Add Promises & Signing to Wallet Classes (#105)

* add validation for raw tx

* add node module, add signing lib

* add tx & message signing, promise everything

* remove unnecessary returns

* move isValidRawTx to for loop

* add & use new type RawTx

* implement cleaner promises, reject instead of throw

common/libs/signing.js

@@ -0,0 +1,40 @@
+// @flow
+
+import EthTx from 'ethereumjs-tx';
+import { sha3, ecsign } from 'ethereumjs-util';
+import { isValidRawTx } from 'libs/validators';
+import type { RawTx } from 'libs/validators';
+
+export function signRawTxWithPrivKey(privKey: Buffer, rawTx: RawTx): string {
+  if (!isValidRawTx(rawTx)) {
+    throw new Error('Invalid raw transaction');
+  }
+
+  let eTx = new EthTx(rawTx);
+  eTx.sign(privKey);
+  return '0x' + eTx.serialize().toString('hex');
+}
+
+export function signMessageWithPrivKey(
+  privKey: Buffer,
+  msg: string,
+  address: string,
+  date: string
+): string {
+  let spacer = msg.length > 0 && date.length > 0 ? ' ' : '';
+  let fullMessage = msg + spacer + date;
+  let hash = sha3(fullMessage);
+  let signed = ecsign(hash, privKey);
+  let combined = Buffer.concat([
+    Buffer.from(signed.r),
+    Buffer.from(signed.s),
+    Buffer.from([signed.v])
+  ]);
+  let combinedHex = combined.toString('hex');
+
+  return JSON.stringify({
+    address: address,
+    msg: fullMessage,
+    sig: '0x' + combinedHex
+  });
+}

common/libs/validators.js

@@ -84,3 +84,53 @@ export function isPositiveIntegerOrZero(number: number): boolean {
   }
   return number >= 0 && parseInt(number) === number;
 }
+
+export type RawTx = {
+  nonce: string,
+  gasPrice: string,
+  gasLimit: string,
+  to: string,
+  value: string,
+  data: string,
+  chainId: number
+};
+
+export function isValidRawTx(rawTx: RawTx): boolean {
+  const propReqs = [
+    { name: 'nonce', type: 'string', lenReq: true },
+    { name: 'gasPrice', type: 'string', lenReq: true },
+    { name: 'gasLimit', type: 'string', lenReq: true },
+    { name: 'to', type: 'string', lenReq: true },
+    { name: 'value', type: 'string', lenReq: true },
+    { name: 'data', type: 'string', lenReq: false },
+    { name: 'chainId', type: 'number' }
+  ];
+
+  //ensure rawTx has above properties
+  //ensure all specified types match
+  //ensure length !0 for strings where length is required
+  //ensure valid hex for strings
+  //ensure all strings begin with '0x'
+  //ensure valid address for 'to' prop
+  //ensure rawTx only has above properties
+
+  for (let i = 0; i < propReqs.length; i++) {
+    const prop = propReqs[i];
+    const value = rawTx[prop.name];
+
+    if (!rawTx.hasOwnProperty(prop.name)) return false;
+    if (typeof value !== prop.type) return false;
+    if (prop.type === 'string') {
+      if (prop.lenReq && value.length === 0) return false;
+      if (value.length && value.substring(0, 2) !== '0x') {
+        return false;
+      }
+      if (!isValidHex(value)) return false;
+    }
+  }
+
+  if (!isValidETHAddress(rawTx.to)) return false;
+  if (Object.keys(rawTx).length !== propReqs.length) return false;
+
+  return true;
+}

common/libs/wallet/base.js

@@ -1,11 +1,15 @@
 // @flow
 
 export default class BaseWallet {
-  getAddress(): string {
-    throw 'Implement me';
+  getAddress(): Promise<any> {
+    return Promise.reject('Implement me');
   }
 
-  getNakedAddress(): string {
-    return this.getAddress().replace('0x', '').toLowerCase();
+  getNakedAddress(): Promise<any> {
+    return new Promise(resolve => {
+      this.getAddress.then(address => {
+        resolve(address.replace('0x', '').toLowerCase());
+      });
+    });
   }
 }

common/libs/wallet/privkey.js

@@ -7,6 +7,8 @@ import {
 } from 'ethereumjs-util';
 import { randomBytes } from 'crypto';
 import { pkeyToKeystore } from 'libs/keystore';
+import { signRawTxWithPrivKey, signMessageWithPrivKey } from 'libs/signing';
+import type { RawTx } from 'libs/validators';
 
 export default class PrivKeyWallet extends BaseWallet {
   privKey: Buffer;
@@ -19,8 +21,10 @@ export default class PrivKeyWallet extends BaseWallet {
     this.address = publicToAddress(this.pubKey);
   }
 
-  getAddress() {
-    return toChecksumAddress(`0x${this.address.toString('hex')}`);
+  getAddress(): Promise<any> {
+    return new Promise(resolve => {
+      resolve(toChecksumAddress(`0x${this.address.toString('hex')}`));
+    });
   }
 
   getPrivateKey() {
@@ -31,7 +35,35 @@ export default class PrivKeyWallet extends BaseWallet {
     return new PrivKeyWallet(randomBytes(32));
   }
 
-  toKeystore(password: string): Object {
-    return pkeyToKeystore(this.privKey, this.getNakedAddress(), password);
+  toKeystore(password: string): Promise<any> {
+    return new Promise(resolve => {
+      this.getNakedAddress().then(address => {
+        resolve(pkeyToKeystore(this.privKey, address, password));
+      });
+    });
+  }
+
+  unlock(): Promise<any> {
+    return Promise.resolve();
+  }
+
+  signRawTransaction(rawTx: RawTx): Promise<any> {
+    return new Promise((resolve, reject) => {
+      try {
+        resolve(signRawTxWithPrivKey(this.privKey, rawTx));
+      } catch (err) {
+        reject(err);
+      }
+    });
+  }
+
+  signMessage(msg: string, address: string, date: string): Promise<any> {
+    return new Promise((resolve, reject) => {
+      try {
+        resolve(signMessageWithPrivKey(this.privKey, msg, address, date));
+      } catch (err) {
+        reject(err);
+      }
+    });
   }
 }

package.json

@@ -10,6 +10,7 @@
   "dependencies": {
     "big.js": "^3.1.3",
     "ethereum-blockies": "git+https://github.com/MyEtherWallet/blockies.git",
+    "ethereumjs-tx": "^1.3.3",
     "ethereumjs-util": "^5.1.2",
     "ethereumjs-wallet": "^0.6.0",
     "font-awesome": "^4.7.0",