Package com.southernstorm.noise.protocol

Class ChaChaPolyCipherState

java.lang.Object

com.southernstorm.noise.protocol.ChaChaPolyCipherState

All Implemented Interfaces:

CipherState, Destroyable, Cloneable

public class ChaChaPolyCipherState
extends Object
implements CipherState

Implements the ChaChaPoly cipher for Noise.

Constructor Summary

Constructors

Modifier	Constructor	Description
	ChaChaPolyCipherState()	Constructs a new cipher state for the "ChaChaPoly" algorithm.
protected	ChaChaPolyCipherState(ChaChaPolyCipherState o)	Copy constructor for cloning

Method Summary

Modifier and Type	Method	Description
ChaChaPolyCipherState	clone()	I2P
int	decryptWithAd(byte[] ad, byte[] ciphertext, int ciphertextOffset, byte[] plaintext, int plaintextOffset, int length)	Decrypts a ciphertext buffer using the cipher and a block of associated data.
void	destroy()	Destroys all sensitive state in the current object.
int	encryptWithAd(byte[] ad, byte[] plaintext, int plaintextOffset, byte[] ciphertext, int ciphertextOffset, int length)	Encrypts a plaintext buffer using the cipher and a block of associated data.
CipherState	fork(byte[] key, int offset)	Creates a new instance of this cipher and initializes it with a key.
String	getCipherName()	Gets the Noise protocol name for this cipher.
int	getKeyLength()	Gets the length of the key values for this cipher.
int	getMACLength()	Gets the length of the MAC values for this cipher.
boolean	hasKey()	Determine if this cipher object has been configured with a key.
void	initializeKey(byte[] key, int offset)	Initializes the key on this cipher object.
void	setNonce(long nonce)	Sets the nonce value.
String	toString()	I2P debug

Methods inherited from class java.lang.Object

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

Constructor Detail

ChaChaPolyCipherState

public ChaChaPolyCipherState()

Constructs a new cipher state for the "ChaChaPoly" algorithm.

ChaChaPolyCipherState

protected ChaChaPolyCipherState(ChaChaPolyCipherState o)
                         throws CloneNotSupportedException

Copy constructor for cloning

Throws:

CloneNotSupportedException

Since:

0.9.44

Method Detail

destroy

public void destroy()

Description copied from interface: Destroyable

Destroys all sensitive state in the current object.

Specified by:

destroy in interface Destroyable

getCipherName

public String getCipherName()

Description copied from interface: CipherState

Gets the Noise protocol name for this cipher.

Specified by:

getCipherName in interface CipherState

Returns:

The cipher name.

getKeyLength

public int getKeyLength()

Description copied from interface: CipherState

Gets the length of the key values for this cipher.

Specified by:

getKeyLength in interface CipherState

Returns:

The length of the key in bytes; usually 32.

getMACLength

public int getMACLength()

Description copied from interface: CipherState

Gets the length of the MAC values for this cipher.

Specified by:

getMACLength in interface CipherState

Returns:

The length of MAC values in bytes, or zero if the key has not yet been initialized.

initializeKey

public void initializeKey(byte[] key,
                          int offset)

Description copied from interface: CipherState

Initializes the key on this cipher object.

Specified by:

initializeKey in interface CipherState

Parameters:

key - Points to a buffer that contains the key.

offset - The offset of the key in the key buffer. The key buffer must contain at least getKeyLength() bytes starting at offset.

See Also:

CipherState.hasKey()

hasKey

public boolean hasKey()

Description copied from interface: CipherState

Determine if this cipher object has been configured with a key.

Specified by:

hasKey in interface CipherState

Returns:

true if this cipher object has a key; false if the key has not yet been set with initializeKey().

See Also:

CipherState.initializeKey(byte[], int)

encryptWithAd

public int encryptWithAd(byte[] ad,
                         byte[] plaintext,
                         int plaintextOffset,
                         byte[] ciphertext,
                         int ciphertextOffset,
                         int length)
                  throws ShortBufferException

Description copied from interface: CipherState

Encrypts a plaintext buffer using the cipher and a block of associated data.

Specified by:

encryptWithAd in interface CipherState

Parameters:

ad - The associated data, or null if there is none.

plaintext - The buffer containing the plaintext to encrypt.

plaintextOffset - The offset within the plaintext buffer of the first byte or plaintext data.

ciphertext - The buffer to place the ciphertext in. This can be the same as the plaintext buffer.

ciphertextOffset - The first offset within the ciphertext buffer to place the ciphertext and the MAC tag.

length - The length of the plaintext.

Returns:

The length of the ciphertext plus the MAC tag, or -1 if the ciphertext buffer is not large enough to hold the result.

Throws:

ShortBufferException - The ciphertext buffer does not have enough space to hold the ciphertext plus MAC.

decryptWithAd

public int decryptWithAd(byte[] ad,
                         byte[] ciphertext,
                         int ciphertextOffset,
                         byte[] plaintext,
                         int plaintextOffset,
                         int length)
                  throws ShortBufferException,
                         BadPaddingException

Description copied from interface: CipherState

Decrypts a ciphertext buffer using the cipher and a block of associated data.

Specified by:

decryptWithAd in interface CipherState

Parameters:

ad - The associated data, or null if there is none.

ciphertext - The buffer containing the ciphertext to decrypt.

ciphertextOffset - The offset within the ciphertext buffer of the first byte of ciphertext data.

plaintext - The buffer to place the plaintext in. This can be the same as the ciphertext buffer.

plaintextOffset - The first offset within the plaintext buffer to place the plaintext.

length - The length of the incoming ciphertext plus the MAC tag.

Returns:

The length of the plaintext with the MAC tag stripped off.

Throws:

ShortBufferException - The plaintext buffer does not have enough space to store the decrypted data.

BadPaddingException - The MAC value failed to verify.

fork

public CipherState fork(byte[] key,
                        int offset)

Description copied from interface: CipherState

Creates a new instance of this cipher and initializes it with a key.

Specified by:

fork in interface CipherState

Parameters:

key - The buffer containing the key.

offset - The offset into the key buffer of the first key byte.

Returns:

A new CipherState of the same class as this one.

setNonce

public void setNonce(long nonce)

Description copied from interface: CipherState

Sets the nonce value.

Specified by:

setNonce in interface CipherState

Parameters:

nonce - The new nonce value, which must be greater than or equal to the current value. This function is intended for testing purposes only. If the nonce value goes backwards then security may be compromised.

clone

public ChaChaPolyCipherState clone()
                            throws CloneNotSupportedException

I2P

Specified by:

clone in interface CipherState

Overrides:

clone in class Object

Throws:

CloneNotSupportedException

Since:

0.9.44

toString

public String toString()

I2P debug

Overrides:

toString in class Object