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:

java.lang.Cloneable

public class StandardDecryptor
extends Decryptor
implements java.lang.Cloneable

Field Summary

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

DEFAULT_PASSWORD, DEFAULT_POIFS_ENTRY, encryptionInfo

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	StandardDecryptor()

Method Summary

Modifier and Type	Method and Description
StandardDecryptor	clone()
protected static byte[]	fillAndXor(byte[] hash, byte fillByte)
protected static javax.crypto.SecretKey	generateSecretKey(java.lang.String password, EncryptionVerifier ver, int keySize)
java.io.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(java.lang.String password)

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

StandardDecryptor

protected StandardDecryptor()

Method Detail

verifyPassword

public boolean verifyPassword(java.lang.String password)

Specified by:

verifyPassword in class Decryptor

generateSecretKey

protected static javax.crypto.SecretKey generateSecretKey(java.lang.String password,
                                                          EncryptionVerifier ver,
                                                          int keySize)

fillAndXor

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

getDataStream

public java.io.InputStream getDataStream(DirectoryNode dir)
                                  throws java.io.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:

java.io.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)

clone

public StandardDecryptor clone()
                        throws java.lang.CloneNotSupportedException

Overrides:

clone in class Decryptor

Throws:

java.lang.CloneNotSupportedException