com.google.crypto.tink.subtle

Class Bytes

java.lang.Object

com.google.crypto.tink.subtle.Bytes

public final class Bytes
extends Object

Helper methods that deal with byte arrays.

Since:

1.0.0

Method Summary

Modifier and Type	Method and Description
static int	byteArrayToInt(byte[] bytes) Transforms a passed LSB first byte array to an int
static int	byteArrayToInt(byte[] bytes, int length) Transforms a passed LSB first byte array to an int
static int	byteArrayToInt(byte[] bytes, int offset, int length) Transforms a passed LSB first byte array to an int
static byte[]	concat(byte[]... chunks) Returns the concatenation of the input arrays in a single array.
static boolean	equal(byte[] x, byte[] y) Best effort fix-timing array comparison.
static byte[]	intToByteArray(int capacity, int value) Transforms a passed value to a LSB first byte array with the size of the specified capacity
static byte[]	xor(byte[] x, byte[] y) Computes the xor of two byte arrays of equal size.
static byte[]	xor(byte[] x, int offsetX, byte[] y, int offsetY, int len) Computes the xor of two byte arrays, specifying offsets and the length to xor.
static void	xor(ByteBuffer output, ByteBuffer x, ByteBuffer y, int len) Computes the xor of two byte buffers, specifying the length to xor, and stores the result to output.
static byte[]	xorEnd(byte[] a, byte[] b) xors b to the end of a.

Methods inherited from class java.lang.Object

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

Method Detail

equal

public static final boolean equal(byte[] x,
                                  byte[] y)

Best effort fix-timing array comparison.

Returns:

true if two arrays are equal.

concat

public static byte[] concat(byte[]... chunks)
                     throws GeneralSecurityException

Returns the concatenation of the input arrays in a single array. For example, concat(new byte[] {a, b}, new byte[] {}, new byte[] {c} returns the array {a, b, c}.

Returns:

a single array containing all the values from the source arrays, in order

Throws:

GeneralSecurityException

xor

public static final byte[] xor(byte[] x,
                               int offsetX,
                               byte[] y,
                               int offsetY,
                               int len)

Computes the xor of two byte arrays, specifying offsets and the length to xor.

Returns:

a new byte[] of length len.

xor

public static final void xor(ByteBuffer output,
                             ByteBuffer x,
                             ByteBuffer y,
                             int len)

Computes the xor of two byte buffers, specifying the length to xor, and stores the result to output.

xor

public static final byte[] xor(byte[] x,
                               byte[] y)

Computes the xor of two byte arrays of equal size.

Returns:

a new byte[] of length x.length.

xorEnd

public static final byte[] xorEnd(byte[] a,
                                  byte[] b)

xors b to the end of a.

Returns:

a new byte[] of length x.length.

intToByteArray

public static byte[] intToByteArray(int capacity,
                                    int value)

Transforms a passed value to a LSB first byte array with the size of the specified capacity

Parameters:

capacity - size of the resulting byte array

value - that should be represented as a byte array

byteArrayToInt

public static int byteArrayToInt(byte[] bytes)

Transforms a passed LSB first byte array to an int

Parameters:

bytes - that should be transformed to a byte array

byteArrayToInt

public static int byteArrayToInt(byte[] bytes,
                                 int length)

Transforms a passed LSB first byte array to an int

Parameters:

bytes - that should be transformed to a byte array

length - amount of the passed bytes that should be transformed

byteArrayToInt

public static int byteArrayToInt(byte[] bytes,
                                 int offset,
                                 int length)

Transforms a passed LSB first byte array to an int

Parameters:

bytes - that should be transformed to a byte array

offset - start index to start the transformation

length - amount of the passed bytes that should be transformed