iaik.asn1
Class ASN

java.lang.Object
  |
  +--iaik.asn1.ASN

All Implemented Interfaces:

Cloneable

public class ASN

extends Object

implements Cloneable

The ASN class registers the several ASN.1 types. These types are represented at the Java level with ASN.XXX literals.

This class also acts as a factory for creating ASN.1 OBJECT subclasses for various kinds of Java objects.

This class consists of a static and a dynamic part. The static part may be used to statically register, create and/or parse ASN1 objects of already exising type. The dynamic part may be used for dynamically creating new ASN1 types to be registered within the IAIK-JCE ASN.1 architecture.

Each new created ASN.1 type has to be registered in the factory by specifying the class that implements the particular ASN.1 type. When dynamically creating a new ASN.1 type, the tag class, the tag number, and a name has to be specified for refering to the new type. Within the ASN.1 syntax, tags are used for unequivocally identifying some specific ASN.1 type. Each tag consists of a tag class and a tag number within this tag class. Four tag classes are defined:

• UNIVERSAL: reserved for types defined within the ASN.1 standard
• APPLICATION: to be used within some application specific scope
• PRIVATE: to be used within some enterprise specific scope
• CONTEXT SPECIFIC: to be used within the context of a structered ASN.1 type

As an example, the following code sequence creates a new class "MyPrivateType" that implements a private ASN.1 type "MyPrivateType" with tag number 1, and subsequently registers the new type within the ASN.1 factory:

 class MyPrivateType extends ASN1Object {

   private static ASN private_type = new ASN(0x01, "MyPrivateType", ASN.PRIVATE);

    static {
      // register this class as the implementation of the private tag 0x01
      ASN.register(private_type, MyPrivateType.class);
   }
   ...
 }
 

Once an ASN.1 type has been registered within the IAIK-JCE ASN.1 environment, one of the static create methods of this class may be used for creating an instance of this specific type. The following example creates an instance of the already registered universal ASN.1 type OCTET_STRING for the byte value 0x01 0xE3 0x54:

 ASN1Object obj = null;
 byte[] value = { (byte)0x01, (byte)0xE3, (byte)0x54 };
 obj = ASN.create(ASN.OCTET_STRING, value);
 

When a class implements the ASN1Type interface, the static createSequenceOf respectively createSetOf methods of this class may be used for constructing ASN.1 SEQUENCE OF respectively ASN.1 SET OF structures of the pearticular ASN.1 type in mind, e.g.:

 classThatImplementsASN1Type[] cASN1Type = ...;
 ASN1Object obj = ASN.createSequenceOf(cASN1Type);
 

The chain may be parsed back again by using the parseSequenceOf method, which may be utilized for both, SEQUENCE OF and SET OF structures:

 classThatImplementsASN1Type[] cASN1Type1 =
   (classThatImplementsASN1Type[])ASN.parseSequenceOf(obj, classThatImplementsASN1Type.class);
 

Version:

File Revision 31

See Also:

