Package javacard.security

Interface DHPrivateKey

All Superinterfaces:

DHKey, Key, PrivateKey

public interface DHPrivateKey
extends PrivateKey, DHKey

The DHPrivateKey interface is used to sign data using the DH algorithm. An implementation of DHPrivateKey interface must also implement the DHKey interface methods.

When all three components of the key (X,P,G) are set, the key is initialized and ready for use.

See Also:

DHPublicKey, KeyBuilder, Signature, javacardx.crypto.KeyEncryption

Method Summary

Modifier and Type	Method	Description
short	getX(byte[] buffer, short offset)	Returns the value of the key in plain text.
void	setX(byte[] buffer, short offset, short length)	Sets the value of the key.

Methods inherited from interface javacard.security.DHKey

getG, getP, getQ, setG, setP, setQ

Methods inherited from interface javacard.security.Key

clearKey, getSize, getType, isInitialized

Method Detail

setX

void setX(byte[] buffer,
          short offset,
          short length)
   throws CryptoException

Sets the value of the key. When the base, prime and subprime parameters are initialized and the key value is set, the key is ready for use. The plain text data format is big-endian and right-aligned (the least significant bit is the least significant bit of last byte). Input key data is copied into the internal representation.

Note:

• If the key object implements the javacardx.crypto.KeyEncryption interface and the Cipher object specified via setKeyCipher() is not null, the key value is decrypted using the Cipher object.

Parameters:

buffer - the input buffer

offset - the offset into the input buffer at which the modulus value begins

length - the length of the modulus

Throws:

CryptoException - with the following reason code:

• CryptoException.ILLEGAL_VALUE if the input key data length is inconsistent with the implementation or if input data decryption is required and fails.

getX

short getX(byte[] buffer,
           short offset)

Returns the value of the key in plain text. The data format is big-endian and right-aligned (the least significant bit is the least significant bit of last byte).

Parameters:

buffer - the output buffer

offset - the offset into the output buffer at which the key value starts

Returns:

the byte length of the key value returned

Throws:

CryptoException - with the following reason code:

• CryptoException.UNINITIALIZED_KEY if the value of the key has not been successfully initialized since the time the initialized state of the key was set to false.

See Also:

Key