net.sourceforge.jsdp
Class Key

java.lang.Object
  net.sourceforge.jsdp.Key

All Implemented Interfaces:

Serializable, Cloneable, Field

public class Key
extends Object
implements Field

A Key represents an <k=<field value> field contained in a SDP message.

A SDP message may be used to convey encryption keys, if transported over a secure and trusted channel. Key fields has the form: <method>:<key>, but the key value is optional. The following methods are defined:

• k=clear:<encryption key>, the encryption key is included untransformed in the key field
• k=base64:<encoded encryption key>, the encryption key is included in the key field but has been base64 encoded because it includes characters that are prohibited in SDP
• k=uri:<URI to obtain key>, a Universal Resource Identifier as used by WWW clients is included in the key field. The URI refers to the data containing the key, and may require additional authentication before the key can be returned. When a request is made to the given URI, the MIME content-type of the reply specifies the encoding for the key in the reply
• k=prompt, no key is included in this SDP description, but the session or media stream referred to by the key field is encrypted. The user should be prompted for the key when attempting to join the session, and this user-supplied key should then be used to decrypt the media streams

Since:

0.1.2

Version:

1.0

Author:

Claudio Di Vita

See Also:

Serialized Form

Field Summary

static String	BASE64 The base64 encryption method modifier
static String	CLEAR The clear encryption method modifier
protected String	key The encription key
protected String	method The encryption method
static String	PROMPT The prompt encryption method modifier
static String	URI The uri encryption method modifier

Fields inherited from interface net.sourceforge.jsdp.Field

ATTRIBUTE_FIELD, BANDWITH_FIELD, CONNECTION_FIELD, EMAIL_FIELD, END_OF_FIELD, INFORMATION_FIELD, KEY_FIELD, MEDIA_FIELD, ORIGIN_FIELD, PHONE_FIELD, REPEAT_TIME_FIELD, SESSION_NAME_FIELD, TIME_FIELD, TIMEZONE_FIELD, URI_FIELD, VERSION_FIELD

Constructor Summary

protected	Key() Creates a new Key.
	Key(String method, String key) Creates a new Key.

Method Summary

Object	clone() Returns a clone of this field.
String	getKey() Returns the encryption key.
String	getMethod() Returns the encryption method.
char	getType() Returns the type character for the field.
boolean	hasKey() Determines if the method has an associated key.
static Key	parse(String field) Parse an input string and constructs the equivalent key field.
void	setKey(String key) Sets the encryption key.
void	setMethod(String method) Sets the encryption method.
String	toString() Returns a string representation of the field.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

BASE64

public static final String BASE64

The base64 encryption method modifier

See Also:

Constant Field Values

CLEAR

public static final String CLEAR

The clear encryption method modifier

See Also:

Constant Field Values

PROMPT

public static final String PROMPT

The prompt encryption method modifier

See Also:

Constant Field Values

URI

public static final String URI

The uri encryption method modifier

See Also:

Constant Field Values

method

protected String method

The encryption method

key

protected String key

The encription key

Constructor Detail

Key

protected Key()

Creates a new Key.

Key

public Key(String method,
           String key)
    throws SDPException

Creates a new Key.

Parameters:

method - the encryption method

key - the encryption key

Throws:

SDPException - if the encryption method is not allowed, or the encryption key is not valid for the specified method

Method Detail

parse

public static Key parse(String field)
                 throws SDPParseException

Parse an input string and constructs the equivalent key field.

Parameters:

field - the string to parse

Returns:

a new Key instance

Throws:

SDPParseException - if an error occurs while parsing

clone

public Object clone()

Returns a clone of this field.

Specified by:

clone in interface Field

Overrides:

clone in class Object

Returns:

a clone of this field

getKey

public String getKey()

Returns the encryption key.

Returns:

the encryption key.

getMethod

public String getMethod()

Returns the encryption method.

Returns:

the encryption method

getType

public char getType()

Returns the type character for the field.

Specified by:

getType in interface Field

Returns:

the field type character: k

hasKey

public boolean hasKey()

Determines if the method has an associated key.

Returns:

true if the method has an associated key, false otherwise

setKey

public void setKey(String key)
            throws SDPException

Sets the encryption key.

Parameters:

key - the encryption key to set

Throws:

SDPException - if the key is not valid

setMethod

public void setMethod(String method)
               throws SDPException

Sets the encryption method.

Parameters:

method - the encryption method to set

Throws:

SDPException - if the method is not allowed or null

toString

public String toString()

Returns a string representation of the field. The representation has one the following forms:

• k=<method>
• k=<method>:<key>

Specified by:

toString in interface Field

Overrides:

toString in class Object

Returns:

the string representation of the field