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.model.schema.syntaxCheckers; 021 022 023import org.apache.directory.api.i18n.I18n; 024import org.apache.directory.api.ldap.model.constants.SchemaConstants; 025import org.apache.directory.api.ldap.model.schema.SyntaxChecker; 026 027 028/** 029 * A SyntaxChecker which verifies that a value is a Jpeg according to RFC 4517. 030 * <p> 031 * The JFIF (Jpeg File Interchange Format) specify that a jpeg image starts with 032 * the following bytes : 033 * <pre> 034 * 0xFF 0xD8 (SOI, Start Of Image) 035 * 0xFF 0xE0 (App0 for JFIF) or 0xDD 0xE1 (App1 for Exif) 036 * 0xNN 0xNN (Header length) 037 * "JFIF\0" (JFIF string with an ending \0) 038 * some other bytes which are related to the image. 039 * </pre> 040 * 041 * We will check for those 11 bytes, except the length. 042 * 043 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 044 */ 045@SuppressWarnings("serial") 046public final class JpegSyntaxChecker extends SyntaxChecker 047{ 048 /** 049 * A static instance of JpegSyntaxChecker 050 */ 051 public static final JpegSyntaxChecker INSTANCE = new JpegSyntaxChecker( SchemaConstants.JPEG_SYNTAX ); 052 053 /** 054 * A static Builder for this class 055 */ 056 public static final class Builder extends SCBuilder<JpegSyntaxChecker> 057 { 058 /** 059 * The Builder constructor 060 */ 061 private Builder() 062 { 063 super( SchemaConstants.JPEG_SYNTAX ); 064 } 065 066 067 /** 068 * Create a new instance of JpegSyntaxChecker 069 * @return A new instance of JpegSyntaxChecker 070 */ 071 @Override 072 public JpegSyntaxChecker build() 073 { 074 return new JpegSyntaxChecker( oid ); 075 } 076 } 077 078 079 /** 080 * Creates a new instance of JpegSyntaxChecker. 081 * 082 * @param oid The OID to use for this SyntaxChecker 083 */ 084 private JpegSyntaxChecker( String oid ) 085 { 086 super( oid ); 087 } 088 089 090 /** 091 * @return An instance of the Builder for this class 092 */ 093 public static Builder builder() 094 { 095 return new Builder(); 096 } 097 098 099 /** 100 * {@inheritDoc} 101 */ 102 @Override 103 public boolean isValidSyntax( Object value ) 104 { 105 if ( value == null ) 106 { 107 if ( LOG.isDebugEnabled() ) 108 { 109 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, "null" ) ); 110 } 111 112 return false; 113 } 114 115 // The value must be a byte array 116 if ( !( value instanceof byte[] ) ) 117 { 118 if ( LOG.isDebugEnabled() ) 119 { 120 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) ); 121 } 122 123 return false; 124 } 125 126 byte[] bytes = ( byte[] ) value; 127 128 // The header must be at least 11 bytes long 129 if ( bytes.length < 11 ) 130 { 131 if ( LOG.isDebugEnabled() ) 132 { 133 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) ); 134 } 135 136 return false; 137 } 138 139 // SOI or APP0 or APP1 format 140 if ( ( bytes[0] == ( byte ) 0x00FF ) 141 && ( bytes[1] == ( byte ) 0x00D8 ) 142 && ( bytes[2] == ( byte ) 0x00FF ) ) 143 { 144 // JFIF format 145 if ( ( bytes[3] == ( byte ) 0x00E0 ) 146 && ( bytes[6] == 'J' ) 147 && ( bytes[7] == 'F' ) 148 && ( bytes[8] == 'I' ) 149 && ( bytes[9] == 'F' ) 150 && ( bytes[10] == 0x00 ) ) 151 { 152 if ( LOG.isDebugEnabled() ) 153 { 154 LOG.debug( I18n.msg( I18n.MSG_13701_SYNTAX_VALID, value ) ); 155 } 156 157 return true; 158 } 159 // EXIF Format 160 else if ( ( bytes[3] == ( byte ) 0x00E1 ) 161 && ( bytes[6] == 'E' ) 162 && ( bytes[7] == 'x' ) 163 && ( bytes[8] == 'i' ) 164 && ( bytes[9] == 'f' ) 165 && ( bytes[10] == 0x00 ) ) 166 { 167 if ( LOG.isDebugEnabled() ) 168 { 169 LOG.debug( I18n.msg( I18n.MSG_13701_SYNTAX_VALID, value ) ); 170 } 171 172 return true; 173 } 174 } 175 176 if ( LOG.isDebugEnabled() ) 177 { 178 LOG.debug( I18n.err( I18n.ERR_13210_SYNTAX_INVALID, value ) ); 179 } 180 181 return false; 182 } 183}