Field Summary

Constructor Summary

Method Summary

Field Details

• appRandom

  protected SecureRandom appRandom

  Application-specified source of randomness.

Constructor Details

• SignatureSpi

  public SignatureSpi()

  Constructor for subclasses to call.

Method Details

• engineInitVerify

  protected abstract void engineInitVerify(PublicKey publicKey) throwsInvalidKeyException

  Initializes thisSignature object with the specified public key for verification operations.

  Parameters:

  publicKey - the public key of the identity whose signature is going to be verified.

  Throws:

  InvalidKeyException - if the key is improperly encoded, parameters are missing, and so on.

• engineInitSign

  protected abstract void engineInitSign(PrivateKey privateKey) throwsInvalidKeyException

  Initializes thisSignature object with the specified private key for signing operations.

  Parameters:

  privateKey - the private key of the identity whose signature will be generated.

  Throws:

  InvalidKeyException - if the key is improperly encoded, parameters are missing, and so on.

• engineInitSign

  protected void engineInitSign(PrivateKey privateKey,SecureRandom random) throwsInvalidKeyException

  Initializes thisSignature object with the specified private key and source of randomness for signing operations.

  This concrete method has been added to this previously-defined abstract class. (For backwards compatibility, it cannot be abstract.)

  Parameters:

  privateKey - the private key of the identity whose signature will be generated.

  random - the source of randomness

  Throws:

  InvalidKeyException - if the key is improperly encoded, parameters are missing, and so on.

• engineUpdate

  protected abstract void engineUpdate(byte b) throwsSignatureException

  Updates the data to be signed or verified using the specified byte.

  Parameters:

  b - the byte to use for the update.

  Throws:

  SignatureException - if the engine is not initialized properly.

• engineUpdate

  protected abstract void engineUpdate(byte[] b, int off, int len) throwsSignatureException

  Updates the data to be signed or verified, using the specified array of bytes, starting at the specified offset.

  Parameters:

  b - the array of bytes

  off - the offset to start from in the array of bytes

  len - the number of bytes to use, starting at offset

  Throws:

  SignatureException - if the engine is not initialized properly

• engineUpdate

  protected void engineUpdate(ByteBuffer input)

  Updates the data to be signed or verified using the specified ByteBuffer. Processes thedata.remaining() bytes starting atdata.position(). Upon return, the buffer's position will be equal to its limit; its limit will not have changed.

  Parameters:

  input - the ByteBuffer

  Since:

  1.5

• engineSign

  protected abstract byte[] engineSign() throwsSignatureException

  Returns the signature bytes of all the data updated so far. The format of the signature depends on the underlying signature scheme.

  Returns:

  the signature bytes of the signing operation's result.

  Throws:

  SignatureException - if the engine is not initialized properly or if this signature algorithm is unable to process the input data provided.

• engineSign

  protected int engineSign(byte[] outbuf, int offset, int len) throwsSignatureException

  Finishes this signature operation and stores the resulting signature bytes in the provided bufferoutbuf, starting atoffset. The format of the signature depends on the underlying signature scheme.

  The signature implementation is reset to its initial state (the state it was in after a call to one of theengineInitSign methods) and can be reused to generate further signatures with the same private key. This method should be abstract, but we leave it concrete for binary compatibility. Knowledgeable providers should override this method.

  Parameters:

  outbuf - buffer for the signature result.

  offset - offset intooutbuf where the signature is stored.

  len - number of bytes withinoutbuf allotted for the signature. Both this default implementation and the SUN provider do not return partial digests. If the value of this parameter is less than the actual signature length, this method will throw aSignatureException. This parameter is ignored if its value is greater than or equal to the actual signature length.

  Returns:

  the number of bytes placed intooutbuf

  Throws:

  SignatureException - if the engine is not initialized properly, if this signature algorithm is unable to process the input data provided, or iflen is less than the actual signature length.

  Since:

  1.2

• engineVerify

  protected abstract boolean engineVerify(byte[] sigBytes) throwsSignatureException

  Verifies the passed-in signature.

