node-aes-cmac
A pure Node.js implementation of the AES-CMAC algorithm
per NIST Special Publication 800-38B
and (RFC 4493).
This algorithm creates a cryptographic message authentication code (CMAC)
from a given message using the AES cipher with 128, 192, and 256 bit keys.
Why?
At work we had a need to run AES-CMAC from Node.js.
A coworker created an implementation which uses a C++ addon which wrapped Crypto++,
but unfortunately the module was only known to build correctly on Ubuntu.
OS X support was added through some further hacking, but Windows support was extremely difficult.
Searching the web yielded no alternatives, so I started this project with a goal to
create an AES-CMAC implementation to share with the Node.js community which would be easy to use on
OS X, Windows, and Linux.
Currently the project only uses the built-in cryptographic functions provided by Node.js and avoids using C/C++ addons.
This was a conscious trade-off favoring simplicity over raw performance.
Installation
npm install node-aes-cmac
Usage
The module exposes a single method: aesCmac(key, message[, options])
Arguments
key - (string | Buffer) the cryptographic key to use for the operation.
Must be 128, 192, or 256 bits in length.message - (string | Buffer) the message.options - (object optional) a set of extra options to pass into the method:
returnAsBuffer - (boolean) set to true to get the returned CMAC as a Buffer
instead of a string. Defaults to false.
Return Value
The method normally returns the CMAC as a lowercase hexadecimal string.
It can also return a Buffer if the returnAsBuffer option is set to true.
Example
var aesCmac = require('node-aes-cmac').aesCmac;
// Simple example.
var key = 'k3Men*p/2.3j4abB';
var message = 'this|is|a|test|message';
var cmac = aesCmac(key, message);
// cmac will be: '0125c538f8be7c4eea370f992a4ffdcb'
// Example with buffers.
var bufferKey = new Buffer('6b334d656e2a702f322e336a34616242', 'hex');
var bufferMessage = new Buffer('this|is|a|test|message');
var options = {returnAsBuffer: true};
cmac = aesCmac(bufferKey, bufferMessage, options);
// cmac will be a Buffer containing:
// <01 25 c5 38 f8 be 7c 4e ea 37 0f 99 2a 4f fd cb>
License
This code is provided under an MIT license. See the LICENSE file for full details.
