From 9e6160daffb25ea1d208755d55f115c786f3ea3e Mon Sep 17 00:00:00 2001
From: Leslie Krause <rkrause@inbox.com>
Date: Wed, 13 Feb 2019 23:37:00 -0500
Subject: [PATCH] BUILD 01

---
 README.txt | 32 ++++++++++++++++++++++++++++++
 cipher.awk | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 init.lua   | 47 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 136 insertions(+)
 create mode 100644 README.txt
 create mode 100644 cipher.awk
 create mode 100644 init.lua

diff --git a/README.txt b/README.txt
new file mode 100644
index 0000000..7ae5a08
--- /dev/null
+++ b/README.txt
@@ -0,0 +1,32 @@
+Simple Cipher Mod v1.0
+By Leslie E. Krause
+
+Simple Cipher is a lightweight, portable hashing algorithm providing a minimal degree
+of security for non mission-critical data (e.g. unique, non-guessable URLs).
+
+
+Source Code License
+----------------------
+
+MIT License
+
+Copyright (c) 2016-2019, Leslie E. Krause.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this
+software and associated documentation files (the "Software"), to deal in the Software
+without restriction, including without limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of the Software, and to permit
+persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+
+For more details:
+https://opensource.org/licenses/MIT
diff --git a/cipher.awk b/cipher.awk
new file mode 100644
index 0000000..97af265
--- /dev/null
+++ b/cipher.awk
@@ -0,0 +1,57 @@
+#!/bin/awk -f
+
+function ord_init( _low, _high, _i, _t )
+{
+	_low = 0;
+	_high = 127;
+	for( _i = _low; _i <= _high; _i++ ) {
+		_t = sprintf( "%c", _i );
+		ord_data[ _t ] = _i;
+	}
+}
+
+function ord( _s, _i )
+{
+	return ord_data[ substr( _s, _i, 1 ) ]
+}
+
+function chr( _c )
+{
+	return sprintf( "%c", _c );
+}
+
+function getToken( idx, _alphabet, _str, _base )
+{
+	_alphabet = "7pdy3jbhvms5zxrftnc9gqw";
+	_base = length( _alphabet );
+
+	idx += 4294836226;
+	while( idx > 0 ) {
+		_str = _str substr( _alphabet, idx % _base + 1, 1 );
+		idx = int( idx / _base );
+        }
+
+        return _str;
+}
+
+function getChecksum( input, _a, _b, _hash, _idx )
+{
+	_a = 378551;
+	_b = 63689;
+	_hash = 0;
+	_i = 0;
+
+	for( _i = 0; _i < length( input ); _i++ ) {
+		_hash = ( _hash * _a + ord( input, _i + 1 ) ) % 2147483648;
+		_a = ( _a * _b ) % 65536;
+	}
+	return 4294967295 - _hash;
+}
+
+BEGIN {
+	ord_init( );
+
+	x = "sorcerykid";
+	print getChecksum( x ) "->" getToken( getChecksum( x ) )
+}
+
diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..881b005
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,47 @@
+--------------------------------------------------------
+-- Minetest :: Simple Cipher Mod v1.0 (cipher)
+--
+-- See README.txt for licensing and other information.
+-- Copyright (c) 2016-2019, Leslie E. Krause
+--
+-- ./games/just_test_tribute/mods/cipher/init.lua
+--------------------------------------------------------
+
+-- alphabet soup to be used by the tokenizer
+local alphabet = "pdy3jbh7vms5zxrftnc9gqw"
+
+cipher = { }
+
+cipher.tokenize = function ( hash )
+	local base = #alphabet
+	local str = ""
+
+	hash = hash + 4294836226
+
+	while hash > 0 do
+		local idx = hash % base + 1
+		str = str .. string.sub( alphabet, idx, idx )
+		hash = math.floor( hash / base )
+	end
+
+	return str
+end
+
+cipher.get_checksum = function ( input )
+	local a = 378551
+	local b = 63689
+	local hash = 0
+	local i = 0
+
+	for i = 1, #input do
+		hash = ( hash * a + string.byte( input, i ) ) % 2147483648
+		a = ( a * b ) % 65536
+	end
+
+	return 4294967295 - hash
+end
+
+if cipher.tokenize( cipher.get_checksum( "sorcerykid" ) ) ~= "gfwd9pmd" then
+	-- basic sanity check upon startup
+	error( "[cipher] Failed to generate correct token from hash!" )
+end