gov.nist.secauto.swid.client.totp

Class Hotp

java.lang.Object

gov.nist.secauto.swid.client.totp.Hotp

public class Hotp
extends Object

A direct implementation of https://tools.ietf.org/html/rfc4226 and https://tools.ietf.org/html/rfc6238 C = counter K = key Digits = length of OTP Note that a strict implementation of RFC 4226 will only support HMAC-SHA-1.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Hotp.HashAlgorithm

Constructor Summary

Constructors

Constructor and Description
Hotp(Hotp.HashAlgorithm algorithm, int length) Creates a new instance

Method Summary

Modifier and Type	Method and Description
String	generate(byte[] key, long counter) Generates an HOTP value according to RFC 4226

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Hotp

public Hotp(Hotp.HashAlgorithm algorithm,
            int length)

Creates a new instance

Parameters:

algorithm - the algorithm to use

length - the number of digits

Method Detail

generate

public String generate(byte[] key,
                       long counter)

Generates an HOTP value according to RFC 4226

Parameters:

key - the shared secret ('K')

counter - the counter ('C') value

Returns:

the HOTP value