org.kocakosm.pitaya.security

Interface MAC

public interface MAC

MAC (Message Authentication Code) engine. A MAC provides a way to check the integrity of information transmitted over or stored in an unreliable medium, based on a secret key. Typically, message authentication codes are used between two parties that share a secret key in order to validate information transmitted between these parties. Note that implementations of this interface are not meant to be thread-safe.

Author:

Osman KOCAK

See Also:

HMAC

Method Summary

Modifier and Type	Method and Description
byte[]	digest() Completes the MAC computation.
byte[]	digest(byte... input) Performs a final update on the MAC using the specified array of bytes, then completes the MAC computation.
byte[]	digest(byte[] input, int off, int len) Performs a final update on the MAC using the specified data bytes, then completes the MAC computation.
int	length() Returns the MAC's length (in bytes).
MAC	reset() Resets the engine.
MAC	update(byte... input) Updates the MAC using the specified array of bytes.
MAC	update(byte input) Updates the MAC using the given byte.
MAC	update(byte[] input, int off, int len) Updates the MAC using the specified number of bytes from the given array of bytes, starting at the specified offset.

Method Detail

length

int length()

Returns the MAC's length (in bytes).

Returns:

the MAC's length (in bytes).

reset

MAC reset()

Resets the engine.

Returns:

this object.

update

MAC update(byte input)

Updates the MAC using the given byte.

Parameters:

input - the byte with which to update the MAC.

Returns:

this object.

update

MAC update(byte... input)

Updates the MAC using the specified array of bytes.

Parameters:

input - the array of bytes with which to update the MAC.

Returns:

this object.

Throws:

NullPointerException - if input is null.

update

MAC update(byte[] input,
           int off,
           int len)

Updates the MAC using the specified number of bytes from the given array of bytes, starting at the specified offset.

Parameters:

input - the array of bytes.

off - the offset to start from in the array of bytes, inclusive.

len - the number of bytes to use, starting at offset.

Returns:

this object.

Throws:

NullPointerException - if input is null.

IndexOutOfBoundsException - if off is negative or if off + len is greater than input's length.

digest

byte[] digest()

Completes the MAC computation. Note that the engine is reset after this call is made.

Returns:

the resulting MAC.

digest

byte[] digest(byte... input)

Performs a final update on the MAC using the specified array of bytes, then completes the MAC computation. That is, this method first calls update(byte...), passing the input array to the update method, then calls digest(). Note that the engine is reset after this call is made.

Parameters:

input - the array of bytes with which to update the MAC before completing its computation.

Returns:

the resulting MAC.

Throws:

NullPointerException - if input is null.

digest

byte[] digest(byte[] input,
              int off,
              int len)

Performs a final update on the MAC using the specified data bytes, then completes the MAC computation. That is, this method first calls update(byte[], int, int), passing the input array to the update method, then calls digest(). Note that the engine is reset after this call is made.

Parameters:

input - the array of bytes.

off - the offset to start from in the array of bytes, inclusive.

len - the number of bytes to use, starting at off.

Returns:

the resulting MAC.

Throws:

NullPointerException - if input is null.

IndexOutOfBoundsException - if off is negative or if off + len is greater than input's length.