  Parameters:

  sigBytes - the signature bytes to be verified.

  Returns:

  true if the signature was verified,false if not.

  Throws:

  SignatureException - if the engine is not initialized properly, the passed-in signature is improperly encoded or of the wrong type, if this signature algorithm is unable to process the input data provided, etc.

• engineVerify

  protected boolean engineVerify(byte[] sigBytes, int offset, int length) throwsSignatureException

  Verifies the passed-in signature in the specified array of bytes, starting at the specified offset.

  Note: Subclasses should overwrite the default implementation.

  Parameters:

  sigBytes - the signature bytes to be verified.

  offset - the offset to start from in the array of bytes.

  length - the number of bytes to use, starting at offset.

  Returns:

  true if the signature was verified,false if not.

  Throws:

  SignatureException - if the engine is not initialized properly, the passed-in signature is improperly encoded or of the wrong type, if this signature algorithm is unable to process the input data provided, etc.

  Since:

  1.4

• engineSetParameter

  @Deprecatedprotected abstract void engineSetParameter(String param,Object value) throwsInvalidParameterException

  Deprecated.

  Replaced byengineSetParameter.

  Sets the specified algorithm parameter to the specified value. This method supplies a general-purpose mechanism through which it is possible to set the various parameters of this object. A parameter may be any settable parameter for the algorithm, such as a parameter size, or a source of random bits for signature generation (if appropriate), or an indication of whether to perform a specific but optional computation. A uniform algorithm-specific naming scheme for each parameter is desirable but left unspecified at this time.

  Parameters:

  param - the string identifier of the parameter.

  value - the parameter value.

  Throws:

  InvalidParameterException - ifparam is an invalid parameter for thisSignature object, the parameter is already set and cannot be set again, a security exception occurs, and so on.

• engineSetParameter

  protected void engineSetParameter(AlgorithmParameterSpec params) throwsInvalidAlgorithmParameterException

  Initializes thisSignature object with the specified parameter values.

  Parameters:

  params - the parameters

  Throws:

  UnsupportedOperationException - if this method is not overridden by a provider

  InvalidAlgorithmParameterException - if this method is overridden by a provider and the given parameters are inappropriate for thisSignature object

• engineGetParameters

  protected AlgorithmParameters engineGetParameters()

  Returns the parameters used with thisSignature object.

  The returned parameters may be the same that were used to initialize thisSignature object, or may contain additional default or random parameter values used by the underlying signature scheme. If the required parameters were not supplied and can be generated by theSignature object, the generated parameters are returned; otherwisenull is returned.

  However, if the signature scheme does not support returning the parameters asAlgorithmParameters,null is always returned.

  Returns:

  the parameters used with thisSignature object, ornull

  Throws:

  UnsupportedOperationException - if this method is not overridden by a provider

  Since:

  1.4

• engineGetParameter

  @Deprecatedprotected abstract Object engineGetParameter(String param) throwsInvalidParameterException

  Deprecated.

  Gets the value of the specified algorithm parameter. This method supplies a general-purpose mechanism through which it is possible to get the various parameters of this object. A parameter may be any settable parameter for the algorithm, such as a parameter size, or a source of random bits for signature generation (if appropriate), or an indication of whether to perform a specific but optional computation. A uniform algorithm-specific naming scheme for each parameter is desirable but left unspecified at this time.

  Parameters:

  param - the string name of the parameter.

  Returns:

  the object that represents the parameter value, ornull if there is none.

  Throws:

  InvalidParameterException - ifparam is an invalid parameter for this engine, or another exception occurs while trying to get this parameter.

• clone

  public Object clone() throwsCloneNotSupportedException

  Returns a clone if the implementation is cloneable.

  Overrides:

  clone in class Object

  Returns:

  a clone if the implementation is cloneable.

  Throws:

  CloneNotSupportedException - if this is called on an implementation that does not supportCloneable.

  See Also:

  • Cloneable