💾 Archived View for gemini.bortzmeyer.org › rfc-mirror › rfc2713.txt captured on 2023-09-08 at 20:01:19.
⬅️ Previous capture (2021-11-30)
-=-=-=-=-=-=-
Network Working Group V. Ryan
Request for Comments: 2713 S. Seligman
Category: Informational R. Lee
Sun Microsystems, Inc.
October 1999
Schema for Representing Java(tm) Objects in an LDAP Directory
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1999). All Rights Reserved.
Abstract
This document defines the schema for representing Java(tm) objects in
an LDAP directory [LDAPv3]. It defines schema elements to represent
a Java serialized object [Serial], a Java marshalled object [RMI], a
Java remote object [RMI], and a JNDI reference [JNDI].
1. Introduction
This document assumes that the reader has a general knowledge of the
Java programming language [Java]. For brevity we use the term "Java
object" in place of "object in the Java programming language"
throughout this text.
Traditionally, LDAP directories have been used to store data. Users
and programmers think of the directory as a hierarchy of directory
entries, each containing a set of attributes. You look up an entry
from the directory and extract the attribute(s) of interest. For
example, you can look up a person's telephone number from the
directory. Alternatively, you can search the directory for entries
with a particular set of attributes. For example, you can search for
all persons in the directory with the surname "Smith".
For applications written in the Java programming language, a kind of
data that is typically shared are Java objects themselves. For such
applications, it makes sense to be able to use the directory as a
repository for Java objects. The directory provides a centrally
administered, and possibly replicated, service for use by Java
applications distributed across the network.
Ryan, et al. Informational [Page 1]
RFC 2713 Schema for Java Objects October 1999
For example, an application server might use the directory for
"registering" objects representing the services that it manages, so
that a client can later search the directory to locate those services
as it needs.
The motivation for this document is to define a common way for
applications to store and retrieve Java objects from the directory.
Using this common schema, any Java application that needs to read or
store Java objects in the directory can do so in an interoperable
way.
2 Representation of Java Objects
This document defines schema elements to represent three types of
Java objects: a Java serialized object, a Java marshalled object,
and a JNDI reference. A Java remote object is stored as either a Java
marshalled object or a JNDI reference.
2.1 Common Representations
A Java object is stored in the LDAP directory by using the object
class javaObject. This is the base class from which other Java object
related classes derive: javaSerializedObject, javaMarshalledObject,
and javaNamingReference. javaObject is an abstract object class,
which means that a javaObject cannot exist by itself in the
directory; only auxiliary or structural subclasses of it can exist in
the directory.
The object class javaContainer represents a directory entry dedicated
to storing a Java object. It is a structural object class. In cases
where a subclass of javaObject is mixed in with another structural
object class, javaContainer is not required.
The definitions for the object classes javaObject and javaContainer
are presented in Section 4.
The javaObject class has one mandatory attribute (javaClassName) and
four optional attributes (javaClassNames, javaCodebase, javaDoc,
description). javaClassName is a single valued attribute that is
used to store the fully qualified name of the object's Java class
(for example, "java.lang.String"). This may be the object's most
derived class's name, but does not have to be; that of a superclass
or interface in some cases might be most appropriate. This attribute
is intended for storing the name of the object's "distinguished"
class, that is, the class or interface with which the object should
be identified.
Ryan, et al. Informational [Page 2]
RFC 2713 Schema for Java Objects October 1999
javaClassNames is a multivalued attribute that is used to store the
fully qualified names of the object's Java classes and interfaces
(for example, "java.lang.Byte"). Like all multivalued attributes, the
javaClassNames attribute's values are unordered and so no one value
is more "distinguished" than the others. This attribute is intended
for storing an object's class and interface names and those of its
ancestor classes and interfaces, although the list of values does not
have to be complete. If the javaClassNames attribute is present, it
should include the value of javaClassName.
For example, suppose an object is stored in the directory with a
javaClassName attribute of "java.io.FilePermission", and a
javaClassNames attribute of {"java.security.Permission",
"java.io.FilePermission", "java.security.Guard",
"java.io.Serializable"}. An application searching a directory for
Java objects might use javaClassName to produce a summary of the
names and types of Java objects in that directory. Another
application might use the javaClassNames attribute to find, for
example, all java.security.Permission objects.
javaCodebase is a multivalued attribute that is used to store the
location(s) of the object's class definition. javaDoc is used to
store a pointer (URL) to the Java documentation for the class.
description is used to store a textual description of a Java object
and is defined in [v3Schema]. The definitions of these attributes are
presented in Section 3.
