org.apache.poi.poifs.crypt.agile

Class AgileDecryptor

java.lang.Object

org.apache.poi.poifs.crypt.Decryptor

org.apache.poi.poifs.crypt.agile.AgileDecryptor

All Implemented Interfaces:

java.lang.Cloneable

public class AgileDecryptor
extends Decryptor
implements java.lang.Cloneable

Decryptor implementation for Agile Encryption

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	AgileDecryptor()

Method Summary

Modifier and Type	Method and Description
AgileDecryptor	clone()
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).
protected static int	getNextBlockSize(int inputLen, int blockSize)
protected static javax.crypto.Cipher	initCipherForBlock(javax.crypto.Cipher existing, int block, boolean lastChunk, EncryptionInfo encryptionInfo, javax.crypto.SecretKey skey, int encryptionMode)
boolean	verifyPassword(java.security.KeyPair keyPair, java.security.cert.X509Certificate x509) instead of a password, it's also possible to decrypt via certificate.
boolean	verifyPassword(java.lang.String password) set decryption password

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

getBlockSizeInBytes, getDataStream, getDataStream, 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

AgileDecryptor

protected AgileDecryptor()

Method Detail

verifyPassword

public boolean verifyPassword(java.lang.String password)
                       throws java.security.GeneralSecurityException

set decryption password

Specified by:

verifyPassword in class Decryptor

Throws:

java.security.GeneralSecurityException

verifyPassword

public boolean verifyPassword(java.security.KeyPair keyPair,
                              java.security.cert.X509Certificate x509)
                       throws java.security.GeneralSecurityException

instead of a password, it's also possible to decrypt via certificate. Warning: this code is experimental and hasn't been validated

Parameters:

keyPair -

x509 -

Returns:

true, when the data can be successfully decrypted with the given private key

Throws:

java.security.GeneralSecurityException

See Also:

Agile encryption with certificates

getNextBlockSize

protected static int getNextBlockSize(int inputLen,
                                      int blockSize)

getDataStream

public java.io.InputStream getDataStream(DirectoryNode dir)
                                  throws java.io.IOException,
                                         java.security.GeneralSecurityException

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

java.security.GeneralSecurityException

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:

length of the encrypted data

initCipherForBlock

protected static javax.crypto.Cipher initCipherForBlock(javax.crypto.Cipher existing,
                                                        int block,
                                                        boolean lastChunk,
                                                        EncryptionInfo encryptionInfo,
                                                        javax.crypto.SecretKey skey,
                                                        int encryptionMode)
                                                 throws java.security.GeneralSecurityException

Throws:

java.security.GeneralSecurityException

clone

public AgileDecryptor clone()
                     throws java.lang.CloneNotSupportedException

Overrides:

clone in class Decryptor

Throws:

java.lang.CloneNotSupportedException