public Object clone() throws CloneNotSupportedException 
{
        if (this instanceof Cloneable) {
            return super.clone();
        } else {
            throw new CloneNotSupportedException();
        }
}

Returns a clone if the implementation is cloneable.

 abstract protected Object engineGetParameter(String param) throws InvalidParameterExceptionDeprecated! 
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.

 protected AlgorithmParameters engineGetParameters() 
{
        throw new UnsupportedOperationException();
}

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.

 abstract protected  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 
{
            this.appRandom = random;
            engineInitSign(privateKey);
}

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.)

 abstract protected  void engineInitVerify(PublicKey publicKey) throws InvalidKeyException
Initializes this signature object with the specified
public key for verification operations.

 protected  void engineSetParameter(AlgorithmParameterSpec params) throws InvalidAlgorithmParameterException 
{
            throw new UnsupportedOperationException();
}

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

 abstract protected  void engineSetParameter(String param,
    Object value) throws InvalidParameterExceptionDeprecated! Replaced -  by engineSetParameter .

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.

 abstract protected 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 
{
        byte[] sig = engineSign();
        if (len <  sig.length) {
                throw new SignatureException
                    ("partial signatures not returned");
        }
        if (outbuf.length - offset <  sig.length) {
                throw new SignatureException
                    ("insufficient space in the output buffer to store the "
                     + "signature");
        }
        System.arraycopy(sig, 0, outbuf, offset, sig.length);
        return sig.length;
}

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.

 abstract protected  void engineUpdate(byte b) throws SignatureException
Updates the data to be signed or verified
using the specified byte.

 protected  void engineUpdate(ByteBuffer input) 
{
        if (input.hasRemaining() == false) {
            return;
        }
        try {
            if (input.hasArray()) {
                byte[] b = input.array();
                int ofs = input.arrayOffset();
                int pos = input.position();
                int lim = input.limit();
                engineUpdate(b, ofs + pos, lim - pos);
                input.position(lim);
            } else {
                int len = input.remaining();
                byte[] b = new byte[JCAUtil.getTempArraySize(len)];
                while (len  > 0) {
                    int chunk = Math.min(len, b.length);
                    input.get(b, 0, chunk);
                    engineUpdate(b, 0, chunk);
                    len -= chunk;
                }
            }
        } catch (SignatureException e) {
            // is specified to only occur when the engine is not initialized
            // this case should never occur as it is caught in Signature.java
            throw new ProviderException("update() failed", e);
        }
}

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

 abstract protected  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.

 abstract protected boolean engineVerify(byte[] sigBytes) throws SignatureException
Verifies the passed-in signature.

 protected boolean engineVerify(byte[] sigBytes,
    int offset,
    int length) throws SignatureException 
{
        byte[] sigBytesCopy = new byte[length];
        System.arraycopy(sigBytes, offset, sigBytesCopy, 0, length);
        return engineVerify(sigBytesCopy);
}

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

Note: Subclasses should overwrite the default implementation.