From 387f4ebf5d6e6d72a45d7eb03c82d63d28d8eaa6 Mon Sep 17 00:00:00 2001
From: ansuz <ansuz@transitiontech.ca>
Date: Wed, 28 Dec 2016 11:01:14 +0100
Subject: [PATCH] add this important js file I forgot

---
 www/user/credential.js | 65 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 www/user/credential.js

diff --git a/www/user/credential.js b/www/user/credential.js
new file mode 100644
index 000000000..97d660fb6
--- /dev/null
+++ b/www/user/credential.js
@@ -0,0 +1,65 @@
+define([
+    '/bower_components/scrypt-async/scrypt-async.min.js',
+], function () {
+    var Cred = {};
+    var Scrypt = window.scrypt;
+
+    var isString = Cred.isString = function (x) {
+        return typeof(x) === 'string';
+    };
+
+    var isValidUsername = Cred.isValidUsername = function (name) {
+        return !!(name && isString(name));
+    };
+
+    var isValidPassword = Cred.isValidPassword = function (passwd) {
+        return !!(passwd && isString(passwd));
+    };
+
+    var passwordsMatch = Cred.passwordsMatch = function (a, b) {
+        return isString(a) && isString(b) && a === b;
+    };
+
+    var deriveFromPassphrase = Cred.deriveFromPassphrase = function 
+    (username, password, len, cb) {
+        Scrypt(password,
+            username,
+            8, // memoryCost (n)
+            1024, // block size parameter (r)
+            len || 128, // dkLen
+            200, // interruptStep
+            cb,
+            undefined); // format, could be 'base64'
+    };
+
+    var dispenser = Cred.dispenser = function (bytes) {
+        var entropy = {
+            used: 0,
+        };
+
+        // crypto hygeine
+        var consume = function (n) {
+            // explode if you run out of bytes
+            if (entropy.used + n > bytes.length) {
+                throw new Error('exceeded available entropy');
+            }
+            if (typeof(n) !== 'number') { throw new Error('expected a number'); }
+            if (n <= 0) {
+                throw new Error('expected to consume a positive number of bytes');
+            }
+
+            // grab an unused slice of the entropy
+            var A = bytes.slice(entropy.used, entropy.used + n);
+
+            // account for the bytes you used so you don't reuse bytes
+            entropy.used += n;
+
+            //console.info("%s bytes of entropy remaining", bytes.length - entropy.used);
+            return A;
+        };
+
+        return consume;
+    };
+
+    return Cred;
+});