Additional RPCs for password management (#2779)

* Add personal_testPassword and stub for personal_changePassword

* Add change-password functionality.

* Address grumble.

* Update tests.

* Update build.

ethcore/src/account_provider.rs

@@ -265,6 +265,20 @@ impl AccountProvider {
 		Ok(())
 	}
 
+	/// Returns `true` if the password for `account` is `password`. `false` if not.
+	pub fn test_password(&self, account: &Address, password: String) -> Result<bool, Error> {
+		match self.sstore.sign(&account, &password, &Default::default()) {
+			Ok(_) => Ok(true),
+			Err(SSError::InvalidPassword) => Ok(false),
+			Err(e) => Err(Error::SStore(e)),
+		}
+	} 
+
+	/// Changes the password of `account` from `password` to `new_password`. Fails if incorrect `password` given.
+	pub fn change_password(&self, account: &Address, password: String, new_password: String) -> Result<(), Error> {
+		self.sstore.change_password(&account, &password, &new_password).map_err(Error::SStore)
+	} 
+
 	/// Helper method used for unlocking accounts.
 	fn unlock_account(&self, account: Address, password: String, unlock: Unlock) -> Result<(), Error> {
 		// verify password by signing dump message

rpc/src/v1/impls/personal.rs

@@ -132,7 +132,34 @@ impl<C: 'static, M: 'static> Personal for PersonalClient<C, M> where C: MiningBl
 					Ok(_) => Ok(Value::Bool(true)),
 					Err(_) => Ok(Value::Bool(false)),
 				}
-			})
+			}
+		)
+	}
+
+	fn test_password(&self, params: Params) -> Result<Value, Error> {
+		try!(self.active());
+		from_params::<(RpcH160, String)>(params).and_then(
+			|(account, password)| {
+				let account: Address = account.into();
+				take_weak!(self.accounts)
+					.test_password(&account, password)
+					.map(|b| Value::Bool(b))
+					.map_err(|e| errors::account("Could not fetch account info.", e))
+			}
+		)
+	}
+
+	fn change_password(&self, params: Params) -> Result<Value, Error> {
+		try!(self.active());
+		from_params::<(RpcH160, String, String)>(params).and_then(
+			|(account, password, new_password)| {
+				let account: Address = account.into();
+				take_weak!(self.accounts)
+					.change_password(&account, password, new_password)
+					.map(|_| Value::Null)
+					.map_err(|e| errors::account("Could not fetch account info.", e))
+			}
+		)
 	}
 
 	fn sign_and_send_transaction(&self, params: Params) -> Result<Value, Error> {

rpc/src/v1/traits/personal.rs

@@ -39,6 +39,14 @@ pub trait Personal: Sized + Send + Sync + 'static {
 	/// Unlocks specified account for use (can only be one unlocked account at one moment)
 	fn unlock_account(&self, _: Params) -> Result<Value, Error>;
 
+	/// Returns true if given `password` would unlock given `account`.
+	/// Arguments: `account`, `password`.
+	fn test_password(&self, _: Params) -> Result<Value, Error>;
+
+	/// Changes an account's password.
+	/// Arguments: `account`, `password`, `new_password`.
+	fn change_password(&self, _: Params) -> Result<Value, Error>;
+
 	/// Sends transaction and signs it in single call. The account is not unlocked in such case.
 	fn sign_and_send_transaction(&self, _: Params) -> Result<Value, Error>;
 
@@ -69,6 +77,8 @@ pub trait Personal: Sized + Send + Sync + 'static {
 		delegate.add_method("personal_newAccountFromPhrase", Personal::new_account_from_phrase);
 		delegate.add_method("personal_newAccountFromWallet", Personal::new_account_from_wallet);
 		delegate.add_method("personal_unlockAccount", Personal::unlock_account);
+		delegate.add_method("personal_testPassword", Personal::test_password);
+		delegate.add_method("personal_changePassword", Personal::change_password);
 		delegate.add_method("personal_signAndSendTransaction", Personal::sign_and_send_transaction);
 		delegate.add_method("personal_setAccountName", Personal::set_account_name);
 		delegate.add_method("personal_setAccountMeta", Personal::set_account_meta);