2.2 Serialized Objects
To "serialize" an object means to convert its state into a byte
stream in such a way that the byte stream can be converted back into
a copy of the object. A Java object is "serializable" if its class
or any of its superclasses implements either the java.io.Serializable
interface or its subinterface java.io.Externalizable.
"Deserialization" is the process of converting the serialized form of
an object back into a copy of the object. When an object is
serialized, the entire tree of objects rooted at the object is also
serialized. When it is deserialized, the tree is reconstructed. For
example, suppose a serializable Book object contains (a serializable
field of) an array of Page objects. When a Book object is
serialized, so is the array of Page objects.
The Java platform specifies a default algorithm by which serializable
objects are serialized. A Java class can also override this default
serialization with its own algorithm. [Serial] describes object
serialization in detail.
Ryan, et al. Informational [Page 3]
RFC 2713 Schema for Java Objects October 1999
When an object is serialized, information that identifies its class
is recorded in the serialized stream. However, the class's definition
("class file") itself is not recorded. It is the responsibility of
the system that is deserializing the object to determine the
mechanism to use for locating and loading the associated class
definitions. For example, the Java application might include in its
classpath a JAR file containing the class definitions of the
serialized object, or load the class definitions using information
from the directory, as explained below.
2.2.1 Representation in the Directory
A serialized object is represented in the directory by the attributes
javaClassName, javaClassNames, javaCodebase, and javaSerializedData,
as defined in Section 3. The mandatory attribute,
javaSerializedData, contains the serialized form of the object.
Although the serialized form already contains the class name, the
mandatory javaClassName attribute also records the class name of the
serialized object so that applications can determined class
information without having to first deserialize the object. The
optional javaClassNames attribute is used to record additional class
information about the serialized object. The optional javaCodebase
attribute is used to record the locations of the class definitions
needed to deserialize the serialized object.
A directory entry that contains a serialized object is represented by
the object class javaSerializedObject, which is a subclass of
javaObject. javaSerializedObject is an auxiliary object class, which
means that it needs to be mixed in with a structural object class.
javaSerializedObject's definition is given in Section 4.
2.3 Marshalled Objects
To "marshal" an object means to record its state and codebase(s) in
such a way that when the marshalled object is "unmarshalled," a copy
of the original object is obtained, possibly by automatically loading
the class definitions of the object. You can marshal any object that
is serializable or remote (that is, implements the java.rmi.Remote
interface). Marshalling is like serialization, except marshalling
also records codebases. Marshalling is different from serialization
in that marshalling treats remote objects specially. If an object is
a java.rmi.Remote object, marshalling records the remote object's
"stub" (see Section 2.5), instead of the remote object itself. Like
serialization, when an object is marshalled, the entire tree of
objects rooted at the object is marshalled. When it is unmarshalled,
the tree is reconstructed.
Ryan, et al. Informational [Page 4]
RFC 2713 Schema for Java Objects October 1999
A "marshalled" object is the represented by the
java.rmi.MarshalledObject class. Here's an example of how to create
MarshalledObjects for serializable and remote objects:
java.io.Serializable sobj = ...;
java.rmi.MarshalledObject mobj1 =
new java.rmi.MarshalledObject(sobj);
java.rmi.Remote robj = ...;
java.rmi.MarshalledObject mobj2 =
new java.rmi.MarshalledObject(robj);
Then, to retrieve the original objects from the MarshalledObjects, do
as follows:
java.io.Serializable sobj = (java.io.Serializable) mobj1.get();
java.io.Remote rstub = (java.io.Remote) mobj2.get();
MarshalledObject is available only on the Java 2 Platform, Standard
Edition, v1.2, and higher releases.
2.3.1 Representation in the Directory
A marshalled object is represented in the directory by the attributes
javaClassName, javaClassNames, and javaSerializedData, as defined in
Section 3. The mandatory attribute, javaSerializedData, contains the
serialized form of the marshalled object (that is, the serialized
form of a MarshalledObject instance). The mandatory javaClassName
attribute records the distinguished class name of the object before
it has been marshalled. The optional javaClassNames attribute is
used to record additional class information about the object before
it has been marshalled.
A directory entry that contains a marshalled object is represented by
the object class javaMarshalledObject, which is a subclass of
javaObject. javaMarshalledObject is an auxiliary object class, which
means that it needs to be mixed in with a structural object class.
javaMarshalledObject's definition is given in Section 4.
