Package org.apache.poi.poifs.crypt.standard

Class StandardDecryptor

java.lang.Object

org.apache.poi.poifs.crypt.Decryptor

org.apache.poi.poifs.crypt.standard.StandardDecryptor

All Implemented Interfaces:

GenericRecord

public class StandardDecryptor
extends Decryptor

Field Summary

Fields inherited from class org.apache.poi.poifs.crypt.Decryptor

DEFAULT_PASSWORD, DEFAULT_POIFS_ENTRY, encryptionInfo

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	StandardDecryptor()
protected	StandardDecryptor(StandardDecryptor other)

Method Summary

Modifier and Type	Method	Description
StandardDecryptor	copy()
protected static byte[]	fillAndXor(byte[] hash, byte fillByte)
protected static SecretKey	generateSecretKey(String password, EncryptionVerifier ver, int keySize)
InputStream	getDataStream(DirectoryNode dir)	Return a stream with decrypted data.
long	getLength()	Returns the length of the encrypted data that can be safely read with Decryptor.getDataStream(org.apache.poi.poifs.filesystem.DirectoryNode).
boolean	verifyPassword(String password)

Methods inherited from class org.apache.poi.poifs.crypt.Decryptor

getBlockSizeInBytes, getDataStream, getDataStream, getEncryptionInfo, getGenericProperties, getInstance, getIntegrityHmacKey, getIntegrityHmacValue, getKeySizeInBytes, getSecretKey, getVerifier, initCipherForBlock, setChunkSize, setEncryptionInfo, setIntegrityHmacKey, setIntegrityHmacValue, setSecretKey, setVerifier

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.poi.common.usermodel.GenericRecord

getGenericChildren, getGenericRecordType

Constructor Detail

StandardDecryptor

protected StandardDecryptor()

StandardDecryptor

protected StandardDecryptor(StandardDecryptor other)

Method Detail

verifyPassword

public boolean verifyPassword(String password)

Specified by:

verifyPassword in class Decryptor

generateSecretKey

protected static SecretKey generateSecretKey(String password,
                                             EncryptionVerifier ver,
                                             int keySize)

fillAndXor

protected static byte[] fillAndXor(byte[] hash,
                                   byte fillByte)

getDataStream

public InputStream getDataStream(DirectoryNode dir)
                          throws IOException

Description copied from class: Decryptor

Return a stream with decrypted data.

Use Decryptor.getLength() to get the size of that data that can be safely read from the stream. Just reading to the end of the input stream is not sufficient because there are normally padding bytes that must be discarded

Specified by:

getDataStream in class Decryptor

Parameters:

dir - the node to read from

Returns:

decrypted stream

Throws:

IOException

getLength

public long getLength()

Description copied from class: Decryptor

Returns the length of the encrypted data that can be safely read with Decryptor.getDataStream(org.apache.poi.poifs.filesystem.DirectoryNode). Just reading to the end of the input stream is not sufficient because there are normally padding bytes that must be discarded

The length variable is initialized in Decryptor.getDataStream(org.apache.poi.poifs.filesystem.DirectoryNode), an attempt to call getLength() prior to getDataStream() will result in IllegalStateException.

Specified by:

getLength in class Decryptor

Returns:

the length of the stream returned by getDataStream(DirectoryNode)

copy

public StandardDecryptor copy()

Specified by:

copy in class Decryptor