Github user ottobackwards commented on a diff in the pull request: https://github.com/apache/nifi/pull/2980#discussion_r214883268 --- Diff: nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/security/util/crypto/HashService.java --- @@ -0,0 +1,121 @@ +/* + * 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.security.util.crypto; + +import java.nio.charset.Charset; +import java.nio.charset.StandardCharsets; +import org.apache.commons.codec.binary.Hex; +import org.apache.commons.codec.digest.DigestUtils; +import org.bouncycastle.crypto.digests.Blake2bDigest; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * This class provides a generic service for cryptographic hashing. It is used in + * {@link org.apache.nifi.processors.standard.CalculateAttributeHash} and + * {@link org.apache.nifi.processors.standard.HashContent}. + * <p> + * See also: + * * {@link HashAlgorithm} + */ +public class HashService { + private static final Logger logger = LoggerFactory.getLogger(HashService.class); + + /** + * Returns the hex-encoded hash of the specified value. + * + * @param algorithm the hash algorithm to use + * @param value the value to hash (cannot be {@code null} but can be an empty String) + * @param charset the charset to use + * @return the hash value in hex + */ + public static String hashValue(HashAlgorithm algorithm, String value, Charset charset) { + byte[] rawHash = hashValueRaw(algorithm, value, charset); + return Hex.encodeHexString(rawHash); + } + + /** + * Returns the hex-encoded hash of the specified value. The default charset ({@code StandardCharsets.UTF_8}) is used. + * + * @param algorithm the hash algorithm to use + * @param value the value to hash (cannot be {@code null} but can be an empty String) + * @return the hash value in hex + */ + public static String hashValue(HashAlgorithm algorithm, String value) { + return hashValue(algorithm, value, StandardCharsets.UTF_8); + } + + /** + * Returns the raw {@code byte[]} hash of the specified value. + * + * @param algorithm the hash algorithm to use + * @param value the value to hash (cannot be {@code null} but can be an empty String) + * @param charset the charset to use + * @return the hash value in bytes + */ + public static byte[] hashValueRaw(HashAlgorithm algorithm, String value, Charset charset) { + if (value == null) { + throw new IllegalArgumentException("The value cannot be null"); + } + return hashValueRaw(algorithm, value.getBytes(charset)); + } + + /** + * Returns the raw {@code byte[]} hash of the specified value. The default charset ({@code StandardCharsets.UTF_8}) is used. + * + * @param algorithm the hash algorithm to use + * @param value the value to hash (cannot be {@code null} but can be an empty String) + * @return the hash value in bytes + */ + public static byte[] hashValueRaw(HashAlgorithm algorithm, String value) { + return hashValueRaw(algorithm, value, StandardCharsets.UTF_8); + } + + /** + * Returns the raw {@code byte[]} hash of the specified value. + * + * @param algorithm the hash algorithm to use + * @param value the value to hash + * @return the hash value in bytes + */ + public static byte[] hashValueRaw(HashAlgorithm algorithm, byte[] value) { + if (algorithm == null) { + throw new IllegalArgumentException("The hash algorithm cannot be null"); + } + if (value == null) { + throw new IllegalArgumentException("The value cannot be null"); + } + if (algorithm.isBlake2()) { + return blake2Hash(algorithm, value); + } else { + return traditionalHash(algorithm, value); + } + } + --- End diff -- Could we put this functionality in the enum and simplify this class? Having the specialization there?
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