protected abstract void engineInitVerify​(PublicKey publicKey)
                                  throws InvalidKeyException

Initializes this signature object with the specified public key for verification operations.

protected abstract void engineInitSign​(PrivateKey privateKey)
                                throws InvalidKeyException

Initializes this signature object with the specified private key for signing operations.

protected void engineInitSign​(PrivateKey privateKey,
                              SecureRandom random)
                       throws InvalidKeyException

Initializes this signature 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.)

protected abstract void engineUpdate​(byte b)
                              throws SignatureException

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

protected abstract void engineUpdate​(byte[] b,
                                     int off,
                                     int len)
                              throws SignatureException

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

protected void engineUpdate​(ByteBuffer input)

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

protected abstract byte[] engineSign()
                              throws SignatureException

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

protected int engineSign​(byte[] outbuf,
                         int offset,
                         int len)
                  throws SignatureException

Finishes this signature operation and stores the resulting signature bytes in the provided buffer outbuf, starting at offset. 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 the engineInitSign 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.

protected abstract boolean engineVerify​(byte[] sigBytes)
                                 throws SignatureException

Verifies the passed-in signature.

protected boolean engineVerify​(byte[] sigBytes,
                               int offset,
                               int length)
                        throws SignatureException

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

Note: Subclasses should overwrite the default implementation.

@Deprecated
protected abstract void engineSetParameter​(String param,
                                           Object value)
                                    throws InvalidParameterException

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 or not to perform a specific but optional computation. A uniform algorithm-specific naming scheme for each parameter is desirable but left unspecified at this time.

protected void engineSetParameter​(AlgorithmParameterSpec params)
                           throws InvalidAlgorithmParameterException

This method is overridden by providers to initialize this signature engine with the specified parameter set.

protected AlgorithmParameters engineGetParameters()

This method is overridden by providers to return the parameters used with this signature engine, or null if.

If this signature engine does not use anyhas been previously initialized with parameters .The returned parameters may be(by calling the engineSetParameter method), this method returns the same that were used to initializeparameters. If this signature engine , orhas not been initialized with parameters, this method may containreturn a combination of default and randomly generated parameter values used byif the underlying signature implementation if this signature engine requires algorithm parameters but was not initialized with anysupports it and can successfully generate them. Otherwise, null is returned.

protected AlgorithmParameters engineGetParameters()

This method is overridden by providers to return the parameters used with this signature engine, or null if this signature engine does not use any parameters.

The returned parameters may be the same that were used to initialize this signature engine, or may contain a combination of default and randomly generated parameter values used by the underlying signature implementation if this signature engine requires algorithm parameters but was not initialized with any.

protected AlgorithmParameters engineGetParameters()

This method is overridden by providers to return the parameters used with this signature engine.

If this signature engine has been previously initialized with parameters (by calling the engineSetParameter method), this method returns the same parameters. If this signature engine has not been initialized with parameters, this method may return a combination of default and randomly generated parameter values if the underlying signature implementation supports it and can successfully generate them. Otherwise, null is returned.

@Deprecated
protected abstract Object engineGetParameter​(String param)
                                      throws InvalidParameterException

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 or not to perform a specific but optional computation. A uniform algorithm-specific naming scheme for each parameter is desirable but left unspecified at this time.