package org.bouncycastle.pqc.jcajce.interfaces;

import java.nio.ByteBuffer;
import java.security.InvalidKeyException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.SignatureException;
import java.security.cert.Certificate;

This interface is implemented by Signature classes returned by the PQC provider where the signature
algorithm is one where the private key is updated for each signature generated. Examples of these
are algorithms such as GMSS, XMSS, and XMSS^MT.
/**
 * This interface is implemented by Signature classes returned by the PQC provider where the signature
 * algorithm is one where the private key is updated for each signature generated. Examples of these
 * are algorithms such as GMSS, XMSS, and XMSS^MT.
 */
public interface StateAwareSignature
{
    void initVerify(PublicKey publicKey)
        throws InvalidKeyException;

    void initVerify(Certificate certificate)
        throws InvalidKeyException;

    void initSign(PrivateKey privateKey)
        throws InvalidKeyException;

    void initSign(PrivateKey privateKey, SecureRandom random)
        throws InvalidKeyException;

    byte[] sign()
        throws SignatureException;

    int sign(byte[] outbuf, int offset, int len)
        throws SignatureException;

    boolean verify(byte[] signature)
        throws SignatureException;

    boolean verify(byte[] signature, int offset, int length)
        throws SignatureException;

    void update(byte b)
        throws SignatureException;

    void update(byte[] data)
        throws SignatureException;

    void update(byte[] data, int off, int len)
        throws SignatureException;

    void update(ByteBuffer data)
        throws SignatureException;

    String getAlgorithm();

    
Return true if this Signature object can be used for signing. False otherwise.
Returns:
true if we are capable of making signatures./**
     * Return true if this Signature object can be used for signing. False otherwise.
     *
     * @return true if we are capable of making signatures.
     */
    boolean isSigningCapable();

    
Return the current version of the private key with the updated state.

Note: calling this method will effectively disable the Signature object from being used for further
 signature generation without another call to initSign().

Returns:
an updated private key object, which can be used for later signature generation./**
     * Return the current version of the private key with the updated state.
     * <p>
     * <b>Note:</b> calling this method will effectively disable the Signature object from being used for further
     *  signature generation without another call to initSign().
     * </p>
     * @return an updated private key object, which can be used for later signature generation.
     */
   PrivateKey getUpdatedPrivateKey();
}