org.apache.sshd.common.cipher

Class ChaCha20Cipher

java.lang.Object

org.apache.sshd.common.cipher.ChaCha20Cipher

All Implemented Interfaces:

AlgorithmNameProvider, Cipher, CipherInformation, KeySizeIndicator

public class ChaCha20Cipher
extends Object
implements Cipher

AEAD cipher based on the OpenSSH ChaCha20-Poly1305 cipher extension.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	ChaCha20Cipher.ChaChaEngine

Nested classes/interfaces inherited from interface org.apache.sshd.common.cipher.Cipher

Cipher.Mode

Field Summary

Fields

Modifier and Type	Field and Description
protected ChaCha20Cipher.ChaChaEngine	bodyEngine
protected ChaCha20Cipher.ChaChaEngine	headerEngine
protected Mac	mac
protected Cipher.Mode	mode

Constructor Summary

Constructors

Constructor and Description
ChaCha20Cipher()

Method Summary

Modifier and Type	Method and Description
String	getAlgorithm()
int	getAuthenticationTagSize()
int	getCipherBlockSize()
int	getIVSize()
int	getKdfSize()
int	getKeySize()
String	getTransformation()
void	init(Cipher.Mode mode, byte[] key, byte[] iv) Initialize the cipher for encryption or decryption with the given key and initialization vector
void	update(byte[] input, int inputOffset, int inputLen) Performs in-place encryption or decryption on the given data.
void	updateAAD(byte[] data, int offset, int length) Adds the provided input data as additional authenticated data during encryption or decryption.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.sshd.common.cipher.Cipher

checkSupported, update, updateAAD, updateWithAAD

Field Detail

headerEngine

protected final ChaCha20Cipher.ChaChaEngine headerEngine

bodyEngine

protected final ChaCha20Cipher.ChaChaEngine bodyEngine

mac

protected final Mac mac

mode

protected Cipher.Mode mode

Constructor Detail

ChaCha20Cipher

public ChaCha20Cipher()

Method Detail

getAlgorithm

public String getAlgorithm()

Specified by:

getAlgorithm in interface AlgorithmNameProvider

init

public void init(Cipher.Mode mode,
                 byte[] key,
                 byte[] iv)
          throws Exception

Description copied from interface: Cipher

Initialize the cipher for encryption or decryption with the given key and initialization vector

Specified by:

init in interface Cipher

Parameters:

mode - Encrypt/Decrypt initialization

key - Key bytes

iv - Initialization vector bytes

Throws:

Exception - If failed to initialize

updateAAD

public void updateAAD(byte[] data,
                      int offset,
                      int length)
               throws Exception

Description copied from interface: Cipher

Adds the provided input data as additional authenticated data during encryption or decryption.

Specified by:

updateAAD in interface Cipher

Parameters:

data - The additional data to authenticate

offset - The offset of the additional data in the buffer

length - The number of bytes in the buffer to use for authentication

Throws:

Exception - If failed to execute

update

public void update(byte[] input,
                   int inputOffset,
                   int inputLen)
            throws Exception

Description copied from interface: Cipher

Performs in-place encryption or decryption on the given data.

Specified by:

update in interface Cipher

Parameters:

input - The input/output bytes

inputOffset - The offset of the data in the data buffer

inputLen - The number of bytes to update, starting at the given offset; must be a multiple of the cipher's block size

Throws:

Exception - If failed to execute

getTransformation

public String getTransformation()

Specified by:

getTransformation in interface CipherInformation

Returns:

The actual transformation used - e.g., AES/CBC/NoPadding

getIVSize

public int getIVSize()

Specified by:

getIVSize in interface CipherInformation

Returns:

Size of the initialization vector (in bytes)

getAuthenticationTagSize

public int getAuthenticationTagSize()

Specified by:

getAuthenticationTagSize in interface CipherInformation

Returns:

Size of the authentication tag (AT) in bytes or 0 if this cipher does not support authentication

getCipherBlockSize

public int getCipherBlockSize()

Specified by:

getCipherBlockSize in interface CipherInformation

Returns:

Size of block data used by the cipher (in bytes). For stream ciphers this value is (currently) used to indicate some average work buffer size to be used for the automatic re-keying mechanism described in RFC 4253 - Section 9

getKdfSize

public int getKdfSize()

Specified by:

getKdfSize in interface CipherInformation

Returns:

The block size (in bytes) used to derive the secret key for this cipher

getKeySize

public int getKeySize()

Specified by:

getKeySize in interface KeySizeIndicator

Returns:

The number of bits used in the key