SecretStore: do not cache ACL contract + on-chain key servers configuration (#6107)

* do not cache ACL storage contract

* when error comes before initialization

* initial KeyServerSet commit

* update_nodes_set in maintain

* do not connect to self

* fixed connection establishing

* removed println

* improved KeyServerSet tracing

* moved parsing to KeyServerSet

* re-read only when blockchain is changed

* do not try to connect if not a part of cluster

* improved logging

* fixed tests

Cargo.lock

@@ -723,6 +723,7 @@ dependencies = [
  "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-cpupool 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.10.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "native-contracts 0.1.0",
  "parking_lot 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",

ethcore/native_contracts/build.rs

@@ -21,6 +21,7 @@ use std::fs::File;
 use std::io::Write;
 
 // TODO: just walk the "res" directory and generate whole crate automatically.
+const KEY_SERVER_SET_ABI: &'static str = include_str!("res/key_server_set.json");
 const REGISTRY_ABI: &'static str = include_str!("res/registrar.json");
 const URLHINT_ABI: &'static str = include_str!("res/urlhint.json");
 const SERVICE_TRANSACTION_ABI: &'static str = include_str!("res/service_transaction.json");
@@ -45,6 +46,7 @@ fn build_test_contracts() {
 }
 
 fn main() {
+	build_file("KeyServerSet", KEY_SERVER_SET_ABI, "key_server_set.rs");
 	build_file("Registry", REGISTRY_ABI, "registry.rs");
 	build_file("Urlhint", URLHINT_ABI, "urlhint.rs");
 	build_file("ServiceTransactionChecker", SERVICE_TRANSACTION_ABI, "service_transaction.rs");

ethcore/native_contracts/res/key_server_set.json

@@ -0,0 +1 @@
+[{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"keyServersList","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_new","type":"address"}],"name":"setOwner","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"keyServer","type":"address"}],"name":"getKeyServerPublic","outputs":[{"name":"","type":"bytes"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"getKeyServers","outputs":[{"name":"","type":"address[]"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"keyServer","type":"address"}],"name":"getKeyServerAddress","outputs":[{"name":"","type":"string"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"keyServer","type":"address"}],"name":"removeKeyServer","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"keyServerPublic","type":"bytes"},{"name":"keyServerIp","type":"string"}],"name":"addKeyServer","outputs":[],"payable":false,"type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"keyServer","type":"address"}],"name":"KeyServerAdded","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"keyServer","type":"address"}],"name":"KeyServerRemoved","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"old","type":"address"},{"indexed":true,"name":"current","type":"address"}],"name":"NewOwner","type":"event"}]

ethcore/native_contracts/src/key_server_set.rs

@@ -0,0 +1,21 @@
+// Copyright 2015-2017 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+#![allow(unused_mut, unused_variables, unused_imports)]
+
+//! Secret store Key Server set contract.
+
+include!(concat!(env!("OUT_DIR"), "/key_server_set.rs"));

ethcore/native_contracts/src/lib.rs

@@ -23,6 +23,7 @@ extern crate byteorder;
 extern crate ethabi;
 extern crate ethcore_util as util;
 
+mod key_server_set;
 mod registry;
 mod urlhint;
 mod service_transaction;
@@ -32,6 +33,7 @@ mod validator_report;
 
 pub mod test_contracts;
 
+pub use self::key_server_set::KeyServerSet;
 pub use self::registry::Registry;
 pub use self::urlhint::Urlhint;
 pub use self::service_transaction::ServiceTransactionChecker;

secret_store/Cargo.toml

@@ -35,3 +35,4 @@ ethcore-logger = { path = "../logger" }
 ethcrypto = { path = "../ethcrypto" }
 ethkey = { path = "../ethkey" }
 native-contracts = { path = "../ethcore/native_contracts" }
+lazy_static = "0.2"

secret_store/src/acl_storage.rs

@@ -14,12 +14,13 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-use std::sync::Arc;
+use std::sync::{Arc, Weak};
 use futures::{future, Future};
 use parking_lot::Mutex;
 use ethkey::public_to_address;
-use ethcore::client::{Client, BlockChainClient, BlockId};
+use ethcore::client::{Client, BlockChainClient, BlockId, ChainNotify};
 use native_contracts::SecretStoreAclStorage;
+use util::{H256, Address, Bytes};
 use types::all::{Error, ServerKeyId, Public};
 
 const ACL_CHECKER_CONTRACT_REGISTRY_NAME: &'static str = "secretstore_acl_checker";
@@ -32,40 +33,82 @@ pub trait AclStorage: Send + Sync {
 
