Clear();
curNodePresence.addresses.Add(curNodePresenceAddress);
updateEntry(curNodePresence);
listEntry = presences.Find(x => x.wallet.SequenceEqual(wallet));
}
// Check if no such wallet found in presence list
if (listEntry == null)
{
// request for additional data
using (MemoryStream mw = new MemoryStream())
{
using (BinaryWriter writer = new BinaryWriter(mw))
{
writer.Write(wallet.Length);
writer.Write(wallet);
if (endpoint != null && endpoint.isConnected())
{
endpoint.sendData(ProtocolMessageCode.getPresence, mw.ToArray(), wallet);
}
else
{
CoreProtocolMessage.broadcastProtocolMessageToSingleRandomNode(new char[] { 'M', 'R', 'H' }, ProtocolMessageCode.getPresence, mw.ToArray(), 0, null);
}
}
}
return(false);
}
// Verify the signature
if (CryptoManager.lib.verifySignature(bytes.Take(bytes.Length - sigLen - 4).ToArray(), listEntry.pubkey, signature) == false)
{
Logging.warn(string.Format("[PL] KEEPALIVE tampering for {0} {1}, incorrect Sig.", Base58Check.Base58CheckEncoding.EncodePlain(listEntry.wallet), hostname));
return(false);
}
PresenceAddress pa = listEntry.addresses.Find(x => x.address == hostname && x.device == deviceid);
if (pa != null)
{
// Check the node type
if (pa.lastSeenTime != timestamp)
{
// Check for outdated timestamp
if (timestamp < pa.lastSeenTime)
{
// We already have a newer timestamp for this entry
return(false);
}
int expiration_time = CoreConfig.serverPresenceExpiration;
if (pa.type == 'C')
{
expiration_time = CoreConfig.clientPresenceExpiration;
}
// Check for tampering. Includes a +300, -30 second synchronization zone
if ((currentTime - timestamp) > expiration_time)
{
Logging.warn(string.Format("[PL] Received expired KEEPALIVE for {0} {1}. Timestamp {2}", Base58Check.Base58CheckEncoding.EncodePlain(listEntry.wallet), pa.address, timestamp));
return(false);
}
if ((currentTime - timestamp) < -30)
{
Logging.warn(string.Format("[PL] Potential KEEPALIVE tampering for {0} {1}. Timestamp {2}", Base58Check.Base58CheckEncoding.EncodePlain(listEntry.wallet), pa.address, timestamp));
return(false);
}
// Update the timestamp
pa.lastSeenTime = timestamp;
pa.signature = signature;
pa.version = keepAliveVersion;
if (pa.type != node_type)
{
lock (presenceCount)
{
presenceCount[pa.type]--;
if (!presenceCount.ContainsKey(node_type))
{
presenceCount.Add(node_type, 0);
}
presenceCount[node_type]++;
}
}
pa.type = node_type;
//Console.WriteLine("[PL] LASTSEEN for {0} - {1} set to {2}", hostname, deviceid, pa.lastSeenTime);
return(true);
}
}
else
{
if (wallet.SequenceEqual(IxianHandler.getWalletStorage().getPrimaryAddress()))
{
curNodePresence.addresses.Clear();
curNodePresence.addresses.Add(curNodePresenceAddress);
updateEntry(curNodePresence);
return(true);
}
else
{
using (MemoryStream mw = new MemoryStream())
{
using (BinaryWriter writer = new BinaryWriter(mw))
{
writer.Write(wallet.Length);
writer.Write(wallet);
if (endpoint != null && endpoint.isConnected())
{
endpoint.sendData(ProtocolMessageCode.getPresence, mw.ToArray(), wallet);
}
else
{
CoreProtocolMessage.broadcastProtocolMessageToSingleRandomNode(new char[] { 'M', 'R', 'H' }, ProtocolMessageCode.getPresence, mw.ToArray(), 0, null);
}
}
}
return(false);
}
}
}
}
}
}
catch (Exception e)
{
Logging.error("Exception occured in receiveKeepAlive: " + e);
return(false);
}
return(false);
}
// Sends perioding keepalive network messages
private static void keepAlive()
{
forceSendKeepAlive = true;
while (autoKeepalive)
{
TLC.Report();
int keepalive_interval = CoreConfig.serverKeepAliveInterval;
if (curNodePresenceAddress.type == 'C')
{
keepalive_interval = CoreConfig.clientKeepAliveInterval;
}
// Wait x seconds before rechecking
for (int i = 0; i < keepalive_interval; i++)
{
if (autoKeepalive == false)
{
return;
}
if (IxianHandler.publicIP == "")
{
// do not send KA
i = 0;
}
else
{
if (forceSendKeepAlive)
{
Thread.Sleep(1000);
forceSendKeepAlive = false;
break;
}
}
// Sleep for one second
Thread.Sleep(1000);
}
if (curNodePresenceAddress.type == 'W')
{
continue; // no need to send PL for worker nodes
}
try
{
byte[] ka_bytes = null;
ka_bytes = keepAlive_v1();
byte[] address = null;
// Update self presence
PresenceList.receiveKeepAlive(ka_bytes, out address, null);
// Send this keepalive to all connected non-clients
