org.zalando.crypto.aws.kms.KmsDecrypter.java Source code

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Here is the source code for org.zalando.crypto.aws.kms.KmsDecrypter.java

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/**
 * Copyright (C) 2015 Zalando SE (http://tech.zalando.com)
 *
 * Licensed 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.zalando.crypto.aws.kms;

import static com.google.common.base.Strings.isNullOrEmpty;

import java.nio.ByteBuffer;

import org.zalando.crypto.Decrypter;
import org.zalando.crypto.Prefixed;

import com.amazonaws.services.kms.AWSKMS;
import com.amazonaws.services.kms.model.DecryptRequest;
import com.amazonaws.services.kms.model.DecryptResult;
import com.amazonaws.util.Base64;

/**
 * 
 * @author jbellmann
 *
 */
public class KmsDecrypter extends KmsBase implements Decrypter, Prefixed {

    private static final String PREFIX = "aws:kms:";

    private final AWSKMS kms;

    public KmsDecrypter(AWSKMS kms) {
        this.kms = kms;
    }

    @Override
    public String decrypt(String encryptedText) {
        if (isNullOrEmpty(encryptedText)) {
            return EMPTY_STRING;
        } else {

            // Assuming the encryptedText is encoded in Base64
            final ByteBuffer encryptedBytes = ByteBuffer.wrap(Base64.decode(encryptedText.getBytes()));

            final DecryptRequest decryptRequest = new DecryptRequest().withCiphertextBlob(encryptedBytes);

            return extractString(decryptByKms(decryptRequest).getPlaintext());
        }
    }

    protected DecryptResult decryptByKms(DecryptRequest decryptRequest) {
        return kms.decrypt(decryptRequest);
    }

    public String getPrefix() {
        return PREFIX;
    }
}