 /// On-chain ACL storage implementation.
 pub struct OnChainAclStorage {
+	/// Cached on-chain contract.
+	contract: Mutex<CachedContract>,
+}
+
+/// Cached on-chain ACL storage contract.
+struct CachedContract {
 	/// Blockchain client.
-	client: Arc<Client>,
-	/// On-chain contract.
-	contract: Mutex<Option<SecretStoreAclStorage>>,
+	client: Weak<Client>,
+	/// Contract address.
+	contract_addr: Option<Address>,
+	/// Contract at given address.
+	contract: Option<SecretStoreAclStorage>,
 }
 
 impl OnChainAclStorage {
-	pub fn new(client: Arc<Client>) -> Self {
-		OnChainAclStorage {
-			client: client,
-			contract: Mutex::new(None),
-		}
+	pub fn new(client: &Arc<Client>) -> Arc<Self> {
+		let acl_storage = Arc::new(OnChainAclStorage {
+			contract: Mutex::new(CachedContract::new(client)),
+		});
+		client.add_notify(acl_storage.clone());
+		acl_storage
 	}
 }
 
 impl AclStorage for OnChainAclStorage {
 	fn check(&self, public: &Public, document: &ServerKeyId) -> Result<bool, Error> {
-		let mut contract = self.contract.lock();
-		if !contract.is_some() {
-			*contract = self.client.registry_address(ACL_CHECKER_CONTRACT_REGISTRY_NAME.to_owned())
-				.and_then(|contract_addr| {
+		self.contract.lock().check(public, document)
+	}
+}
+
+impl ChainNotify for OnChainAclStorage {
+	fn new_blocks(&self, _imported: Vec<H256>, _invalid: Vec<H256>, enacted: Vec<H256>, retracted: Vec<H256>, _sealed: Vec<H256>, _proposed: Vec<Bytes>, _duration: u64) {
+		if !enacted.is_empty() || !retracted.is_empty() {
+			self.contract.lock().update()
+		}
+	}
+}
+
+impl CachedContract {
+	pub fn new(client: &Arc<Client>) -> Self {
+		CachedContract {
+			client: Arc::downgrade(client),
+			contract_addr: None,
+			contract: None,
+		}
+	}
+
+	pub fn update(&mut self) {
+		if let Some(client) = self.client.upgrade() {
+			let new_contract_addr = client.registry_address(ACL_CHECKER_CONTRACT_REGISTRY_NAME.to_owned());
+			if self.contract_addr.as_ref() != new_contract_addr.as_ref() {
+				self.contract = new_contract_addr.map(|contract_addr| {
 					trace!(target: "secretstore", "Configuring for ACL checker contract from {}", contract_addr);
 
-					Some(SecretStoreAclStorage::new(contract_addr))
-				})
+					SecretStoreAclStorage::new(contract_addr)
+				});
+
+				self.contract_addr = new_contract_addr;
+			}
 		}
-		if let Some(ref contract) = *contract {
-			let address = public_to_address(&public);
-			let do_call = |a, d| future::done(self.client.call_contract(BlockId::Latest, a, d));
-			contract.check_permissions(do_call, address, document.clone())
-				.map_err(|err| Error::Internal(err))
-				.wait()
-		} else {
-			Err(Error::Internal("ACL checker contract is not configured".to_owned()))
+	}
+
+	pub fn check(&mut self, public: &Public, document: &ServerKeyId) -> Result<bool, Error> {
+		match self.contract.as_ref() {
+			Some(contract) => {
+				let address = public_to_address(&public);
+				let do_call = |a, d| future::done(
+					self.client
+						.upgrade()
+						.ok_or("Calling contract without client".into())
+						.and_then(|c| c.call_contract(BlockId::Latest, a, d)));
+				contract.check_permissions(do_call, address, document.clone())
+					.map_err(|err| Error::Internal(err))
+					.wait()
+			},
+			None => Err(Error::Internal("ACL checker contract is not configured".to_owned())),
 		}
 	}
 }

secret_store/src/key_server.rs

@@ -24,6 +24,7 @@ use ethcrypto;
 use ethkey;
 use super::acl_storage::AclStorage;
 use super::key_storage::KeyStorage;
+use super::key_server_set::KeyServerSet;
 use key_server_cluster::{math, ClusterCore};
 use traits::{ServerKeyGenerator, DocumentKeyServer, MessageSigner, KeyServer};
 use types::all::{Error, Public, RequestSignature, ServerKeyId, EncryptedDocumentKey, EncryptedDocumentKeyShadow,
@@ -44,9 +45,9 @@ pub struct KeyServerCore {
 
 impl KeyServerImpl {
 	/// Create new key server instance
-	pub fn new(config: &ClusterConfiguration, acl_storage: Arc<AclStorage>, key_storage: Arc<KeyStorage>) -> Result<Self, Error> {
+	pub fn new(config: &ClusterConfiguration, key_server_set: Arc<KeyServerSet>, acl_storage: Arc<AclStorage>, key_storage: Arc<KeyStorage>) -> Result<Self, Error> {
 		Ok(KeyServerImpl {
-			data: Arc::new(Mutex::new(KeyServerCore::new(config, acl_storage, key_storage)?)),
+			data: Arc::new(Mutex::new(KeyServerCore::new(config, key_server_set, acl_storage, key_storage)?)),
 		})
 	}
 
