com.google.crypto.tink.aead.internal

Class InsecureNonceChaCha20

java.lang.Object

com.google.crypto.tink.aead.internal.InsecureNonceChaCha20

public class InsecureNonceChaCha20
extends Object

A stream cipher, as described in RFC 8439 https://tools.ietf.org/html/rfc8439, section 2.4.

This cipher is meant to be used to construct an AEAD with Poly1305.

Constructor Summary

Constructors

Constructor and Description
InsecureNonceChaCha20(byte[] key, int initialCounter)

Method Summary

Modifier and Type	Method and Description
int[]	createInitialState(int[] nonce, int counter) Returns the initial state from nonce and counter.
byte[]	decrypt(byte[] nonce, byte[] ciphertext) Decrypts ciphertext using nonce.
byte[]	decrypt(byte[] nonce, ByteBuffer ciphertext) Decrypts ciphertext using nonce.
byte[]	encrypt(byte[] nonce, byte[] plaintext) Encrypts plaintext using nonce.
void	encrypt(ByteBuffer output, byte[] nonce, byte[] plaintext) Encrypts plaintext using nonce and writes result to output.
int	nonceSizeInBytes() The size of the randomly generated nonces.

Methods inherited from class java.lang.Object

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

Constructor Detail

InsecureNonceChaCha20

public InsecureNonceChaCha20(byte[] key,
                             int initialCounter)
                      throws InvalidKeyException

Throws:

InvalidKeyException

Method Detail

createInitialState

public int[] createInitialState(int[] nonce,
                                int counter)

Returns the initial state from nonce and counter.

nonceSizeInBytes

public int nonceSizeInBytes()

The size of the randomly generated nonces.

ChaCha20 uses 12-byte nonces, but XChaCha20 use 24-byte nonces.

encrypt

public byte[] encrypt(byte[] nonce,
                      byte[] plaintext)
               throws GeneralSecurityException

Encrypts plaintext using nonce.

Throws:

GeneralSecurityException

encrypt

public void encrypt(ByteBuffer output,
                    byte[] nonce,
                    byte[] plaintext)
             throws GeneralSecurityException

Encrypts plaintext using nonce and writes result to output.

Throws:

GeneralSecurityException

decrypt

public byte[] decrypt(byte[] nonce,
                      byte[] ciphertext)
               throws GeneralSecurityException

Decrypts ciphertext using nonce.

Throws:

GeneralSecurityException

decrypt

public byte[] decrypt(byte[] nonce,
                      ByteBuffer ciphertext)
               throws GeneralSecurityException

Decrypts ciphertext using nonce.

Throws:

GeneralSecurityException