DigestUtils.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.util.HashMap;
import java.util.Map;

import org.openspcoop2.utils.UtilsException;
import org.openspcoop2.utils.io.Base64Utilities;
import org.openspcoop2.utils.io.HexBinaryUtilities;

/**
 * DigestUtils
 *
 * @author Poli Andrea (apoli@link.it)
 * @author $Author$
 * @version $Rev$, $Date$
 */
public class DigestUtils {
    
    private DigestUtils() {}

    private static UtilsException newUtilsExceptionDigestEncodingUndefined() {
        return new UtilsException("Digest encoding undefined");
    }
    
    public static byte[] getDigestValue(byte[] content, String algorithm) throws UtilsException{
        if(content==null) {
            throw new UtilsException("Digest content undefined");
        }
        if(algorithm==null) {
            throw new UtilsException("Digest algorithm undefined");
        }
        
        MessageDigest digest = null;
        try {
            digest = MessageDigestFactory.getMessageDigest(algorithm);
        }catch(Exception e) {
            throw new UtilsException("Message digest (algorithm: '"+algorithm+"') initialization failed: "+e.getMessage(),e);
        }
        try {
            return digest.digest(content); // md5Data
        }catch(Exception e) {
            throw new UtilsException(e.getMessage(),e);
        }
    }
    
    public static String getDigestValue(byte[] content, String algorithm, DigestEncoding digestEncoding) throws UtilsException{
        return getDigestValue(content, algorithm, digestEncoding, false);
    }
    public static String getDigestValue(byte[] content, String algorithm, DigestEncoding digestEncoding, boolean rfc3230) throws UtilsException{
        byte[]md5Data = getDigestValue(content, algorithm);
        if(digestEncoding==null) {
            throw newUtilsExceptionDigestEncodingUndefined();
        }
        return encode(md5Data, digestEncoding, rfc3230, algorithm);
    }
    
    public static Map<DigestEncoding, String> getDigestValues(byte[] content, String algorithm, DigestEncoding ... digestEncoding) throws UtilsException{
        return getDigestValues(content, algorithm, false, digestEncoding);
    }
    public static Map<DigestEncoding, String> getDigestValues(byte[] content, String algorithm, boolean rfc3230, DigestEncoding ... digestEncoding) throws UtilsException{

        byte[]md5Data = getDigestValue(content, algorithm);
        if(digestEncoding==null || digestEncoding.length<=0) {
            throw newUtilsExceptionDigestEncodingUndefined();
        }
        
        Map<DigestEncoding, String> map = new HashMap<>();
        for (DigestEncoding de : digestEncoding) {
            try {
                String digestValue = encode(md5Data, de, rfc3230, algorithm);
                map.put(de, digestValue);
            }catch(Exception e) {
                throw new UtilsException(e.getMessage(),e);
            }
        }
        return map;
    }
    
    private static String encode(byte[] md5Data, DigestEncoding digestEncoding, boolean rfc3230, String algorithm) throws UtilsException{

        if(digestEncoding==null) {
            throw newUtilsExceptionDigestEncodingUndefined();
        }
        
        try {
            String digestValue = null;
            if(DigestEncoding.HEX.equals(digestEncoding)) {
                digestValue = HexBinaryUtilities.encodeAsString(md5Data);
            }
            else if(DigestEncoding.BASE64.equals(digestEncoding)) {
                digestValue = Base64Utilities.encodeAsString(md5Data);
            }
            else {
                throw new UtilsException("DigestEncoding '"+digestEncoding+"' unsupported");
            }
            if(rfc3230) {
                return algorithm+"="+digestValue;
            }
            else {
                return digestValue;
            }
        }catch(Exception e) {
            throw new UtilsException(e.getMessage(),e);
        }
    }
}