@@ -143,14 +144,12 @@ impl MessageSigner for KeyServerImpl {
 }
 
 impl KeyServerCore {
-	pub fn new(config: &ClusterConfiguration, acl_storage: Arc<AclStorage>, key_storage: Arc<KeyStorage>) -> Result<Self, Error> {
+	pub fn new(config: &ClusterConfiguration, key_server_set: Arc<KeyServerSet>, acl_storage: Arc<AclStorage>, key_storage: Arc<KeyStorage>) -> Result<Self, Error> {
 		let config = NetClusterConfiguration {
 			threads: config.threads,
 			self_key_pair: ethkey::KeyPair::from_secret_slice(&config.self_private)?,
 			listen_address: (config.listener_address.address.clone(), config.listener_address.port),
-			nodes: config.nodes.iter()
-				.map(|(node_id, node_address)| (node_id.clone(), (node_address.address.clone(), node_address.port)))
-				.collect(),
+			key_server_set: key_server_set,
 			allow_connecting_to_higher_nodes: config.allow_connecting_to_higher_nodes,
 			acl_storage: acl_storage,
 			key_storage: key_storage,
@@ -193,10 +192,13 @@ impl Drop for KeyServerCore {
 pub mod tests {
 	use std::time;
 	use std::sync::Arc;
+	use std::net::SocketAddr;
+	use std::collections::BTreeMap;
 	use ethcrypto;
 	use ethkey::{self, Secret, Random, Generator};
 	use acl_storage::tests::DummyAclStorage;
 	use key_storage::tests::DummyKeyStorage;
+	use key_server_set::tests::MapKeyServerSet;
 	use key_server_cluster::math;
 	use util::H256;
 	use types::all::{Error, Public, ClusterConfiguration, NodeAddress, RequestSignature, ServerKeyId,
@@ -254,8 +256,11 @@ pub mod tests {
 					})).collect(),
 				allow_connecting_to_higher_nodes: false,
 			}).collect();
+		let key_servers_set: BTreeMap<Public, SocketAddr> = configs[0].nodes.iter()
+			.map(|(k, a)| (k.clone(), format!("{}:{}", a.address, a.port).parse().unwrap()))
+			.collect();
 		let key_servers: Vec<_> = configs.into_iter().map(|cfg|
-			KeyServerImpl::new(&cfg, Arc::new(DummyAclStorage::default()), Arc::new(DummyKeyStorage::default())).unwrap()
+			KeyServerImpl::new(&cfg, Arc::new(MapKeyServerSet::new(key_servers_set.clone())), Arc::new(DummyAclStorage::default()), Arc::new(DummyKeyStorage::default())).unwrap()
 		).collect();
 
 		// wait until connections are established. It is fast => do not bother with events here

secret_store/src/key_server_cluster/cluster.rs

@@ -28,7 +28,7 @@ use tokio_core::reactor::{Handle, Remote, Interval};
 use tokio_core::net::{TcpListener, TcpStream};
 use ethkey::{Public, KeyPair, Signature, Random, Generator};
 use util::H256;
-use key_server_cluster::{Error, NodeId, SessionId, AclStorage, KeyStorage};
+use key_server_cluster::{Error, NodeId, SessionId, AclStorage, KeyStorage, KeyServerSet};
 use key_server_cluster::cluster_sessions::{ClusterSession, ClusterSessions, GenerationSessionWrapper, EncryptionSessionWrapper,
 	DecryptionSessionWrapper, SigningSessionWrapper};
 use key_server_cluster::message::{self, Message, ClusterMessage, GenerationMessage, EncryptionMessage, DecryptionMessage,
@@ -102,8 +102,8 @@ pub struct ClusterConfiguration {
 	pub self_key_pair: KeyPair,
 	/// Interface to listen to.
 	pub listen_address: (String, u16),
-	/// Cluster nodes.
-	pub nodes: BTreeMap<NodeId, (String, u16)>,
+	/// Cluster nodes set.
+	pub key_server_set: Arc<KeyServerSet>,
 	/// Reference to key storage
 	pub key_storage: Arc<KeyStorage>,
 	/// Reference to ACL storage
@@ -158,9 +158,17 @@ pub struct ClusterConnections {
 	/// Self node id.
 	pub self_node_id: NodeId,
 	/// All known other key servers.
-	pub nodes: BTreeMap<NodeId, SocketAddr>,
+	pub key_server_set: Arc<KeyServerSet>,
+	/// Connections data.
+	pub data: RwLock<ClusterConnectionsData>,
+}
+
+/// Cluster connections data.
+pub struct ClusterConnectionsData {
+	/// Active key servers set.
+	pub nodes: BTreeMap<Public, SocketAddr>,
 	/// Active connections to key servers.
-	pub connections: RwLock<BTreeMap<NodeId, Arc<Connection>>>,
+	pub connections: BTreeMap<NodeId, Arc<Connection>>,
 }
 
 /// Cluster view core.
@@ -281,8 +289,7 @@ impl ClusterCore {
 
 	/// Accept connection future.
 	fn accept_connection_future(handle: &Handle, data: Arc<ClusterData>, stream: TcpStream, node_address: SocketAddr) -> BoxedEmptyFuture {
-		let disconnected_nodes = data.connections.disconnected_nodes().keys().cloned().collect();
-		net_accept_connection(node_address, stream, handle, data.self_key_pair.clone(), disconnected_nodes)
+		net_accept_connection(node_address, stream, handle, data.self_key_pair.clone())
 			.then(move |result| ClusterCore::process_connection_result(data, true, result))
 			.then(|_| finished(()))
 			.boxed()
@@ -354,6 +361,7 @@ impl ClusterCore {
 
