connectbot/sshlib

/*
 * Copyright 2017 Jonas Dippel, Michael Perk, Marc Totzke
 */

package com.trilead.ssh2.auth;

import java.io.IOException;
import java.security.PublicKey;

public abstract class SignatureProxy
{
    public static final String SHA1 = "SHA-1";
    public static final String SHA256 = "SHA-256";
    public static final String SHA384 = "SHA-384";
    public static final String SHA512 = "SHA-512";

    /**
     * Holds the public key which belongs to the private key which is used in the signing process.
     */
    private PublicKey mPublicKey;

    /**
     * Instantiates a new SignatureProxy which needs a public key for the
     * later authentication process.
     *
     * @param publicKey The public key.
     * @throws IllegalArgumentException Might be thrown id the public key is invalid.
     */
    public SignatureProxy(PublicKey publicKey)
    {
        if (publicKey == null)
        {
            throw new IllegalArgumentException("Public key must not be null");
        }
        mPublicKey = publicKey;
    }

    /**
     * This method should sign a given byte array message using the private key.
     *
     * @param message The message which should be signed.
     * @param hashAlgorithm The hashing algorithm which should be used.
     * @return The signed message.
     * @throws IOException This exception might be thrown during the signing process.
     */
    public abstract byte[] sign(byte[] message, String hashAlgorithm) throws IOException;

    public PublicKey getPublicKey()
    {
        return mPublicKey;
    }
}