CoreProtocolMessage.broadcastProtocolMessage(new char[] { 'M', 'H', 'W' }, ProtocolMessageCode.keepAlivePresence, ka_bytes, address);
// Send this keepalive message to all connected clients
CoreProtocolMessage.broadcastEventDataMessage(NetworkEvents.Type.keepAlive, address, ProtocolMessageCode.keepAlivePresence, ka_bytes, address);
}
catch (Exception e)
{
Logging.error("Exception occured while generating keepalive: " + e);
}
}
}
/// <summary>
/// Prepares and sends an Ixian protocol 'Hello' message to the specified remote endpoint.
/// </summary>
/// <remarks>
/// A valid Ixian 'Hello' message includes certain Node data, verified by a public-key signature, which this function prepares using
/// the primary wallet's keypair. If this message is a reply to the other endpoint's hello message, then
/// </remarks>
/// <param name="endpoint">Remote endpoint to send the message to.</param>
/// <param name="sendHelloData">True if the message is the first hello sent to the remote node, false if it is a reply to the challenge.</param>
/// <param name="challenge_response">Response byte-field to the other node's hello challenge</param>
public static void sendHelloMessage(RemoteEndpoint endpoint, bool sendHelloData, byte[] challenge_response)
{
using (MemoryStream m = new MemoryStream(1856))
{
using (BinaryWriter writer = new BinaryWriter(m))
{
string publicHostname = IxianHandler.getFullPublicAddress();
// Send the node version
writer.Write(CoreConfig.protocolVersion);
// Send the public node address
byte[] address = IxianHandler.getWalletStorage().getPrimaryAddress();
writer.Write(address.Length);
writer.Write(address);
// Send the testnet designator
writer.Write(CoreConfig.isTestNet);
char node_type = PresenceList.myPresenceType;
writer.Write(node_type);
// Send the version
writer.Write(CoreConfig.productVersion);
// Send the node device id
writer.Write(CoreConfig.device_id);
// Send the wallet public key
writer.Write(IxianHandler.getWalletStorage().getPrimaryPublicKey().Length);
writer.Write(IxianHandler.getWalletStorage().getPrimaryPublicKey());
// Send listening port
writer.Write(IxianHandler.publicPort);
// Send timestamp
long timestamp = Clock.getTimestamp() + endpoint.calculateTimeDifference();
writer.Write(timestamp);
// send signature
byte[] signature = CryptoManager.lib.getSignature(Encoding.UTF8.GetBytes(ConsensusConfig.ixianChecksumLockString + "-" + CoreConfig.device_id + "-" + timestamp + "-" + publicHostname), IxianHandler.getWalletStorage().getPrimaryPrivateKey());
writer.Write(signature.Length);
writer.Write(signature);
if (sendHelloData)
{
Block block = IxianHandler.getLastBlock();
if (block == null)
{
Logging.warn("Clients are connecting, but we have no blocks yet to send them!");
CoreProtocolMessage.sendBye(endpoint, ProtocolByeCode.notReady, string.Format("The node isn't ready yet, please try again later."), "", true);
return;
}
ulong lastBlock = block.blockNum;
writer.Write(lastBlock);
writer.Write(block.blockChecksum.Length);
writer.Write(block.blockChecksum);
writer.Write(block.walletStateChecksum.Length);
writer.Write(block.walletStateChecksum);
writer.Write((int)0); // deprecated, can be replaced with something else of type int32
writer.Write(block.version);
// Write the legacy level
writer.Write((ulong)0); // deprecated, can be replaced with something else of type UInt64
writer.Write(challenge_response.Length);
writer.Write(challenge_response);
#if TRACE_MEMSTREAM_SIZES
Logging.info(String.Format("CoreProtocolMessage::sendHelloMessage: {0}", m.Length));
#endif
endpoint.sendData(ProtocolMessageCode.helloData, m.ToArray());
}
else
{
List <byte> challenge = new List <byte>();
challenge.AddRange(IxianHandler.getWalletStorage().getPrimaryAddress());
Random rnd = new Random();
challenge.AddRange(BitConverter.GetBytes(rnd.Next(20000)));
byte[] challenge_bytes = challenge.ToArray();
endpoint.challenge = challenge_bytes;
writer.Write(challenge_bytes.Length);
writer.Write(challenge_bytes);
#if TRACE_MEMSTREAM_SIZES
Logging.info(String.Format("CoreProtocolMessage::sendHelloMessage: {0}", m.Length));
#endif
endpoint.sendData(ProtocolMessageCode.hello, m.ToArray());
}
}
}
}
/// <summary>
/// Processes a Hello Ixian protocol message and updates the `PresenceList` as appropriate.