 	/// Try to connect to every disconnected node.
 	fn connect_disconnected_nodes(data: Arc<ClusterData>) {
+		data.connections.update_nodes_set();
 		for (node_id, node_address) in data.connections.disconnected_nodes() {
 			if data.config.allow_connecting_to_higher_nodes || data.self_key_pair.public() < &node_id {
 				ClusterCore::connect(data.clone(), node_address);
@@ -372,14 +380,16 @@ impl ClusterCore {
 					finished(Ok(())).boxed()
 				}
 			},
-			Ok(DeadlineStatus::Meet(Err(_))) => {
+			Ok(DeadlineStatus::Meet(Err(err))) => {
+				warn!(target: "secretstore_net", "{}: protocol error {} when establishind connection", data.self_key_pair.public(), err);
 				finished(Ok(())).boxed()
 			},
 			Ok(DeadlineStatus::Timeout) => {
+				warn!(target: "secretstore_net", "{}: timeout when establishind connection", data.self_key_pair.public());
 				finished(Ok(())).boxed()
 			},
-			Err(_) => {
-				// network error
+			Err(err) => {
+				warn!(target: "secretstore_net", "{}: network error {} when establishind connection", data.self_key_pair.public(), err);
 				finished(Ok(())).boxed()
 			},
 		}
@@ -665,33 +675,38 @@ impl ClusterCore {
 
 impl ClusterConnections {
 	pub fn new(config: &ClusterConfiguration) -> Result<Self, Error> {
-		let mut connections = ClusterConnections {
+		let mut nodes = config.key_server_set.get();
+		nodes.remove(config.self_key_pair.public());
+
+		Ok(ClusterConnections {
 			self_node_id: config.self_key_pair.public().clone(),
-			nodes: BTreeMap::new(),
-			connections: RwLock::new(BTreeMap::new()),
-		};
-
-		for (node_id, &(ref node_addr, node_port)) in config.nodes.iter().filter(|&(node_id, _)| node_id != config.self_key_pair.public()) {
-			let socket_address = make_socket_address(&node_addr, node_port)?;
-			connections.nodes.insert(node_id.clone(), socket_address);
-		}
-
-		Ok(connections)
+			key_server_set: config.key_server_set.clone(),
+			data: RwLock::new(ClusterConnectionsData {
+				nodes: nodes,
+				connections: BTreeMap::new(),
+			}),
+		})
 	}
 
 	pub fn cluster_state(&self) -> ClusterState {
 		ClusterState {
-			connected: self.connections.read().keys().cloned().collect(),
+			connected: self.data.read().connections.keys().cloned().collect(),
 		}
 	}
 
 	pub fn get(&self, node: &NodeId) -> Option<Arc<Connection>> {
-		self.connections.read().get(node).cloned()
+		self.data.read().connections.get(node).cloned()
 	}
 
 	pub fn insert(&self, connection: Arc<Connection>) -> bool {
-		let mut connections = self.connections.write();
-		if connections.contains_key(connection.node_id()) {
+		let mut data = self.data.write();
+		if !data.nodes.contains_key(connection.node_id()) {
+			// incoming connections are checked here
+			trace!(target: "secretstore_net", "{}: ignoring unknown connection from {} at {}", self.self_node_id, connection.node_id(), connection.node_address());
+			debug_assert!(connection.is_inbound());
+			return false;
+		}
+		if data.connections.contains_key(connection.node_id()) {
 			// we have already connected to the same node
 			// the agreement is that node with lower id must establish connection to node with higher id
 			if (&self.self_node_id < connection.node_id() && connection.is_inbound())
@@ -700,14 +715,15 @@ impl ClusterConnections {
 			}
 		}
 
-		trace!(target: "secretstore_net", "{}: inserting connection to {} at {}", self.self_node_id, connection.node_id(), connection.node_address());
-		connections.insert(connection.node_id().clone(), connection);
+		trace!(target: "secretstore_net", "{}: inserting connection to {} at {}. Connected to {} of {} nodes",
+			self.self_node_id, connection.node_id(), connection.node_address(), data.connections.len() + 1, data.nodes.len());
+		data.connections.insert(connection.node_id().clone(), connection);
 		true
 	}
 
 	pub fn remove(&self, node: &NodeId, is_inbound: bool) {
-		let mut connections = self.connections.write();
-		if let Entry::Occupied(entry) = connections.entry(node.clone()) {
+		let mut data = self.data.write();
+		if let Entry::Occupied(entry) = data.connections.entry(node.clone()) {
 			if entry.get().is_inbound() != is_inbound {
 				return;
 			}
@@ -718,20 +734,64 @@ impl ClusterConnections {
 	}
 
 	pub fn connected_nodes(&self) -> BTreeSet<NodeId> {
-		self.connections.read().keys().cloned().collect()
+		self.data.read().connections.keys().cloned().collect()
 	}
 
 	pub fn active_connections(&self)-> Vec<Arc<Connection>> {
-		self.connections.read().values().cloned().collect()
+		self.data.read().connections.values().cloned().collect()
 	}
 
