DigestImpl.java

/*
 * GovWay - A customizable API Gateway 
 * https://govway.org
 * 
 * Copyright (c) 2005-2025 Link.it srl (https://link.it). 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3, as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
package org.openspcoop2.utils.digest;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;

import org.bouncycastle.jcajce.provider.digest.SHA3;
import org.openspcoop2.utils.UtilsException;
import org.slf4j.Logger;

/**
 * DigestImpl
 *
 * @author Tommaso Burlon (tommaso.burlon@link.it)
 * @author $Author$
 * @version $Rev$, $Date$
 */
public class DigestImpl implements IDigest {

    protected DigestConfig config;
    protected Logger log;
    
    @Override
    public void init(Logger log, DigestConfig config) {
        this.config = config;
        this.log = log;
    }

    
    private byte[] standardDigest(byte[] msg) throws NoSuchAlgorithmException {
        MessageDigest digest = MessageDigest.getInstance(this.config.getDigestType().getAlgorithmName());
        return digest.digest(msg);
    }
    
    private byte[] shakeDigest(byte[] msg) throws NoSuchAlgorithmException {
        MessageDigest digest = null;
        
        if (this.config.getDigestType().equals(DigestType.SHAKE128)) {
            digest = new SHA3.DigestShake128_256();
        } else if (this.config.getDigestType().equals(DigestType.SHAKE256)) {
            digest = new SHA3.DigestShake256_512();
        } else {
            throw new NoSuchAlgorithmException("digest algorithm : " + this.config.getDigestType().getAlgorithmName() + " not found ");
        }
        return digest.digest(msg);
    }
    
    
    
    @Override
    public byte[] digest(byte[] input, byte[] salt) throws UtilsException {
        byte[] output = null;
        
        if (salt.length != this.config.getSaltLength())
            throw new UtilsException("lunghezza salt fornito: " + salt.length + ", lunghezza attesa: " + this.config.getSaltLength());
        
        byte[] msg = this.config.composeMessage(input, salt);
        
        try {
            switch (this.config.getDigestType()) {
            case SHAKE128:
            case SHAKE256:
                output = shakeDigest(msg);
                break;
            case SHA256:
            case SHA384:
            case SHA3_256:
            case SHA3_384:
            case SHA3_512:
            case SHA512:
            case SHA512_256:
                output = standardDigest(msg);
                break;
            }
        } catch (NoSuchAlgorithmException e) {
            throw new UtilsException("Algorithm not found: " + this.config.getDigestType().getAlgorithmName(), e);
        }
        
        if (this.config.isBase64Encode()) {
            output = Base64.getEncoder().encode(output);
        }
        
        return output;
    }

    @Override
    public boolean check(byte[] input, byte[] salt, byte[] digest) throws UtilsException {
        
        byte[] generated = this.digest(input, salt);
        if (generated.length != digest.length)
            return false;
        
        boolean isEqual = true;
        for (int i = 0; i < generated.length; i++) {
            isEqual &= (generated[i] == digest[i]);
        }
        return isEqual;
    }

}