net.rim.device.api.crypto
Class DHKeyAgreement

java.lang.Object
  net.rim.device.api.crypto.DHKeyAgreement

public final class DHKeyAgreement
extends Object

Implements the Diffie-Hellman key agreement algorithm.

Diffie-Hellman ( DH ) is defined in PKCS #3 and various other spots.

See Also:

DHKeyPair, DHPublicKey, DHPrivateKey, DHCryptoSystem

Category:

Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.

Since:

BlackBerry API 3.6.0

Method Summary
	static byte[]	generateSharedSecret(DHPrivateKey localPrivateKey, DHPublicKey remotePublicKey, boolean useCofactor) Generates the shared secret using a given public key (from another party) and a private key with the option of using cofactor exponentiation.

Methods inherited from class java.lang.Object

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

Method Detail

generateSharedSecret

public static byte[] generateSharedSecret(DHPrivateKey localPrivateKey,
                                          DHPublicKey remotePublicKey,
                                          boolean useCofactor)
                                   throws InvalidCryptoSystemException,
                                          CryptoTokenException,
                                          CryptoUnsupportedOperationException,
                                          InvalidKeyException

Generates the shared secret using a given public key (from another party) and a private key with the option of using cofactor exponentiation. Note that utilizing cofactor exponentation is an expensive operation.

Parameters:

localPrivateKey - The local private key to use.

remotePublicKey - The remote public key to use.

useCofactor - If true, a cofactor is used in the shared secret calculations. If false, it is not used. Note that setting this value to FALSE is the most common usage.

Returns:

A byte array containing the shared secret data. Note that the value returned is the raw shared secret. The caller can then take this byte array and feed it into any PseudoRandomSource to create a symmetric key, etc.

Throws:

InvalidCryptoSystemException - Thrown if the local crypto system is different than the remote crypto system

CryptoTokenException - Thrown if there was an error communicating with the token.

CryptoUnsupportedOperationException - Thrown if a call is made to an unsupported operation.

InvalidKeyException - Thrown if the calculated shared secret is not contained within the expected subgroup. This may be thrown if a small subgroup attack is detected.

Category:

Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.

Since:

BlackBerry API 3.6.0