AesUtil

java.lang.Object
- com.google.crypto.tink.mac.internal.AesUtil

```
public final class AesUtil
extends java.lang.Object
```
A collection of byte-manipulation functions, and some more specific functions for AES-CMAC / AES-SIV.
Beware: some of the functions here are specific to the representation used for AES-CMAC and SIV, as described in their RFCs. These might not work if used in other contexts.

Field Summary

Fields
Modifier and Type Field Description

static int BLOCK_SIZE

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static byte[]`	`cmacPad(byte[] x)`	Pad by adding a 1 bit, then pad with 0 bits to the next block limit.
`static byte[]`	`dbl(byte[] value)`	Multiplies value by x in the finite field GF(2^128) represented using the primitive polynomial x^128 + x^7 + x^2 + x + 1.

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

- Field Detail
  - BLOCK_SIZE
```
public static final int BLOCK_SIZE
```
    See Also:
    
    Constant Field Values
- Method Detail
  - dbl
```
public static byte[] dbl(byte[] value)
```
    Multiplies value by x in the finite field GF(2^128) represented using the primitive polynomial x^128 + x^7 + x^2 + x + 1.
    
    Parameters:
    
    value - an arrays of 16 bytes representing an element of GF(2^128) using bigendian byte order.
  - cmacPad
```
public static byte[] cmacPad(byte[] x)
```
    Pad by adding a 1 bit, then pad with 0 bits to the next block limit. This is the standard for both CMAC and AES-SIV. - https://tools.ietf.org/html/rfc4493#section-2.4 - https://tools.ietf.org/html/rfc5297#section-2.1
    
    Parameters:
    
    x - The array to pad (will be copied)
    
    Returns:
    
    The padded array.