HashUtils.java

/*
 * Zed Attack Proxy (ZAP) and its related class files.
 * 
 * ZAP is an HTTP/HTTPS proxy for assessing web application security.
 * 
 * Copyright 2014 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.zap.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class HashUtils {

	public static String getHash(InputStream in, String algorithm) throws NoSuchAlgorithmException, IOException {
        MessageDigest md = MessageDigest.getInstance(algorithm);
        byte[] dataBytes = new byte[1024];
        int nread = 0;

        while ((nread = in.read(dataBytes)) != -1) {
            md.update(dataBytes, 0, nread);
        }

        byte[] mdbytes = md.digest();

        //convert the byte to hex format
        StringBuilder sb = new StringBuilder("");
        for (int i = 0; i < mdbytes.length; i++) {
            sb.append(Integer.toString((mdbytes[i] & 0xff) + 0x100, 16).substring(1));
        }

        return sb.toString();
	}

	public static String getHash(File file, String algorithm) throws NoSuchAlgorithmException, IOException {
		FileInputStream fis = new FileInputStream(file);
		try {
			return getHash(fis, algorithm);
		} finally {
			fis.close();
		}
	}
}