Java Card API

dsapublickey

2017-05-22 16:37:29 M&W SmartCard 3

javacard.security

Interface DSAPublicKey

All Superinterfaces: DSAKey , Key , PublicKey


The DSAPublicKey interface is used to verify signatures on signed data using the DSA algorithm. An implementation of DSAPublicKey interface must also implement the DSAKey interface methods. When all four components of the key (Y,P,Q,G) are set, the key is initialized and ready for use.

See Also:DSAPrivateKey ,KeyBuilder ,Signature ,javacardx.crypto.KeyEncryption


Method Summary
 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.DSAKey
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


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