Add Mnemonic wallet subprovider

6 files changed, 130 insertions, 4 deletions

diff --git a/packages/subproviders/src/globals.d.ts b/packages/subproviders/src/globals.d.ts
index c5ad26876..754d164e8 100644
--- a/packages/subproviders/src/globals.d.ts
+++ b/packages/subproviders/src/globals.d.ts
@@ -54,7 +54,9 @@ declare module '@ledgerhq/hw-transport-node-hid' {
 // hdkey declarations
 declare module 'hdkey' {
     class HDNode {
+        public static fromMasterSeed(seed: Buffer): HDNode;
         public publicKey: Buffer;
+        public privateKey: Buffer;
         public chainCode: Buffer;
         public constructor();
         public derive(path: string): HDNode;
diff --git a/packages/subproviders/src/index.ts b/packages/subproviders/src/index.ts
index dd553fde4..9c30c6ba1 100644
--- a/packages/subproviders/src/index.ts
+++ b/packages/subproviders/src/index.ts
@@ -13,6 +13,7 @@ export { GanacheSubprovider } from './subproviders/ganache';
 export { Subprovider } from './subproviders/subprovider';
 export { NonceTrackerSubprovider } from './subproviders/nonce_tracker';
 export { PrivateKeyWalletSubprovider } from './subproviders/private_key_wallet_subprovider';
+export { MnemonicWalletSubprovider } from './subproviders/mnemonic_wallet_subprovider';
 export {
     Callback,
     ErrorCallback,
diff --git a/packages/subproviders/src/subproviders/ledger.ts b/packages/subproviders/src/subproviders/ledger.ts
index aa86bf6c0..23ed3c93e 100644
--- a/packages/subproviders/src/subproviders/ledger.ts
+++ b/packages/subproviders/src/subproviders/ledger.ts
@@ -1,5 +1,4 @@
 import { assert } from '@0xproject/assert';
-import { JSONRPCRequestPayload } from '@0xproject/types';
 import { addressUtils } from '@0xproject/utils';
 import EthereumTx = require('ethereumjs-tx');
 import ethUtil = require('ethereumjs-util');
diff --git a/packages/subproviders/src/subproviders/mnemonic_wallet_subprovider.ts b/packages/subproviders/src/subproviders/mnemonic_wallet_subprovider.ts
new file mode 100644
index 000000000..fdb497776
--- /dev/null
+++ b/packages/subproviders/src/subproviders/mnemonic_wallet_subprovider.ts
@@ -0,0 +1,123 @@
+import { assert } from '@0xproject/assert';
+import * as bip39 from 'bip39';
+import ethUtil = require('ethereumjs-util');
+import HDNode = require('hdkey');
+import * as _ from 'lodash';
+
+import { MnemonicSubproviderErrors, PartialTxParams } from '../types';
+
+import { BaseWalletSubprovider } from './base_wallet_subprovider';
+import { PrivateKeyWalletSubprovider } from './private_key_wallet_subprovider';
+
+const DEFAULT_DERIVATION_PATH = `44'/60'/0'`;
+const DEFAULT_NUM_ADDRESSES_TO_FETCH = 10;
+const DEFAULT_ADDRESS_SEARCH_LIMIT = 100;
+
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * This subprovider intercepts all account related RPC requests (e.g message/transaction signing, etc...) and handles
+ * all requests with accounts derived from the supplied mnemonic.
+ */
+export class MnemonicWalletSubprovider extends BaseWalletSubprovider {
+    private _derivationPath: string;
+    private _hdKey: HDNode;
+    private _derivationPathIndex: number;
+    constructor(mnemonic: string, derivationPath: string = DEFAULT_DERIVATION_PATH) {
+        assert.isString('mnemonic', mnemonic);
+        super();
+        this._hdKey = HDNode.fromMasterSeed(bip39.mnemonicToSeed(mnemonic));
+        this._derivationPathIndex = 0;
+        this._derivationPath = derivationPath;
+    }
+    /**
+     * Retrieve the set derivation path
+     * @returns derivation path
+     */
+    public getPath(): string {
+        return this._derivationPath;
+    }
+    /**
+     * Set a desired derivation path when computing the available user addresses
+     * @param derivationPath The desired derivation path (e.g `44'/60'/0'`)
+     */
+    public setPath(derivationPath: string) {
+        this._derivationPath = derivationPath;
+    }
+    /**
+     * Set the final derivation path index. If a user wishes to sign a message with the
+     * 6th address in a derivation path, before calling `signPersonalMessageAsync`, you must
+     * call this method with pathIndex `6`.
+     * @param pathIndex Desired derivation path index
+     */
+    public setPathIndex(pathIndex: number) {
+        this._derivationPathIndex = pathIndex;
+    }
+    /**
+     * Retrieve the account associated with the supplied private key.
+     * This method is implicitly called when issuing a `eth_accounts` JSON RPC request
+     * via your providerEngine instance.
+     * @return An array of accounts
+     */
+    public async getAccountsAsync(numberOfAccounts: number = DEFAULT_NUM_ADDRESSES_TO_FETCH): Promise<string[]> {
+        const accounts: string[] = [];
+        for (let i = 0; i < numberOfAccounts; i++) {