 	pub fn disconnected_nodes(&self) -> BTreeMap<NodeId, SocketAddr> {
-		let connections = self.connections.read();
-		self.nodes.iter()
-			.filter(|&(node_id, _)| !connections.contains_key(node_id))
+		let data = self.data.read();
+		data.nodes.iter()
+			.filter(|&(node_id, _)| !data.connections.contains_key(node_id))
 			.map(|(node_id, node_address)| (node_id.clone(), node_address.clone()))
 			.collect()
 	}
+
+	pub fn update_nodes_set(&self) {
+		let mut data = self.data.write();
+		let mut new_nodes = self.key_server_set.get();
+		// we do not need to connect to self
+		// + we do not need to try to connect to any other node if we are not the part of a cluster
+		if new_nodes.remove(&self.self_node_id).is_none() {
+			new_nodes.clear();
+		}
+
+		let mut num_added_nodes = 0;
+		let mut num_removed_nodes = 0;
+		let mut num_changed_nodes = 0;
+
+		for obsolete_node in data.nodes.keys().cloned().collect::<Vec<_>>() {
+			if !new_nodes.contains_key(&obsolete_node) {
+				if let Entry::Occupied(entry) = data.connections.entry(obsolete_node) {
+					trace!(target: "secretstore_net", "{}: removing connection to {} at {}", self.self_node_id, entry.get().node_id(), entry.get().node_address());
+					entry.remove();
+				}
+
+				data.nodes.remove(&obsolete_node);
+				num_removed_nodes += 1;
+			}
+		}
+
+		for (new_node_public, new_node_addr) in new_nodes {
+			match data.nodes.insert(new_node_public, new_node_addr) {
+				None => num_added_nodes += 1,
+				Some(old_node_addr) => if new_node_addr != old_node_addr {
+					if let Entry::Occupied(entry) = data.connections.entry(new_node_public) {
+						trace!(target: "secretstore_net", "{}: removing connection to {} at {}", self.self_node_id, entry.get().node_id(), entry.get().node_address());
+						entry.remove();
+					}
+					num_changed_nodes += 1;
+				},
+			}
+		}
+
+		if num_added_nodes != 0 || num_removed_nodes != 0 || num_changed_nodes != 0 {
+			trace!(target: "secretstore_net", "{}: updated nodes set: removed {}, added {}, changed {}. Connected to {} of {} nodes",
+				self.self_node_id, num_removed_nodes, num_added_nodes, num_changed_nodes, data.connections.len(), data.nodes.len());
+		}
+	}
 }
 
 impl ClusterData {
@@ -929,7 +989,7 @@ pub mod tests {
 	use parking_lot::Mutex;
 	use tokio_core::reactor::Core;
 	use ethkey::{Random, Generator, Public};
-	use key_server_cluster::{NodeId, SessionId, Error, DummyAclStorage, DummyKeyStorage};
+	use key_server_cluster::{NodeId, SessionId, Error, DummyAclStorage, DummyKeyStorage, MapKeyServerSet};
 	use key_server_cluster::message::Message;
 	use key_server_cluster::cluster::{Cluster, ClusterCore, ClusterConfiguration};
 	use key_server_cluster::generation_session::{Session as GenerationSession, SessionState as GenerationSessionState};
@@ -999,7 +1059,7 @@ pub mod tests {
 	}
 
 	pub fn all_connections_established(cluster: &Arc<ClusterCore>) -> bool {
-		cluster.config().nodes.keys()
+		cluster.config().key_server_set.get().keys()
 			.filter(|p| *p != cluster.config().self_key_pair.public())
 			.all(|p| cluster.connection(p).is_some())
 	}
@@ -1010,9 +1070,9 @@ pub mod tests {
 			threads: 1,
 			self_key_pair: key_pairs[i].clone(),
 			listen_address: ("127.0.0.1".to_owned(), ports_begin + i as u16),
-			nodes: key_pairs.iter().enumerate()
-				.map(|(j, kp)| (kp.public().clone(), ("127.0.0.1".into(), ports_begin + j as u16)))
-				.collect(),
+			key_server_set: Arc::new(MapKeyServerSet::new(key_pairs.iter().enumerate()
+				.map(|(j, kp)| (kp.public().clone(), format!("127.0.0.1:{}", ports_begin + j as u16).parse().unwrap()))
+				.collect())),
 			allow_connecting_to_higher_nodes: false,
 			key_storage: Arc::new(DummyKeyStorage::default()),
 			acl_storage: Arc::new(DummyAclStorage::default()),

secret_store/src/key_server_cluster/cluster_sessions.rs

@@ -135,7 +135,7 @@ impl ClusterSessions {
 	pub fn new(config: &ClusterConfiguration) -> Self {
 		ClusterSessions {
 			self_node_id: config.self_key_pair.public().clone(),
-			nodes: config.nodes.keys().cloned().collect(),
+			nodes: config.key_server_set.get().keys().cloned().collect(),
 			acl_storage: config.acl_storage.clone(),
 			key_storage: config.key_storage.clone(),
 			generation_sessions: ClusterSessionsContainer::new(),

secret_store/src/key_server_cluster/io/handshake.rs

@@ -45,7 +45,7 @@ pub fn handshake_with_plain_confirmation<A>(a: A, self_confirmation_plain: Resul
 		state: state,
 		self_key_pair: self_key_pair,
 		self_confirmation_plain: self_confirmation_plain.unwrap_or(Default::default()),
-		trusted_nodes: trusted_nodes,
+		trusted_nodes: Some(trusted_nodes),
 		other_node_id: None,
 		other_confirmation_plain: None,
 		shared_key: None,
@@ -53,7 +53,7 @@ pub fn handshake_with_plain_confirmation<A>(a: A, self_confirmation_plain: Resul
 }
 
