/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.sling.distribution.util.impl;
import static java.lang.Integer.toHexString;
import static org.apache.commons.io.IOUtils.closeQuietly;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.security.DigestInputStream;
import java.security.DigestOutputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public final class DigestUtils {
private DigestUtils() {
// do nothing
}
public static DigestInputStream openDigestInputStream(InputStream mainInputStream, String digestAlgorithm) {
return new DigestInputStream(mainInputStream, getDigest(digestAlgorithm));
}
public static DigestOutputStream openDigestOutputStream(OutputStream mainOutputStream, String digestAlgorithm) {
return new DigestOutputStream(mainOutputStream, getDigest(digestAlgorithm));
}
private static MessageDigest getDigest(String digestAlgorithm) {
try {
return MessageDigest.getInstance(digestAlgorithm);
} catch (NoSuchAlgorithmException e) {
throw new IllegalArgumentException("Digest algorithm " + digestAlgorithm + " not supported in this version.");
}
}
public static String readDigestMessage(DigestInputStream input) {
return readDigestMessage(input.getMessageDigest());
}
public static String readDigestMessage(DigestOutputStream output) {
return readDigestMessage(output.getMessageDigest());
}
private static String readDigestMessage(MessageDigest messageDigest) {
StringWriter writer = new StringWriter();
try {
readDigest(messageDigest, writer);
} catch (IOException e) {
// it does not happen with the StringWriter
} finally {
closeQuietly(writer);
}
return writer.toString();
}
public static File rewriteDigestMessage(DigestOutputStream digestOutput, File target) throws IOException {
File targetDigest = new File(target.getParentFile(),
target.getName()
+ '.'
+ digestOutput.getMessageDigest()
.getAlgorithm()
.toLowerCase()
.replace('-', Character.MIN_VALUE));
rewriteDigestMessage(digestOutput, new FileOutputStream(targetDigest));
return targetDigest;
}
private static void rewriteDigestMessage(DigestOutputStream digestOutput, OutputStream target) throws IOException {
final Writer writer = new OutputStreamWriter(target);
try {
readDigest(digestOutput.getMessageDigest(), writer);
} finally {
closeQuietly(writer);
closeQuietly(target);
}
}
private static void readDigest(MessageDigest messageDigest, Writer writer) throws IOException {
final byte[] data = messageDigest.digest();
for (byte element: data) {
int intVal = element & 0xff;
if (intVal < 0x10){
// append a zero before a one digit hex
// number to make it two digits.
writer.append('0');
}
writer.append(toHexString(intVal));
}
}
}