/*
 * Zed Attack Proxy (ZAP) and its related class files.
 *
 * ZAP is an HTTP/HTTPS proxy for assessing web application security.
 *
 * Copyright 2022 The ZAP Development Team
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.zaproxy.addon.encoder.processors.predefined;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.parosproxy.paros.control.Control;
import org.zaproxy.addon.encoder.EncodeDecodeOptions;
import org.zaproxy.addon.encoder.ExtensionEncoder;

public class HashProcessor extends DefaultEncodeDecodeProcessor {

    private final String algorithm;

    public HashProcessor(String algorithm) {
        this.algorithm = algorithm;
    }

    @Override
    protected String processInternal(String value) throws NoSuchAlgorithmException {
        EncodeDecodeOptions encDecOpts =
                Control.getSingleton()
                        .getExtensionLoader()
                        .getExtension(ExtensionEncoder.class)
                        .getOptions();
        String output = HexStringEncoder.getHexString(getHash(value.getBytes()));
        return encDecOpts.isHashersLowerCase() ? output.toLowerCase() : output;
    }

    private byte[] getHash(byte[] buf) throws NoSuchAlgorithmException {
        MessageDigest hasher = MessageDigest.getInstance(algorithm);
        hasher.update(buf);
        return hasher.digest();
    }
}
