001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied. See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 *
019 */
020 package org.apache.directory.server.kerberos.shared.keytab;
021
022
023 import java.io.File;
024 import java.io.FileInputStream;
025 import java.io.FileOutputStream;
026 import java.io.IOException;
027 import java.io.InputStream;
028 import java.nio.channels.FileChannel;
029 import java.util.ArrayList;
030 import java.util.Collections;
031 import java.util.List;
032
033 import org.apache.mina.core.buffer.IoBuffer;
034
035
036 /**
037 * Keytab file.
038 *
039 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
040 * @version $Rev$, $Date$
041 */
042 public class Keytab
043 {
044 /**
045 * Byte array constant for keytab file format 5.1.
046 */
047 public static final byte[] VERSION_51 = new byte[]
048 { ( byte ) 0x05, ( byte ) 0x01 };
049
050 /**
051 * Byte array constant for keytab file format 5.2.
052 */
053 public static final byte[] VERSION_52 = new byte[]
054 { ( byte ) 0x05, ( byte ) 0x02 };
055
056 private byte[] keytabVersion = VERSION_52;
057 private List<KeytabEntry> entries = new ArrayList<KeytabEntry>();
058
059
060 /**
061 * Read a keytab file.
062 *
063 * @param file
064 * @return The keytab.
065 * @throws IOException
066 */
067 public static Keytab read( File file ) throws IOException
068 {
069 IoBuffer buffer = IoBuffer.wrap( getBytesFromFile( file ) );
070 return readKeytab( buffer );
071 }
072
073
074 /**
075 * Returns a new instance of a keytab with the version
076 * defaulted to 5.2.
077 *
078 * @return The keytab.
079 */
080 public static Keytab getInstance()
081 {
082 return new Keytab();
083 }
084
085
086 /**
087 * Write the keytab to a {@link File}.
088 *
089 * @param file
090 * @throws IOException
091 */
092 public void write( File file ) throws IOException
093 {
094 KeytabEncoder writer = new KeytabEncoder();
095 IoBuffer buffer = writer.write( keytabVersion, entries );
096 writeFile( buffer, file );
097 }
098
099
100 /**
101 * @param entries The entries to set.
102 */
103 public void setEntries( List<KeytabEntry> entries )
104 {
105 this.entries = entries;
106 }
107
108
109 /**
110 * @param keytabVersion The keytabVersion to set.
111 */
112 public void setKeytabVersion( byte[] keytabVersion )
113 {
114 this.keytabVersion = keytabVersion;
115 }
116
117
118 /**
119 * @return The entries.
120 */
121 public List<KeytabEntry> getEntries()
122 {
123 return Collections.unmodifiableList( entries );
124 }
125
126
127 /**
128 * @return The keytabVersion.
129 */
130 public byte[] getKeytabVersion()
131 {
132 return keytabVersion;
133 }
134
135
136 /**
137 * Read bytes into a keytab.
138 *
139 * @param bytes
140 * @return The keytab.
141 */
142 static Keytab read( byte[] bytes )
143 {
144 IoBuffer buffer = IoBuffer.wrap( bytes );
145 return readKeytab( buffer );
146 }
147
148
149 /**
150 * Write the keytab to a {@link ByteBuffer}.
151 * @return The buffer.
152 */
153 IoBuffer write()
154 {
155 KeytabEncoder writer = new KeytabEncoder();
156 return writer.write( keytabVersion, entries );
157 }
158
159
160 /**
161 * Read the contents of the buffer into a keytab.
162 *
163 * @param buffer
164 * @return The keytab.
165 */
166 private static Keytab readKeytab( IoBuffer buffer )
167 {
168 KeytabDecoder reader = new KeytabDecoder();
169 byte[] keytabVersion = reader.getKeytabVersion( buffer );
170 List<KeytabEntry> entries = reader.getKeytabEntries( buffer );
171
172 Keytab keytab = new Keytab();
173
174 keytab.setKeytabVersion( keytabVersion );
175 keytab.setEntries( entries );
176
177 return keytab;
178 }
179
180
181 /**
182 * Returns the contents of the {@link File} in a byte array.
183 *
184 * @param file
185 * @return The byte array of the file contents.
186 * @throws IOException
187 */
188 protected static byte[] getBytesFromFile( File file ) throws IOException
189 {
190 InputStream is = new FileInputStream( file );
191
192 long length = file.length();
193
194 // Check to ensure that file is not larger than Integer.MAX_VALUE.
195 if ( length > Integer.MAX_VALUE )
196 {
197 throw new IOException( "File is too large " + file.getName() );
198 }
199
200 // Create the byte array to hold the data.
201 byte[] bytes = new byte[( int ) length];
202
203 // Read in the bytes
204 int offset = 0;
205 int numRead = 0;
206 while ( offset < bytes.length && ( numRead = is.read( bytes, offset, bytes.length - offset ) ) >= 0 )
207 {
208 offset += numRead;
209 }
210
211 // Ensure all the bytes have been read in.
212 if ( offset < bytes.length )
213 {
214 throw new IOException( "Could not completely read file " + file.getName() );
215 }
216
217 // Close the input stream and return bytes.
218 is.close();
219 return bytes;
220 }
221
222
223 /**
224 * Write the contents of the {@link ByteBuffer} to a {@link File}.
225 *
226 * @param buffer
227 * @param file
228 * @throws IOException
229 */
230 protected void writeFile( IoBuffer buffer, File file ) throws IOException
231 {
232 // Set append false to replace existing.
233 FileChannel wChannel = new FileOutputStream( file, false ).getChannel();
234
235 // Write the bytes between the position and limit.
236 wChannel.write( buffer.buf() );
237
238 wChannel.close();
239 }
240 }