MacKey

java.lang.Object
- com.google.crypto.tink.Key
- - com.google.crypto.tink.mac.MacKey

Direct Known Subclasses:

AesCmacKey, HmacKey
```
public abstract class MacKey
extends Key
```
Represents functions to compute and verify a cryptographic MAC.

Constructor Summary

Constructors
Constructor Description

MacKey()

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`abstract Bytes`	`getOutputPrefix()`	Returns a `Bytes` instance which is prefixed to every mac tag.
`abstract MacParameters`	`getParameters()`	Returns the parameters of this key.

Methods inherited from class com.google.crypto.tink.Key
equalsKey, getIdRequirementOrNull

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - MacKey
```
public MacKey()
```
- Method Detail
  - getOutputPrefix
```
public abstract Bytes getOutputPrefix()
```
    Returns a Bytes instance which is prefixed to every mac tag.
    In order to make key rotation more efficient, Tink allows every Mac key to be prefixed with a sequence of bytes. When verifying a tag, only keys with matching prefix have to be tried.
    Note that a priori, the output prefix may not be unique in a keyset (i.e., different keys in a keyset may have the same prefix (or, one prefix may be a prefix of the other). To avoid this, built in Tink keys use the convention that the prefix is either '0x00' or '0x01'. See the Tink keys for details.
  getParameters
  
  public abstract MacParameters getParameters()
  
  Returns the parameters of this key.
  
  Specified by:
  
  getParameters in class Key