ASN1, ASN1Object, ASN1Type

Field Summary

static int	APPLICATION Tag class: application
static ASN	BIT_STRING Global ASN.1 type BIT_STRING
static ASN	BMPString Global ASN.1 type BMPString
static ASN	BOOLEAN Global ASN.1 type BOOLEAN
static ASN	CON_SPEC Global ASN.1 type CON_SPEC (CONTEXTSPECIFIC)
static int	CONTEXT_SPECIFIC Tag class: context-specific
static ASN	ENUMERATED Global ASN.1 type ENUMERATED
static ASN	EXTERNAL Global ASN.1 type EXTERNAL
static ASN	GeneralizedTime Global ASN.1 type GeneralizedTime (any time precision according to the ISO 2014 norm)
static ASN	GeneralString Global ASN.1 type GeneralString
static ASN	IA5String Global ASN.1 type IA5String (String of ASCII characters)
static ASN	INTEGER Global ASN.1 type INTEGER
protected String	name Dynamic part: the name of this ASN.1 type.
static ASN	NULL Global ASN.1 type NULL
static ASN	NumericString Global ASN.1 type NumericString
static ASN	OBJECT_DESCRIPTOR Global ASN.1 type OBJECT_DESCRIPTOR
static ASN	ObjectID Global ASN.1 type ObjectID
static ASN	OCTET_STRING Global ASN.1 type OCTET_STRING
static ASN	PrintableString Global ASN.1 type PrintableString
static int	PRIVATE Tag class: private
static ASN	SEQUENCE Global ASN.1 type SEQUENCE
static ASN	SET Global ASN.1 type SET
static ASN	T61String Global ASN.1 type T61String (TeletexString; eight-bit extension to the ASCII character set )
protected int	tag Dynamic part: the tag number of this specific ASN.1 type.
protected int	tag_class Dynamic part: tag class of this specific ASN.1 type.
static ASN	UNIString Global ASN.1 type UniversalString
static int	UNIVERSAL Tag class: universal
static ASN	UNKNOWN Global ASN.1 type UNKNOWN
static ASN	UTCTime Global ASN.1 type UTCTime (coordinated universal time) (maximum precision down to seconds)
static ASN	UTF8String Global ASN.1 string type UTF8String
static ASN	VisibleString Global ASN.1 type VisibleString (ISO 646 String)

Constructor Summary

ASN(int tag, String name)
Creates a new ASN.1 type with given tag number and name.

ASN(int tag, String name, int tagClass)
Creates a new ASN.1 type with given tag number, name and tag class.

Method Summary

Object	clone() Returns a clone ("field by field copy") of this ASN.1 type with same tag and name.
static ASN1Object	create(ASN type) Craetes a new ASN.1 object for the given ASN.1 type.
static ASN1Object	create(ASN type, Object value) Creates new ASN.1 object for the given ASN.1 type and Java value.
static ASN1Object	createSequenceOf(ASN1Type[] array) Creates a SEQUENCE OF ASN.1 object from the given array of ASN.1 types.
static ASN1Object	createSequenceOf(Vector asn1Type) Creates a SEQUENCE OF ASN.1 object from the given vector of ASN.1 types.
static ASN1Object	createSetOf(ASN1Type[] array) Creates a SET OF ASN.1 object from the given array of ASN.1 types.
static ASN1Object	createSetOf(ASN1Type[] array, boolean sorted) Creates a SET OF ASN.1 object from the given array of ASN.1 types.
static ASN1Object	createSetOf(Vector asn1Type) Creates a SET OF ASN.1 object from the given vector of ASN.1 types.
boolean	equals(Object o) Compares two ASN.1 types by tag number and tag class.
String	getName() Returns the name of this ASN.1 type.
int	getTag() Returns the tag number of this ASN.1 type.
int	getTagClass() Returns the tag class.
int	hashCode() Returns a hashcode for this object.
static ASN1Type[]	parseSequenceOf(ASN1Object obj, Class cls) Parses a SEQUENCE OF ASN.1 object and returns an array containing all the components of the given ASN.1 object.
static void	register(ASN type, Class cls) Registers a new ASN.1 type.
String	toString() Returns a String describing this ASN.1 type.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

