Disable hardware-wallets on platforms that don't support libusb (#8464)

* disable hardware-wallets that don't support libusb

* address grumbles

* nits

* Refactor to get rid off as much annotations asap

* Might consume slight more memory than pure conditional compilation
flags

* formatting nits

* Enable libusb for android

* Tested by it compiling succesfully with `cargo build --target=armv7--linux-androideabi`
* The binary is ~66 MB

```bash
$ size
size target/armv7-linux-androideabi/release/parity
text    	data     	bss     	dec     	hex 		filename
50676230        416200   	31456 		51123886        30c16ae 	target/armv7-linux-androideabi/release/parity
```

* Move all `fake-hardware-wallet` to its own crate

* Removes some conditional compilation flags
* Introduces `fake-hardware-wallet` crate

* return error if no hardware wallets are found

Cargo.lock

@@ -545,6 +545,7 @@ dependencies = [
  "ethkey 0.3.0",
  "ethstore 0.2.0",
  "evm 0.1.0",
+ "fake-hardware-wallet 0.0.1",
  "fetch 0.1.0",
  "hardware-wallet 1.12.0",
  "hashdb 0.1.1",
@@ -1072,6 +1073,14 @@ dependencies = [
  "hyper 0.11.24 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "fake-hardware-wallet"
+version = "0.0.1"
+dependencies = [
+ "ethereum-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ethkey 0.3.0",
+]
+
 [[package]]
 name = "fdlimit"
 version = "0.1.1"
@@ -2238,6 +2247,7 @@ dependencies = [
  "ethkey 0.3.0",
  "ethstore 0.2.0",
  "fake-fetch 0.0.1",
+ "fake-hardware-wallet 0.0.1",
  "fetch 0.1.0",
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-cpupool 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",

ethcore/Cargo.toml

@@ -36,7 +36,6 @@ ethjson = { path = "../json" }
 ethkey = { path = "../ethkey" }
 ethstore = { path = "../ethstore" }
 evm = { path = "evm" }
-hardware-wallet = { path = "../hw" }
 heapsize = "0.4"
 itertools = "0.5"
 lazy_static = "1.0"
@@ -70,6 +69,12 @@ journaldb = { path = "../util/journaldb" }
 tempdir = { version = "0.3", optional = true }
 kvdb-rocksdb = { path = "../util/kvdb-rocksdb" }
 
+[target.'cfg(any(target_os = "linux", target_os = "macos", target_os = "windows", target_os = "android"))'.dependencies]
+hardware-wallet = { path = "../hw" }
+
+[target.'cfg(not(any(target_os = "linux", target_os = "macos", target_os = "windows", target_os = "android")))'.dependencies]
+fake-hardware-wallet = { path = "../util/fake-hardware-wallet" }
+
 [dev-dependencies]
 trie-standardmap = { path = "../util/trie-standardmap" }
 

ethcore/src/account_provider/mod.rs

@@ -20,21 +20,23 @@ mod stores;
 
 use self::stores::{AddressBook, DappsSettingsStore, NewDappsPolicy};
 
-use std::fmt;
 use std::collections::{HashMap, HashSet};
+use std::fmt;
 use std::time::{Instant, Duration};
-use parking_lot::RwLock;
+
+use ethstore::accounts_dir::MemoryDirectory;
+use ethstore::ethkey::{Address, Message, Public, Secret, Password, Random, Generator};
+use ethjson::misc::AccountMeta;
 use ethstore::{
 	SimpleSecretStore, SecretStore, Error as SSError, EthStore, EthMultiStore,
 	random_string, SecretVaultRef, StoreAccountRef, OpaqueSecret,
 };
-use ethstore::accounts_dir::MemoryDirectory;
+use parking_lot::RwLock;
-use ethstore::ethkey::{Address, Message, Public, Secret, Password, Random, Generator};
+
-use ethjson::misc::AccountMeta;
-use hardware_wallet::{Error as HardwareError, HardwareWalletManager, KeyPath, TransactionInfo};
-use super::transaction::{Action, Transaction};
 pub use ethstore::ethkey::Signature;
 pub use ethstore::{Derivation, IndexDerivation, KeyFile};
+pub use hardware_wallet::{Error as HardwareError, HardwareWalletManager, KeyPath, TransactionInfo};
+pub use super::transaction::{Action, Transaction};
 