/// </summary>
/// <remarks>
/// This function should normally be called from `NetworkProtocol.parseProtocolMessage()`
/// </remarks>
/// <param name="endpoint">Remote endpoint from which the message was received.</param>
/// <param name="reader">Reader object placed at the beginning of the hello message data.</param>
/// <returns>True if the message was formatted properly and accepted.</returns>
public static bool processHelloMessage(RemoteEndpoint endpoint, BinaryReader reader)
{
// Node already has a presence
if (endpoint.presence != null)
{
// Ignore the hello message in this case
return(false);
}
// Another layer to catch any incompatible node exceptions for the hello message
try
{
int protocol_version = reader.ReadInt32();
Logging.info(string.Format("Received Hello: Node version {0}", protocol_version));
// Check for incompatible nodes
if (protocol_version < CoreConfig.protocolVersion)
{
Logging.warn(String.Format("Hello: Connected node version ({0}) is too old! Upgrade the node.", protocol_version));
sendBye(endpoint, ProtocolByeCode.deprecated, string.Format("Your node version is too old. Should be at least {0} is {1}", CoreConfig.protocolVersion, protocol_version), CoreConfig.protocolVersion.ToString(), true);
return(false);
}
int addrLen = reader.ReadInt32();
byte[] addr = reader.ReadBytes(addrLen);
bool test_net = reader.ReadBoolean();
char node_type = reader.ReadChar();
string node_version = reader.ReadString();
string device_id = reader.ReadString();
int pkLen = reader.ReadInt32();
byte[] pubkey = null;
if (pkLen > 0)
{
pubkey = reader.ReadBytes(pkLen);
}
endpoint.serverPubKey = pubkey;
int port = reader.ReadInt32();
long timestamp = reader.ReadInt64();
int sigLen = reader.ReadInt32();
byte[] signature = reader.ReadBytes(sigLen);
// Check the testnet designator and disconnect on mismatch
if (test_net != CoreConfig.isTestNet)
{
Logging.warn(string.Format("Rejected node {0} due to incorrect testnet designator: {1}", endpoint.fullAddress, test_net));
sendBye(endpoint, ProtocolByeCode.incorrectNetworkType, string.Format("Incorrect testnet designator: {0}. Should be {1}", test_net, CoreConfig.isTestNet), test_net.ToString(), true);
return(false);
}
// Check the address and pubkey and disconnect on mismatch
if (!addr.SequenceEqual((new Address(pubkey)).address))
{
Logging.warn(string.Format("Pubkey and address do not match."));
sendBye(endpoint, ProtocolByeCode.authFailed, "Pubkey and address do not match.", "", true);
return(false);
}
endpoint.incomingPort = port;
// Verify the signature
if (node_type == 'C')
{
// TODO: verify if the client is connectable, then if connectable, check if signature verifies
/*if (CryptoManager.lib.verifySignature(Encoding.UTF8.GetBytes(ConsensusConfig.ixianChecksumLockString + "-" + device_id + "-" + timestamp + "-" + endpoint.getFullAddress(true)), pubkey, signature) == false)
* {
* CoreProtocolMessage.sendBye(endpoint, ProtocolByeCode.incorrectIp, "Verify signature failed in hello message, likely an incorrect IP was specified. Detected IP:", endpoint.address);
* Logging.warn(string.Format("Connected node used an incorrect signature in hello message, likely an incorrect IP was specified. Detected IP: {0}", endpoint.address));
* return false;
* }*/
// TODO store the full address if connectable
// Store the presence address for this remote endpoint
endpoint.presenceAddress = new PresenceAddress(device_id, "", node_type, node_version, Clock.getNetworkTimestamp() - CoreConfig.clientKeepAliveInterval, null);
}
else
{
