Package org.apache.sshd.common.kex

Class XDH

java.lang.Object

org.apache.sshd.common.kex.AbstractDH

org.apache.sshd.common.kex.XDH

All Implemented Interfaces:

CurveSizeIndicator

public abstract class XDH
extends AbstractDH
implements CurveSizeIndicator

Provides Diffie-Hellman SSH key exchange algorithms for the Montgomery curves specified in RFC 8731.

See Also:

• RFC 8731

Field Summary

Fields

Modifier and Type	Field	Description
protected final MontgomeryCurve	curve
protected byte[]	f
protected final boolean	raw

Fields inherited from class org.apache.sshd.common.kex.AbstractDH

myKeyAgree

Constructor Summary

Constructors

Constructor	Description
XDH(MontgomeryCurve curve, boolean raw)

Method Summary

Modifier and Type	Method	Description
protected byte[]	calculateE()	Lazy-called by AbstractDH.getE() if the public key data has not been generated yet.
protected byte[]	calculateK()	Lazy-called by AbstractDH.getK() if the shared secret data has not been calculated yet
int	getByteLength()	Retrieves the length of a point coordinate in bytes.
void	putE(Buffer buffer, byte[] e)
void	putF(Buffer buffer, byte[] f)
void	setF(byte[] f)

Methods inherited from class org.apache.sshd.common.kex.AbstractDH

checkKeyAgreementNecessity, getE, getHash, getK, getKeyEncapsulation, isPublicDataAvailable, isSharedSecretAvailable, stripLeadingZeroes, toString

Methods inherited from class java.lang.Object

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

Field Details

curve

protected final MontgomeryCurve curve

raw

protected final boolean raw

f

protected byte[] f

Constructor Details

XDH

public XDH(MontgomeryCurve curve,
 boolean raw)
    throws Exception

Throws:

Exception

Method Details

getByteLength

public int getByteLength()

Description copied from interface: CurveSizeIndicator

Retrieves the length of a point coordinate in bytes.

Specified by:

getByteLength in interface CurveSizeIndicator

Returns:

the length

calculateE

protected byte[] calculateE()
                     throws Exception

Description copied from class: AbstractDH

Lazy-called by AbstractDH.getE() if the public key data has not been generated yet.

Specified by:

calculateE in class AbstractDH

Returns:

The calculated public key data

Throws:

Exception - If failed to generate the relevant data

setF

public void setF(byte[] f)

Specified by:

setF in class AbstractDH

putE

public void putE(Buffer buffer,
 byte[] e)

Overrides:

putE in class AbstractDH

putF

public void putF(Buffer buffer,
 byte[] f)

Overrides:

putF in class AbstractDH

calculateK

protected byte[] calculateK()
                     throws Exception

Description copied from class: AbstractDH

Lazy-called by AbstractDH.getK() if the shared secret data has not been calculated yet

Specified by:

calculateK in class AbstractDH

Returns:

The shared secret data

Throws:

Exception - If failed to calculate it