Package javacard.security

Interface DHKey

All Known Subinterfaces:

DHPrivateKey, DHPublicKey

public interface DHKey

The DHKey interface is the base interface for the DH algorithm's private and public key implementations. A DH private key implementation must also implement the DHPrivateKey interface methods. A DH public key implementation must also implement the DHPublicKey interface methods.

Component Q is an optional key component. When the other 3 components of the key (X or Y, P, G) are set, the key is initialized and ready for use.

See Also:

DHPublicKey, DHPrivateKey, KeyBuilder, Signature, javacardx.crypto.KeyEncryption

Method Summary

Modifier and Type	Method	Description
short	getG(byte[] buffer, short offset)	Returns the base parameter value of the key in plain text.
short	getP(byte[] buffer, short offset)	Returns the prime parameter value of the key in plain text.
short	getQ(byte[] buffer, short offset)	Returns the subprime parameter value of the key in plain text.
void	setG(byte[] buffer, short offset, short length)	Sets the base parameter value of the key.
void	setP(byte[] buffer, short offset, short length)	Sets the prime parameter value of the key.
void	setQ(byte[] buffer, short offset, short length)	Sets the optional subprime parameter value of the key.

Method Detail

setP

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

Sets the prime parameter value of the key. The plain text data format is big-endian and right-aligned (the least significant bit is the least significant bit of last byte). Input prime parameter data is copied into the internal representation. The value of P limits the value of the public value Y.

Note:

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

Parameters:

buffer - the input buffer

offset - the offset into the input buffer at which the prime parameter value begins

length - the length of the prime parameter value

Throws:

CryptoException - with the following reason code:

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

setQ

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

Sets the optional subprime parameter value of the key. The plain text data format is big-endian and right-aligned (the least significant bit is the least significant bit of last byte). Input subprime parameter data is copied into the internal representation. The value of Q limits the value of the private value X.

Note:

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

Parameters:

buffer - the input buffer

offset - the offset into the input buffer at which the subprime parameter value begins

length - the length of the subprime parameter value

Throws:

CryptoException - with the following reason code:

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

setG

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

Sets the base parameter value of the key. The plain text data format is big-endian and right-aligned (the least significant bit is the least significant bit of last byte). Input base parameter 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 base parameter value is decrypted using the Cipher object.

Parameters:

buffer - the input buffer

offset - the offset into the input buffer at which the base parameter value begins

length - the length of the base parameter value

Throws:

CryptoException - with the following reason code:

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

getP

short getP(byte[] buffer,
           short offset)

Returns the prime parameter 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 prime parameter value starts

Returns:

the byte length of the prime parameter value returned

Throws:

CryptoException - with the following reason code:

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

See Also:

Key

getQ

short getQ(byte[] buffer,
           short offset)

Returns the subprime parameter 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). The value of q limits the size of the private value X.

Parameters:

buffer - the output buffer

offset - the offset into the output buffer at which the subprime parameter value begins

Returns:

the byte length of the subprime parameter value returned

Throws:

CryptoException - with the following reason code:

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

See Also:

Key

getG

short getG(byte[] buffer,
           short offset)

Returns the base parameter 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 base parameter value begins

Returns:

the byte length of the base parameter value returned

Throws:

CryptoException - with the following reason code:

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

See Also:

Key