if (!CryptoManager.lib.verifySignature(Encoding.UTF8.GetBytes(ConsensusConfig.ixianChecksumLockString + "-" + device_id + "-" + timestamp + "-" + endpoint.getFullAddress(true)), pubkey, signature))
{
CoreProtocolMessage.sendBye(endpoint, ProtocolByeCode.incorrectIp, "Verify signature failed in hello message, likely an incorrect IP was specified. Detected IP:", endpoint.address);
Logging.warn(string.Format("Connected node used an incorrect signature in hello message, likely an incorrect IP was specified. Detected IP: {0}", endpoint.address));
return(false);
}
// Store the presence address for this remote endpoint
endpoint.presenceAddress = new PresenceAddress(device_id, endpoint.getFullAddress(true), node_type, node_version, Clock.getNetworkTimestamp() - CoreConfig.serverKeepAliveInterval, null);
}
// if we're a client update the network time difference
if (endpoint.GetType() == typeof(NetworkClient))
{
long timeDiff = endpoint.calculateTimeDifference();
// amortize +- 2 seconds
if (timeDiff >= -2 && timeDiff <= 2)
{
timeDiff = 0;
}
((NetworkClient)endpoint).timeDifference = timeDiff;
// Check the address and local address and disconnect on mismatch
if (endpoint.serverWalletAddress != null && !addr.SequenceEqual(endpoint.serverWalletAddress))
{
Logging.warn(string.Format("Local address mismatch, possible Man-in-the-middle attack."));
sendBye(endpoint, ProtocolByeCode.addressMismatch, "Local address mismatch.", "", true);
return(false);
}
}
// Create a temporary presence with the client's address and device id
Presence presence = new Presence(addr, pubkey, null, endpoint.presenceAddress);
if (endpoint.GetType() != typeof(NetworkClient))
{
// we're the server
if (node_type == 'M' || node_type == 'H' || node_type == 'R')
{
if (node_type != 'R')
{
// Check the wallet balance for the minimum amount of coins
IxiNumber balance = IxianHandler.getWalletBalance(addr);
if (balance < ConsensusConfig.minimumMasterNodeFunds)
{
Logging.warn(string.Format("Rejected master node {0} due to insufficient funds: {1}", endpoint.getFullAddress(), balance.ToString()));
sendBye(endpoint, ProtocolByeCode.insufficientFunds, string.Format("Insufficient funds. Minimum is {0}", ConsensusConfig.minimumMasterNodeFunds), balance.ToString(), true);
return(false);
}
}
// Limit to one IP per masternode
// TODO TODO TODO - think about this and do it properly
/*string[] hostname_split = hostname.Split(':');
* if (PresenceList.containsIP(hostname_split[0], 'M'))
* {
* using (MemoryStream m2 = new MemoryStream())
* {
* using (BinaryWriter writer = new BinaryWriter(m2))
* {
* writer.Write(string.Format("This IP address ( {0} ) already has a masternode connected.", hostname_split[0]));
* Logging.info(string.Format("Rejected master node {0} due to duplicate IP address", hostname));
* socket.Send(prepareProtocolMessage(ProtocolMessageCode.bye, m2.ToArray()), SocketFlags.None);
* socket.Disconnect(true);
* return;
* }
* }
* }*/
if (!checkNodeConnectivity(endpoint))
{
return(false);
}
}
}
// Retrieve the final presence entry from the list (or create a fresh one)
endpoint.presence = PresenceList.updateEntry(presence);
}
catch (Exception e)
{
// Disconnect the node in case of any reading errors
Logging.warn(string.Format("Exception occured in Hello Message {0}", e.ToString()));
sendBye(endpoint, ProtocolByeCode.deprecated, "Something went wrong during hello, make sure you're running the latest version of Ixian DLT.", "");
return(false);
}
if (NetworkClientManager.getConnectedClients().Count() == 1)
{
PresenceList.forceSendKeepAlive = true;
}
return(true);
}