com.safenetinc.luna.provider.keyagree

Class LunaKeyAgreementEcDhCWithKdf1

java.lang.Object

javax.crypto.KeyAgreementSpi

com.safenetinc.luna.provider.keyagree.LunaKeyAgreementEcDh

com.safenetinc.luna.provider.keyagree.LunaKeyAgreementEcDhCWithKdf1

public class LunaKeyAgreementEcDhCWithKdf1
extends LunaKeyAgreementEcDh

This class implements an Elliptic Curve Diffie-Hellman key agreement with Cofactor multiplication and the SHA1 KDF, where the private key is stored on the HSM. The shared secret is created on the HSM but is extractable.

Field Summary

Fields

Modifier and Type	Field and Description
protected KeyFactory	kf
protected LunaKey	privateKey

Constructor Summary

Constructors

Constructor and Description
LunaKeyAgreementEcDhCWithKdf1()

Method Summary

Modifier and Type	Method and Description
protected void	checkPublicKey(Key key, boolean lastPhase) Checks the parameters to engineDoPhase().
protected int	engineGenerateSecret(byte[] sharedSecret, int offset) Generates the shared secret, and places it into the buffer sharedSecret, beginning at offset inclusive.
protected void	engineInit(Key key, AlgorithmParameterSpec params, SecureRandom random) Initializes this key agreement with the given key.
protected int	getDerivedKeyLength(long algId) Returns the derived key length in bytes for a key of the given algorithm.

Methods inherited from class com.safenetinc.luna.provider.keyagree.LunaKeyAgreementEcDh

engineDoPhase, engineGenerateSecret, engineGenerateSecret, engineGenerateSecretWantBytes, engineInit, getMaxSharedSecretLength

Methods inherited from class java.lang.Object

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

Field Detail

privateKey

protected LunaKey privateKey

kf

protected final KeyFactory kf

Constructor Detail

LunaKeyAgreementEcDhCWithKdf1

public LunaKeyAgreementEcDhCWithKdf1()

Method Detail

engineInit

protected void engineInit(Key key,
                          AlgorithmParameterSpec params,
                          SecureRandom random)
                   throws InvalidKeyException,
                          InvalidAlgorithmParameterException

Initializes this key agreement with the given key.

Specified by:

engineInit in class KeyAgreementSpi

Parameters:

key - The party's private information, typically the local party's private key

params - Any additional information required for the key agreement.

random - Unused. The Luna HSM has its own source of randomness

Throws:

InvalidKeyException - If the given key is of the wrong type for this key agreement or has an incompatible algorithm type

InvalidAlgorithmParameterException

checkPublicKey

protected void checkPublicKey(Key key,
                              boolean lastPhase)
                       throws InvalidKeyException,
                              IllegalStateException

Checks the parameters to engineDoPhase().

Parameters:

key - The other party's public key

lastPhase - Must be set to true

Throws:

IllegalStateException - If this key agreement has not been initialized, or if lastPhase is false

InvalidKeyException - If the pubic key's slot doesn't match the private key's slot

engineGenerateSecret

protected int engineGenerateSecret(byte[] sharedSecret,
                                   int offset)
                            throws IllegalStateException,
                                   ShortBufferException

Generates the shared secret, and places it into the buffer sharedSecret, beginning at offset inclusive.

If the sharedSecret buffer is too small to hold the result, a ShortBufferException is thrown. In this case, the key agreement is not reset and the call can be repeated with a larger output buffer.

Successful completion of this method resets this KeyAgreement object, so that it can be reused for further key agreements. Unless this key agreement is reinitialized with one of the init methods, the same private information will be used for subsequent key agreements. However, doPhase will have to be called after every call to generateSecret in order to re-initialize the public information.

Specified by:

engineGenerateSecret in class KeyAgreementSpi

Parameters:

sharedSecret - The buffer for the shared secret

offset - The offset in sharedSecret where the shared secret will be stored

Returns:

The number of bytes places into sharedSecret

Throws:

IllegalStateException - If this key agreement has not been completed yet

ShortBufferException - If the given output buffer is too small to hold the secret

getDerivedKeyLength

protected int getDerivedKeyLength(long algId)
                           throws NoSuchAlgorithmException

Returns the derived key length in bytes for a key of the given algorithm. A "generic secret" key will have the same length as the DH/ECDH keys used to create it.

Parameters:

algId - Algorithm of the secret key

Returns:

Length of the secret key, in bytes

Throws:

NoSuchAlgorithmException - If the algorithm id is not recognized