As evident in this description, a javaMarshalledObject differs from a
javaSerializedObject only in the interpretation of the javaClassName
and javaClassNames attributes.
Ryan, et al. Informational [Page 5]
RFC 2713 Schema for Java Objects October 1999
2.4 JNDI References
Java Naming and Directory Interface(tm) (JNDI) is a directory access
API specified in the Java programming language [JNDI]. It provides
an object-oriented view of the directory, allowing Java objects to be
added to and retrieved from the directory without requiring the
client to manage data representation issues.
JNDI defines the notion of a "reference" for use when an object
cannot be stored in the directory directly, or when it is
inappropriate or undesirable to do so. An object with an associated
reference is stored in the directory indirectly, by storing its
reference instead.
2.4.1 Contents of a Reference
A JNDI reference is a Java object of class javax.naming.Reference.
It consists of class information about the object being referenced
and an ordered list of addresses. An address is a Java object of
class javax.naming.RefAddr. Each address contains information on how
to construct the object.
A common use for JNDI references is to represent connections to a
network service such as a database, directory, or file system. Each
address may then identify a "communications endpoint" for that
service, containing information on how to contact the service.
Multiple addresses may arise for various reasons, such as replication
or the object offering interfaces over more than one communication
mechanism.
A reference also contains information to assist in the creation of an
instance of the object to which the reference refers. It contains
the Java class name of that object, and the class name and location
of the object factory to be used to create the object. The
procedures for creating an object given its reference and the reverse
are described in [JNDI].
2.4.2 Representation in the Directory
A JNDI reference is stored in the directory by using the attributes
javaClassName, javaClassNames, javaCodebase, javaReferenceAddress,
and javaFactory, defined in Section 3. These attributes store
information corresponding to the contents of a reference described
above. javaReferenceAddress is a multivalued optional attribute for
storing reference addresses. javaFactory is the optional attribute
for storing the object factory's fully qualified class name. The
mandatory javaClassName attribute is used to store the name of the
distinguished class of the object. The optional javaClassNames
Ryan, et al. Informational [Page 6]
RFC 2713 Schema for Java Objects October 1999
attribute is used to record additional class and interface names.
The optional javaCodebase attribute is used to store the locations of
the object factory's and the object's class definitions.
A directory entry containing a JNDI reference is represented by the
object class javaNamingReference, which is a subclass of javaObject.
javaNamingReference is an auxiliary object class, which means that it
needs to be mixed in with a structural object class.
javaNamingReference's definition is given in Section 4.
2.5 Remote Objects
The Java Remote Method Invocation (RMI) system [RMI] is a mechanism
that enables an object on one Java virtual machine to invoke methods
on an object in another Java virtual machine. Any object whose
methods can be invoked in this way must implement the java.rmi.Remote
interface. When such an object is invoked, its arguments are
marshalled and sent from the local virtual machine to the remote one,
where the arguments are unmarshalled and used. When the method
terminates, the results are marshalled from the remote machine and
sent to the caller's virtual machine.
To make a remote object accessible to other virtual machines, a
program typically registers it with the RMI registry. The program
supplies to the RMI registry the string name of the remote object and
the remote object itself. When a program wants to access a remote
object, it supplies the object's string name to the RMI registry on
the same machine as the remote object. The RMI registry returns to
the caller a reference (called "stub") to the remote object. When
the program receives the stub for the remote object, it can invoke
methods on the remote object (through the stub). A program can also
obtain references to remote objects as a result of remote calls to
other remote objects or from other naming services. For example, the
program can look up a reference to a remote object from an LDAP
server that supports the schema defined in this document.
The string name accepted by the RMI registry has the syntax
"rmi://hostname:port/remoteObjectName", where "hostname" and "port"
identify the machine and port on which the RMI registry is running,
respectively, and "remoteObjectName" is the string name of the remote
object. "hostname", "port", and the prefix, "rmi:", are optional. If
"hostname" is not specified, it defaults to the local host. If
"port" is not specified, it defaults to 1099. If "remoteObjectName"
is not specified, then the object being named is the RMI registry
itself. See [RMI] for details.
Ryan, et al. Informational [Page 7]
RFC 2713 Schema for Java Objects October 1999
RMI can be supported using different protocols: the Java Remote
Method Protocol (JRMP) and the Internet Inter-ORB Protocol (IIOP).
