From 205682235a3c90b81049c0b226eb1e529ab3e4da Mon Sep 17 00:00:00 2001
From: Nicholas Dudfield <ndudfield@gmail.com>
Date: Mon, 20 Jul 2015 11:17:48 +0700
Subject: [PATCH] Add generateWallet, walletFromSeed

---
 packages/ripple-keypairs/package.json         |  3 +-
 packages/ripple-keypairs/src/index.js         | 37 +++++++++++++++++-
 .../ripple-keypairs/test/keypairs-test.js     | 38 ++++++++++++++++++-
 3 files changed, 74 insertions(+), 4 deletions(-)

diff --git a/packages/ripple-keypairs/package.json b/packages/ripple-keypairs/package.json
index 90445492..23f3c190 100644
--- a/packages/ripple-keypairs/package.json
+++ b/packages/ripple-keypairs/package.json
@@ -16,6 +16,7 @@
   "dependencies": {
     "babel-runtime": "^5.3.2",
     "bn.js": "^3.1.1",
+    "brorand": "^1.0.5",
     "elliptic": "^5.1.0",
     "hash.js": "^1.0.3",
     "ripple-address-codec": "^1.3.0"
@@ -29,7 +30,7 @@
     "eslint": "^0.23.0",
     "eventemitter2": "^0.4.14",
     "istanbul": "~0.3.5",
-    "lodash": "^3.9.3",
+    "lodash": "^3.10.0",
     "map-stream": "~0.1.0",
     "mocha": "~2.1.0",
     "nock": "^0.34.1",
diff --git a/packages/ripple-keypairs/src/index.js b/packages/ripple-keypairs/src/index.js
index 583fe9a1..23507f98 100644
--- a/packages/ripple-keypairs/src/index.js
+++ b/packages/ripple-keypairs/src/index.js
@@ -3,9 +3,11 @@
 /* -------------------------------- REQUIRES -------------------------------- */
 
 const util = require('util');
+const assert = require('assert');
 const elliptic = require('elliptic');
 const hashjs = require('hash.js');
 const codec = require('ripple-address-codec');
+const rand = require('brorand');
 
 // elliptic
 const secp256k1 = elliptic.ec('secp256k1');
@@ -233,6 +235,37 @@ function keyPairFromSeed(seedString) {
   return pair.fromSeed(decoded.bytes);
 }
 
+function deriveWallet(type, seedBytes) {
+  assert(type === 'secp256k1' || type === 'ed25519');
+
+  let pair;
+  let seed;
+
+  if (type === 'secp256k1') {
+    seed = codec.encodeK256Seed(seedBytes);
+    pair = K256Pair.fromSeed(seedBytes);
+  } else {
+    seed = codec.encodeEdSeed(seedBytes);
+    pair = Ed25519Pair.fromSeed(seedBytes);
+  }
+
+  return {
+    seed,
+    accountID: pair.accountID(),
+    publicKey: pair.pubKeyHex()
+  };
+}
+
+function generateWallet({type='secp256k1', randGen=rand}) {
+  const seedBytes = randGen(16);
+  return deriveWallet(type, seedBytes);
+}
+
+function walletFromSeed(seed) {
+  const {type, bytes} = codec.decodeSeed(seed);
+  return deriveWallet(type, bytes);
+}
+
 module.exports = {
   KeyPair,
   K256Pair,
@@ -240,5 +273,7 @@ module.exports = {
   KeyType,
   seedFromPhrase,
   createAccountID,
-  keyPairFromSeed
+  keyPairFromSeed,
+  generateWallet,
+  walletFromSeed
 };
diff --git a/packages/ripple-keypairs/test/keypairs-test.js b/packages/ripple-keypairs/test/keypairs-test.js
index 8280beee..f8e81a67 100644
--- a/packages/ripple-keypairs/test/keypairs-test.js
+++ b/packages/ripple-keypairs/test/keypairs-test.js
@@ -1,15 +1,18 @@
 'use strict';
 
-const assert = require('assert');
+const assert = require('assert-diff');
 const utils = require('../src/utils');
 const keypairs = require('../src');
+const _ = require('lodash');
 
 const {
   KeyType,
   K256Pair,
   seedFromPhrase,
   Ed25519Pair,
-  keyPairFromSeed
+  keyPairFromSeed,
+  generateWallet,
+  walletFromSeed
 } = keypairs;
 
 const {SerializedObject} = require('ripple-lib');
@@ -87,6 +90,37 @@ describe('keyPairFromSeed', function() {
   });
 });
 
+describe('generateWallet', function() {
+  function randGen(len) {
+    return _.fill(Array(len), 0);
+  }
+
+  it('can generate ed25519 wallets', function() {
+    const expected = {
+      seed: 'sEdSJHS4oiAdz7w2X2ni1gFiqtbJHqE',
+      accountID: 'r9zRhGr7b6xPekLvT6wP4qNdWMryaumZS7',
+      publicKey:
+        'ED' +
+        '1A7C082846CFF58FF9A892BA4BA2593151CCF1DBA59F37714CC9ED39824AF85F'
+    };
+    const actual = generateWallet({type: 'ed25519', randGen});
+    assert.deepEqual(actual, expected);
+    assert.deepEqual(walletFromSeed(actual.seed), expected);
+  });
+  it('can generate secp256k1 wallets (by default)', function() {
+    const expected = {
+      seed: 'sp6JS7f14BuwFY8Mw6bTtLKWauoUs',
+      accountID: 'rGCkuB7PBr5tNy68tPEABEtcdno4hE6Y7f',
+      publicKey:
+        '03' +
+        '90A196799EE412284A5D80BF78C3E84CBB80E1437A0AECD9ADF94D7FEAAFA284'
+    };
+    const actual = generateWallet({type: undefined, randGen});
+    assert.deepEqual(actual, expected);
+    assert.deepEqual(walletFromSeed(actual.seed), expected);
+  });
+});
+
 describe('K256Pair', function() {
   describe('generated tests', function() {
     /*eslint-disable max-len*/