1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.directory.api.ldap.codec.api;
21
22
23 import java.io.InputStream;
24 import java.nio.ByteBuffer;
25
26 import org.apache.directory.api.asn1.DecoderException;
27 import org.apache.directory.api.asn1.ber.Asn1Decoder;
28 import org.apache.directory.api.asn1.ber.tlv.TLVStateEnum;
29 import org.apache.directory.api.i18n.I18n;
30 import org.apache.directory.api.ldap.model.message.Message;
31 import org.slf4j.Logger;
32 import org.slf4j.LoggerFactory;
33
34
35 /**
36 * The LdapDecoder decodes ASN.1 BER encoded PDUs into LDAP messages
37 *
38 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
39 */
40 public class LdapDecoder
41 {
42 /** The logger */
43 private static final Logger LOG = LoggerFactory.getLogger( LdapDecoder.class );
44
45 /** The name of the LdapSession's attribute for the LDAP container used during the decoding */
46 public static final String MESSAGE_CONTAINER_ATTR = "LDAP-container";
47
48 /** The maximum PDU size, stored into the LDAPSession's attribute */
49 public static final String MAX_PDU_SIZE_ATTR = "LDAP-maxPduSize";
50
51
52 /**
53 * Creates an instance of a Ldap Decoder implementation.
54 */
55 public LdapDecoder()
56 {
57 }
58
59
60 /**
61 * Decodes a PDU from an input stream into a Ldap message container. We can only
62 * decode one complete message.
63 *
64 * @param in The input stream to read and decode PDU bytes from
65 * @param container The LdapMessageContainer containing the message to decode
66 * @return return The decoded message
67 * @throws DecoderException If the decoding failed
68 */
69 public Message decode( InputStream in, LdapMessageContainer<? extends Message> container )
70 throws DecoderException
71 {
72 try
73 {
74 int amount;
75
76 while ( in.available() > 0 )
77 {
78 byte[] buf = new byte[in.available()];
79
80 amount = in.read( buf );
81
82 if ( amount == -1 )
83 {
84 break;
85 }
86
87 Asn1Decoder.decode( ByteBuffer.wrap( buf, 0, amount ), container );
88 }
89 }
90 catch ( Exception e )
91 {
92 String message = I18n.err( I18n.ERR_05204_LDAP_DECODER_FAILURE, e.getLocalizedMessage() );
93 LOG.error( message );
94 throw new DecoderException( message, e );
95 }
96
97 if ( container.getState() == TLVStateEnum.PDU_DECODED )
98 {
99 if ( LOG.isDebugEnabled() )
100 {
101 LOG.debug( I18n.msg( I18n.MSG_5200_DECODED_LDAP_MESSAGE, container ) );
102 }
103
104 return container.getMessage();
105 }
106 else
107 {
108 LOG.error( I18n.err( I18n.ERR_05205_PDU_DOES_NOT_CONTAIN_ENOUGH_DATA ) );
109 throw new DecoderException( I18n.err( I18n.ERR_05206_INPUT_STREAM_TOO_SHORT_PDU ) );
110 }
111 }
112 }