Github user alopresto commented on a diff in the pull request:
https://github.com/apache/nifi/pull/1686#discussion_r112980590
--- Diff:
nifi-commons/nifi-data-provenance-utils/src/main/java/org/apache/nifi/provenance/AESProvenanceEventEncryptor.java
---
@@ -0,0 +1,237 @@
+/*
+ * 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.provenance;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.security.KeyManagementException;
+import java.security.SecureRandom;
+import java.security.Security;
+import java.util.Arrays;
+import java.util.List;
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.SecretKey;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.nifi.security.util.EncryptionMethod;
+import org.apache.nifi.security.util.crypto.AESKeyedCipherProvider;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class AESProvenanceEventEncryptor implements
ProvenanceEventEncryptor {
+ private static final Logger logger =
LoggerFactory.getLogger(AESProvenanceEventEncryptor.class);
+ private static final String ALGORITHM = "AES/GCM/NoPadding";
+ private static final int IV_LENGTH = 16;
+ private static final byte[] EMPTY_IV = new byte[IV_LENGTH];
+ private static final String VERSION = "v1";
+ private static final List<String> SUPPORTED_VERSIONS =
Arrays.asList(VERSION);
+ private static final int MIN_METADATA_LENGTH = IV_LENGTH + 3 + 3; // 3
delimiters and 3 non-zero elements
+ private static final int METADATA_DEFAULT_LENGTH = (20 +
ALGORITHM.length() + IV_LENGTH + VERSION.length()) * 2; // Default to twice the
expected length
+ private static final byte[] SENTINEL = new byte[]{0x01};
+
+ private KeyProvider keyProvider;
+
+ private AESKeyedCipherProvider aesKeyedCipherProvider = new
AESKeyedCipherProvider();
+
+ /**
+ * Initializes the encryptor with a {@link KeyProvider}.
+ *
+ * @param keyProvider the key provider which will be responsible for
accessing keys
+ * @throws KeyManagementException if there is an issue configuring the
key provider
+ */
+ @Override
+ public void initialize(KeyProvider keyProvider) throws
KeyManagementException {
+ this.keyProvider = keyProvider;
+
+ if (this.aesKeyedCipherProvider == null) {
+ this.aesKeyedCipherProvider = new AESKeyedCipherProvider();
+ }
+
+ if (Security.getProvider("BC") == null) {
+ Security.addProvider(new BouncyCastleProvider());
+ }
+ }
+
+ /**
+ * Available for dependency injection to override the default {@link
AESKeyedCipherProvider} if necessary.
+ *
+ * @param cipherProvider the AES cipher provider to use
+ */
+ void setCipherProvider(AESKeyedCipherProvider cipherProvider) {
+ this.aesKeyedCipherProvider = cipherProvider;
+ }
+
+ /**
+ * Encrypts the provided {@link ProvenanceEventRecord}, serialized to
a byte[] by the RecordWriter.
+ *
+ * @param plainRecord the plain record, serialized to a byte[]
+ * @param recordId an identifier for this record (eventId,
generated, etc.)
+ * @param keyId the ID of the key to use
+ * @return the encrypted record
+ * @throws EncryptionException if there is an issue encrypting this
record
+ */
+ @Override
+ public byte[] encrypt(byte[] plainRecord, String recordId, String
keyId) throws EncryptionException {
+ if (plainRecord == null || CryptoUtils.isEmpty(keyId)) {
+ throw new EncryptionException("The provenance record and key
ID cannot be missing");
+ }
+
+ if (keyProvider == null || !keyProvider.keyExists(keyId)) {
+ throw new EncryptionException("The requested key ID is not
available");
+ } else {
+ byte[] ivBytes = new byte[IV_LENGTH];
+ new SecureRandom().nextBytes(ivBytes);
+ try {
+ logger.debug("Encrypting provenance record " + recordId +
" with key ID " + keyId);
+ Cipher cipher = initCipher(EncryptionMethod.AES_GCM,
Cipher.ENCRYPT_MODE, keyProvider.getKey(keyId), ivBytes);
+ ivBytes = cipher.getIV();
+
+ // Perform the actual encryption
+ byte[] cipherBytes = cipher.doFinal(plainRecord);
+
+ // Serialize and concat encryption details fields (keyId,
algo, IV, version, CB length) outside of encryption
+ EncryptionMetadata metadata = new
EncryptionMetadata(keyId, ALGORITHM, ivBytes, VERSION, cipherBytes.length);
+ byte[] serializedEncryptionMetadata =
serializeEncryptionMetadata(metadata);
+
+ // Add the sentinel byte of 0x01
+ logger.debug("Encrypted provenance event record " +
recordId + " with key ID " + keyId);
+ return CryptoUtils.concatByteArrays(SENTINEL,
serializedEncryptionMetadata, cipherBytes);
+ } catch (EncryptionException | BadPaddingException |
IllegalBlockSizeException | IOException | KeyManagementException e) {
+ final String msg = "Encountered an exception encrypting
provenance record " + recordId;
+ logger.error(msg, e);
+ throw new EncryptionException(msg, e);
+ }
+ }
+ }
+
+ private byte[] serializeEncryptionMetadata(EncryptionMetadata
metadata) throws IOException {
+ final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+ ObjectOutputStream outputStream = new ObjectOutputStream(baos);
+ outputStream.writeObject(metadata);
+ outputStream.close();
+ return baos.toByteArray();
+ }
+
+ private Cipher initCipher(EncryptionMethod method, int mode, SecretKey
key, byte[] ivBytes) throws EncryptionException {
+ try {
+ if (method == null || key == null || ivBytes == null) {
+ throw new IllegalArgumentException("Missing critical
information");
+ }
+ return aesKeyedCipherProvider.getCipher(method, key, ivBytes,
mode == Cipher.ENCRYPT_MODE);
+ } catch (Exception e) {
+ logger.error("Encountered an exception initializing the
cipher", e);
+ throw new EncryptionException(e);
+ }
+ }
+
+ /**
+ * Decrypts the provided byte[] (an encrypted record with accompanying
metadata).
