Transaction permissioning (#6441)

ethcore/src/error.rs

@@ -80,6 +80,8 @@ pub enum TransactionError {
 	CodeBanned,
 	/// Invalid chain ID given.
 	InvalidChainId,
+	/// Not enough permissions given by permission contract.
+	NotAllowed,
 }
 
 impl fmt::Display for TransactionError {
@@ -104,6 +106,7 @@ impl fmt::Display for TransactionError {
 			RecipientBanned => "Recipient is temporarily banned.".into(),
 			CodeBanned => "Contract code is temporarily banned.".into(),
 			InvalidChainId => "Transaction of this chain ID is not allowed on this chain.".into(),
+			NotAllowed => "Sender does not have permissions to execute this type of transction".into(),
 		};
 
 		f.write_fmt(format_args!("Transaction error ({})", msg))