javacard.security

Interface DHPublicKey

All Superinterfaces:

DHKey, Key, PublicKey

public interface DHPublicKey
extends PublicKey, DHKey

The DHPublicKey interface is used to verify signatures on signed data using the DH algorithm. An implementation of DHPublicKey interface must also implement the DHKey interface methods.

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

See Also:

DHPrivateKey, KeyBuilder, Signature, javacardx.crypto.KeyEncryption

Method Summary

Methods

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

Methods inherited from interface javacard.security.Key

clearKey, getSize, getType, isInitialized

Methods inherited from interface javacard.security.DHKey

getG, getP, getQ, setG, setP, setQ

Method Detail

setY

void setY(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 key value begins

length - the length of the key value

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.

getY

short getY(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 input 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