README.md added with a simple description

README.md

@@ -0,0 +1,48 @@
+hotp-js - A simple JavaScript HOTP implementation
+=================================================
+
+A simple JavaScript HOTP implementation (HMAC-Based One-Time Password Algorithm) as described in [RFC4226](http://tools.ietf.org/html/rfc4226). The library is relying on [crypto-js](http://code.google.com/p/crypto-js/) for the javascript HMAC-SHA1 implementation.
+
+How to use it
+-------------
+
+Load the htop.js, set the private key of the token and the count step.
+
+```javascript
+otp = hotp("3132333435363738393031323334353637383930","4","dec6");
+```
+
+The following output formats are supported:
+
+* hex40 - truncated 10 bytes hexadecimal representation
+* dec6  - truncated 6 bytes decimal representation (HOTP)
+* dec7  - truncated 7 bytes decimal representation
+* dec8  - truncated 8 bytes decimal representation
+
+Security recommendations
+------------------------
+
+* Don't forget to protect the key of the token along with the count value (e.g. local encryption of the software token).
+* Code is experimental.
+
+License
+-------
+
+```
+Copyright (C) 2009 Alexandre Dulaunoy
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+```
+