7 files changed, 671 insertions, 0 deletions
diff --git a/packages/subproviders/src/globals.d.ts b/packages/subproviders/src/globals.d.ts
new file mode 100644
index 000000000..1f9c6e8a6
--- /dev/null
+++ b/packages/subproviders/src/globals.d.ts
@@ -0,0 +1,68 @@
+/// <reference types='chai-typescript-typings' />
+/// <reference types='chai-as-promised-typescript-typings' />
+declare module 'bn.js';
+declare module 'dirty-chai';
+declare module 'ledgerco';
+declare module 'ethereumjs-tx';
+declare module 'es6-promisify';
+declare module 'ethereum-address';
+declare module 'debug';
+
+// tslint:disable:max-classes-per-file
+// tslint:disable:class-name
+// tslint:disable:completed-docs
+declare module 'ledgerco' {
+    interface comm {
+        close_async: Promise<void>;
+        create_async: Promise<void>;
+    }
+    export class comm_node implements comm {
+        public create_async: Promise<void>;
+        public close_async: Promise<void>;
+    }
+    export class comm_u2f implements comm {
+        public create_async: Promise<void>;
+        public close_async: Promise<void>;
+    }
+}
+
+// Semaphore-async-await declarations
+declare module 'semaphore-async-await' {
+    class Semaphore {
+        constructor(permits: number);
+        public wait(): void;
+        public signal(): void;
+    }
+    export default Semaphore;
+}
+
+// web3-provider-engine declarations
+declare module 'web3-provider-engine/subproviders/subprovider' {
+    class Subprovider {}
+    export = Subprovider;
+}
+declare module 'web3-provider-engine/subproviders/rpc' {
+    import * as Web3 from 'web3';
+    class RpcSubprovider {
+        constructor(options: {rpcUrl: string});
+        public handleRequest(
+            payload: Web3.JSONRPCRequestPayload, next: () => void, end: (err: Error|null, data?: any) =>  void,
+        ): void;
+    }
+    export = RpcSubprovider;
+}
+
+declare module 'web3-provider-engine' {
+  class Web3ProviderEngine {
+    public on(event: string, handler: () => void): void;
+    public send(payload: any): void;
+    public sendAsync(payload: any, callback: (error: any, response: any) => void): void;
+    public addProvider(provider: any): void;
+    public start(): void;
+    public stop(): void;
+  }
+  export = Web3ProviderEngine;
+}
+// tslint:enable:max-classes-per-file
+// tslint:enable:class-name
+// tslint:enable:completed-docs
diff --git a/packages/subproviders/src/index.ts b/packages/subproviders/src/index.ts
new file mode 100644
index 000000000..9560c3597
--- /dev/null
+++ b/packages/subproviders/src/index.ts
@@ -0,0 +1,30 @@
+import {
+    comm_node as LedgerNodeCommunication,
+    comm_u2f as LedgerBrowserCommunication,
+    eth as LedgerEthereumClientFn,
+} from 'ledgerco';
+
+import {LedgerEthereumClient} from './types';
+
+export {InjectedWeb3Subprovider} from './subproviders/injected_web3';
+export {RedundantRPCSubprovider} from './subproviders/redundant_rpc';
+export {
+    LedgerSubprovider,
+} from './subproviders/ledger';
+export {
+    ECSignature,
+    LedgerWalletSubprovider,
+    LedgerCommunicationClient,
+} from './types';
+
+export async function ledgerEthereumBrowserClientFactoryAsync(): Promise<LedgerEthereumClient> {
+    const ledgerConnection = await LedgerBrowserCommunication.create_async();
+    const ledgerEthClient = new LedgerEthereumClientFn(ledgerConnection);
+    return ledgerEthClient;
+}
+
+export async function ledgerEthereumNodeJsClientFactoryAsync(): Promise<LedgerEthereumClient> {
+    const ledgerConnection = await LedgerNodeCommunication.create_async();
+    const ledgerEthClient = new LedgerEthereumClientFn(ledgerConnection);
+    return ledgerEthClient;
+}
diff --git a/packages/subproviders/src/subproviders/injected_web3.ts b/packages/subproviders/src/subproviders/injected_web3.ts
new file mode 100644
index 000000000..a3308d142
--- /dev/null
+++ b/packages/subproviders/src/subproviders/injected_web3.ts
@@ -0,0 +1,47 @@
+import * as _ from 'lodash';
+import Web3 = require('web3');
+import Web3ProviderEngine = require('web3-provider-engine');
+
+/*
+ * This class implements the web3-provider-engine subprovider interface and forwards
+ * requests involving user accounts (getAccounts, sendTransaction, etc...) to the injected
+ * web3 instance in their browser.
+ * Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+ */
+export class InjectedWeb3Subprovider {
+    private injectedWeb3: Web3;
+    constructor(injectedWeb3: Web3) {
+        this.injectedWeb3 = injectedWeb3;
+    }
+    public handleRequest(
+        payload: Web3.JSONRPCRequestPayload, next: () => void, end: (err: Error, result: any) => void,
+    ) {
+        switch (payload.method) {
+            case 'web3_clientVersion':
+                this.injectedWeb3.version.getNode(end);
+                return;
+            case 'eth_accounts':
+                this.injectedWeb3.eth.getAccounts(end);
+                return;
+
+            case 'eth_sendTransaction':
+                const [txParams] = payload.params;
+                this.injectedWeb3.eth.sendTransaction(txParams, end);
+                return;
+
+            case 'eth_sign':
+                const [address, message] = payload.params;
+                this.injectedWeb3.eth.sign(address, message, end);
+                return;
+
+            default:
+                next();
+                return;
+        }
+    }
+    // Required to implement this method despite not needing it for this subprovider
+    // tslint:disable-next-line:prefer-function-over-method
+    public setEngine(engine: Web3ProviderEngine) {
+        // noop
+    }
+}
diff --git a/packages/subproviders/src/subproviders/ledger.ts b/packages/subproviders/src/subproviders/ledger.ts
new file mode 100644
index 000000000..931199ed1
--- /dev/null
+++ b/packages/subproviders/src/subproviders/ledger.ts
@@ -0,0 +1,320 @@
+import promisify = require('es6-promisify');
+import {isAddress} from 'ethereum-address';
+import * as EthereumTx from 'ethereumjs-tx';
+import ethUtil = require('ethereumjs-util');
+import * as ledger from 'ledgerco';
+import * as _ from 'lodash';
+import Semaphore from 'semaphore-async-await';
+import Web3 = require('web3');
+
+import {
+    LedgerEthereumClient,
+    LedgerEthereumClientFactoryAsync,
+    LedgerSubproviderConfigs,
+    LedgerSubproviderErrors,
+    PartialTxParams,
+    ResponseWithTxParams,
+    SignPersonalMessageParams,
+} from '../types';
+
+import {Subprovider} from './subprovider';
+
+const DEFAULT_DERIVATION_PATH = `44'/60'/0'`;
+const NUM_ADDRESSES_TO_FETCH = 10;
+const ASK_FOR_ON_DEVICE_CONFIRMATION = false;
+const SHOULD_GET_CHAIN_CODE = false;
+const HEX_REGEX = /^[0-9A-Fa-f]+$/g;
+
+export class LedgerSubprovider extends Subprovider {
+    private _nonceLock: Semaphore;
+    private _connectionLock: Semaphore;
+    private _networkId: number;
+    private _derivationPath: string;
+    private _derivationPathIndex: number;
+    private _ledgerEthereumClientFactoryAsync: LedgerEthereumClientFactoryAsync;
+    private _ledgerClientIfExists?: LedgerEthereumClient;
+    private _shouldAlwaysAskForConfirmation: boolean;
+    private static isValidHex(data: string) {
+        if (!_.isString(data)) {
+            return false;
+        }
+        const isHexPrefixed = data.slice(0, 2) === '0x';
+        if (!isHexPrefixed) {
+            return false;
+        }
+        const nonPrefixed = data.slice(2);
+        const isValid = nonPrefixed.match(HEX_REGEX);
+        return isValid;
+    }
+    private static validatePersonalMessage(msgParams: PartialTxParams) {
+        if (_.isUndefined(msgParams.from) || !isAddress(msgParams.from)) {
+            throw new Error(LedgerSubproviderErrors.FromAddressMissingOrInvalid);
+        }
+        if (_.isUndefined(msgParams.data)) {
+            throw new Error(LedgerSubproviderErrors.DataMissingForSignPersonalMessage);
+        }
+        if (!LedgerSubprovider.isValidHex(msgParams.data)) {
+            throw new Error(LedgerSubproviderErrors.DataNotValidHexForSignPersonalMessage);
+        }
+    }
+    private static validateSender(sender: string) {
+        if (_.isUndefined(sender) || !isAddress(sender)) {
+            throw new Error(LedgerSubproviderErrors.SenderInvalidOrNotSupplied);
+        }
+    }
+    constructor(config: LedgerSubproviderConfigs) {
+        super();
+        this._nonceLock = new Semaphore(1);
+        this._connectionLock = new Semaphore(1);
+        this._networkId = config.networkId;
+        this._ledgerEthereumClientFactoryAsync = config.ledgerEthereumClientFactoryAsync;
+        this._derivationPath = config.derivationPath || DEFAULT_DERIVATION_PATH;
+        this._shouldAlwaysAskForConfirmation = !_.isUndefined(config.accountFetchingConfigs) &&
+                                               !_.isUndefined(
+                                                   config.accountFetchingConfigs.shouldAskForOnDeviceConfirmation,
+                                               ) ?