 /// Wait for handshake procedure to be started by another node from the cluster.
-pub fn accept_handshake<A>(a: A, self_key_pair: KeyPair, trusted_nodes: BTreeSet<NodeId>) -> Handshake<A> where A: AsyncWrite + AsyncRead {
+pub fn accept_handshake<A>(a: A, self_key_pair: KeyPair) -> Handshake<A> where A: AsyncWrite + AsyncRead {
 	let self_confirmation_plain = Random.generate().map(|kp| *kp.secret().clone()).map_err(Into::into);
 	let (error, state) = match self_confirmation_plain.clone() {
 		Ok(_) => (None, HandshakeState::ReceivePublicKey(read_message(a))),
@@ -66,7 +66,7 @@ pub fn accept_handshake<A>(a: A, self_key_pair: KeyPair, trusted_nodes: BTreeSet
 		state: state,
 		self_key_pair: self_key_pair,
 		self_confirmation_plain: self_confirmation_plain.unwrap_or(Default::default()),
-		trusted_nodes: trusted_nodes,
+		trusted_nodes: None,
 		other_node_id: None,
 		other_confirmation_plain: None,
 		shared_key: None,
@@ -89,7 +89,7 @@ pub struct Handshake<A> {
 	state: HandshakeState<A>,
 	self_key_pair: KeyPair,
 	self_confirmation_plain: H256,
-	trusted_nodes: BTreeSet<NodeId>,
+	trusted_nodes: Option<BTreeSet<NodeId>>,
 	other_node_id: Option<NodeId>,
 	other_confirmation_plain: Option<H256>,
 	shared_key: Option<KeyPair>,
@@ -172,7 +172,7 @@ impl<A> Future for Handshake<A> where A: AsyncRead + AsyncWrite {
 					Err(err) => return Ok((stream, Err(err.into())).into()),
 				};
 
-				if !self.trusted_nodes.contains(&*message.node_id) {
+				if !self.trusted_nodes.as_ref().map(|tn| tn.contains(&*message.node_id)).unwrap_or(true) {
 					return Ok((stream, Err(Error::InvalidNodeId)).into());
 				}
 
@@ -300,7 +300,7 @@ mod tests {
 		let trusted_nodes: BTreeSet<_> = vec![io.peer_public().clone()].into_iter().collect();
 		let shared_key = compute_shared_key(self_key_pair.secret(), trusted_nodes.iter().nth(0).unwrap()).unwrap();
 
-		let mut handshake = accept_handshake(io, self_key_pair, trusted_nodes);
+		let mut handshake = accept_handshake(io, self_key_pair);
 		handshake.set_self_confirmation_plain(self_confirmation_plain);
 
 		let handshake_result = handshake.wait().unwrap();

secret_store/src/key_server_cluster/jobs/job_session.rs

@@ -299,22 +299,22 @@ impl<Executor, Transport> JobSession<Executor, Transport> where Executor: JobExe
 			return Err(Error::ConsensusUnreachable);
 		}
 
-		let active_data = self.data.active_data.as_mut()
-			.expect("we have checked that we are on master node; on master nodes active_data is filled during initialization; qed");
-		if active_data.rejects.contains(node) {
-			return Ok(());
-		}
-		if active_data.requests.remove(node) || active_data.responses.remove(node).is_some() {
-			active_data.rejects.insert(node.clone());
-			if self.data.state == JobSessionState::Finished && active_data.responses.len() < self.meta.threshold + 1 {
-				self.data.state = JobSessionState::Active;
-			}
-			if active_data.requests.len() + active_data.responses.len() >= self.meta.threshold + 1 {
+		if let Some(active_data) = self.data.active_data.as_mut() {
+			if active_data.rejects.contains(node) {
 				return Ok(());
 			}
+			if active_data.requests.remove(node) || active_data.responses.remove(node).is_some() {
+				active_data.rejects.insert(node.clone());
+				if self.data.state == JobSessionState::Finished && active_data.responses.len() < self.meta.threshold + 1 {
+					self.data.state = JobSessionState::Active;
+				}
+				if active_data.requests.len() + active_data.responses.len() >= self.meta.threshold + 1 {
+					return Ok(());
+				}
 
-			self.data.state = JobSessionState::Failed;
-			return Err(Error::ConsensusUnreachable);
+				self.data.state = JobSessionState::Failed;
+				return Err(Error::ConsensusUnreachable);
+			}
 		}
 
 		Ok(())

secret_store/src/key_server_cluster/mod.rs

@@ -23,6 +23,7 @@ use super::types::all::ServerKeyId;
 pub use super::types::all::{NodeId, EncryptedDocumentKeyShadow};
 pub use super::acl_storage::AclStorage;
 pub use super::key_storage::{KeyStorage, DocumentKeyShare};
+pub use super::key_server_set::KeyServerSet;
 pub use super::serialization::{SerializableSignature, SerializableH256, SerializableSecret, SerializablePublic, SerializableMessageHash};
 pub use self::cluster::{ClusterCore, ClusterConfiguration, ClusterClient};
 pub use self::generation_session::Session as GenerationSession;
@@ -33,6 +34,8 @@ pub use self::decryption_session::Session as DecryptionSession;
 pub use super::key_storage::tests::DummyKeyStorage;
 #[cfg(test)]
 pub use super::acl_storage::tests::DummyAclStorage;
+#[cfg(test)]
+pub use super::key_server_set::tests::MapKeyServerSet;
 
 pub type SessionId = ServerKeyId;
 

secret_store/src/key_server_cluster/net/accept_connection.rs

@@ -17,19 +17,18 @@
 use std::io;
 use std::net::SocketAddr;
 use std::time::Duration;
-use std::collections::BTreeSet;
 use futures::{Future, Poll};
 use tokio_core::reactor::Handle;
 use tokio_core::net::TcpStream;
 use ethkey::KeyPair;
-use key_server_cluster::{Error, NodeId};
+use key_server_cluster::Error;
 use key_server_cluster::io::{accept_handshake, Handshake, Deadline, deadline};
 use key_server_cluster::net::Connection;
 
