Package com.amazonaws.encryptionsdk

Class CryptoOutputStream<K extends MasterKey<K>>

java.lang.Object

java.io.OutputStream

com.amazonaws.encryptionsdk.CryptoOutputStream<K>

Type Parameters:

K - The type of MasterKeys used to manipulate the data.

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class CryptoOutputStream<K extends MasterKey<K>>
extends OutputStream

A CryptoOutputStream is a subclass of java.io.OutputStream. It performs cryptographic transformation of the bytes passing through it.

The CryptoOutputStream wraps a provided OutputStream object and performs cryptographic transformation of the bytes written to it. The transformed bytes are then written to the wrapped OutputStream. It uses the cryptography handler provided during construction to invoke methods that perform the cryptographic transformations.

In short, writing to the CryptoOutputStream results in those bytes being cryptographically transformed and written to the wrapped OutputStream.

For example, if the crypto handler provides methods for decryption, the CryptoOutputStream will decrypt the provided ciphertext bytes and write the plaintext bytes to the wrapped OutputStream.

This class adheres strictly to the semantics, especially the failure semantics, of its ancestor class java.io.OutputStream. This class overrides all the methods specified in its ancestor class.

To instantiate an instance of this class, please see AwsCrypto.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this output stream and releases any system resources associated with this stream.
CryptoResult<CryptoOutputStream<K>,K>	getCryptoResult()	Returns the result of the cryptographic operations including associate metadata.
void	setMaxInputLength(long size)	Sets an upper bound on the size of the input data.
void	write(byte[] b)	void
write(byte[] b, int off, int len)	void	write(int b)

Methods inherited from class java.io.OutputStream

flush, nullOutputStream

Methods inherited from class java.lang.Object

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

Method Details

write

public void write(byte[] b)
           throws IllegalArgumentException,
IOException,
BadCiphertextException

Overrides:

write in class OutputStream

Throws:

BadCiphertextException - This is thrown only during decryption if b contains invalid or corrupt ciphertext.

IllegalArgumentException

IOException

write

public void write(byte[] b,
 int off,
 int len)
           throws IllegalArgumentException,
IOException,
BadCiphertextException

Overrides:

write in class OutputStream

Throws:

BadCiphertextException - This is thrown only during decryption if b contains invalid or corrupt ciphertext.

IllegalArgumentException

IOException

write

public void write(int b)
           throws IOException,
BadCiphertextException

Specified by:

write in class OutputStream

Throws:

BadCiphertextException - This is thrown only during decryption if b contains invalid or corrupt ciphertext.

IOException

close

public void close()
           throws IOException,
BadCiphertextException

Closes this output stream and releases any system resources associated with this stream.

This method writes any final bytes to the underlying stream that complete the cyptographic transformation of the written bytes. It also calls close on the wrapped OutputStream.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs.

BadCiphertextException - This is thrown only during decryption if b contains invalid or corrupt ciphertext.

setMaxInputLength

public void setMaxInputLength(long size)

Sets an upper bound on the size of the input data. This method should be called before writing any data to the stream. If this method is not called prior to writing data, performance may be reduced (notably, it will not be possible to cache data keys when encrypting).

Among other things, this size is used to enforce limits configured on the CachingCryptoMaterialsManager.

If the size set here is exceeded, an exception will be thrown, and the encyption or decryption will fail.

If this method is called multiple times, the smallest bound will be used.

Parameters:

size - Maximum input size.

getCryptoResult

public CryptoResult<CryptoOutputStream<K>,K> getCryptoResult()

Returns the result of the cryptographic operations including associate metadata.