+                                               config.accountFetchingConfigs.shouldAskForOnDeviceConfirmation :
+                                               ASK_FOR_ON_DEVICE_CONFIRMATION;
+        this._derivationPathIndex = 0;
+    }
+    public getPath(): string {
+        return this._derivationPath;
+    }
+    public setPath(derivationPath: string) {
+        this._derivationPath = derivationPath;
+    }
+    public setPathIndex(pathIndex: number) {
+        this._derivationPathIndex = pathIndex;
+    }
+    public async handleRequest(
+        payload: Web3.JSONRPCRequestPayload, next: () => void, end: (err: Error|null, result?: any) => void,
+    ) {
+        let accounts;
+        let txParams;
+        switch (payload.method) {
+            case 'eth_coinbase':
+                try {
+                    accounts = await this.getAccountsAsync();
+                    end(null, accounts[0]);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            case 'eth_accounts':
+                try {
+                    accounts = await this.getAccountsAsync();
+                    end(null, accounts);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            case 'eth_sendTransaction':
+                txParams = payload.params[0];
+                try {
+                    LedgerSubprovider.validateSender(txParams.from);
+                    const result = await this.sendTransactionAsync(txParams);
+                    end(null, result);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            case 'eth_signTransaction':
+                txParams = payload.params[0];
+                try {
+                    const result = await this.signTransactionWithoutSendingAsync(txParams);
+                    end(null, result);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            case 'personal_sign':
+                // non-standard "extraParams" to be appended to our "msgParams" obj
+                // good place for metadata
+                const extraParams = payload.params[2] || {};
+                const msgParams = _.assign({}, extraParams, {
+                    from: payload.params[1],
+                    data: payload.params[0],
+                });
+
+                try {
+                    LedgerSubprovider.validatePersonalMessage(msgParams);
+                    const ecSignatureHex = await this.signPersonalMessageAsync(msgParams);
+                    end(null, ecSignatureHex);
+                } catch (err) {
+                    end(err);
+                }
+                return;
+
+            default:
+                next();
+                return;
+        }
+    }
+    public async getAccountsAsync(): Promise<string[]> {
+        this._ledgerClientIfExists = await this.createLedgerClientAsync();
+
+        const accounts = [];
+        for (let i = 0; i < NUM_ADDRESSES_TO_FETCH; i++) {
+            try {
+                const derivationPath = `${this._derivationPath}/${i + this._derivationPathIndex}`;
+                const result = await this._ledgerClientIfExists.getAddress_async(
+                    derivationPath, this._shouldAlwaysAskForConfirmation, SHOULD_GET_CHAIN_CODE,
+                );
+                accounts.push(result.address.toLowerCase());
+            } catch (err) {
+                await this.destoryLedgerClientAsync();
+                throw err;
+            }
+        }
+        await this.destoryLedgerClientAsync();
+        return accounts;
+    }
+    public async signTransactionAsync(txParams: PartialTxParams): Promise<string> {
+        this._ledgerClientIfExists = await this.createLedgerClientAsync();
+
+        const tx = new EthereumTx(txParams);
+
+        // Set the EIP155 bits
+        tx.raw[6] = Buffer.from([this._networkId]);  // v
+        tx.raw[7] = Buffer.from([]);         // r
+        tx.raw[8] = Buffer.from([]);         // s
+
+        const txHex = tx.serialize().toString('hex');
+        try {
+            const derivationPath = this.getDerivationPath();
+            const result = await this._ledgerClientIfExists.signTransaction_async(derivationPath, txHex);
+            // Store signature in transaction
+            tx.r = Buffer.from(result.r, 'hex');
+            tx.s = Buffer.from(result.s, 'hex');
+            tx.v = Buffer.from(result.v, 'hex');
+
+            // EIP155: v should be chain_id * 2 + {35, 36}
+            const signedChainId = Math.floor((tx.v[0] - 35) / 2);
+            if (signedChainId !== this._networkId) {
+                await this.destoryLedgerClientAsync();
