Encryption, decryption and public key RPCs. (#1946)

* Fix up pending receipts details.

* Add support for additional params and registry over RPC.

* Fix tests.

* Add test, additional fix.

Fixes #1932.

* Fix up tests.

* Fix test.

* Fix test.

* Remove unused use.

* Add encryption, decryption and public-key RPCs.

* Remove &

ethcore/src/account_provider.rs

@@ -322,6 +322,26 @@ impl AccountProvider {
 		Ok(signature)
 	}
 
+	/// Decrypts a message. Account must be unlocked.
+	pub fn decrypt(&self, account: Address, shared_mac: &[u8], message: &[u8]) -> Result<Vec<u8>, Error> {
+		let data = {
+			let mut unlocked = self.unlocked.lock();
+			let data = try!(unlocked.get(&account).ok_or(Error::NotUnlocked)).clone();
+			if let Unlock::Temp = data.unlock {
+				unlocked.remove(&account).expect("data exists: so key must exist: qed");
+			}
+			if let Unlock::Timed((ref start, ref duration)) = data.unlock {
+				if start.elapsed() > Duration::from_millis(*duration as u64) {
+					unlocked.remove(&account).expect("data exists: so key must exist: qed");
+					return Err(Error::NotUnlocked);
+				}
+			}
+			data
+		};
+
+		Ok(try!(self.sstore.decrypt(&account, &data.password, shared_mac, message)))
+	}
+
 	/// Unlocks an account, signs the message, and locks it again.
 	pub fn sign_with_password(&self, account: Address, password: String, message: Message) -> Result<Signature, Error> {
 		let signature = try!(self.sstore.sign(&account, &password, &message));

ethcore/src/client/traits.rs

@@ -215,8 +215,11 @@ pub trait BlockChainClient : Sync + Send {
 /// Extended client interface used for mining
 pub trait MiningBlockChainClient : BlockChainClient {
 	/// Returns OpenBlock prepared for closing.
-	fn prepare_open_block(&self, author: Address, gas_range_target: (U256, U256), extra_data: Bytes)
-		-> OpenBlock;
+	fn prepare_open_block(&self,
+		author: Address,
+		gas_range_target: (U256, U256),
+		extra_data: Bytes
+	) -> OpenBlock;
 
 	/// Returns EvmFactory.
 	fn vm_factory(&self) -> &EvmFactory;

ethcore/src/types/transaction.rs

@@ -21,7 +21,7 @@ use std::cell::*;
 use rlp::*;
 use util::sha3::Hashable;
 use util::{H256, Address, U256, Bytes};
-use ethkey::{Signature, sign, Secret, recover, public_to_address, Error as EthkeyError};
+use ethkey::{Signature, sign, Secret, Public, recover, public_to_address, Error as EthkeyError};
 use error::*;
 use evm::Schedule;
 use header::BlockNumber;
@@ -305,13 +305,18 @@ impl SignedTransaction {
 		match sender {
 			Some(s) => Ok(s),
 			None => {
-				let s = public_to_address(&try!(recover(&self.signature(), &self.unsigned.hash())));
+				let s = public_to_address(&try!(self.public_key()));
 				self.sender.set(Some(s));
 				Ok(s)
 			}
 		}
 	}
 
+	/// Returns the public key of the sender.
+	pub fn public_key(&self) -> Result<Public, Error> {
+		Ok(try!(recover(&self.signature(), &self.unsigned.hash())))
+	}
+
 	/// Do basic validation, checking for valid signature and minimum gas,
 	// TODO: consider use in block validation.
 	#[cfg(test)]