Package org.cryptacular.generator

Class AbstractOTPGenerator

java.lang.Object

org.cryptacular.generator.AbstractOTPGenerator

Direct Known Subclasses:

HOTPGenerator, TOTPGenerator

public abstract class AbstractOTPGenerator
extends Object

Abstract base class for HOTP and TOTP OTP generation schemes.

Author:

Middleware Services

Field Summary

Fields

Modifier and Type	Field	Description
protected static final int	DEFAULT_NUMBER_OF_DIGITS	Default number of digits to generate.

Constructor Summary

Constructors

Constructor	Description
AbstractOTPGenerator()	Creates a new abstract OTP generator.
AbstractOTPGenerator(int numberOfDigits)	Creates a new abstract OTP generator.

Method Summary

Modifier and Type	Method	Description
protected int	generateInternal(byte[] key, long count)	Internal OTP generation method.
protected abstract org.bouncycastle.crypto.Digest	getDigest()
int	getNumberOfDigits()

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_NUMBER_OF_DIGITS

protected static final int DEFAULT_NUMBER_OF_DIGITS

Default number of digits to generate.

See Also:

• Constant Field Values

Constructor Details

AbstractOTPGenerator

public AbstractOTPGenerator()

Creates a new abstract OTP generator.

AbstractOTPGenerator

public AbstractOTPGenerator(int numberOfDigits)

Creates a new abstract OTP generator.

Parameters:

numberOfDigits - Number of digits in generated OTP. MUST be in the range 6 - 9.

Method Details

getNumberOfDigits

public int getNumberOfDigits()

Returns:

Number of digits in generated OTP.

generateInternal

protected int generateInternal(byte[] key,
 long count)

Internal OTP generation method.

Parameters:

key - Per-user key.

count - Counter moving factor.

Returns:

Integer OTP.

getDigest

protected abstract org.bouncycastle.crypto.Digest getDigest()

Returns:

Digest algorithm used for HMAC operation.