UNIVERSAL

public static final int UNIVERSAL

Tag class: universal

APPLICATION

public static final int APPLICATION

Tag class: application

CONTEXT_SPECIFIC

public static final int CONTEXT_SPECIFIC

Tag class: context-specific

PRIVATE

public static final int PRIVATE

Tag class: private

UNKNOWN

public static final ASN UNKNOWN

Global ASN.1 type UNKNOWN

BOOLEAN

public static final ASN BOOLEAN

Global ASN.1 type BOOLEAN

INTEGER

public static final ASN INTEGER

Global ASN.1 type INTEGER

BIT_STRING

public static final ASN BIT_STRING

Global ASN.1 type BIT_STRING

OCTET_STRING

public static final ASN OCTET_STRING

Global ASN.1 type OCTET_STRING

NULL

public static final ASN NULL

Global ASN.1 type NULL

ObjectID

public static final ASN ObjectID

Global ASN.1 type ObjectID

OBJECT_DESCRIPTOR

public static final ASN OBJECT_DESCRIPTOR

Global ASN.1 type OBJECT_DESCRIPTOR

EXTERNAL

public static final ASN EXTERNAL

Global ASN.1 type EXTERNAL

ENUMERATED

public static final ASN ENUMERATED

Global ASN.1 type ENUMERATED

UTF8String

public static final ASN UTF8String

Global ASN.1 string type UTF8String

SEQUENCE

public static final ASN SEQUENCE

Global ASN.1 type SEQUENCE

SET

public static final ASN SET

Global ASN.1 type SET

NumericString

public static final ASN NumericString

Global ASN.1 type NumericString

PrintableString

public static final ASN PrintableString

Global ASN.1 type PrintableString

T61String

public static final ASN T61String

Global ASN.1 type T61String (TeletexString; eight-bit extension to the ASCII character set )

IA5String

public static final ASN IA5String

Global ASN.1 type IA5String (String of ASCII characters)

UTCTime

public static final ASN UTCTime

Global ASN.1 type UTCTime (coordinated universal time) (maximum precision down to seconds)

GeneralizedTime

public static final ASN GeneralizedTime

Global ASN.1 type GeneralizedTime (any time precision according to the ISO 2014 norm)

VisibleString

public static final ASN VisibleString

Global ASN.1 type VisibleString (ISO 646 String)

GeneralString

public static final ASN GeneralString

Global ASN.1 type GeneralString

UNIString

public static final ASN UNIString

Global ASN.1 type UniversalString

BMPString

public static final ASN BMPString

Global ASN.1 type BMPString

CON_SPEC

public static final ASN CON_SPEC

Global ASN.1 type CON_SPEC (CONTEXTSPECIFIC)

tag

protected int tag

Dynamic part: the tag number of this specific ASN.1 type.

tag_class

protected int tag_class

Dynamic part: tag class of this specific ASN.1 type.

name

protected String name

Dynamic part: the name of this ASN.1 type.

Constructor Detail

ASN

public ASN(int tag,
           String name)

Creates a new ASN.1 type with given tag number and name. The tag class is set to UNIVERSAL.

Parameters:

tag - the tag number of the new ASN.1 type

name - the name of the new ASN.1 type

ASN

public ASN(int tag,
           String name,
           int tagClass)

Creates a new ASN.1 type with given tag number, name and tag class. Each new created ASN.1 type has to be registered in the factory by specifying the class that implements the particular ASN.1 type. As an example, the following code sequence creates a new class "MyPrivateType" that implements a private ASN.1 type "MyPrivateType" with tag number 1, and subsequently registers the new type within the ASN.1 factory:

 class MyPrivateType extends ASN1Object {

   private static ASN private_type = new ASN(0x01, "MyPrivateType", ASN.PRIVATE);

    static {
      // register this class as the implementation of the private tag 0x01
      ASN.register(private_type, MyPrivateType.class);
   }
   ...
 }
 

Parameters:

tag - the tag number of the new ASN.1 type

name - the name of the new ASN.1 type

tagClass - the tag class (UNIVERSAL, APPLICATION, CONTEXT_SPECIFIC, or PRIVATE)

Method Detail

create

public static ASN1Object create(ASN type)
                         throws InstantiationException

Craetes a new ASN.1 object for the given ASN.1 type. If null is supplied as type, an ASN.1 NULL object is returned.
Only ASN.1 objects of already registered type can be created by this method. The following example creates a new instance of an ASN.1 object of registered universal type OCTET_STRING:

 ASN1Object obj = null;
 obj = ASN.create(ASN.OCTET_STRING);
 

Parameters:

type - the ASN.1 type name of the new ASN.1 object to be created

Returns:

the new created ASN.1 object which is a ASN.1 NULL object if the given type is null

Throws:

InstantiationException - if the internal factory cannot create an instance of requested type

See Also:

