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javax.crypto
Class KeyAgreement  

java.lang.Object
  javax.crypto.KeyAgreement

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public class KeyAgreement

extends java.lang.Object

Key agreement is a method in which two or more parties may agree on a secret key for symmetric cryptography or message authentication without transmitting any secrets in the clear. Key agreement algorithms typically use a public/private key pair, and the public key (along with some additional information) is sent across untrusted networks.

The most common form of key agreement used today is the Diffie-Hellman key exchange algorithm, described in PKCS #3 - Diffie Hellman Key Agreement Standard.

Since:

1.4

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Field Summary
private  java.lang.String	algorithm           The name of this instance's algorithm.
private  KeyAgreementSpi	kaSpi           The underlying key agreement implementation.
private  java.security.Provider	provider           The provider of this implementation.
private static java.lang.String	SERVICE
private  boolean	virgin           Singnals whether or not this instance has been initialized.

 

Constructor Summary
protected	KeyAgreement(KeyAgreementSpi kaSpi, java.security.Provider provider, java.lang.String algorithm)

 

Method Summary
java.security.Key	doPhase(java.security.Key key, boolean lastPhase)           Do a phase in the key agreement.
byte[]	generateSecret()           Generate the shared secret in a new byte array.
int	generateSecret(byte[] sharedSecret, int offset)           Generate the shared secret and store it into the supplied array.
SecretKey	generateSecret(java.lang.String algorithm)           Generate the shared secret and return it as an appropriate SecretKey.
java.lang.String	getAlgorithm()           Return the name of this key-agreement algorithm.
static KeyAgreement	getInstance(java.lang.String algorithm)           Get an implementation of an algorithm from the first provider that implements it.
static KeyAgreement	getInstance(java.lang.String algorithm, java.security.Provider provider)           Get an implementation of an algorithm from a specific provider.
static KeyAgreement	getInstance(java.lang.String algorithm, java.lang.String provider)           Get an implementation of an algorithm from a named provider.
java.security.Provider	getProvider()           Return the provider of the underlying implementation.
void	init(java.security.Key key)           Initialize this key agreement with a key.
void	init(java.security.Key key, java.security.spec.AlgorithmParameterSpec params)           Initialize this key agreement with a key and parameters.
void	init(java.security.Key key, java.security.spec.AlgorithmParameterSpec params, java.security.SecureRandom random)           Initialize this key agreement with a key, parameters, and source of randomness.
void	init(java.security.Key key, java.security.SecureRandom random)           Initialize this key agreement with a key and a source of randomness.

 

Methods inherited from class java.lang.Object

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

 

Field Detail

SERVICE

private static final java.lang.String SERVICE

See Also:

Constant Field Values

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kaSpi

private KeyAgreementSpi kaSpi

The underlying key agreement implementation.

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provider

private java.security.Provider provider

The provider of this implementation.

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algorithm

private java.lang.String algorithm

The name of this instance's algorithm.

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virgin

private boolean virgin

Singnals whether or not this instance has been initialized.

Constructor Detail

KeyAgreement

protected KeyAgreement(KeyAgreementSpi kaSpi,
                       java.security.Provider provider,
                       java.lang.String algorithm)

Method Detail

getInstance

public static final KeyAgreement getInstance(java.lang.String algorithm)
                                      throws java.security.NoSuchAlgorithmException

Get an implementation of an algorithm from the first provider that implements it.

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getInstance

public static final KeyAgreement getInstance(java.lang.String algorithm,
                                             java.lang.String provider)
                                      throws java.security.NoSuchAlgorithmException,
                                             java.security.NoSuchProviderException

Get an implementation of an algorithm from a named provider.

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getInstance

public static final KeyAgreement getInstance(java.lang.String algorithm,
                                             java.security.Provider provider)
                                      throws java.security.NoSuchAlgorithmException

Get an implementation of an algorithm from a specific provider.

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doPhase

public final java.security.Key doPhase(java.security.Key key,
                                       boolean lastPhase)
                                throws java.lang.IllegalStateException,
                                       java.security.InvalidKeyException

Do a phase in the key agreement. The number of times this method is called depends upon the algorithm and the number of parties involved, but must be called at least once with the lastPhase flag set to true.

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generateSecret

public final byte[] generateSecret()
                            throws java.lang.IllegalStateException

Generate the shared secret in a new byte array.

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generateSecret

public final int generateSecret(byte[] sharedSecret,
                                int offset)
                         throws java.lang.IllegalStateException,
                                ShortBufferException

Generate the shared secret and store it into the supplied array.

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generateSecret

public final SecretKey generateSecret(java.lang.String algorithm)
                               throws java.lang.IllegalStateException,
                                      java.security.InvalidKeyException,
                                      java.security.NoSuchAlgorithmException

Generate the shared secret and return it as an appropriate SecretKey.

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getAlgorithm

public final java.lang.String getAlgorithm()

Return the name of this key-agreement algorithm.

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getProvider

public final java.security.Provider getProvider()

Return the provider of the underlying implementation.

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init

public final void init(java.security.Key key)
                throws java.security.InvalidKeyException

Initialize this key agreement with a key. This method will use the highest-priority java.security.SecureRandom as its source of randomness.

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init

public final void init(java.security.Key key,
                       java.security.SecureRandom random)
                throws java.security.InvalidKeyException

Initialize this key agreement with a key and a source of randomness.

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init

public final void init(java.security.Key key,
                       java.security.spec.AlgorithmParameterSpec params)
                throws java.security.InvalidAlgorithmParameterException,
                       java.security.InvalidKeyException

Initialize this key agreement with a key and parameters. This method will use the highest-priority java.security.SecureRandom as its source of randomness.

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init

public final void init(java.security.Key key,
                       java.security.spec.AlgorithmParameterSpec params,
                       java.security.SecureRandom random)
                throws java.security.InvalidAlgorithmParameterException,
                       java.security.InvalidKeyException

Initialize this key agreement with a key, parameters, and source of randomness.

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Home >> All >> javax >> [ crypto overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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