Package javax.crypto

Class SealedObject

java.lang.Object

javax.crypto.SealedObject

All Implemented Interfaces:

Serializable

public class SealedObject
extends Object
implements Serializable

A SealedObject is a wrapper around a serializable object instance and encrypts it using a cryptographic cipher.

Since a SealedObject instance is serializable it can either be stored or transmitted over an insecure channel.

The wrapped object can later be decrypted (unsealed) using the corresponding key and then be deserialized to retrieve the original object. The sealed object itself keeps track of the cipher and corresponding parameters.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected byte[]	encodedParams	The cipher's AlgorithmParameters in encoded format.

Constructor Summary

Constructors

Modifier	Constructor	Description
	SealedObject(Serializable object, Cipher c)	Creates a new SealedObject instance wrapping the specified object and sealing it using the specified cipher.
protected	SealedObject(SealedObject so)	Creates a new SealedObject instance by copying the data from the specified object.

Method Summary

Modifier and Type	Method	Description
String	getAlgorithm()	Returns the algorithm this object was sealed with.
Object	getObject(Key key)	Returns the wrapped object, decrypting it using the specified key.
Object	getObject(Key key, String provider)	Returns the wrapped object, decrypting it using the specified key.
Object	getObject(Cipher c)	Returns the wrapped object, decrypting it using the specified cipher.

Methods inherited from class java.lang.Object

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

Field Details

encodedParams

protected byte[] encodedParams

The cipher's AlgorithmParameters in encoded format. Equivalent to cipher.getParameters().getEncoded(), or null if the cipher did not use any parameters.

Constructor Details

SealedObject

public SealedObject(Serializable object,
Cipher c)
             throws IOException,
IllegalBlockSizeException

Creates a new SealedObject instance wrapping the specified object and sealing it using the specified cipher.

The cipher must be fully initialized.

Parameters:

object - the object to seal, can be null.

c - the cipher to encrypt the object.

Throws:

IOException - if the serialization fails.

IllegalBlockSizeException - if the specified cipher is a block cipher and the length of the serialized data is not a multiple of the ciphers block size.

NullPointerException - if the cipher is null.

SealedObject

protected SealedObject(SealedObject so)

Creates a new SealedObject instance by copying the data from the specified object.

Parameters:

so - the object to copy.

Method Details

getAlgorithm

public final String getAlgorithm()

Returns the algorithm this object was sealed with.

Returns:

the algorithm this object was sealed with.

getObject

public final Object getObject(Key key)
                       throws IOException,
ClassNotFoundException,
NoSuchAlgorithmException,
InvalidKeyException

Returns the wrapped object, decrypting it using the specified key.

Parameters:

key - the key to decrypt the data with.

Returns:

the encapsulated object.

Throws:

IOException - if deserialization fails.

ClassNotFoundException - if deserialization fails.

NoSuchAlgorithmException - if the algorithm to decrypt the data is not available.

InvalidKeyException - if the specified key cannot be used to decrypt the data.

getObject

public final Object getObject(Cipher c)
                       throws IOException,
ClassNotFoundException,
IllegalBlockSizeException,
BadPaddingException

Returns the wrapped object, decrypting it using the specified cipher.

Parameters:

c - the cipher to decrypt the data.

Returns:

the encapsulated object.

Throws:

IOException - if deserialization fails.

ClassNotFoundException - if deserialization fails.

IllegalBlockSizeException - if the specified cipher is a block cipher and the length of the serialized data is not a multiple of the ciphers block size.

BadPaddingException - if the padding of the data does not match the padding scheme.

getObject

public final Object getObject(Key key,
String provider)
                       throws IOException,
ClassNotFoundException,
NoSuchAlgorithmException,
NoSuchProviderException,
InvalidKeyException

Returns the wrapped object, decrypting it using the specified key. The specified provider is used to retrieve the cipher algorithm.

Parameters:

key - the key to decrypt the data.

provider - the name of the provider that provides the cipher algorithm.

Returns:

the encapsulated object.

Throws:

IOException - if deserialization fails.

ClassNotFoundException - if deserialization fails.

NoSuchAlgorithmException - if the algorithm used to decrypt the data is not available.

NoSuchProviderException - if the specified provider is not available.

InvalidKeyException - if the specified key cannot be used to decrypt the data.