ASN1Object

create

public static ASN1Object create(ASN type,
                                Object value)
                         throws InstantiationException

Creates new ASN.1 object for the given ASN.1 type and Java value. If, for instance, the new ASN.1 object is of ASN.1 type IA5String, the corresponding Java value will be a Java String object.
Only ASN.1 objects of already registered type can be created by this method. The following example creates an instance of the already registered universal ASN.1 type OCTET_STRING for the byte value 0x01 0xE3 0x54:

 ASN1Object obj = null;
 byte[] value = { (byte)0x01, (byte)0xE3, (byte)0x54 };
 obj = ASN.create(ASN.OCTET_STRING, value);
 

Parameters:

type - the ASN.1 type name of the new ASN.1 object to be created

value - the Java value to be set for this ASN.1 object

Returns:

the new created ASN.1 object which is a ASN.1 NULL object if the given type is null

Throws:

InstantiationException - if the internal factory cannot create an instance of requested type

See Also:

ASN1Object

register

public static void register(ASN type,
                            Class cls)

Registers a new ASN.1 type. Called by the OBJECT classes' static initializers to register those ASN.1 types that the OBJECT classes know of.

As an example, the following code sequence creates a new class "MyPrivateType" that implements a private ASN.1 type "MyPrivateType" with tag number 1, and subsequently registers the new type within the ASN.1 factory:

 class MyPrivateType extends ASN1Object {

   private static ASN private_type = new ASN(0x01, "MyPrivateType", ASN.PRIVATE);

    static {
      // register this class as the implementation of the private tag 0x01
      ASN.register(private_type, MyPrivateType.class);
   }
   ...
 }
 

Parameters:

type - the new ASN.1 type to be registered

cls - the class that implements the ASN.1 type to be registered

createSequenceOf

public static ASN1Object createSequenceOf(ASN1Type[] array)
                                   throws CodingException

Creates a SEQUENCE OF ASN.1 object from the given array of ASN.1 types. All components have to be of the same ASN.1 type. This method only can be utilized for instances of classes that implement the ASN1Type interface, e.g.:

 classThatImplementsASN1Type[] cASN1Type = ...;
 ASN1Object obj = ASN.createSequenceOf(cASN1Type);
 

The chain may be parsed back again by using the parseSequenceOf method.

Parameters:

array - the array of objects

Returns:

the created ASN1Object as SEQUENCE OF ASN1Type

Throws:

CodingException - if there occurs an error while constructing the ASN1Object

See Also:

ASN1Object, ASN1Type, SEQUENCE

createSequenceOf

public static ASN1Object createSequenceOf(Vector asn1Type)
                                   throws CodingException

Creates a SEQUENCE OF ASN.1 object from the given vector of ASN.1 types. All components have to be of the same ASN.1 type. This method only can be utilized for instances of classes that implement the ASN1Type interface, e.g.:

 Vector vectorOfASN1TypeImplementingClassInstances = ...;
 ...
 ASN1Object obj = ASN.createSequenceOf(vectorOfASN1TypeImplementingClassInstances);
 

The class instances may be parsed back again by using the parseSequenceOf method.

Parameters:

asn1Type - a Vector containing the ASN1Type objects

Returns:

the created ASN1Object as SEQUENCE OF ASN1Type

Throws:

CodingException - if there occurs an error while constructing the ASN1Object

See Also:

ASN1Object, ASN1Type, SEQUENCE

createSetOf

public static ASN1Object createSetOf(ASN1Type[] array)
                              throws CodingException

Creates a SET OF ASN.1 object from the given array of ASN.1 types. All components have to be of the same ASN.1 type. This method only can be utilized for instances of classes that implement the ASN1Type interface, e.g.:

 classThatImplementsASN1Type[] cASN1Type = ...;
 ASN1Object obj = ASN.createSetOf(cASN1Type);
 

The chain may be parsed back again by using the parseSequenceOf method.