+                const err = new Error(LedgerSubproviderErrors.TooOldLedgerFirmware);
+                throw err;
+            }
+
+            const signedTxHex = `0x${tx.serialize().toString('hex')}`;
+            await this.destoryLedgerClientAsync();
+            return signedTxHex;
+        } catch (err) {
+            await this.destoryLedgerClientAsync();
+            throw err;
+        }
+    }
+    public async signPersonalMessageAsync(msgParams: SignPersonalMessageParams): Promise<string> {
+        this._ledgerClientIfExists = await this.createLedgerClientAsync();
+        try {
+            const derivationPath = this.getDerivationPath();
+            const result = await this._ledgerClientIfExists.signPersonalMessage_async(
+                derivationPath, ethUtil.stripHexPrefix(msgParams.data));
+            const v = result.v - 27;
+            let vHex = v.toString(16);
+            if (vHex.length < 2) {
+                vHex = `0${v}`;
+            }
+            const signature = `0x${result.r}${result.s}${vHex}`;
+            await this.destoryLedgerClientAsync();
+            return signature;
+        } catch (err) {
+            await this.destoryLedgerClientAsync();
+            throw err;
+        }
+    }
+    private getDerivationPath() {
+        const derivationPath = `${this.getPath()}/${this._derivationPathIndex}`;
+        return derivationPath;
+    }
+    private async createLedgerClientAsync(): Promise<LedgerEthereumClient> {
+        await this._connectionLock.wait();
+        if (!_.isUndefined(this._ledgerClientIfExists)) {
+            this._connectionLock.signal();
+            throw new Error(LedgerSubproviderErrors.MultipleOpenConnectionsDisallowed);
+        }
+        const ledgerEthereumClient = await this._ledgerEthereumClientFactoryAsync();
+        this._connectionLock.signal();
+        return ledgerEthereumClient;
+    }
+    private async destoryLedgerClientAsync() {
+        await this._connectionLock.wait();
+        if (_.isUndefined(this._ledgerClientIfExists)) {
+            this._connectionLock.signal();
+            return;
+        }
+        await this._ledgerClientIfExists.comm.close_async();
+        this._ledgerClientIfExists = undefined;
+        this._connectionLock.signal();
+    }
+    private async sendTransactionAsync(txParams: PartialTxParams): Promise<any> {
+        await this._nonceLock.wait();
+        try {
+            // fill in the extras
+            const filledParams = await this.populateMissingTxParamsAsync(txParams);
+            // sign it
+            const signedTx = await this.signTransactionAsync(filledParams);
+            // emit a submit
+            const payload = {
+                method: 'eth_sendRawTransaction',
+                params: [signedTx],
+            };
+            const result = await this.emitPayloadAsync(payload);
+            this._nonceLock.signal();
+            return result;
+        } catch (err) {
+            this._nonceLock.signal();
+            throw err;
+        }
+    }
+    private async signTransactionWithoutSendingAsync(txParams: PartialTxParams): Promise<ResponseWithTxParams> {
+        await this._nonceLock.wait();
+        try {
+            // fill in the extras
+            const filledParams = await this.populateMissingTxParamsAsync(txParams);
+            // sign it
+            const signedTx = await this.signTransactionAsync(filledParams);
+
+            this._nonceLock.signal();
+            const result = {
+                raw: signedTx,
+                tx: txParams,
+            };
+            return result;
+        } catch (err) {
+            this._nonceLock.signal();
+            throw err;
+        }
+    }
+    private async populateMissingTxParamsAsync(txParams: PartialTxParams): Promise<PartialTxParams> {
+        if (_.isUndefined(txParams.gasPrice)) {
+            const gasPriceResult = await this.emitPayloadAsync({
+                method: 'eth_gasPrice',
+                params: [],
+            });
+            const gasPrice = gasPriceResult.result.toString();
+            txParams.gasPrice = gasPrice;
+        }
+        if (_.isUndefined(txParams.nonce)) {
+            const nonceResult = await this.emitPayloadAsync({
+                method: 'eth_getTransactionCount',
+                params: [txParams.from, 'pending'],
+            });
+            const nonce = nonceResult.result;
+            txParams.nonce = nonce;
+        }
+        if (_.isUndefined(txParams.gas)) {
+            const gasResult = await this.emitPayloadAsync({
