com.southernstorm.noise.crypto.chacha20

Class ChaChaCore

java.lang.Object

com.southernstorm.noise.crypto.chacha20.ChaChaCore

public final class ChaChaCore
extends Object

Implementation of the ChaCha20 core hash transformation.

Method Summary

Modifier and Type	Method and Description
static void	hash(int[] output, int[] input) Hashes an input block with ChaCha20.
static void	initIV(int[] output, long iv) Initializes the 64-bit initialization vector in a ChaCha20 block.
static void	initKey256(int[] output, byte[] key, int offset) Initializes a ChaCha20 block with a 256-bit key.
static void	xorBlock(byte[] input, int inputOffset, byte[] output, int outputOffset, int length, int[] block) XOR's the output of ChaCha20 with a byte buffer.

Methods inherited from class java.lang.Object

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

Method Detail

hash

public static void hash(int[] output,
                        int[] input)

Hashes an input block with ChaCha20.

Parameters:

output - The output block, which must contain at least 16 elements and must not overlap with the input.

input - The input block, which must contain at least 16 elements.

initIV

public static void initIV(int[] output,
                          long iv)

Initializes the 64-bit initialization vector in a ChaCha20 block.

Parameters:

output - The output block, which must consist of at least 16 words and must have been initialized by initKey256() or initKey128().

iv - The 64-bit initialization vector value. The counter portion of the output block is set to zero.

initKey256

public static void initKey256(int[] output,
                              byte[] key,
                              int offset)

Initializes a ChaCha20 block with a 256-bit key.

Parameters:

output - The output block, which must consist of at least 16 words.

key - The buffer containing the key.

offset - Offset of the key in the buffer.

xorBlock

public static void xorBlock(byte[] input,
                            int inputOffset,
                            byte[] output,
                            int outputOffset,
                            int length,
                            int[] block)

XOR's the output of ChaCha20 with a byte buffer.

Parameters:

input - The input byte buffer.

inputOffset - The offset of the first input byte.

output - The output byte buffer (can be the same as the input).

outputOffset - The offset of the first output byte.

length - The number of bytes to XOR between 1 and 64.

block - The ChaCha20 output block.