com.amazonaws.encryptionsdk.caching

Class CachingCryptoMaterialsManager

java.lang.Object

com.amazonaws.encryptionsdk.caching.CachingCryptoMaterialsManager

All Implemented Interfaces:

CryptoMaterialsManager

public class CachingCryptoMaterialsManager
extends Object
implements CryptoMaterialsManager

The CachingCryptoMaterialsManager wraps another CryptoMaterialsManager, and caches its results. This helps reduce the number of calls made to the underlying CryptoMaterialsManager and/or MasterKeyProvider, which may help reduce cost and/or improve performance.

The CachingCryptoMaterialsManager helps enforce a number of usage limits on encrypt. Specifically, it limits the number of individual messages encrypted with a particular data key, and the number of plaintext bytes encrypted with the same data key. It also allows you to configure a maximum time-to-live for cache entries.

Note that when performing streaming encryption operations, unless you set the stream size before writing any data using CryptoOutputStream.setMaxInputLength(long) or CryptoInputStream.setMaxInputLength(long), the size of the message will not be known, and to avoid exceeding byte use limits, caching will not be performed.

By default, two different CachingCryptoMaterialsManagers will not share cached entries, even when using the same CryptoMaterialsCache. However, it's possible to make different CachingCryptoMaterialsManagers share the same cached entries by assigning a partition ID to them; all CachingCryptoMaterialsManagers with the same partition ID will share the same cached entries.

Assigning partition IDs manually requires great care; if the backing CryptoMaterialsManagers are not equivalent, having entries cross over between them can result in problems such as encrypting messages to the wrong key, or accidentally bypassing access controls. For this reason we recommend not supplying a partition ID unless required for your use case.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CachingCryptoMaterialsManager.Builder

Method Summary

Modifier and Type	Method and Description
DecryptionMaterials	decryptMaterials(DecryptionMaterialsRequest request)
EncryptionMaterials	getMaterialsForEncrypt(EncryptionMaterialsRequest request) Prepares materials for an encrypt request.
static CachingCryptoMaterialsManager.Builder	newBuilder()

Methods inherited from class java.lang.Object

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

Method Detail

newBuilder

public static CachingCryptoMaterialsManager.Builder newBuilder()

getMaterialsForEncrypt

public EncryptionMaterials getMaterialsForEncrypt(EncryptionMaterialsRequest request)

Description copied from interface: CryptoMaterialsManager

Prepares materials for an encrypt request. The resulting materials result must have a cleartext data key and (if applicable for the crypto algorithm in use) a trailing signature key.

The encryption context returned may be different from the one passed in the materials request, and will be serialized (in cleartext) within the encrypted message.

Specified by:

getMaterialsForEncrypt in interface CryptoMaterialsManager

Returns:

See Also:

EncryptionMaterials, EncryptionMaterialsRequest

decryptMaterials

public DecryptionMaterials decryptMaterials(DecryptionMaterialsRequest request)

Specified by:

decryptMaterials in interface CryptoMaterialsManager