javacard.security
Interface DSAPrivateKey

public abstract interface DSAPrivateKey

extends PrivateKey, DSAKey

The DSAPrivateKey interface is used to sign data using the DSA algorithm. An implementation of DSAPrivateKey interface must also implement the DSAKey interface methods.

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

See Also:

DSAPublicKey, KeyBuilder, Signature, KeyEncryption

Method Summary

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.DSAKey

getG, getP, getQ, setG, setP, setQ

Methods inherited from interface javacard.security.Key

clearKey, getSize, getType, isInitialized

Method Detail

setX

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

Sets the value of the key. When the base, prime and subprime parameters are intialized and the key value is set, the key is ready for use. The plaintext 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.

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.

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.

getX

public 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