+            const derivedHDNode = this._hdKey.derive(`m/${this._derivationPath}/${i + this._derivationPathIndex}`);
+            const derivedPublicKey = derivedHDNode.publicKey;
+            const shouldSanitizePublicKey = true;
+            const ethereumAddressUnprefixed = ethUtil
+                .publicToAddress(derivedPublicKey, shouldSanitizePublicKey)
+                .toString('hex');
+            const ethereumAddressPrefixed = ethUtil.addHexPrefix(ethereumAddressUnprefixed);
+            accounts.push(ethereumAddressPrefixed.toLowerCase());
+        }
+        return accounts;
+    }
+
+    /**
+     * Signs a transaction with the from account (if specificed in txParams) or the first account.
+     * If you've added this Subprovider to your  app's provider, you can simply send
+     * an `eth_sendTransaction` JSON RPC request, and * this method will be called auto-magically.
+     * If you are not using this via a ProviderEngine instance, you can call it directly.
+     * @param txParams Parameters of the transaction to sign
+     * @return Signed transaction hex string
+     */
+    public async signTransactionAsync(txParams: PartialTxParams): Promise<string> {
+        const accounts = await this.getAccountsAsync();
+        const hdKey = this._findHDKeyByPublicAddress(txParams.from || accounts[0]);
+        const privateKeyWallet = new PrivateKeyWalletSubprovider(hdKey.privateKey.toString('hex'));
+        const signedTx = privateKeyWallet.signTransactionAsync(txParams);
+        return signedTx;
+    }
+    /**
+     * Sign a personal Ethereum signed message. The signing address will be
+     * derived from the set path.
+     * If you've added the PKWalletSubprovider to your app's provider, you can simply send an `eth_sign`
+     * or `personal_sign` JSON RPC request, and this method will be called auto-magically.
+     * If you are not using this via a ProviderEngine instance, you can call it directly.
+     * @param data Message to sign
+     * @return Signature hex string (order: rsv)
+     */
+    public async signPersonalMessageAsync(data: string): Promise<string> {
+        const accounts = await this.getAccountsAsync();
+        const hdKey = this._findHDKeyByPublicAddress(accounts[0]);
+        const privateKeyWallet = new PrivateKeyWalletSubprovider(hdKey.privateKey.toString('hex'));
+        const sig = await privateKeyWallet.signPersonalMessageAsync(data);
+        return sig;
+    }
+
+    private _findHDKeyByPublicAddress(address: string, searchLimit: number = DEFAULT_ADDRESS_SEARCH_LIMIT): HDNode {
+        for (let i = 0; i < searchLimit; i++) {
+            const derivedHDNode = this._hdKey.derive(`m/${this._derivationPath}/${i + this._derivationPathIndex}`);
+            const derivedPublicKey = derivedHDNode.publicKey;
+            const shouldSanitizePublicKey = true;
+            const ethereumAddressUnprefixed = ethUtil
+                .publicToAddress(derivedPublicKey, shouldSanitizePublicKey)
+                .toString('hex');
+            const ethereumAddressPrefixed = ethUtil.addHexPrefix(ethereumAddressUnprefixed);
+            if (ethereumAddressPrefixed === address) {
+                return derivedHDNode;
+            }
+        }
+        throw new Error(MnemonicSubproviderErrors.AddressSearchExhausted);
+    }
+}
diff --git a/packages/subproviders/src/subproviders/private_key_wallet_subprovider.ts b/packages/subproviders/src/subproviders/private_key_wallet_subprovider.ts
index c3a53773a..0aa2fb590 100644
--- a/packages/subproviders/src/subproviders/private_key_wallet_subprovider.ts
+++ b/packages/subproviders/src/subproviders/private_key_wallet_subprovider.ts
@@ -1,13 +1,11 @@
 import { assert } from '@0xproject/assert';
-import { JSONRPCRequestPayload } from '@0xproject/types';
 import EthereumTx = require('ethereumjs-tx');
 import * as ethUtil from 'ethereumjs-util';
 import * as _ from 'lodash';
 
-import { Callback, ErrorCallback, PartialTxParams, ResponseWithTxParams, WalletSubproviderErrors } from '../types';
+import { PartialTxParams, WalletSubproviderErrors } from '../types';
 
 import { BaseWalletSubprovider } from './base_wallet_subprovider';
-import { Subprovider } from './subprovider';
 
 /**
  * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
diff --git a/packages/subproviders/src/types.ts b/packages/subproviders/src/types.ts
index bacb7091b..de04499ce 100644
--- a/packages/subproviders/src/types.ts
+++ b/packages/subproviders/src/types.ts
@@ -95,6 +95,9 @@ export interface ResponseWithTxParams {
     tx: PartialTxParams;
 }
 
+export enum MnemonicSubproviderErrors {
+    AddressSearchExhausted = 'ADDRESS_SEARCH_EXHAUSTED',
+}
 export enum WalletSubproviderErrors {
     DataMissingForSignPersonalMessage = 'DATA_MISSING_FOR_SIGN_PERSONAL_MESSAGE',
     SenderInvalidOrNotSupplied = 'SENDER_INVALID_OR_NOT_SUPPLIED',