The JRMP is a specialized protocol designed for RMI; the IIOP is the
standard protocol for communication between CORBA objects [CORBA].
RMI over IIOP allows Java remote objects to communicate with CORBA
objects which might be written in a non-Java programming language
[RMI-IIOP].
2.5.1 Representation in the Directory
Remote objects that use the IIOP are represented in the directory as
CORBA object references [CORBA-LDAP]. Remote objects that use the
JRMP are represented in the directory in one of two ways: as a
marshalled object, or as a JNDI reference.
A marshalled object records the codebases of the remote object's stub
and any serializable or remote objects that it references, and
replaces remote objects with their stubs. To store a Remote object
as a marshalled object (java.rmi.MarshalledObject), you first create
a java.rmi.MarshalledObject instance for it.
java.rmi.Remote robj = ...;
java.rmi.MarshalledObject mobj =
new java.rmi.MarshalledObject(robj);
You can then store the MarshalledObject instance as a
javaMarshalledObject. The javaClassName attribute should contain the
fully qualified name of the distinguished class of the remote object.
The javaClassNames attribute should contain the names of the classes
and interfaces of the remote object. To read the remote object back
from the directory, first deserialize the contents of the
javaSerializedData to get a MarshalledObject (mobj), then retrieve it
from the MarshalledObject as follows:
java.rmi.Remote robj = (java.rmi.Remote)mobj.get();
This returns the remote stub, which you can then use to invoke remote
methods.
MarshalledObject is available only on the Java 2 Platform, Standard
Edition, v1.2 and higher releases. Therefore, a remote object stored
as a MarshalledObject can only be read by clients using the the Java
2 Platform, Standard Edition, v1.2 or higher releases.
Ryan, et al. Informational [Page 8]
RFC 2713 Schema for Java Objects October 1999
To store a remote object as a JNDI reference, you first create a
javax.naming.Reference object instance for it using the remote
object's string name as it has been, or will be, recorded with the
RMI registry, with the additional restriction that the "rmi:" prefix
must be present. Here's an example:
javax.naming.Reference ref = new javax.naming.Reference(
obj.getClass().getName(),
new javax.naming.StringRefAddr("URL",
"rmi://rserver/AppRemoteObjectX"));
You then store the javax.naming.Reference instance as a
javaNamingReference. The advantage of using a JNDI reference is that
this can be done without a reference to the remote object. In fact,
the remote object does not have to exist at the time that this
recording in the directory is made. The remote object needs to exist
and be bound with the RMI registry when the object is looked up from
the directory.
2.6 Serialized Objects Vs. Marshalled Objects Vs. References
The object classes defined in this document store different aspects
of the Java objects.
A javaSerializedObject or a serializable object stored as a
javaMarshalledObject represents the object itself, while a
javaNamingReference or a remote object stored as a
javaMarshalledObject represents a "pointer" to the object.
When storing a serializable object in the directory, you have a
choice of storing it as a javaSerializedObject or a
javaMarshalledObject. The javaSerializedObject object class provides
the basic way in which to store serializable objects. When you create
an LDAP entry using the javaSerializableObject object class, you must
explicitly set the javaCodebase attribute if you want readers of that
entry to know where to load the class definitions of the object. When
you create an LDAP entry using the javaMarshalledObject object class,
you use the MarshalledObject class. The MarshalledObject class uses
the RMI infrastructure available on the Java platform to automate how
codebase information is gathered and recorded, thus freeing you from
having to set the javaCodebase attribute. On the other hand, the
javaCodebase attribute is human-readable and can be updated easily by
using text-based tools without having to change other parts of the
entry. This allows you, for instance, to move the class definitions
to another location and then update the javaCodebase attribute to
reflect the move without having to update the serialized object
itself.
Ryan, et al. Informational [Page 9]
RFC 2713 Schema for Java Objects October 1999
A javaNamingReference provides a way of recording address information
about an object which itself is not directly stored in the directory.
A remote object stored as a javaMarshalledObject also records address
information (the object's "stub") of an object which itself is not
directory stored in the directory. In other words, you can think of
these as compact representations of the information required to
access the object.
A javaNamingReference typically consists of a small number of human-
readable strings. Standard text-based tools for directory
administration may therefore be used to add, read, or modify
reference entries -- if so desired -- quite easily. Serialized and
marshalled objects are not intended to be read or manipulated
directly by humans.
