From d7991bb56c09666f8d65c3a001785dc334b680a9 Mon Sep 17 00:00:00 2001
From: Robbie Antenesse <dev@alamantus.com>
Date: Tue, 20 Feb 2018 23:38:46 -0700
Subject: [PATCH] Add error message if input pad is too short.

---
 index.html |  1 +
 index.js   | 23 +++++++++++++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/index.html b/index.html
index ab212b8..0159795 100644
--- a/index.html
+++ b/index.html
@@ -18,6 +18,7 @@
   <textarea id="input"></textarea><br>
   <strong>One-Time Pad</strong><br>
   <textarea id="inputPad"></textarea><br>
+  <em id="inputError" style="color:red"></em>
   <button id="encryptInput">Encrypt</button><br>
   <br>
   <strong>Encrypted Message</strong><br>
diff --git a/index.js b/index.js
index 12007c6..300f7d0 100644
--- a/index.js
+++ b/index.js
@@ -14,8 +14,12 @@ const generatePad = (length) => {
   return pad;
 }
 
+const stripString = (string) => {
+  return string.replace(/[\s]+/g, '&').replace(/[^a-zA-Z0-9\&]/g, '$');
+}
+
 export const encrypt = (string, pad = null) => {
-  const strippedString = string.replace(/[\s]+/g, '&').replace(/[^a-zA-Z0-9\&]/g, '$');
+  const strippedString = stripString(string);
   pad = pad ? pad : generatePad(strippedString.length);
   return {
     oneTimePad: pad,
@@ -38,12 +42,19 @@ export const decrypt = (string, pad) => {
 }
 
 document.getElementById('encryptInput').onclick = () => {
+  const error = document.getElementById('inputError');
   const input = document.getElementById('input').value;
-  const inputPad = document.getElementById('inputPad').value;
-  const pad = inputPad !== '' && inputPad.length >= input.length ? inputPad.split('') : null;
-  const encryption = encrypt(input, pad);
-  document.getElementById('inputPad').value = encryption.oneTimePad.join('');
-  document.getElementById('encrypted').innerHTML = encryption.encryptedMessage;
+  const inputPad = stripString(document.getElementById('inputPad').value).toUpperCase();
+  const pad = inputPad !== '' ? inputPad.split('') : null;
+  if (pad !== null && pad.length < input.length) {
+    document.getElementById('inputPad').value = pad.join('');
+    error.innerHTML = 'The pad must be at least as long as the input';
+  } else {
+    error.innerHTML = '';
+    const encryption = encrypt(input, pad);
+    document.getElementById('inputPad').value = encryption.oneTimePad.join('');
+    document.getElementById('encrypted').innerHTML = encryption.encryptedMessage;
+  }
 }
 
 document.getElementById('decryptInput').onclick = () => {