 /// Type of unlock.
 #[derive(Clone, PartialEq)]
@@ -165,6 +167,7 @@ impl AccountProvider {
 	/// Creates new account provider.
 	pub fn new(sstore: Box<SecretStore>, settings: AccountProviderSettings) -> Self {
 		let mut hardware_store = None;
+		
 		if settings.enable_hardware_wallets {
 			match HardwareWalletManager::new() {
 				Ok(manager) => {
@@ -289,8 +292,12 @@ impl AccountProvider {
 
 	/// Returns addresses of hardware accounts.
 	pub fn hardware_accounts(&self) -> Result<Vec<Address>, Error> {
-		let accounts = self.hardware_store.as_ref().map_or(Vec::new(), |h| h.list_wallets());
+		if let Some(accounts) = self.hardware_store.as_ref().map(|h| h.list_wallets()) { 
-		Ok(accounts.into_iter().map(|a| a.address).collect())
+			if !accounts.is_empty() {
+				return Ok(accounts.into_iter().map(|a| a.address).collect());
+			}
+		}
+		Err(SSError::Custom("No hardware wallet accounts were found".into()))
 	}
 
 	/// Get a list of paths to locked hardware wallets

ethcore/src/lib.rs

@@ -75,7 +75,7 @@ extern crate ethcore_transaction as transaction;
 extern crate ethereum_types;
 extern crate ethjson;
 extern crate ethkey;
-extern crate hardware_wallet;
+
 extern crate hashdb;
 extern crate itertools;
 extern crate kvdb;
@@ -99,7 +99,6 @@ extern crate ansi_term;
 extern crate unexpected;
 extern crate util_error;
 extern crate snappy;
-
 extern crate ethabi;
 extern crate rustc_hex;
 extern crate stats;
@@ -112,6 +111,12 @@ extern crate journaldb;
 #[cfg(any(test, feature = "json-tests", feature = "test-helpers"))]
 extern crate tempdir;
 
+#[cfg(any(target_os = "linux", target_os = "macos", target_os = "windows", target_os = "android"))]
+extern crate hardware_wallet;
+
+#[cfg(not(any(target_os = "linux", target_os = "macos", target_os = "windows", target_os = "android")))]
+extern crate fake_hardware_wallet as hardware_wallet;
+
 #[macro_use]
 extern crate ethabi_derive;
 #[macro_use]

rpc/Cargo.toml

@@ -64,6 +64,12 @@ rlp = { path = "../util/rlp" }
 stats = { path = "../util/stats" }
 vm = { path = "../ethcore/vm" }
 
+[target.'cfg(any(target_os = "linux", target_os = "macos", target_os = "windows", target_os = "android"))'.dependencies]
+hardware-wallet = { path = "../hw" }
+
+[target.'cfg(not(any(target_os = "linux", target_os = "macos", target_os = "windows", target_os = "android")))'.dependencies]
+fake-hardware-wallet = { path = "../util/fake-hardware-wallet" }
+
 [dev-dependencies]
 ethcore = { path = "../ethcore", features = ["test-helpers"] }
 ethcore-network = { path = "../util/network" }

rpc/src/lib.rs

@@ -58,17 +58,21 @@ extern crate ethcore_transaction as transaction;
 extern crate ethereum_types;
 extern crate ethkey;
 extern crate ethstore;
-extern crate vm;
 extern crate fetch;
+extern crate keccak_hash as hash;
 extern crate node_health;
 extern crate parity_reactor;
 extern crate parity_updater as updater;
 extern crate parity_version as version;
+extern crate patricia_trie as trie;
 extern crate rlp;
 extern crate stats;
-extern crate keccak_hash as hash;
+extern crate vm;
+
+#[cfg(any(target_os = "linux", target_os = "macos", target_os = "windows", target_os = "android"))]
 extern crate hardware_wallet;
-extern crate patricia_trie as trie;
+#[cfg(not(any(target_os = "linux", target_os = "macos", target_os = "windows", target_os = "android")))]
+extern crate fake_hardware_wallet as hardware_wallet;
 
 #[macro_use]
 extern crate log;

rpc/src/v1/helpers/dispatch.rs

@@ -24,7 +24,6 @@ use light::cache::Cache as LightDataCache;
 use light::client::LightChainClient;
 use light::on_demand::{request, OnDemand};
 use light::TransactionQueue as LightTransactionQueue;
-use rlp;
 use hash::keccak;
 use ethereum_types::{H256, H520, Address, U256};
 use bytes::Bytes;
@@ -52,6 +51,7 @@ use v1::types::{
 	SignRequest as RpcSignRequest,
 	DecryptRequest as RpcDecryptRequest,
 };
+use rlp;
 
 pub use self::nonce::Reservations;
 
