From e664a406ddee0c53f816e911d5be18d4a330974b Mon Sep 17 00:00:00 2001
From: Jovan Gerodetti <jovan.gerodetti@titannano.de>
Date: Sun, 25 Sep 2016 16:26:46 +0200
Subject: [PATCH] wrapper for the native sha-256 algorithm

---
 modules/sha-256.js | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 modules/sha-256.js

diff --git a/modules/sha-256.js b/modules/sha-256.js
new file mode 100644
index 0000000..5200621
--- /dev/null
+++ b/modules/sha-256.js
@@ -0,0 +1,36 @@
+
+
+let binaryToHex = function(buffer) {
+    let result = '';
+
+    // choose chunk size
+    if (buffer.length * 8 % 32 === 0) {
+        buffer = new Uint32Array(buffer);
+    } else if (buffer.length * 8 % 16 === 0) {
+        buffer = new Uint16Array(buffer);
+    } else {
+        buffer = new Uint8Array(buffer);
+    }
+
+    buffer.forEach(chunk => {
+        chunk = chunk.toString(16);
+
+        while (chunk.length < (buffer.BYTES_PER_ELEMENT * 2)) {
+            chunk = '0' + chunk;
+        }
+
+        result += chunk;
+    });
+
+    return result;
+}
+
+export const sha256Native = function(data) {
+    if (typeof data === 'string') {
+        data = (new TextEncoder('utf-8')).encode(data);
+    }
+
+    return window.crypto.subtle.digest('SHA-256', data).then(hashBuffer => {
+        return binaryToHex(hashBuffer);
+    });
+}