README

This is a java library (API) for the YubiHSM, http://yubico.com/yubihsm

Requirements:
- RXTX, a native library providing serial and parallel communication for the Java Development Toolkit (JDK),
  http://rxtx.qbang.org/wiki/index.php/Main_Page



How to build
------------

$ mvn package

to skip tests (tests require a YubiHSM configured in 'debug' mode):

$ mvn -Dmaven.test.skip=true package

To test a HSM with a device name other than '/dev/ttyACM0' do as follows:

$ mvn test -DargLine="-Dhsm.test.deviceName=/dev/tty.usbmodem14331"


How to configure HSM in debug mode
----------------------------------

The HSM is a serial device, I recommend using screen to connect with the device (ie screen /dev/ttyACM0).

Prepare the HSM as follows:

    zap
    yes
    hsm ffffffff
    <enter>
    <enter>
    <enter>
    yes
    exit
    yes



Usage
-----

Build the javadoc to get the API documentation.

$ mvn javadoc:javadoc


Code example 1 - Generate a HMACSHA1
------------

int keyHandle = 12337; // The key to use in the YubiHSM (0x3031)
String mySecret = "qwerty";

// Instance of YubiHSM that opens the device /dev/ttyACM0
YubiHSM hsm = new YubiHSM();

// Generate HmacSHA1 for mySecret
String sha1 = hsm.generateHMACSHA1(mySecret, keyHandle, true, false).get("hash");


Code example 2 - OATH-HOTP generate OATH-HOTP AEAD and OTP validation
--------------

// Nonce should be stored for later use when validating an OTP
String randomNonce = "a1a2a3a4a5a6";

// This is the token seed which should be treated as a secret (don't store this)
String tokenSeed = "3132333435363738393031323334353637383930";

// A one-time password from the token with seed above
String otp = "026920";

// Current one-time password counter, this counter should be stored and updated
// for each time the OTP have been validated
int counter = 30;

// How many iterations we should look ahead to find a matching OTP
int lookAhead = 10;

// This is the key handle with permission to generate AEAD
int keyHandle = 8192;

// Instance of YubiHSM that opens the device /dev/ttyACM0
YubiHSM hsm = new YubiHSM();

// Generate OATH-HOTP AEAD from the token seed, the AEAD can be safely stored in an database along with the nonce
// This step is only performed once to recieve an AEAD which can be re-used for OTP validation.
String aead = hsm.generateOathHotpAEAD(randomNonce, keyHandle, tokenSeed);

// Validate the one-time password "026920". If the counter result is 0 the validation failed.
// In this case we expect a value of 31.
counter = hsm.validateOathHOTP(hsm, keyHandle, randomNonce, aead, counter, otp, lookAhead);