@@ -699,7 +699,6 @@ pub fn execute<D: Dispatcher + 'static>(
 			if accounts.is_hardware_address(&address) {
 				return Box::new(future::err(errors::unsupported("Decrypting via hardware wallets is not supported.", None)));
 			}
-
 			let res = decrypt(&accounts, address, data, pass)
 				.map(|result| result
 					.map(RpcBytes)

rpc/src/v1/impls/parity.rs

@@ -34,7 +34,6 @@ use ethcore::state::StateInfo;
 use ethcore_logger::RotatingLogger;
 use node_health::{NodeHealth, Health};
 use updater::{Service as UpdateService};
-
 use jsonrpc_core::{BoxFuture, Result};
 use jsonrpc_core::futures::{future, Future};
 use jsonrpc_macros::Trailing;

rpc/src/v1/impls/parity_accounts.rs

@@ -22,7 +22,6 @@ use ethereum_types::Address;
 use ethkey::{Brain, Generator, Secret};
 use ethstore::KeyFile;
 use ethcore::account_provider::AccountProvider;
-
 use jsonrpc_core::Result;
 use v1::helpers::errors;
 use v1::traits::ParityAccounts;

util/fake-hardware-wallet/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+description = "Fake hardware-wallet, for OS' that don't support libusb"
+name = "fake-hardware-wallet"
+version = "0.0.1"
+license = "GPL-3.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+
+[dependencies]
+ethereum-types = "0.3"
+ethkey = { path = "../../ethkey" }

util/fake-hardware-wallet/src/lib.rs

@@ -0,0 +1,101 @@
+// Copyright 2015-2018 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/>.
+
+//! Dummy module for platforms that does not provide support for hardware wallets (libusb)
+
+extern crate ethereum_types;
+extern crate ethkey;
+
+use std::fmt;
+use ethereum_types::U256;
+use ethkey::{Address, Signature};
+
+pub struct WalletInfo {
+	pub address: Address,
+	pub name: String,
+	pub manufacturer: String,
+}
+
+#[derive(Debug)]
+/// `ErrorType` for devices with no `hardware wallet`
+pub enum Error {
+	NoWallet,
+	KeyNotFound,
+}
+
+pub struct TransactionInfo {
+	/// Nonce
+	pub nonce: U256,
+	/// Gas price
+	pub gas_price: U256,
+	/// Gas limit
+	pub gas_limit: U256,
+	/// Receiver
+	pub to: Option<Address>,
+	/// Value
+	pub value: U256,
+	/// Data
+	pub data: Vec<u8>,
+	/// Chain ID
+	pub chain_id: Option<u64>,
+}
+
+pub enum KeyPath {
+	/// Ethereum.
+	Ethereum,
+	/// Ethereum classic.
+	EthereumClassic,
+}
+
+/// `HardwareWalletManager` for devices with no `hardware wallet`
+pub struct HardwareWalletManager;
+
+impl HardwareWalletManager {
+	pub fn new() -> Result<Self, Error> {
+		Err(Error::NoWallet)
+	}
+
+	pub fn set_key_path(&self, _key_path: KeyPath) {}
+
+	pub fn wallet_info(&self, _: &Address) -> Option<WalletInfo> { 
+		None 
+	}
+
+	pub fn list_wallets(&self) -> Vec<WalletInfo> {
+		Vec::with_capacity(0)
+	}
+
+	pub fn list_locked_wallets(&self) -> Result<Vec<String>, Error> {
+		Err(Error::NoWallet)
+	}
+
+	pub fn pin_matrix_ack(&self, _: &str, _: &str) -> Result<bool, Error> { 
+		Err(Error::NoWallet)
+	}
+	
+	pub fn sign_transaction(&self, _address: &Address, _transaction: &TransactionInfo, _rlp_transaction: &[u8]) -> Result<Signature, Error> { 
+		Err(Error::NoWallet) }
+	
+	pub fn sign_message(&self, _address: &Address, _msg: &[u8]) -> Result<Signature, Error> {
+		Err(Error::NoWallet)
+	}
+}
+
+impl fmt::Display for Error {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 
+		write!(f, "No hardware wallet!!") 
+	}
+}