com.amazonaws.encryptionsdk.MasterKeyProvider Maven / Gradle / Ivy
/*
* Copyright 2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except
* in compliance with the License. A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
*/
package com.amazonaws.encryptionsdk;
import com.amazonaws.encryptionsdk.exception.AwsCryptoException;
import com.amazonaws.encryptionsdk.exception.CannotUnwrapDataKeyException;
import com.amazonaws.encryptionsdk.exception.NoSuchMasterKeyException;
import com.amazonaws.encryptionsdk.exception.UnsupportedProviderException;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
/**
* Represents the logic necessary to select and construct {@link MasterKey}s for encrypting and
* decrypting messages. This is an abstract class.
*
* @param the type of {@link MasterKey} returned by this provider
*/
public abstract class MasterKeyProvider> {
/** ProviderId used by this instance when no other is specified. */
public abstract String getDefaultProviderId();
/**
* Returns true if this MasterKeyProvider can provide keys from the specified @{code provider}.
*
* @param provider
* @return
*/
public boolean canProvide(final String provider) {
return getDefaultProviderId().equals(provider);
}
/**
* Equivalent to calling {@link #getMasterKey(String, String)} using {@link
* #getDefaultProviderId()} as the provider.
*/
public K getMasterKey(final String keyId)
throws UnsupportedProviderException, NoSuchMasterKeyException {
return getMasterKey(getDefaultProviderId(), keyId);
}
/**
* Returns the specified {@link MasterKey} if possible.
*
* @param provider
* @param keyId
* @return
* @throws UnsupportedProviderException if this object cannot return {@link MasterKey}s associated
* with the given provider
* @throws NoSuchMasterKeyException if this object cannot find (and thus construct) the {@link
* MasterKey} associated with {@code keyId}
*/
public abstract K getMasterKey(String provider, String keyId)
throws UnsupportedProviderException, NoSuchMasterKeyException;
/**
* Returns all {@link MasterKey}s which should be used to protect the plaintext described by
* {@code request}.
*/
public abstract List getMasterKeysForEncryption(MasterKeyRequest request);
/**
* Iterates through {@code encryptedDataKeys} and returns the first one which can be successfully
* decrypted.
*
* @return a DataKey if one can be decrypted, otherwise returns {@code null}
* @throws UnsupportedProviderException if the {@code encryptedDataKey} is associated with an
* unsupported provider
* @throws CannotUnwrapDataKeyException if the {@code encryptedDataKey} cannot be decrypted
*/
public abstract DataKey decryptDataKey(
CryptoAlgorithm algorithm,
Collection encryptedDataKeys,
Map encryptionContext)
throws UnsupportedProviderException, AwsCryptoException;
protected AwsCryptoException buildCannotDecryptDksException() {
return buildCannotDecryptDksException(Collections.emptyList());
}
protected AwsCryptoException buildCannotDecryptDksException(Throwable t) {
return buildCannotDecryptDksException(Collections.singletonList(t));
}
protected AwsCryptoException buildCannotDecryptDksException(List t) {
if (t == null || t.isEmpty()) {
return new CannotUnwrapDataKeyException("Unable to decrypt any data keys");
} else {
final CannotUnwrapDataKeyException ex =
new CannotUnwrapDataKeyException("Unable to decrypt any data keys", t.get(0));
for (final Throwable e : t) {
ex.addSuppressed(e);
}
return ex;
}
}
}