 /// Create future for accepting incoming connection.
-pub fn accept_connection(address: SocketAddr, stream: TcpStream, handle: &Handle, self_key_pair: KeyPair, trusted_nodes: BTreeSet<NodeId>) -> Deadline<AcceptConnection> {
+pub fn accept_connection(address: SocketAddr, stream: TcpStream, handle: &Handle, self_key_pair: KeyPair) -> Deadline<AcceptConnection> {
 	let accept = AcceptConnection {
-		handshake: accept_handshake(stream, self_key_pair, trusted_nodes),
+		handshake: accept_handshake(stream, self_key_pair),
 		address: address,
 	};
 

secret_store/src/key_server_set.rs

@@ -0,0 +1,204 @@
+// Copyright 2015-2017 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::sync::{Arc, Weak};
+use std::net::SocketAddr;
+use std::collections::BTreeMap;
+use futures::{future, Future};
+use parking_lot::Mutex;
+use ethcore::filter::Filter;
+use ethcore::client::{Client, BlockChainClient, BlockId, ChainNotify};
+use native_contracts::KeyServerSet as KeyServerSetContract;
+use util::{H256, Address, Bytes, Hashable};
+use types::all::{Error, Public, NodeAddress};
+
+const KEY_SERVER_SET_CONTRACT_REGISTRY_NAME: &'static str = "secretstore_server_set";
+
+/// Key server has been added to the set.
+const ADDED_EVENT_NAME: &'static [u8] = &*b"KeyServerAdded(address)";
+/// Key server has been removed from the set.
+const REMOVED_EVENT_NAME: &'static [u8] = &*b"KeyServerRemoved(address)";
+
+lazy_static! {
+	static ref ADDED_EVENT_NAME_HASH: H256 = ADDED_EVENT_NAME.sha3();
+	static ref REMOVED_EVENT_NAME_HASH: H256 = REMOVED_EVENT_NAME.sha3();
+}
+
+/// Key Server set
+pub trait KeyServerSet: Send + Sync {
+	/// Get set of configured key servers
+	fn get(&self) -> BTreeMap<Public, SocketAddr>;
+}
+
+/// On-chain Key Server set implementation.
+pub struct OnChainKeyServerSet {
+	/// Cached on-chain contract.
+	contract: Mutex<CachedContract>,
+}
+
+/// Cached on-chain Key Server set contract.
+struct CachedContract {
+	/// Blockchain client.
+	client: Weak<Client>,
+	/// Contract address.
+	contract_addr: Option<Address>,
+	/// Active set of key servers.
+	key_servers: BTreeMap<Public, SocketAddr>,
+}
+
+impl OnChainKeyServerSet {
+	pub fn new(client: &Arc<Client>, key_servers: BTreeMap<Public, NodeAddress>) -> Result<Arc<Self>, Error> {
+		let mut cached_contract = CachedContract::new(client, key_servers)?;
+		let key_server_contract_address = client.registry_address(KEY_SERVER_SET_CONTRACT_REGISTRY_NAME.to_owned());
+		// only initialize from contract if it is installed. otherwise - use default nodes
+		// once the contract is installed, all default nodes are lost (if not in the contract' set)
+		if key_server_contract_address.is_some() {
+			cached_contract.read_from_registry(&*client, key_server_contract_address);
+		}
+
+		let key_server_set = Arc::new(OnChainKeyServerSet {
+			contract: Mutex::new(cached_contract),
+		});
+		client.add_notify(key_server_set.clone());
+		Ok(key_server_set)
+	}
+}
+
+impl KeyServerSet for OnChainKeyServerSet {
+	fn get(&self) -> BTreeMap<Public, SocketAddr> {
+		self.contract.lock().get()
+	}
+}
+
+impl ChainNotify for OnChainKeyServerSet {
+	fn new_blocks(&self, _imported: Vec<H256>, _invalid: Vec<H256>, enacted: Vec<H256>, retracted: Vec<H256>, _sealed: Vec<H256>, _proposed: Vec<Bytes>, _duration: u64) {
+		if !enacted.is_empty() || !retracted.is_empty() {
+			self.contract.lock().update(enacted, retracted)
+		}
+	}
+}
+
+impl CachedContract {
+	pub fn new(client: &Arc<Client>, key_servers: BTreeMap<Public, NodeAddress>) -> Result<Self, Error> {
+		Ok(CachedContract {
+			client: Arc::downgrade(client),
+			contract_addr: None,
+			key_servers: key_servers.into_iter()
+				.map(|(p, addr)| {
+					let addr = format!("{}:{}", addr.address, addr.port).parse()
+						.map_err(|err| Error::Internal(format!("error parsing node address: {}", err)))?;
+					Ok((p, addr))
+				})
+				.collect::<Result<BTreeMap<_, _>, Error>>()?,
+		})
+	}
+
+	pub fn update(&mut self, enacted: Vec<H256>, retracted: Vec<H256>) {
+		if let Some(client) = self.client.upgrade() {
+			let new_contract_addr = client.registry_address(KEY_SERVER_SET_CONTRACT_REGISTRY_NAME.to_owned());
+
+			// new contract installed => read nodes set from the contract
+			if self.contract_addr.as_ref() != new_contract_addr.as_ref() {
+				self.read_from_registry(&*client, new_contract_addr);
+				return;
+			}
+
+			// check for contract events
+			let is_set_changed = self.contract_addr.is_some() && enacted.iter()
+				.chain(retracted.iter())
+				.any(|block_hash| !client.logs(Filter {
+					from_block: BlockId::Hash(block_hash.clone()),
+					to_block: BlockId::Hash(block_hash.clone()),
+					address: self.contract_addr.clone().map(|a| vec![a]),
+					topics: vec![
+						Some(vec![*ADDED_EVENT_NAME_HASH, *REMOVED_EVENT_NAME_HASH]),
+						None,
+						None,
+						None,
+					],
+					limit: Some(1),
+				}).is_empty());
+			// to simplify processing - just re-read the whole nodes set from the contract
+			if is_set_changed {
+				self.read_from_registry(&*client, new_contract_addr);
+			}
+		}
+	}
+
+	pub fn get(&self) -> BTreeMap<Public, SocketAddr> {
+		self.key_servers.clone()
+	}
+
+	fn read_from_registry(&mut self, client: &Client, new_contract_address: Option<Address>) {
+		self.key_servers = new_contract_address.map(|contract_addr| {
+			trace!(target: "secretstore", "Configuring for key server set contract from {}", contract_addr);
+
+			KeyServerSetContract::new(contract_addr)
+		})
+		.map(|contract| {
+			let mut key_servers = BTreeMap::new();
+			let do_call = |a, d| future::done(client.call_contract(BlockId::Latest, a, d));
+			let key_servers_list = contract.get_key_servers(do_call).wait()
+				.map_err(|err| { trace!(target: "secretstore", "Error {} reading list of key servers from contract", err); err })
+				.unwrap_or_default();
+			for key_server in key_servers_list {
+				let key_server_public = contract.get_key_server_public(
+					|a, d| future::done(client.call_contract(BlockId::Latest, a, d)), key_server).wait()
+					.and_then(|p| if p.len() == 64 { Ok(Public::from_slice(&p)) } else { Err(format!("Invalid public length {}", p.len())) });
+				let key_server_ip = contract.get_key_server_address(
+					|a, d| future::done(client.call_contract(BlockId::Latest, a, d)), key_server).wait()
+					.and_then(|a| a.parse().map_err(|e| format!("Invalid ip address: {}", e)));
+
+				// only add successfully parsed nodes
+				match (key_server_public, key_server_ip) {
+					(Ok(key_server_public), Ok(key_server_ip)) => { key_servers.insert(key_server_public, key_server_ip); },
+					(Err(public_err), _) => warn!(target: "secretstore_net", "received invalid public from key server set contract: {}", public_err),
+					(_, Err(ip_err)) => warn!(target: "secretstore_net", "received invalid IP from key server set contract: {}", ip_err),
+				}
+			}
+			key_servers
+		})
+		.unwrap_or_default();
+		self.contract_addr = new_contract_address;
+	}
+}
+
+#[cfg(test)]
+pub mod tests {
+	use std::collections::BTreeMap;
+	use std::net::SocketAddr;
+	use ethkey::Public;
+	use super::KeyServerSet;
+
+	#[derive(Default)]
+	pub struct MapKeyServerSet {
+		nodes: BTreeMap<Public, SocketAddr>,
+	}
+
+	impl MapKeyServerSet {
+		pub fn new(nodes: BTreeMap<Public, SocketAddr>) -> Self {
+			MapKeyServerSet {
+				nodes: nodes,
+			}
+		}
+	}
+
+	impl KeyServerSet for MapKeyServerSet {
+		fn get(&self) -> BTreeMap<Public, SocketAddr> {
+			self.nodes.clone()
+		}
+	}
+}

