From b6709863c443d0093512b83d4592871bcfdea45f Mon Sep 17 00:00:00 2001
From: Patrick Hurley <phurley@gmail.com>
Date: Mon, 16 Mar 2020 22:26:39 -0400
Subject: [PATCH] Support keys

---
 decrypto.js | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 index.html  |  1 +
 2 files changed, 54 insertions(+)

diff --git a/decrypto.js b/decrypto.js
index 92ce948..b4606e4 100644
--- a/decrypto.js
+++ b/decrypto.js
@@ -14,6 +14,43 @@ function loadWordList() {
 	return wordList;
 }
 
+function xmur3(str) {
+    for(var i = 0, h = 1779033703 ^ str.length; i < str.length; i++)
+        h = Math.imul(h ^ str.charCodeAt(i), 3432918353),
+        h = h << 13 | h >>> 19;
+    return function() {
+        h = Math.imul(h ^ h >>> 16, 2246822507);
+        h = Math.imul(h ^ h >>> 13, 3266489909);
+        return (h ^= h >>> 16) >>> 0;
+    }
+}
+
+function sfc32(a, b, c, d) {
+    return function() {
+      a >>>= 0; b >>>= 0; c >>>= 0; d >>>= 0;
+      var t = (a + b) | 0;
+      a = b ^ b >>> 9;
+      b = c + (c << 3) | 0;
+      c = (c << 21 | c >>> 11);
+      d = d + 1 | 0;
+      t = t + d | 0;
+      c = c + t | 0;
+      return (t >>> 0) / 4294967296;
+    }
+}
+
+var my_random = function() {
+  return Math.random;
+}
+
+_.random = function(min, max) {
+  if (max == null) {
+    max = min;
+    min = 0;
+  }
+  return min + Math.floor(my_random() * (max - min + 1));
+};
+
 function pickWords(numWords) {
 	return _.sample(wordList, numWords);
 }
@@ -51,10 +88,23 @@ function loadCode() {
 	}
 }
 
+var seed = function() { return 0; };
+
 function newGame() {
+  var seedkey = document.getElementById("gameseed").value;
+  if (seedkey.length > 0) {
+    seed = xmur3(seedkey);
+  } else {
+    seed = xmur3((new Date()).toJSON());
+  }
+  my_random = sfc32(seed(), seed(), seed(), seed());
 	var words = pickWords(4);
 	Cookies.set("words", words);
 	Cookies.remove("code");
+
+  seed = xmur3((new Date()).toJSON());
+  my_random = sfc32(seed(), seed(), seed(), seed());
+
 	$('#revealCodeButton').hide();
 	return words;
 }
@@ -111,6 +161,9 @@ function initialize() {
 	wordList = loadWordList();
 	loadCode();
 
+  seed = xmur3((new Date()).toJSON());
+  my_random = sfc32(seed(), seed(), seed(), seed());
+
 	var words = loadWords();
 
 	if (words) {
diff --git a/index.html b/index.html
index c77af66..58fc4ec 100644
--- a/index.html
+++ b/index.html
@@ -144,6 +144,7 @@ <h5 class="modal-title" id="newGameModalLabel">New Game</h5>
       </div>
       <div class="modal-body">
         Do you want to start a new game?
+        <p>Optional Game Key: <input type='text' id='gameseed'>
       </div>
       <div class="modal-footer">
         <button type="button" class="btn btn-secondary" data-dismiss="modal" id="newGameModalCancelButton">Cancel</button>