+                method: 'eth_estimateGas',
+                params: [txParams],
+            });
+            const gas = gasResult.result.toString();
+            txParams.gas = gas;
+        }
+        return txParams;
+    }
+}
diff --git a/packages/subproviders/src/subproviders/redundant_rpc.ts b/packages/subproviders/src/subproviders/redundant_rpc.ts
new file mode 100644
index 000000000..43d711ee6
--- /dev/null
+++ b/packages/subproviders/src/subproviders/redundant_rpc.ts
@@ -0,0 +1,46 @@
+import promisify = require('es6-promisify');
+import * as _ from 'lodash';
+import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
+import Subprovider = require('web3-provider-engine/subproviders/subprovider');
+
+import {JSONRPCPayload} from '../types';
+
+export class RedundantRPCSubprovider extends Subprovider {
+    private rpcs: RpcSubprovider[];
+    private static async firstSuccessAsync(
+        rpcs: RpcSubprovider[], payload: JSONRPCPayload, next: () => void,
+    ): Promise<any> {
+        let lastErr: Error|undefined;
+        for (const rpc of rpcs) {
+            try {
+                const data = await promisify(rpc.handleRequest.bind(rpc))(payload, next);
+                return data;
+            } catch (err) {
+                lastErr = err;
+                continue;
+            }
+        }
+        if (!_.isUndefined(lastErr)) {
+            throw lastErr;
+        }
+    }
+    constructor(endpoints: string[]) {
+        super();
+        this.rpcs = _.map(endpoints, endpoint => {
+            return new RpcSubprovider({
+                rpcUrl: endpoint,
+            });
+        });
+    }
+    public async handleRequest(payload: JSONRPCPayload, next: () => void,
+                               end: (err?: Error, data?: any) =>  void): Promise<void> {
+        const rpcsCopy = this.rpcs.slice();
+        try {
+            const data = await RedundantRPCSubprovider.firstSuccessAsync(rpcsCopy, payload, next);
+            end(undefined, data);
+        } catch (err) {
+            end(err);
+        }
+
+    }
+}
diff --git a/packages/subproviders/src/subproviders/subprovider.ts b/packages/subproviders/src/subproviders/subprovider.ts
new file mode 100644
index 000000000..07f4d6353
--- /dev/null
+++ b/packages/subproviders/src/subproviders/subprovider.ts
@@ -0,0 +1,45 @@
+import promisify = require('es6-promisify');
+import Web3 = require('web3');
+
+import {
+    JSONRPCPayload,
+} from '../types';
+/*
+ * A version of the base class Subprovider found in providerEngine
+ * This one has an async/await `emitPayloadAsync` and also defined types.
+ * Altered version of: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+ */
+export class Subprovider {
+    private engine: any;
+    private currentBlock: any;
+    private static getRandomId() {
+        const extraDigits = 3;
+        // 13 time digits
+        const datePart = new Date().getTime() * Math.pow(10, extraDigits);
+        // 3 random digits
+        const extraPart = Math.floor(Math.random() * Math.pow(10, extraDigits));
+        // 16 digits
+        return datePart + extraPart;
+    }
+    private static createFinalPayload(payload: JSONRPCPayload): Web3.JSONRPCRequestPayload {
+        const finalPayload = {
+            // defaults
+            id: Subprovider.getRandomId(),
+            jsonrpc: '2.0',
+            params: [],
+            ...payload,
+        };
+        return finalPayload;
+    }
+    public setEngine(engine: any): void {
+        this.engine = engine;
+        engine.on('block', (block: any) => {
+            this.currentBlock = block;
+        });
+    }
+    public async emitPayloadAsync(payload: JSONRPCPayload): Promise<any> {
+        const finalPayload = Subprovider.createFinalPayload(payload);
+        const response = await promisify(this.engine.sendAsync, this.engine)(finalPayload);
+        return response;
+    }
+}
diff --git a/packages/subproviders/src/types.ts b/packages/subproviders/src/types.ts
new file mode 100644
index 000000000..4564c5229
--- /dev/null
+++ b/packages/subproviders/src/types.ts
@@ -0,0 +1,115 @@
+import * as _ from 'lodash';
+import * as Web3 from 'web3';
+
+export interface LedgerCommunicationClient {
+    exchange: (apduHex: string, statusList: number[]) => Promise<any[]>;
+    setScrambleKey: (key: string) => void;
+    close_async: () => Promise<void>;
+}
+
+/*
+ * The LedgerEthereumClient sends Ethereum-specific requests to the Ledger Nano S
+ * It uses an internal LedgerCommunicationClient to relay these requests. Currently
+ * NodeJs and Browser communication are supported.
