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 &

ethcrypto/src/lib.rs

@@ -22,6 +22,7 @@ extern crate crypto as rcrypto;
 extern crate secp256k1;
 extern crate ethkey;
 
+use std::fmt;
 use tiny_keccak::Keccak;
 use rcrypto::pbkdf2::pbkdf2;
 use rcrypto::scrypt::{scrypt, ScryptParams};
@@ -39,6 +40,17 @@ pub enum Error {
 	InvalidMessage,
 }
 
+impl fmt::Display for Error {
+	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+		let s = match *self {
+			Error::Secp(ref err) => err.to_string(),
+			Error::InvalidMessage => "Invalid message".into(),
+		};
+
+		write!(f, "{}", s)
+	}
+}
+
 impl From<SecpError> for Error {
 	fn from(e: SecpError) -> Self {
 		Error::Secp(e)