3 Attribute Type Definitions
The following attribute types are defined in this document:
javaClassName
javaClassNames
javaCodebase
javaSerializedData
javaFactory
javaReferenceAddress
javaDoc
3.1 javaClassName
This attribute stores the fully qualified name of the Java object's
"distinguished" class or interface (for example, "java.lang.String").
It is a single-valued attribute. This attribute's syntax is '
Directory String' and its case is significant.
( 1.3.6.1.4.1.42.2.27.4.1.6
NAME 'javaClassName'
DESC 'Fully qualified name of distinguished Java class or
interface'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
SINGLE-VALUE
)
Ryan, et al. Informational [Page 10]
RFC 2713 Schema for Java Objects October 1999
3.2 javaCodebase
This attribute stores the Java class definition's locations. It
specifies the locations from which to load the class definition for
the class specified by the javaClassName attribute. Each value of
the attribute contains an ordered list of URLs, separated by spaces.
For example, a value of "url1 url2 url3" means that the three
(possibly interdependent) URLs (url1, url2, and url3) form the
codebase for loading in the Java class definition.
If the javaCodebase attribute contains more than one value, each
value is an independent codebase. That is, there is no relationship
between the URLs in one value and those in another; each value can be
viewed as an alternate source for loading the Java class definition.
See [Java] for information regarding class loading.
This attribute's syntax is 'IA5 String' and its case is significant.
( 1.3.6.1.4.1.42.2.27.4.1.7
NAME 'javaCodebase'
DESC 'URL(s) specifying the location of class definition'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26
)
3.3 javaClassNames
This attribute stores the Java object's fully qualified class or
interface names (for example, "java.lang.String"). It is a
multivalued attribute. When more than one value is present, each is
the name of a class or interface, or ancestor class or interface, of
this object.
This attribute's syntax is 'Directory String' and its case is
significant.
( 1.3.6.1.4.1.42.2.27.4.1.13
NAME 'javaClassNames'
DESC 'Fully qualified Java class or interface name'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
)
Ryan, et al. Informational [Page 11]
RFC 2713 Schema for Java Objects October 1999
3.4 javaSerializedData
This attribute stores the serialized form of a Java object. The
serialized form is described in [Serial].
This attribute's syntax is 'Octet String'.
( 1.3.6.1.4.1.42.2.27.4.1.8
NAME 'javaSerializedData
DESC 'Serialized form of a Java object'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
SINGLE-VALUE
)
3.5 javaFactory
This attribute stores the fully qualified class name of the object
factory (for example, "com.wiz.jndi.WizObjectFactory") that can be
used to create an instance of the object identified by the
javaClassName attribute.
This attribute's syntax is 'Directory String' and its case is
significant.
( 1.3.6.1.4.1.42.2.27.4.1.10
NAME 'javaFactory'
DESC 'Fully qualified Java class name of a JNDI object factory'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
SINGLE-VALUE
)
3.6 javaReferenceAddress
This attribute represents the sequence of addresses of a JNDI
reference. Each of its values represents one address, a Java object
of type javax.naming.RefAddr. Its value is a concatenation of the
address type and address contents, preceded by a sequence number (the
order of addresses in a JNDI reference is significant). For example:
#0#TypeA#ValA
#1#TypeB#ValB
#2#TypeC##rO0ABXNyABpq...
In more detail, the value is encoded as follows:
Ryan, et al. Informational [Page 12]
RFC 2713 Schema for Java Objects October 1999
The delimiter is the first character of the value. For readability
the character '#' is recommended when it is not otherwise used
anywhere in the value, but any character may be used subject to
restrictions given below.
The first delimiter is followed by the sequence number. The sequence
number of an address is its position in the JNDI reference, with the
first address being numbered 0. It is represented by its shortest
string form, in decimal notation.
The sequence number is followed by a delimiter, then by the address
type, and then by another delimiter. If the address is of Java class
javax.naming.StringRefAddr, then this delimiter is followed by the
value of the address contents (which is a string). Otherwise, this
delimiter is followed immediately by another delimiter, and then by
the Base64 encoding of the serialized form of the entire address.
The delimiter may be any character other than a digit or a character
contained in the address type. In addition, if the address contents
is a string, the delimiter may not be the first character of that
string.
This attribute's syntax is 'Directory String' and its case is
significant. It can contain multiple values.