Parameters:

array - the array of objects

Returns:

the created ASN1Object as SET OF ASN1Type

Throws:

CodingException - if there was an error while constructing the ASN1Object

See Also:

ASN1Object, ASN1Type, SET

createSetOf

public static ASN1Object createSetOf(ASN1Type[] array,
                                     boolean sorted)
                              throws CodingException

Creates a SET OF ASN.1 object from the given array of ASN.1 types. If the parameter sorted is set to true, the SET OF will be sorted by the component encodings to give a proper DER encoding. Otherwise the components appear unsorted to give a BER encoding.

Parameters:

array - the array of objects

sorted - whether to sort the components or not

Returns:

the created ASN1Object as SET OF ASN1Type

Throws:

CodingException - if there was an error while constructing the ASN1Object

See Also:

ASN1Object, ASN1Type, SET

createSetOf

public static ASN1Object createSetOf(Vector asn1Type)
                              throws CodingException

Creates a SET OF ASN.1 object from the given vector of ASN.1 types. All components have to be of the same ASN.1 type. This method only can be utilized for instances of classes that implement the ASN1Type interface, e.g.:

 Vector vectorOfASN1TypeImplementingClassInstances = ...;
 ...
 ASN1Object obj = ASN.createSetOf(vectorOfASN1TypeImplementingClassInstances);
 

The class instances may be parsed back again by using the parseSequenceOf method.

Parameters:

asn1Type - a Vector containing the ASN1Type objects

Returns:

the created ASN1Object as SET OF ASN1Type

Throws:

CodingException - if there occurs an error while constructing the ASN1Object

See Also:

ASN1Object, ASN1Type, SET

parseSequenceOf

public static ASN1Type[] parseSequenceOf(ASN1Object obj,
                                         Class cls)
                                  throws CodingException

Parses a SEQUENCE OF ASN.1 object and returns an array containing all the components of the given ASN.1 object. All components are of the same ASN.1 type specified by the given class implementing the ASN.1 type in mind. This class has to implement the ASN1Type interface. This method also may be used for parsing a SET OF ASN.1 objects that may have been created by means of the createSetOf method, e.g.:

 classThatImplementsASN1Type[] cASN1Type1 =
   (classThatImplementsASN1Type[])ASN.parseSequenceOf(obj, classThatImplementsASN1Type.class);
 

Parameters:

obj - the ASN1Object to be parsed

className - the name of the class that implements the components´ ASN.1 type

Returns:

an ASN1Type array containing the components of the parsed ASN.1 object

Throws:

CodingException - if the ASN1Object could not be parsed

See Also:

ASN1Type, ASN1Object

getName

public String getName()

Returns the name of this ASN.1 type.

Returns:

the name of this ASN.1 type

getTag

public int getTag()

Returns the tag number of this ASN.1 type. The tag number unequivocally identifies some specific ASN.1 type within its tag class.

Returns:

the tag number of this ASN.1 type

getTagClass

public int getTagClass()

Returns the tag class. The tag class may be:

• UNIVERSAL: reserved for types defined within the ASN.1 standard
• APPLICATION: to be used within some application specific scope
• PRIVATE: to be used within some enterprise specific scope
• CONTEXT SPECIFIC: to be used within the context of a structered ASN.1 type

Returns:

the tag class

equals

public boolean equals(Object o)

Compares two ASN.1 types by tag number and tag class. This method returns true, if the two ASN.1 types have the same tag class and the same tag number; otherwise it returns false.

Overrides:

equals in class Object

Parameters:

o - the ASN.1 type to be compared with the actual ASN.1 type

Returns:

true if the two ASN.1 types match, false otherwise

hashCode

public int hashCode()

Returns a hashcode for this object.

Overrides:

hashCode in class Object

Returns:

a hashcode

clone

public Object clone()

Returns a clone ("field by field copy") of this ASN.1 type with same tag and name.

Overrides:

clone in class Object

Returns:

a clone of this ASN.1 type

toString

public String toString()

Returns a String describing this ASN.1 type.

Overrides:

toString in class Object

Returns:

a string specifying tag and name of this ASN.1 type