1 files changed, 70 insertions, 0 deletions
diff --git a/packages/subproviders/src/subproviders/private_key_wallet_subprovider.ts b/packages/subproviders/src/subproviders/private_key_wallet_subprovider.ts
new file mode 100644
index 000000000..c3a53773a
--- /dev/null
+++ b/packages/subproviders/src/subproviders/private_key_wallet_subprovider.ts
@@ -0,0 +1,70 @@
+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 { BaseWalletSubprovider } from './base_wallet_subprovider';
+import { Subprovider } from './subprovider';
+
+/**
+ * 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 the supplied Ethereum private key.
+ */
+export class PrivateKeyWalletSubprovider extends BaseWalletSubprovider {
+    private _address: string;
+    private _privateKeyBuffer: Buffer;
+    constructor(privateKey: string) {
+        assert.isString('privateKey', privateKey);
+        super();
+        this._privateKeyBuffer = new Buffer(privateKey, 'hex');
+        this._address = `0x${ethUtil.privateToAddress(this._privateKeyBuffer).toString('hex')}`;
+    }
+    /**
+     * Retrieve the account associated with the supplied private key.
+     * This method is implicitly called when issuing a `eth_accounts` JSON RPC request
+     * via your providerEngine instance.
+     * @return An array of accounts
+     */
+    public async getAccountsAsync(): Promise<string[]> {
+        return [this._address];
+    }
+    /**
+     * Sign a transaction with the private key. If you've added this Subprovider to your
+     * app's provider, you can simply send an `eth_sendTransaction` JSON RPC request, and
+     * this method will be called auto-magically. If you are not using this via a ProviderEngine
+     * instance, you can call it directly.
+     * @param txParams Parameters of the transaction to sign
+     * @return Signed transaction hex string
+     */
+    public async signTransactionAsync(txParams: PartialTxParams): Promise<string> {
+        PrivateKeyWalletSubprovider._validateTxParams(txParams);
+        const tx = new EthereumTx(txParams);
+        tx.sign(this._privateKeyBuffer);
+        const rawTx = `0x${tx.serialize().toString('hex')}`;
+        return rawTx;
+    }
+    /**
+     * Sign a personal Ethereum signed message. The signing address will be
+     * calculated from the private key.
+     * 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(dataIfExists: string): Promise<string> {
+        if (_.isUndefined(dataIfExists)) {
+            throw new Error(WalletSubproviderErrors.DataMissingForSignPersonalMessage);
+        }
+        assert.isHexString('data', dataIfExists);
+        const dataBuff = ethUtil.toBuffer(dataIfExists);
+        const msgHashBuff = ethUtil.hashPersonalMessage(dataBuff);
+        const sig = ethUtil.ecsign(msgHashBuff, this._privateKeyBuffer);
+        const rpcSig = ethUtil.toRpcSig(sig.v, sig.r, sig.s);
+        return rpcSig;
+    }
+}