/*
* 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.ftpserver.command.impl;
import java.io.IOException;
import java.io.InputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.apache.ftpserver.command.AbstractCommand;
import org.apache.ftpserver.ftplet.FtpFile;
import org.apache.ftpserver.ftplet.FtpReply;
import org.apache.ftpserver.ftplet.FtpRequest;
import org.apache.ftpserver.impl.FtpIoSession;
import org.apache.ftpserver.impl.FtpServerContext;
import org.apache.ftpserver.impl.LocalizedFtpReply;
import org.apache.ftpserver.util.IoUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <strong>Internal class, do not use directly.</strong>
*
* <code>MD5 <SP> <pathname> <CRLF></code><br>
* <code>MMD5 <SP> <pathnames> <CRLF></code><br>
*
* Returns the MD5 value for a file or multiple files according to
* draft-twine-ftpmd5-00.txt.
*
* @author <a href="http://mina.apache.org">Apache MINA Project</a>
*/
public class MD5 extends AbstractCommand {
private final Logger LOG = LoggerFactory.getLogger(MD5.class);
/**
* Execute command.
*/
public void execute(final FtpIoSession session,
final FtpServerContext context, final FtpRequest request)
throws IOException {
// reset state variables
session.resetState();
boolean isMMD5 = false;
if ("MMD5".equals(request.getCommand())) {
isMMD5 = true;
}
// print file information
String argument = request.getArgument();
if (argument == null || argument.trim().length() == 0) {
session
.write(LocalizedFtpReply
.translate(
session,
request,
context,
FtpReply.REPLY_504_COMMAND_NOT_IMPLEMENTED_FOR_THAT_PARAMETER,
"MD5.invalid", null));
return;
}
String[] fileNames = null;
if (isMMD5) {
fileNames = argument.split(",");
} else {
fileNames = new String[] { argument };
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < fileNames.length; i++) {
String fileName = fileNames[i].trim();
// get file object
FtpFile file = null;
try {
file = session.getFileSystemView().getFile(fileName);
} catch (Exception ex) {
LOG.debug("Exception getting the file object: " + fileName, ex);
}
if (file == null) {
session
.write(LocalizedFtpReply
.translate(
session,
request,
context,
FtpReply.REPLY_504_COMMAND_NOT_IMPLEMENTED_FOR_THAT_PARAMETER,
"MD5.invalid", fileName));
return;
}
// check file
if (!file.isFile()) {
session
.write(LocalizedFtpReply
.translate(
session,
request,
context,
FtpReply.REPLY_504_COMMAND_NOT_IMPLEMENTED_FOR_THAT_PARAMETER,
"MD5.invalid", fileName));
return;
}
InputStream is = null;
try {
is = file.createInputStream(0);
String md5Hash = md5(is);
if (i > 0) {
sb.append(", ");
}
boolean nameHasSpaces = fileName.indexOf(' ') >= 0;
if(nameHasSpaces) {
sb.append('"');
}
sb.append(fileName);
if(nameHasSpaces) {
sb.append('"');
}
sb.append(' ');
sb.append(md5Hash);
} catch (NoSuchAlgorithmException e) {
LOG.debug("MD5 algorithm not available", e);
session.write(LocalizedFtpReply.translate(session, request, context,
FtpReply.REPLY_502_COMMAND_NOT_IMPLEMENTED,
"MD5.notimplemened", null));
} finally {
IoUtils.close(is);
}
}
if (isMMD5) {
session.write(LocalizedFtpReply.translate(session, request, context,
252, "MMD5", sb.toString()));
} else {
session.write(LocalizedFtpReply.translate(session, request, context,
251, "MD5", sb.toString()));
}
}
/**
* @param is
* InputStream for which the MD5 hash is calculated
* @return The hash of the content in the input stream
* @throws IOException
* @throws NoSuchAlgorithmException
*/
private String md5(InputStream is) throws IOException,
NoSuchAlgorithmException {
MessageDigest digest = MessageDigest.getInstance("MD5");
DigestInputStream dis = new DigestInputStream(is, digest);
byte[] buffer = new byte[1024];
int read = dis.read(buffer);
while (read > -1) {
read = dis.read(buffer);
}
return new String(encodeHex(dis.getMessageDigest().digest()));
}
/**
* Converts an array of bytes into an array of characters representing the
* hexidecimal values of each byte in order. The returned array will be
* double the length of the passed array, as it takes two characters to
* represent any given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @return A char[] containing hexidecimal characters
*/
public static char[] encodeHex(byte[] data) {
int l = data.length;
char[] out = new char[l << 1];
// two characters form the hex value.
for (int i = 0, j = 0; i < l; i++) {
out[j++] = DIGITS[(0xF0 & data[i]) >>> 4];
out[j++] = DIGITS[0x0F & data[i]];
}
return out;
}
/**
* Used to build output as Hex
*/
private static final char[] DIGITS = { '0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
}