/*
* 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.hadoop.hbase.security;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.security.Key;
import java.security.KeyException;
import java.security.SecureRandom;
import javax.crypto.spec.SecretKeySpec;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.io.crypto.Cipher;
import org.apache.hadoop.hbase.io.crypto.Encryption;
import org.apache.hadoop.hbase.protobuf.generated.EncryptionProtos;
import org.apache.hadoop.hbase.util.ByteStringer;
import org.apache.hadoop.hbase.util.Bytes;
/**
* Some static utility methods for encryption uses in hbase-client.
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class EncryptionUtil {
static private final SecureRandom RNG = new SecureRandom();
/**
* Protect a key by encrypting it with the secret key of the given subject.
* The configuration must be set up correctly for key alias resolution.
* @param conf configuration
* @param key the raw key bytes
* @param algorithm the algorithm to use with this key material
* @return the encrypted key bytes
* @throws IOException
*/
public static byte[] wrapKey(Configuration conf, byte[] key, String algorithm)
throws IOException {
return wrapKey(conf,
conf.get(HConstants.CRYPTO_MASTERKEY_NAME_CONF_KEY, User.getCurrent().getShortName()),
new SecretKeySpec(key, algorithm));
}
/**
* Protect a key by encrypting it with the secret key of the given subject.
* The configuration must be set up correctly for key alias resolution. Keys
* are always wrapped using AES.
* @param conf configuration
* @param subject subject key alias
* @param key the key
* @return the encrypted key bytes
*/
public static byte[] wrapKey(Configuration conf, String subject, Key key)
throws IOException {
// Wrap the key with AES
Cipher cipher = Encryption.getCipher(conf, "AES");
if (cipher == null) {
throw new RuntimeException("Cipher 'AES' not available");
}
EncryptionProtos.WrappedKey.Builder builder = EncryptionProtos.WrappedKey.newBuilder();
builder.setAlgorithm(key.getAlgorithm());
byte[] iv = null;
if (cipher.getIvLength() > 0) {
iv = new byte[cipher.getIvLength()];
RNG.nextBytes(iv);
builder.setIv(ByteStringer.wrap(iv));
}
byte[] keyBytes = key.getEncoded();
builder.setLength(keyBytes.length);
builder.setHash(ByteStringer.wrap(Encryption.hash128(keyBytes)));
ByteArrayOutputStream out = new ByteArrayOutputStream();
Encryption.encryptWithSubjectKey(out, new ByteArrayInputStream(keyBytes), subject,
conf, cipher, iv);
builder.setData(ByteStringer.wrap(out.toByteArray()));
// Build and return the protobuf message
out.reset();
builder.build().writeDelimitedTo(out);
return out.toByteArray();
}
/**
* Unwrap a key by decrypting it with the secret key of the given subject.
* The configuration must be set up correctly for key alias resolution. Keys
* are always unwrapped using AES.
* @param conf configuration
* @param subject subject key alias
* @param value the encrypted key bytes
* @return the raw key bytes
* @throws IOException
* @throws KeyException
*/
public static Key unwrapKey(Configuration conf, String subject, byte[] value)
throws IOException, KeyException {
EncryptionProtos.WrappedKey wrappedKey = EncryptionProtos.WrappedKey.PARSER
.parseDelimitedFrom(new ByteArrayInputStream(value));
Cipher cipher = Encryption.getCipher(conf, "AES");
if (cipher == null) {
throw new RuntimeException("Algorithm 'AES' not available");
}
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] iv = wrappedKey.hasIv() ? wrappedKey.getIv().toByteArray() : null;
Encryption.decryptWithSubjectKey(out, wrappedKey.getData().newInput(),
wrappedKey.getLength(), subject, conf, cipher, iv);
byte[] keyBytes = out.toByteArray();
if (wrappedKey.hasHash()) {
if (!Bytes.equals(wrappedKey.getHash().toByteArray(), Encryption.hash128(keyBytes))) {
throw new KeyException("Key was not successfully unwrapped");
}
}
return new SecretKeySpec(keyBytes, wrappedKey.getAlgorithm());
}
}