org.apache.nifi.processors.aws.s3.encryption.ClientSideCMKEncryptionStrategy.java Source code

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Here is the source code for org.apache.nifi.processors.aws.s3.encryption.ClientSideCMKEncryptionStrategy.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License 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 org.apache.nifi.processors.aws.s3.encryption;

import com.amazonaws.ClientConfiguration;
import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.AmazonS3EncryptionClient;
import com.amazonaws.services.s3.model.CryptoConfiguration;
import com.amazonaws.services.s3.model.EncryptionMaterials;
import com.amazonaws.services.s3.model.StaticEncryptionMaterialsProvider;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.StringUtils;
import org.apache.nifi.components.ValidationResult;

import javax.crypto.spec.SecretKeySpec;

/**
 * This strategy uses a client master key to perform client-side encryption.   Use this strategy when you want the client to perform the encryption,
 * (thus incurring the cost of processing) and when you want to manage the key material yourself.
 *
 * See https://docs.aws.amazon.com/AmazonS3/latest/dev/UsingClientSideEncryption.html#client-side-encryption-client-side-master-key-intro
 *
 */
public class ClientSideCMKEncryptionStrategy implements S3EncryptionStrategy {
    /**
     * Create an encryption client.
     *
     * @param credentialsProvider AWS credentials provider.
     * @param clientConfiguration Client configuration
     * @param region AWS region
     * @param keyIdOrMaterial client master key, always base64 encoded
     * @return AWS S3 client
     */
    @Override
    public AmazonS3Client createEncryptionClient(AWSCredentialsProvider credentialsProvider,
            ClientConfiguration clientConfiguration, String region, String keyIdOrMaterial)
            throws SecurityException {
        if (!validateKey(keyIdOrMaterial).isValid()) {
            throw new SecurityException("Invalid client key; ensure key material is base64 encoded.");
        }

        byte[] keyMaterial = Base64.decodeBase64(keyIdOrMaterial);
        SecretKeySpec symmetricKey = new SecretKeySpec(keyMaterial, "AES");
        StaticEncryptionMaterialsProvider encryptionMaterialsProvider = new StaticEncryptionMaterialsProvider(
                new EncryptionMaterials(symmetricKey));
        boolean haveRegion = StringUtils.isNotBlank(region);
        CryptoConfiguration cryptoConfig = new CryptoConfiguration();
        Region awsRegion = null;

        if (haveRegion) {
            awsRegion = Region.getRegion(Regions.fromName(region));
            cryptoConfig.setAwsKmsRegion(awsRegion);
        }

        AmazonS3EncryptionClient client = new AmazonS3EncryptionClient(credentialsProvider,
                encryptionMaterialsProvider, cryptoConfig);
        if (haveRegion && awsRegion != null) {
            client.setRegion(awsRegion);
        }

        return client;
    }

    public ValidationResult validateKey(String keyValue) {
        if (StringUtils.isBlank(keyValue) || !Base64.isBase64(keyValue)) {
            return new ValidationResult.Builder().valid(false).build();
        }

        boolean decoded = false;
        boolean sized = false;
        byte[] keyMaterial;

        try {
            keyMaterial = Base64.decodeBase64(keyValue);
            decoded = true;
            sized = keyMaterial.length == 32 || keyMaterial.length == 24 || keyMaterial.length == 16;
        } catch (final Exception ignored) {
        }

        return new ValidationResult.Builder().valid(decoded && sized).build();
    }
}