com.ibm.crypto.hdwrCCA.provider

Class ECDHKeyAgreement

java.lang.Object

javax.crypto.KeyAgreementSpi

com.ibm.crypto.hdwrCCA.provider.ECDHKeyAgreement

public final class ECDHKeyAgreement
extends javax.crypto.KeyAgreementSpi

This class is a concrete implementation of the Service Provider Interface (SPI) for key agreement using the Elliptic Curve Diffie-Hellman key agreement algorithm.

Constructor Summary

Constructors

Constructor and Description
ECDHKeyAgreement()

Method Summary

Modifier and Type	Method and Description
protected java.security.Key	engineDoPhase(java.security.Key key, boolean lastPhase) Executes the next phase of this Elliptic Curve Diffie-Hellman key agreement with the given key that was received from one of the other parties involved in this key agreement.
protected byte[]	engineGenerateSecret() Generates the shared secret and returns it in a new buffer.
protected int	engineGenerateSecret(byte[] sharedSecret, int offset) Generates the shared secret, and places it into the buffer sharedSecret, beginning at offset.
protected javax.crypto.SecretKey	engineGenerateSecret(java.lang.String algorithm) Creates and derives the shared secret and returns it as a secret key object of the requested algorithm type.
protected void	engineInit(java.security.Key key, java.security.spec.AlgorithmParameterSpec params, java.security.SecureRandom random) Initializes this Elliptic Curve Diffie-Hellman key agreement with the given key, set of algorithm parameters, and source of randomness.
protected void	engineInit(java.security.Key key, java.security.SecureRandom random) Initializes this Elliptic Curve Diffie-Hellman key agreement with the given key and source of randomness.

Methods inherited from class java.lang.Object

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

Constructor Detail

ECDHKeyAgreement

public ECDHKeyAgreement()

Method Detail

engineInit

protected void engineInit(java.security.Key key,
                          java.security.spec.AlgorithmParameterSpec params,
                          java.security.SecureRandom random)
                   throws java.security.InvalidKeyException,
                          java.security.InvalidAlgorithmParameterException

Initializes this Elliptic Curve Diffie-Hellman key agreement with the given key, set of algorithm parameters, and source of randomness.

Specified by:

engineInit in class javax.crypto.KeyAgreementSpi

Parameters:

key - the party's private information, this would be the party's own Elliptic Curve private key

params - the algorithm parameters for the Elliptic Curve Diffie-Hellman key agreement operation

random - the source of randomness, this is ignored

Throws:

java.security.InvalidKeyException - if the given key is inappropriate for this key agreement

java.security.InvalidAlgorithmParameterException - if the given parameters are inappropriate for this key agreement

engineInit

protected void engineInit(java.security.Key key,
                          java.security.SecureRandom random)
                   throws java.security.InvalidKeyException

Initializes this Elliptic Curve Diffie-Hellman key agreement with the given key and source of randomness. The given key is required to contain all the algorithm parameters required for this key agreement.

Specified by:

engineInit in class javax.crypto.KeyAgreementSpi

Parameters:

key - the party's private information, this would be the party's own Elliptic Curve private key

random - the source of randomness, this is ignored

Throws:

java.security.InvalidKeyException - if the given key is inappropriate for this key agreement

engineDoPhase

protected java.security.Key engineDoPhase(java.security.Key key,
                                          boolean lastPhase)
                                   throws java.security.InvalidKeyException,
                                          java.lang.IllegalStateException

Executes the next phase of this Elliptic Curve Diffie-Hellman key agreement with the given key that was received from one of the other parties involved in this key agreement.

Specified by:

engineDoPhase in class javax.crypto.KeyAgreementSpi

Parameters:

key - the other party's Elliptic Curve public key in a two party key agreement

lastPhase - flag which indicates whether or not this is the last phase of this key agreement. This must be true for a two party key agreement

Returns:

the null value, because this phase does not yield a key

Throws:

java.security.InvalidKeyException - if the given key is inappropriate for this phase

java.lang.IllegalStateException - if this key agreement has not been initialized

engineGenerateSecret

protected byte[] engineGenerateSecret()
                               throws java.lang.IllegalStateException

Generates the shared secret and returns it in a new buffer. This method resets this key agreement object, so that it can be reused for further key agreements. Unless this key agreement is re-initialized, the same private information and algorithm parameters will be used for subsequent key agreements.

Specified by:

engineGenerateSecret in class javax.crypto.KeyAgreementSpi

Returns:

the new buffer with the shared secret

Throws:

java.lang.IllegalStateException - if this key agreement has not been completed yet

engineGenerateSecret

protected int engineGenerateSecret(byte[] sharedSecret,
                                   int offset)
                            throws java.lang.IllegalStateException,
                                   javax.crypto.ShortBufferException

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

If the sharedSecret buffer is too small to hold the result, a ShortBufferException will be thrown. In this case, this call should be repeated with a larger output buffer. This method resets this key agreement object, so that it can be reused for further key agreements. Unless this key agreement is re-initialized, the same private information and algorithm parameters will be used for subsequent key agreements.

Specified by:

engineGenerateSecret in class javax.crypto.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 placed into sharedSecret

Throws:

java.lang.IllegalStateException - if this key agreement has not been completed yet

java.lang.NullPointerException - if the supplied shared secret buffer is null

java.lang.IndexOutOfBoundsException - if the offset value is not appropriate for the shared secret buffer

javax.crypto.ShortBufferException - if the given output buffer is too small to hold the secret

engineGenerateSecret

protected javax.crypto.SecretKey engineGenerateSecret(java.lang.String algorithm)
                                               throws java.lang.IllegalStateException,
                                                      java.security.NoSuchAlgorithmException,
                                                      java.security.InvalidKeyException

Creates and derives the shared secret and returns it as a secret key object of the requested algorithm type.

Supported key algorithms are DES, Triple-DES, AES, and TlsPremasterSecret. Secret keys are derived as SymmetricKeyConstants.KeyType.SECURE_INTERNAL_TOKEN keys by default, with the exception of TlsPremasterSecret, which bypasses key derivation and is returned only as a clear shared secret.

Triple length Triple-DES keys are not supported for key derivation.

This method resets this key agreement object, so that it can be reused for further key agreements. Unless this key agreement is re-initialized, the same private information and algorithm parameters will be used for subsequent key agreements.

Specified by:

engineGenerateSecret in class javax.crypto.KeyAgreementSpi

Parameters:

algorithm - the requested secret key algorithm

Returns:

the shared secret key

Throws:

java.lang.NullPointerException - if the supplied algorithm is null

java.lang.IllegalStateException - if this key agreement has not been completed yet

java.security.NoSuchAlgorithmException - if the requested secret key algorithm is not available

java.security.InvalidKeyException - if the shared secret key material cannot be used to generate a secret key of the requested algorithm type or if the NoCvKEK option has been requested but the requested algorithm is not DESede, 3DES, or TripleDES.