iaik.cms

Class CompressedData

java.lang.Object

iaik.cms.CompressedDataStream

iaik.cms.CompressedData

All Implemented Interfaces:

Content, ContentStream

public class CompressedData
extends CompressedDataStream
implements Content

Field Summary

Fields inherited from class iaik.cms.CompressedDataStream

contentType, DEFAULT_BLOCKSIZE, EXPLICIT, IMPLICIT, m_blockSize, m_compressionAlgorithm, m_encapContentType, m_inputStream, m_version

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CompressedData() Default constructor for dynamic object creation in ContentInfo.
	CompressedData(byte[] content, AlgorithmID algorithmid, int mode) Creates a new CompressedData object where the content to be compressed is read from the supplied byte array using the Algorithm specified by the AlgorithmID.
	CompressedData(java.io.InputStream inputstream) Creates a new CompressedData where the DER encoded data is read from the given InputStream.
	CompressedData(ObjectID objectid, byte[] data, AlgorithmID algorithmid, int mode) Creates a new CompressedData object where the content to be compressed is read from the supplied byte array using the Algorithm specified by the AlgorithmID.

Method Summary

Modifier and Type	Method and Description
void	decode(ASN1Object asn1object) Decodes the given CompressedData ASN1 object.
byte[]	getContent() Returns the content as byte array.
byte[]	getEncoded() Returns the DER encoding of this CompressedData in a byte array.
java.io.InputStream	getInputStream() This method will return an InputStream which can be used to read the compressed or decompressed content.
void	setContent(byte[] content) Sets the content to be compressed/decompressed.
protected ASN1Object	toASN1Object(int blocksize) Returns this CompressedData as ASN1Object where a constructed OCTET STRING is used for encoding the encrypted content.

Methods inherited from class iaik.cms.CompressedDataStream

decode, getBlockSize, getCompressionAlgorithm, getCompressionProvider, getContentType, getEncapsulatedContentInfoStream, getEncapsulatedContentType, getMode, getVersion, setBlockSize, setCompressionProvider, setInputStream, toASN1Object, toString, toString, writeTo, writeTo

Methods inherited from class java.lang.Object

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

Methods inherited from interface iaik.cms.ContentStream

decode, getBlockSize, getContentType, setBlockSize, toASN1Object, toString

Constructor Detail

CompressedData

public CompressedData(byte[] content,
                      AlgorithmID algorithmid,
                      int mode)
               throws java.io.IOException,
                      java.security.NoSuchAlgorithmException

Creates a new CompressedData object where the content to be compressed is read from the supplied byte array using the Algorithm specified by the AlgorithmID. The mode specifies whether to include the compressed (CompressedData.IMPLICIT) or not include the compressed data (CompressedData.EXPLICIT)

Parameters:

content - the byte array containing the data to compress

algorithmid - the algorithm used to compress the data

mode - the mode CompressedData.IMPLICIT (to include data) or CompressedData.EXPLICIT (to not include the data).

Throws:

java.io.IOException - if an I/O error occurs

java.security.NoSuchAlgorithmException - if algorithm not available

CompressedData

public CompressedData(java.io.InputStream inputstream)
               throws CMSParsingException,
                      java.io.IOException

Creates a new CompressedData where the DER encoded data is read from the given InputStream. The given input stream supplies the DER encoding of an already existing CMS CompressedData object.

Parameters:

inputstream - the InputStream holding a DER encoded CMS CompressedData object

Throws:

java.io.IOException - if an I/O error occurs during reading from the InputStream

CMSParsingException - if an error occurs while parsing the object

CompressedData

public CompressedData(ObjectID objectid,
                      byte[] data,
                      AlgorithmID algorithmid,
                      int mode)
               throws java.io.IOException,
                      java.security.NoSuchAlgorithmException

Creates a new CompressedData object where the content to be compressed is read from the supplied byte array using the Algorithm specified by the AlgorithmID. The mode specifies whether to include the compressed (CompressedData.IMPLICIT) or not include the compressed data (CompressedData.EXPLICIT)
The content type is set to CMS Data.

Parameters:

objectid - the content type of the data to be compressed

data - the byte array containing the data to compress

algorithmid - the algorithm used to compress the data

mode - the mode CompressedData.IMPLICIT (to include data) or CompressedData.EXPLICIT (to not include the data).

Throws:

java.io.IOException - if an I/O error occurs

java.security.NoSuchAlgorithmException - if the compression algorithm is not specified

CompressedData

protected CompressedData()

Default constructor for dynamic object creation in ContentInfo.

Method Detail

toASN1Object

protected ASN1Object toASN1Object(int blocksize)
                           throws CMSException

Returns this CompressedData as ASN1Object where a constructed OCTET STRING is used for encoding the encrypted content.

Overrides:

toASN1Object in class CompressedDataStream

Parameters:

blocksize - the block size defining the encoding scheme - and specifying the length of each primitive encoded octet string component, if positive

Returns:

this EncryptedData as ASN1Object

Throws:

CMSException - if the ASN1Object could not be created

setContent

public void setContent(byte[] content)
                throws java.io.IOException,
                       java.security.NoSuchAlgorithmException

Sets the content to be compressed/decompressed. When having created a new CompressedData object and setting the content now this method will the compress the content. When parsing an existing CompressedData from its ASN.1 or DER representation and setting the compressed content now, this method will decompress the compressed content.

Parameters:

content - the raw/compressed content

Throws:

java.security.NoSuchAlgorithmException - if the requested compresesion algorithm is not supported

java.io.IOException - if an I/O error occurs

getInputStream

public java.io.InputStream getInputStream()
                                   throws java.io.IOException,
                                          java.security.NoSuchAlgorithmException

This method will return an InputStream which can be used to read the compressed or decompressed content. When parsing an existing CompressedData from its ASN.1 or DER representation, this method returns the decompressed content. After initially creating the compressed content, it will return the compressed content.

Overrides:

getInputStream in class CompressedDataStream

Returns:

an InputStream for reading the decrypted data

Throws:

java.io.IOException - if an I/O error occurs

java.security.NoSuchAlgorithmException - if the requested compresesion algorithm is not supported

getEncoded

public byte[] getEncoded()
                  throws CMSException

Returns the DER encoding of this CompressedData in a byte array.

If the blockSize value of the inherent EncryptedContentInfostructure has been set to a positive value, the encrypted content is encoded as indefinite constructed octet string being composed of a certain number of definite primitive encoded octet strings of blockSize length. If no - or a not-positive - blockSize value has been specified whole the encrypted content will be encoded as definite primitive octet string.

Returns:

a byte array holding the DER encoding of this EncryptedData

Throws:

CMSException - if an error occurs during the encoding procedure

getContent

public byte[] getContent()
                  throws java.io.IOException,
                         java.security.NoSuchAlgorithmException

Returns the content as byte array.

The returned content depends on whether creating a new CompressedData or parsing an existing one:

• When creating a new CompressedData:
  If the content yet has not been compressed, the plain content is returned
• When parsing an existing CompressedData:
  If the content yet has not been compressed, the compressed content is returned

Returns:

a byte array holding the content

Throws:

java.io.IOException - if an I/O error occurs

java.security.NoSuchAlgorithmException

decode

public void decode(ASN1Object asn1object)
            throws CMSParsingException

Decodes the given CompressedData ASN1 object.

Specified by:

decode in interface Content

Parameters:

asn1object - the ASN1Object representing an already exisiting CompressedData object

Throws:

CMSParsingException - if an error occurs when parsing the given ASN1Object