+ */
+export interface LedgerEthereumClient {
+    getAddress_async: (derivationPath: string, askForDeviceConfirmation: boolean,
+                       shouldGetChainCode: boolean) => Promise<LedgerGetAddressResult>;
+    signPersonalMessage_async: (derivationPath: string, messageHex: string) => Promise<ECSignature>;
+    signTransaction_async: (derivationPath: string, txHex: string) => Promise<ECSignatureString>;
+    comm: LedgerCommunicationClient;
+}
+
+export interface ECSignatureString {
+    v: string;
+    r: string;
+    s: string;
+}
+
+export interface ECSignature {
+    v: number;
+    r: string;
+    s: string;
+}
+
+export type LedgerEthereumClientFactoryAsync = () => Promise<LedgerEthereumClient>;
+
+/*
+ * networkId: The ethereum networkId to set as the chainId from EIP155
+ * ledgerConnectionType: Environment in which you wish to connect to Ledger (nodejs or browser)
+ * derivationPath: Initial derivation path to use e.g 44'/60'/0'
+ * accountFetchingConfigs: configs related to fetching accounts from a Ledger
+ */
+export interface LedgerSubproviderConfigs {
+    networkId: number;
+    ledgerEthereumClientFactoryAsync: LedgerEthereumClientFactoryAsync;
+    derivationPath?: string;
+    accountFetchingConfigs?: AccountFetchingConfigs;
+}
+
+/*
+ * numAddressesToReturn: Number of addresses to return from 'eth_accounts' call
+ * shouldAskForOnDeviceConfirmation: Whether you wish to prompt the user on their Ledger
+ *                                   before fetching their addresses
+ */
+export interface AccountFetchingConfigs {
+    numAddressesToReturn?: number;
+    shouldAskForOnDeviceConfirmation?: boolean;
+}
+
+export interface SignatureData {
+    hash: string;
+    r: string;
+    s: string;
+    v: number;
+}
+
+export interface LedgerGetAddressResult {
+    address: string;
+}
+
+export interface LedgerWalletSubprovider {
+    getPath: () => string;
+    setPath: (path: string) => void;
+    setPathIndex: (pathIndex: number) => void;
+}
+
+export interface SignPersonalMessageParams {
+    data: string;
+}
+
+export interface PartialTxParams {
+    nonce: string;
+    gasPrice?: string;
+    gas: string;
+    to: string;
+    from?: string;
+    value?: string;
+    data?: string;
+    chainId: number; // EIP 155 chainId - mainnet: 1, ropsten: 3
+}
+
+export type DoneCallback = (err?: Error) => void;
+
+export interface JSONRPCPayload {
+    params: any[];
+    method: string;
+}
+
+export interface LedgerCommunication {
+    close_async: () => Promise<void>;
+}
+
+export interface ResponseWithTxParams {
+    raw: string;
+    tx: PartialTxParams;
+}
+
+export enum LedgerSubproviderErrors {
+    TooOldLedgerFirmware = 'TOO_OLD_LEDGER_FIRMWARE',
+    FromAddressMissingOrInvalid = 'FROM_ADDRESS_MISSING_OR_INVALID',
+    DataMissingForSignPersonalMessage = 'DATA_MISSING_FOR_SIGN_PERSONAL_MESSAGE',
+    DataNotValidHexForSignPersonalMessage = 'DATA_NOT_VALID_HEX_FOR_SIGN_PERSONAL_MESSAGE',
+    SenderInvalidOrNotSupplied = 'SENDER_INVALID_OR_NOT_SUPPLIED',
+    MultipleOpenConnectionsDisallowed = 'MULTIPLE_OPEN_CONNECTIONS_DISALLOWED',
+}