+ *
+ * @param encryptedRecord the encrypted record in byte[] form
+ * @param recordId an identifier for this record (eventId,
generated, etc.)
+ * @return the decrypted record
+ * @throws EncryptionException if there is an issue decrypting this
record
+ */
+ @Override
+ public byte[] decrypt(byte[] encryptedRecord, String recordId) throws
EncryptionException {
+ if (encryptedRecord == null) {
+ throw new EncryptionException("The encrypted provenance record
cannot be missing");
+ }
+
+ EncryptionMetadata metadata;
+ try {
+ metadata = extractEncryptionMetadata(encryptedRecord);
+ } catch (IOException | ClassNotFoundException e) {
+ final String msg = "Encountered an error reading the
encryption metadata: ";
+ logger.error(msg, e);
+ throw new EncryptionException(msg, e);
+ }
+
+ if (!SUPPORTED_VERSIONS.contains(metadata.version)) {
+ throw new EncryptionException("The event was encrypted with
version " + metadata.version + " which is not in the list of supported versions
" + StringUtils.join(SUPPORTED_VERSIONS, ","));
+ }
+
+ // TODO: Actually use the version to determine schema, etc.
+
+ if (keyProvider == null || !keyProvider.keyExists(metadata.keyId)
|| CryptoUtils.isEmpty(metadata.keyId)) {
+ throw new EncryptionException("The requested key ID " +
metadata.keyId + " is not available");
+ } else {
+ try {
+ logger.debug("Decrypting provenance record " + recordId +
" with key ID " + metadata.keyId);
+ EncryptionMethod method =
EncryptionMethod.forAlgorithm(metadata.algorithm);
+ Cipher cipher = initCipher(method, Cipher.DECRYPT_MODE,
keyProvider.getKey(metadata.keyId), metadata.ivBytes);
+
+ // Strip the metadata away to get just the cipher bytes
+ byte[] cipherBytes = extractCipherBytes(encryptedRecord,
metadata);
+
+ // Perform the actual decryption
+ byte[] plainBytes = cipher.doFinal(cipherBytes);
+
+ logger.debug("Decrypted provenance event record " +
recordId + " with key ID " + metadata.keyId);
+ return plainBytes;
+ } catch (EncryptionException | BadPaddingException |
IllegalBlockSizeException | KeyManagementException e) {
+ final String msg = "Encountered an exception decrypting
provenance record " + recordId;
+ logger.error(msg, e);
+ throw new EncryptionException(msg, e);
+ }
+ }
+ }
+
+ /**
+ * Returns a valid key identifier for this encryptor (valid for
encryption and decryption) or throws an exception if none are available.
+ *
+ * @return the key ID
+ * @throws KeyManagementException if no available key IDs are valid
for both operations
+ */
+ @Override
+ public String getNextKeyId() throws KeyManagementException {
+ if (keyProvider != null) {
+ List<String> availableKeyIds =
keyProvider.getAvailableKeyIds();
+ if (!availableKeyIds.isEmpty()) {
+ return availableKeyIds.get(0);
+ }
+ }
+ throw new KeyManagementException("No available key IDs");
+ }
+
+ private EncryptionMetadata extractEncryptionMetadata(byte[]
encryptedRecord) throws EncryptionException, IOException,
ClassNotFoundException {
+ if (encryptedRecord == null || encryptedRecord.length <
MIN_METADATA_LENGTH) {
+ throw new EncryptionException("The encrypted record is too
short to contain the metadata");
+ }
+
+ // Skip the first byte (SENTINEL) and don't need to copy all the
serialized record
+ byte[] metadataBytes = Arrays.copyOfRange(encryptedRecord, 1,
encryptedRecord.length);
--- End diff --
Good catch.
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