org.alfresco.encryption

Class EncryptingOutputStream

java.lang.Object

java.io.OutputStream

org.alfresco.encryption.EncryptingOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

public class EncryptingOutputStream
extends java.io.OutputStream

An output stream that encrypts data to another output stream. A lightweight yet secure hybrid encryption scheme is used. A random symmetric key is generated and encrypted using the receiver's public key. The supplied data is then encrypted using the symmetric key and sent to the underlying stream on a streaming basis. An HMAC checksum is also computed on an ongoing basis and appended to the output when the stream is closed. This class can be used in conjunction with DecryptingInputStream to transport data securely.

Constructor Summary

Constructors

Constructor and Description
EncryptingOutputStream(java.io.OutputStream wrapped, java.security.PublicKey receiverKey, java.security.SecureRandom rand) Constructs an EncryptingOutputStream using default symmetric encryption parameters.
EncryptingOutputStream(java.io.OutputStream wrapped, java.security.PublicKey receiverKey, java.lang.String algorithm, java.security.SecureRandom rand, int strength, java.lang.String mode, java.lang.String padding) Constructs an EncryptingOutputStream.

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
void	flush()
void	write(byte[] b)
void	write(byte[] b, int off, int len)
void	write(int b)

Methods inherited from class java.lang.Object

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

Constructor Detail

EncryptingOutputStream

public EncryptingOutputStream(java.io.OutputStream wrapped,
                      java.security.PublicKey receiverKey,
                      java.security.SecureRandom rand)
                       throws java.io.IOException,
                              java.security.NoSuchAlgorithmException,
                              javax.crypto.NoSuchPaddingException,
                              java.security.InvalidKeyException,
                              javax.crypto.IllegalBlockSizeException,
                              javax.crypto.BadPaddingException

Constructs an EncryptingOutputStream using default symmetric encryption parameters.

Parameters:

wrapped - outputstream to store the encrypted data

receiverKey - the receiver's public key for encrypting the symmetric key

rand - a secure source of randomness

Throws:

java.io.IOException - Signals that an I/O exception has occurred.

java.security.NoSuchAlgorithmException - the no such algorithm exception

javax.crypto.NoSuchPaddingException - the no such padding exception

java.security.InvalidKeyException - the invalid key exception

javax.crypto.BadPaddingException - the bad padding exception

javax.crypto.IllegalBlockSizeException - the illegal block size exception

EncryptingOutputStream

public EncryptingOutputStream(java.io.OutputStream wrapped,
                      java.security.PublicKey receiverKey,
                      java.lang.String algorithm,
                      java.security.SecureRandom rand,
                      int strength,
                      java.lang.String mode,
                      java.lang.String padding)
                       throws java.io.IOException,
                              java.security.NoSuchAlgorithmException,
                              javax.crypto.NoSuchPaddingException,
                              java.security.InvalidKeyException,
                              javax.crypto.IllegalBlockSizeException,
                              javax.crypto.BadPaddingException

Constructs an EncryptingOutputStream.

Parameters:

wrapped - outputstream to store the encrypted data

receiverKey - the receiver's public key for encrypting the symmetric key

algorithm - symmetric encryption algorithm (e.g. "AES")

rand - a secure source of randomness

strength - the key size in bits (e.g. 128)

mode - encryption mode (e.g. "CBC")

padding - padding scheme (e.g. "PKCS5PADDING")

Throws:

java.io.IOException - Signals that an I/O exception has occurred.

java.security.NoSuchAlgorithmException - the no such algorithm exception

javax.crypto.NoSuchPaddingException - the no such padding exception

java.security.InvalidKeyException - the invalid key exception

javax.crypto.BadPaddingException - the bad padding exception

javax.crypto.IllegalBlockSizeException - the illegal block size exception

Method Detail

write

public void write(int b)
           throws java.io.IOException

Specified by:

write in class java.io.OutputStream

Throws:

java.io.IOException

write

public void write(byte[] b)
           throws java.io.IOException

Overrides:

write in class java.io.OutputStream

Throws:

java.io.IOException

write

public void write(byte[] b,
         int off,
         int len)
           throws java.io.IOException

Overrides:

write in class java.io.OutputStream

Throws:

java.io.IOException

flush

public void flush()
           throws java.io.IOException

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.OutputStream

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.OutputStream

Throws:

java.io.IOException