( 1.3.6.1.4.1.42.2.27.4.1.11
NAME 'javaReferenceAddress'
DESC 'Addresses associated with a JNDI Reference'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
)
3.7 javaDoc
This attribute stores a pointer to the Java documentation for the
class. It's value is a URL. For example, the following URL points to
the specification of the java.lang.String class:
http://java.sun.com/products/jdk/1.2/docs/api/java/lang/String.html
This attribute's syntax is 'IA5 String' and its case is significant.
( 1.3.6.1.4.1.42.2.27.4.1.12
NAME 'javaDoc'
DESC 'The Java documentation for the class'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26
)
Ryan, et al. Informational [Page 13]
RFC 2713 Schema for Java Objects October 1999
4 Object Class Definitions
The following object classes are defined in this document:
javaContainer
javaObject
javaSerializedObject
javaMarshalledObject
javaNamingReference
4.1 javaContainer
This structural object class represents a container for a Java
object.
( 1.3.6.1.4.1.42.2.27.4.2.1
NAME 'javaContainer'
DESC 'Container for a Java object'
SUP top
STRUCTURAL
MUST ( cn )
)
4.2 javaObject
This abstract object class represents a Java object. A javaObject
cannot exist in the directory; only auxiliary or structural
subclasses of it can exist in the directory.
( 1.3.6.1.4.1.42.2.27.4.2.4
NAME 'javaObject'
DESC 'Java object representation'
SUP top
ABSTRACT
MUST ( javaClassName )
MAY ( javaClassNames $
javaCodebase $
javaDoc $
description )
)
Ryan, et al. Informational [Page 14]
RFC 2713 Schema for Java Objects October 1999
4.3 javaSerializedObject
This auxiliary object class represents a Java serialized object. It
must be mixed in with a structural object class.
( 1.3.6.1.4.1.42.2.27.4.2.5
NAME 'javaSerializedObject'
DESC 'Java serialized object'
SUP javaObject
AUXILIARY
MUST ( javaSerializedData )
)
4.4 javaMarshalledObject
This auxiliary object class represents a Java marshalled object. It
must be mixed in with a structural object class.
( 1.3.6.1.4.1.42.2.27.4.2.8
NAME 'javaMarshalledObject'
DESC 'Java marshalled object'
SUP javaObject
AUXILIARY
MUST ( javaSerializedData )
)
4.5 javaNamingReference
This auxiliary object class represents a JNDI reference. It must be
mixed in with a structural object class.
( 1.3.6.1.4.1.42.2.27.4.2.7
NAME 'javaNamingReference'
DESC 'JNDI reference'
SUP javaObject
AUXILIARY
MAY ( javaReferenceAddress $
javaFactory )
)
Ryan, et al. Informational [Page 15]
RFC 2713 Schema for Java Objects October 1999
5. Security Considerations
Serializing an object and storing it into the directory enables (a
copy of) the object to be examined and used outside the environment
in which it was originally created. The directory entry containing
the serialized object could be read and modified within the
constraints imposed by the access control mechanisms of the
directory. If an object contains sensitive information or
information that could be misused outside of the context in which it
was created, the object should not be stored in the directory. For
more details on security issues relating to serialization in general,
see [Serial].
6. Acknowledgements
We would like to thank Joseph Fialli, Peter Jones, Roger Riggs, Bob
Scheifler, and Ann Wollrath of Sun Microsystems for their comments
and suggestions.
7. References
[CORBA] The Object Management Group, "Common Object Request
Broker Architecture Specification 2.0,"
http://www.omg.org
[CORBA-LDAP] Ryan, V., Lee, R. and S. Seligman, "Schema for
Representing CORBA Object References in an LDAP
Directory", RFC 2714, October 1999.
[Java] Ken Arnold and James Gosling, "The Java(tm) Programming
Language," Second Edition, ISBN 0-201-31006-6.
[JNDI] Java Software, Sun Microsystems, Inc., "The Java(tm)
Naming and Directory Interface (tm) Specification,"
February 1998. http://java.sun.com/products/jndi/
[LDAPv3] Wahl, M., Howes, T. and S. Kille, "Lightweight
Directory Access Protocol (v3)", RFC 2251, December
1997.