secret_store/src/lib.rs

@@ -21,6 +21,8 @@ extern crate log;
 extern crate futures;
 extern crate futures_cpupool;
 extern crate hyper;
+#[macro_use]
+extern crate lazy_static;
 extern crate parking_lot;
 extern crate rustc_hex;
 extern crate serde;
@@ -56,6 +58,7 @@ mod http_listener;
 mod key_server;
 mod key_storage;
 mod serialization;
+mod key_server_set;
 
 use std::sync::Arc;
 use ethcore::client::Client;
@@ -68,9 +71,10 @@ pub use traits::{KeyServer};
 pub fn start(client: Arc<Client>, config: ServiceConfiguration) -> Result<Box<KeyServer>, Error> {
 	use std::sync::Arc;
 
-	let acl_storage = Arc::new(acl_storage::OnChainAclStorage::new(client));
+	let acl_storage = acl_storage::OnChainAclStorage::new(&client);
+	let key_server_set = key_server_set::OnChainKeyServerSet::new(&client, config.cluster_config.nodes.clone())?;
 	let key_storage = Arc::new(key_storage::PersistentKeyStorage::new(&config)?);
-	let key_server = key_server::KeyServerImpl::new(&config.cluster_config, acl_storage, key_storage)?;
+	let key_server = key_server::KeyServerImpl::new(&config.cluster_config, key_server_set, acl_storage, key_storage)?;
 	let listener = http_listener::KeyServerHttpListener::start(&config.listener_address, key_server)?;
 	Ok(Box::new(listener))
 }