001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019package org.apache.commons.crypto.utils; 020 021import java.security.NoSuchAlgorithmException; 022 023import javax.crypto.NoSuchPaddingException; 024 025/** 026 * Transformation algorithm, mode and padding, in the format "Algorithm/Mode/Padding", for example "AES/CBC/NoPadding". 027 * 028 * @since 1.2.0 029 */ 030public class Transformation { 031 032 private static final int T_DELIM_PARTS = 3; 033 private static final String T_DELIM_REGEX = "/"; 034 035 /** 036 * Parses a transformation. 037 * 038 * @param transformation current transformation 039 * @return the Transformation 040 * @throws NoSuchAlgorithmException if the algorithm is not supported 041 * @throws NoSuchPaddingException Thrown when the padding is unsupported. 042 */ 043 public static Transformation parse(final String transformation) throws NoSuchAlgorithmException, NoSuchPaddingException { 044 if (transformation == null) { 045 throw new NoSuchAlgorithmException("No transformation given."); 046 } 047 048 // 049 // Array containing the components of a Cipher transformation: index 0: 050 // algorithm (e.g., AES) index 1: mode (e.g., CTR) index 2: padding (e.g., 051 // NoPadding) 052 // 053 final String[] parts = transformation.split(T_DELIM_REGEX, T_DELIM_PARTS + 1); 054 if (parts.length != T_DELIM_PARTS) { 055 throw new NoSuchAlgorithmException("Invalid transformation format: " + transformation); 056 } 057 return new Transformation(parts[0], parts[1], parts[2]); 058 } 059 060 private final String algorithm; 061 private final String mode; 062 private final Padding padding; 063 064 /** 065 * Constructs a new instance. 066 * 067 * @param algorithm the algorithm name 068 * @param mode the mode name 069 * @param padding the padding name 070 */ 071 private Transformation(final String algorithm, final String mode, final Padding padding) { 072 this.algorithm = algorithm; 073 this.mode = mode; 074 this.padding = padding; 075 } 076 077 /** 078 * Constructs a new instance. 079 * 080 * @param algorithm the algorithm name 081 * @param mode the mode name 082 * @param padding the padding name 083 * @throws NoSuchPaddingException Thrown when the padding is unsupported. 084 */ 085 private Transformation(final String algorithm, final String mode, final String padding) throws NoSuchPaddingException { 086 this(algorithm, mode, Padding.get(padding)); 087 } 088 089 /** 090 * Gets the algorithm. 091 * 092 * @return the algorithm. 093 */ 094 public String getAlgorithm() { 095 return algorithm; 096 } 097 098 /** 099 * Gets the mode. 100 * 101 * @return the mode. 102 */ 103 public String getMode() { 104 return mode; 105 } 106 107 /** 108 * Gets the padding. 109 * 110 * @return the padding. 111 */ 112 public Padding getPadding() { 113 return padding; 114 } 115}