[RMI] Java Software, Sun Microsystems, Inc., "Remote Method
Invocation," November 1998.
http://java.sun.com/products/jdk/1.2/docs/guide/rmi
Ryan, et al. Informational [Page 16]
RFC 2713 Schema for Java Objects October 1999
[RMI-IIOP] IBM and Java Software, Sun Microsystems, Inc., "RMI over
IIOP", June 1999.
http://java.sun.com/products/rmi-iiop/
[Serial] Java Software, Sun Microsystems, Inc., "Object
Serialization Specification," November 1998.
http://java.sun.com/products/jdk/1.2/docs/guide/
serialization
[v3Schema] Wahl, M., "A Summary of the X.500(96) User Schema for
use with LDAPv3", RFC 2256, December 1997.
8. Authors' Addresses
Vincent Ryan
Sun Microsystems, Inc.
Mail Stop EDUB03
901 San Antonio Road
Palo Alto, CA 94303
USA
Phone: +353 1 819 9151
EMail: vincent.ryan@ireland.sun.com
Scott Seligman
Sun Microsystems, Inc.
Mail Stop UCUP02-209
901 San Antonio Road
Palo Alto, CA 94303
USA
Phone: +1 408 863 3222
EMail: scott.seligman@eng.sun.com
Rosanna Lee
Sun Microsystems, Inc.
Mail Stop UCUP02-206
901 San Antonio Road
Palo Alto, CA 94303
USA
Phone: +1 408 863 3221
EMail: rosanna.lee@eng.sun.com
Ryan, et al. Informational [Page 17]
RFC 2713 Schema for Java Objects October 1999
Appendix - LDAP Schema
-- Attribute types --
( 1.3.6.1.4.1.42.2.27.4.1.6
NAME 'javaClassName'
DESC 'Fully qualified name of distinguished Java class or interface'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
SINGLE-VALUE
)
( 1.3.6.1.4.1.42.2.27.4.1.7
NAME 'javaCodebase'
DESC 'URL(s) specifying the location of class definition'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26
)
( 1.3.6.1.4.1.42.2.27.4.1.8
NAME 'javaSerializedData'
DESC 'Serialized form of a Java object'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
SINGLE-VALUE
)
( 1.3.6.1.4.1.42.2.27.4.1.10
NAME 'javaFactory'
DESC 'Fully qualified Java class name of a JNDI object factory'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
SINGLE-VALUE
)
( 1.3.6.1.4.1.42.2.27.4.1.11
NAME 'javaReferenceAddress'
DESC 'Addresses associated with a JNDI Reference'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
)
( 1.3.6.1.4.1.42.2.27.4.1.12
NAME 'javaDoc'
DESC 'The Java documentation for the class'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26
)
Ryan, et al. Informational [Page 18]
RFC 2713 Schema for Java Objects October 1999
( 1.3.6.1.4.1.42.2.27.4.1.13
NAME 'javaClassNames'
DESC 'Fully qualified Java class or interface name'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
)
-- from RFC-2256 --
( 2.5.4.13
NAME 'description'
EQUALITY caseIgnoreMatch
SUBSTR caseIgnoreSubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{1024}
)
-- Object classes --
( 1.3.6.1.4.1.42.2.27.4.2.1
NAME 'javaContainer'
DESC 'Container for a Java object'
SUP top
STRUCTURAL
MUST ( cn )
)
( 1.3.6.1.4.1.42.2.27.4.2.4
NAME 'javaObject'
DESC 'Java object representation'
SUP top
ABSTRACT
MUST ( javaClassName )
MAY ( javaClassNames $ javaCodebase $ javaDoc $ description )
)
( 1.3.6.1.4.1.42.2.27.4.2.5
NAME 'javaSerializedObject'
DESC 'Java serialized object'
SUP javaObject
AUXILIARY
MUST ( javaSerializedData )
)
Ryan, et al. Informational [Page 19]
RFC 2713 Schema for Java Objects October 1999
( 1.3.6.1.4.1.42.2.27.4.2.7
NAME 'javaNamingReference'
DESC 'JNDI reference'
SUP javaObject
AUXILIARY
MAY ( javaReferenceAddress $ javaFactory )
)
( 1.3.6.1.4.1.42.2.27.4.2.8
NAME 'javaMarshalledObject'
DESC 'Java marshalled object'
SUP javaObject
AUXILIARY
MUST ( javaSerializedData )
)
-- Matching rule from ISO X.520 --
( 2.5.13.5
NAME 'caseExactMatch'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
)
Ryan, et al. Informational [Page 20]
RFC 2713 Schema for Java Objects October 1999
Full Copyright Statement
Copyright (C) The Internet Society (1999). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
Ryan, et al. Informational [Page 21]