com.google.crypto.tink.mac

Class AesCmacParameters

java.lang.Object

com.google.crypto.tink.Parameters

com.google.crypto.tink.mac.MacParameters

com.google.crypto.tink.mac.AesCmacParameters

public final class AesCmacParameters
extends MacParameters

Describes the parameters of an AesCmacKey.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AesCmacParameters.Variant Describes details of the mac computation.

Method Summary

Modifier and Type	Method and Description
static AesCmacParameters	create(int tagSize) Equivalent to createForKeysetWithCryptographicTagSize(tagSize, Variant.NO_PREFIX);
static AesCmacParameters	createForKeysetWithCryptographicTagSize(int tagSizeBytes, AesCmacParameters.Variant variant) Creates a new parameters object.
boolean	equals(Object o)
int	getCryptographicTagSizeBytes() Returns the size of the tag which is computed cryptographically from the message.
int	getTotalTagSizeBytes() Returns the size of the security relevant tag plus the size of the prefix with which this key prefixes every tag.
AesCmacParameters.Variant	getVariant() Returns a variant object.
int	hashCode()
boolean	hasIdRequirement() Returns true if a key created with the parameters in this object has to have a certain ID when it is in a keyset.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

create

public static AesCmacParameters create(int tagSize)
                                throws GeneralSecurityException

Equivalent to createForKeysetWithCryptographicTagSize(tagSize, Variant.NO_PREFIX);

Throws:

GeneralSecurityException

createForKeysetWithCryptographicTagSize

public static AesCmacParameters createForKeysetWithCryptographicTagSize(int tagSizeBytes,
                                                                        AesCmacParameters.Variant variant)
                                                                 throws GeneralSecurityException

Creates a new parameters object.

Throws:

GeneralSecurityException - if tagSizeBytes not in {10, …, 16}.

getCryptographicTagSizeBytes

public int getCryptographicTagSizeBytes()

Returns the size of the tag which is computed cryptographically from the message.

This may differ from the total size of the tag, as for some keys, Tink prefixes the tag with a key dependent output prefix.

getTotalTagSizeBytes

public int getTotalTagSizeBytes()

Returns the size of the security relevant tag plus the size of the prefix with which this key prefixes every tag.

getVariant

public AesCmacParameters.Variant getVariant()

Returns a variant object.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

hasIdRequirement

public boolean hasIdRequirement()

Description copied from class: Parameters

Returns true if a key created with the parameters in this object has to have a certain ID when it is in a keyset.

In Tink, certain keys change their behavior depending on the key id (for example, an Aead object can prefix the ciphertext with the big endian encoding of the key id). If this is the case, such a key should require a unique id in Key#getIdRequirement and return true here.

Specified by:

hasIdRequirement in class Parameters

toString

public String toString()

Overrides:

toString in class Object