Bouncy Castle Cryptography 1.11 API Specification: Class JCEDHKeyAgreement
Bouncy Castle Cryptography 1.11

org.bouncycastle.jce.provider
Class JCEDHKeyAgreement

java.lang.Object
  |
  +--javax.crypto.KeyAgreementSpi
        |
        +--org.bouncycastle.jce.provider.JCEDHKeyAgreement

public class JCEDHKeyAgreement
extends KeyAgreementSpi

Diffie-Hellman key agreement. There's actually a better way of doing this if you are using long term public keys, see the light-weight version for details.


Constructor Summary
JCEDHKeyAgreement()
           
 
Method Summary
protected  java.security.Key engineDoPhase(java.security.Key key, boolean lastPhase)
          Executes the next phase of this 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 inclusive.
protected  SecretKey engineGenerateSecret(java.lang.String algorithm)
          Creates 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 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 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

JCEDHKeyAgreement

public JCEDHKeyAgreement()
Method Detail

engineDoPhase

protected java.security.Key engineDoPhase(java.security.Key key,
                                          boolean lastPhase)
                                   throws java.security.InvalidKeyException,
                                          java.lang.IllegalStateException
Description copied from class: KeyAgreementSpi
Executes the next phase of this key agreement with the given key that was received from one of the other parties involved in this key agreement.
Overrides:
engineDoPhase in class KeyAgreementSpi
Following copied from class: javax.crypto.KeyAgreementSpi
Parameters:
key - the key for this phase. For example, in the case of Diffie-Hellman between 2 parties, this would be the other party's Diffie-Hellman public key.
lastPhase - flag which indicates whether or not this is the last phase of this key agreement.
Returns:
the (intermediate) key resulting from this phase, or null if 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
Description copied from class: KeyAgreementSpi
Generates the shared secret and returns it in a new buffer.

This method resets this KeyAgreementSpi object, so that it can be reused for further key agreements. Unless this key agreement is reinitialized with one of the engineInit methods, the same private information and algorithm parameters will be used for subsequent key agreements.

Overrides:
engineGenerateSecret in class KeyAgreementSpi
Following copied from 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,
                                   ShortBufferException
Description copied from class: KeyAgreementSpi
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, this call should be repeated with a larger output buffer.

This method resets this KeyAgreementSpi object, so that it can be reused for further key agreements. Unless this key agreement is reinitialized with one of the engineInit methods, the same private information and algorithm parameters will be used for subsequent key agreements.

Overrides:
engineGenerateSecret in class KeyAgreementSpi
Following copied from 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
ShortBufferException - if the given output buffer is too small to hold the secret

engineGenerateSecret

protected SecretKey engineGenerateSecret(java.lang.String algorithm)
Description copied from class: KeyAgreementSpi
Creates the shared secret and returns it as a secret key object of the requested algorithm type.

This method resets this KeyAgreementSpi object, so that it can be reused for further key agreements. Unless this key agreement is reinitialized with one of the engineInit methods, the same private information and algorithm parameters will be used for subsequent key agreements.

Overrides:
engineGenerateSecret in class KeyAgreementSpi
Following copied from class: javax.crypto.KeyAgreementSpi
Parameters:
algorithm - the requested secret key algorithm
Returns:
the shared secret key
Throws:
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 (e.g., the key material is too short)

engineInit

protected void engineInit(java.security.Key key,
                          java.security.spec.AlgorithmParameterSpec params,
                          java.security.SecureRandom random)
                   throws java.security.InvalidKeyException,
                          java.security.InvalidAlgorithmParameterException
Description copied from class: KeyAgreementSpi
Initializes this key agreement with the given key, set of algorithm parameters, and source of randomness.
Overrides:
engineInit in class KeyAgreementSpi
Following copied from class: javax.crypto.KeyAgreementSpi
Parameters:
key - the party's private information. For example, in the case of the Diffie-Hellman key agreement, this would be the party's own Diffie-Hellman private key.
params - the key agreement parameters
random - the source of randomness
Throws:
java.security.InvalidKeyException - if the given key is inappropriate for this key agreement, e.g., is of the wrong type or has an incompatible algorithm type.
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
Description copied from class: KeyAgreementSpi
Initializes this 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.

If the key agreement algorithm requires random bytes, it gets them from the given source of randomness, random. However, if the underlying algorithm implementation does not require any random bytes, random is ignored.

Overrides:
engineInit in class KeyAgreementSpi
Following copied from class: javax.crypto.KeyAgreementSpi
Parameters:
key - the party's private information. For example, in the case of the Diffie-Hellman key agreement, this would be the party's own Diffie-Hellman private key.
random - the source of randomness
Throws:
java.security.InvalidKeyException - if the given key is inappropriate for this key agreement, e.g., is of the wrong type or has an incompatible algorithm type.

Bouncy Castle Cryptography 1.11