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.ldap.model.constants.SchemaConstants; 024import org.apache.directory.api.ldap.model.schema.SyntaxChecker; 025import org.slf4j.Logger; 026import org.slf4j.LoggerFactory; 027 028 029/** 030 * A SyntaxChecker which verifies that a value is a Jpeg according to RFC 4517. 031 * 032 * The JFIF (Jpeg File Interchange Format) specify that a jpeg image starts with 033 * the following bytes : 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 * 040 * We will check for those 11 bytes, except the length. 041 * 042 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 043 */ 044@SuppressWarnings("serial") 045public class JpegSyntaxChecker extends SyntaxChecker 046{ 047 /** A logger for this class */ 048 private static final Logger LOG = LoggerFactory.getLogger( JpegSyntaxChecker.class ); 049 050 /** 051 * Creates a new instance of JpegSyntaxChecker. 052 */ 053 public JpegSyntaxChecker() 054 { 055 super( SchemaConstants.JPEG_SYNTAX ); 056 } 057 058 059 /** 060 * {@inheritDoc} 061 */ 062 public boolean isValidSyntax( Object value ) 063 { 064 if ( value == null ) 065 { 066 LOG.debug( "Syntax invalid for 'null'" ); 067 return false; 068 } 069 070 // The value must be a byte array 071 if ( !( value instanceof byte[] ) ) 072 { 073 LOG.debug( "Syntax invalid for '{}'", value ); 074 return false; 075 } 076 077 byte[] bytes = ( byte[] ) value; 078 079 // The header must be at least 11 bytes long 080 if ( bytes.length < 11 ) 081 { 082 LOG.debug( "Syntax invalid for '{}'", value ); 083 return false; 084 } 085 086 if ( ( bytes[0] == ( byte ) 0x00FF ) // SOI 087 && ( bytes[1] == ( byte ) 0x00D8 ) 088 && ( bytes[2] == ( byte ) 0x00FF ) ) // APP0 or APP1 089 { 090 if ( bytes[3] == (byte)0x00E0 ) 091 { 092 // JFIF format 093 if ( ( bytes[6] == 'J' ) // JFIF 094 && ( bytes[7] == 'F' ) // JFIF 095 && ( bytes[8] == 'I' ) // JFIF 096 && ( bytes[9] == 'F' ) 097 && ( bytes[10] == 0x00 ) ) // \0 098 { 099 LOG.debug( "Syntax valid for '{}'", value ); 100 return true; 101 } 102 } 103 else if ( bytes[3] == (byte)0x00E1 ) 104 { 105 // Exif format 106 if ( ( bytes[6] == 'E' ) // Exif 107 && ( bytes[7] == 'x' ) // Exif 108 && ( bytes[8] == 'i' ) // Exif 109 && ( bytes[9] == 'f' ) // Exif 110 && ( bytes[10] == 0x00 ) ) // \0 111 { 112 LOG.debug( "Syntax valid for '{}'", value ); 113 return true; 114 } 115 } 116 } 117 118 LOG.debug( "Syntax invalid for '{}'", value ); 119 return false; 120 } 121}