From abcc7ca65450654f5fe062db94b73f7796aa55b3 Mon Sep 17 00:00:00 2001
From: Chris <christian@haschek.at>
Date: Wed, 19 Sep 2018 22:38:49 +0200
Subject: [PATCH] preparation for encrypted storage

---
 classes/crypto.php | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 classes/crypto.php

diff --git a/classes/crypto.php b/classes/crypto.php
new file mode 100644
index 0000000..6efc0ca
--- /dev/null
+++ b/classes/crypto.php
@@ -0,0 +1,24 @@
+<?php 
+
+class Crypto
+{
+    function encrypt($inputfile,$outputfile)
+    {
+        if(!file_exists($inputfile)) return;
+        $data = base64_encode(file_get_contents($inputfile));
+        $nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
+        $ciphertext = sodium_crypto_secretbox($data, $nonce, ENCRYPTION_KEY);
+        $encoded = base64_encode($nonce . $ciphertext);
+        file_put_contents($outputfile,$encoded);
+    }
+
+    function decrypt($inputfile,$outputfile)
+    {
+        if(!file_exists($inputfile)) return;
+        $decoded = base64_decode(file_get_contents($inputfile));
+        $nonce = mb_substr($decoded, 0, SODIUM_CRYPTO_SECRETBOX_NONCEBYTES, '8bit');
+        $ciphertext = mb_substr($decoded, SODIUM_CRYPTO_SECRETBOX_NONCEBYTES, null, '8bit');
+        $plaintext = sodium_crypto_secretbox_open($ciphertext, $nonce, ENCRYPTION_KEY);
+        file_put_contents($outputfile,base64_decode($plaintext));
+    }
+}
\ No newline at end of file