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 */ 020package org.apache.directory.api.ldap.codec.api; 021 022 023import java.io.InputStream; 024import java.nio.ByteBuffer; 025 026import org.apache.directory.api.asn1.DecoderException; 027import org.apache.directory.api.asn1.ber.Asn1Decoder; 028import org.apache.directory.api.asn1.ber.tlv.TLVStateEnum; 029import org.apache.directory.api.i18n.I18n; 030import org.apache.directory.api.ldap.model.message.Message; 031import org.slf4j.Logger; 032import org.slf4j.LoggerFactory; 033 034 035/** 036 * The LdapDecoder decodes ASN.1 BER encoded PDUs into LDAP messages 037 * 038 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 039 */ 040public class LdapDecoder 041{ 042 /** The logger */ 043 private static final Logger LOG = LoggerFactory.getLogger( LdapDecoder.class ); 044 045 /** A speedup for logger */ 046 private static final boolean IS_DEBUG = LOG.isDebugEnabled(); 047 048 /** The ASN 1 decoder instance */ 049 private Asn1Decoder asn1Decoder; 050 051 /** The name of the LdapSession's attribute for the LDAP container used during the decoding */ 052 public static final String MESSAGE_CONTAINER_ATTR = "LDAP-container"; 053 054 /** The maximum PDU size, stored into the LDAPSession's attribute */ 055 public static final String MAX_PDU_SIZE_ATTR = "LDAP-maxPduSize"; 056 057 058 /** 059 * Creates an instance of a Ldap Decoder implementation. 060 */ 061 public LdapDecoder() 062 { 063 asn1Decoder = new Asn1Decoder(); 064 } 065 066 067 /** 068 * Decodes a PDU from an input stream into a Ldap message container. We can only 069 * decode one complete message. 070 * 071 * @param in The input stream to read and decode PDU bytes from 072 * @param container The LdapMessageContainer containing the message to decode 073 * @return return The decoded message 074 * @throws DecoderException If the decoding failed 075 */ 076 public Message decode( InputStream in, LdapMessageContainer<MessageDecorator<? extends Message>> container ) 077 throws DecoderException 078 { 079 try 080 { 081 int amount; 082 083 while ( in.available() > 0 ) 084 { 085 byte[] buf = new byte[in.available()]; 086 087 amount = in.read( buf ); 088 if ( amount == -1 ) 089 { 090 break; 091 } 092 093 asn1Decoder.decode( ByteBuffer.wrap( buf, 0, amount ), container ); 094 } 095 } 096 catch ( Exception e ) 097 { 098 String message = I18n.err( I18n.ERR_04060, e.getLocalizedMessage() ); 099 LOG.error( message ); 100 throw new DecoderException( message, e ); 101 } 102 103 if ( container.getState() == TLVStateEnum.PDU_DECODED ) 104 { 105 if ( IS_DEBUG ) 106 { 107 LOG.debug( "Decoded LdapMessage : " + container ); 108 } 109 110 return container.getMessage(); 111 } 112 else 113 { 114 LOG.error( I18n.err( I18n.ERR_04062 ) ); 115 throw new DecoderException( I18n.err( I18n.ERR_04063 ) ); 116 } 117 } 118}