1 /*
2 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package sun.security.util;
27
28 import java.util.HashSet;
29 import java.util.Set;
30 import java.util.Arrays;
31 import java.util.Collection;
32 import java.util.regex.Pattern;
33
34 /**
35 * The class decomposes standard algorithms into sub-elements.
36 */
37 public class AlgorithmDecomposer {
38
39 // '(?<!padd)in': match 'in' but not preceded with 'padd'.
40 private static final Pattern PATTERN =
41 Pattern.compile("with|and|(?<!padd)in", Pattern.CASE_INSENSITIVE);
42
43 private static Set<String> decomposeImpl(String algorithm) {
44 Set<String> elements = new HashSet<>();
45
46 // algorithm/mode/padding
47 String[] transTokens = algorithm.split("/");
48
49 for (String transToken : transTokens) {
50 if (transToken == null || transToken.isEmpty()) {
51 continue;
52 }
53
54 // PBEWith<digest>And<encryption>
55 // PBEWith<prf>And<encryption>
56 // OAEPWith<digest>And<mgf>Padding
57 // <digest>with<encryption>
58 // <digest>with<encryption>and<mgf>
59 // <digest>with<encryption>in<format>
60 String[] tokens = PATTERN.split(transToken);
61
62 for (String token : tokens) {
63 if (token == null || token.isEmpty()) {
64 continue;
65 }
66
67 elements.add(token);
68 }
69 }
70 return elements;
71 }
72
73 /**
74 * Decompose the standard algorithm name into sub-elements.
75 * <p>
76 * For example, we need to decompose "SHA1WithRSA" into "SHA1" and "RSA"
77 * so that we can check the "SHA1" and "RSA" algorithm constraints
78 * separately.
79 * <p>
80 * Please override the method if need to support more name pattern.
81 */
82 public Set<String> decompose(String algorithm) {
83 if (algorithm == null || algorithm.length() == 0) {
84 return new HashSet<>();
85 }
86
87 Set<String> elements = decomposeImpl(algorithm);
88
89 // In Java standard algorithm name specification, for different
90 // purpose, the SHA-1 and SHA-2 algorithm names are different. For
91 // example, for MessageDigest, the standard name is "SHA-256", while
92 // for Signature, the digest algorithm component is "SHA256" for
93 // signature algorithm "SHA256withRSA". So we need to check both
94 // "SHA-256" and "SHA256" to make the right constraint checking.
95
96 // handle special name: SHA-1 and SHA1
97 if (elements.contains("SHA1") && !elements.contains("SHA-1")) {
98 elements.add("SHA-1");
99 }
100 if (elements.contains("SHA-1") && !elements.contains("SHA1")) {
101 elements.add("SHA1");
102 }
103
104 // handle special name: SHA-224 and SHA224
105 if (elements.contains("SHA224") && !elements.contains("SHA-224")) {
106 elements.add("SHA-224");
107 }
108 if (elements.contains("SHA-224") && !elements.contains("SHA224")) {
109 elements.add("SHA224");
110 }
111
112 // handle special name: SHA-256 and SHA256
113 if (elements.contains("SHA256") && !elements.contains("SHA-256")) {
114 elements.add("SHA-256");
115 }
116 if (elements.contains("SHA-256") && !elements.contains("SHA256")) {
117 elements.add("SHA256");
118 }
119
120 // handle special name: SHA-384 and SHA384
121 if (elements.contains("SHA384") && !elements.contains("SHA-384")) {
122 elements.add("SHA-384");
123 }
124 if (elements.contains("SHA-384") && !elements.contains("SHA384")) {
125 elements.add("SHA384");
126 }
127
128 // handle special name: SHA-512 and SHA512
129 if (elements.contains("SHA512") && !elements.contains("SHA-512")) {
130 elements.add("SHA-512");
131 }
132 if (elements.contains("SHA-512") && !elements.contains("SHA512")) {
133 elements.add("SHA512");
134 }
135
136 return elements;
137 }
138
139 /**
140 * Get aliases of the specified algorithm.
141 *
142 * May support more algorithms in the future.
143 */
144 public static Collection<String> getAliases(String algorithm) {
145 String[] aliases;
146 if (algorithm.equalsIgnoreCase("DH") ||
147 algorithm.equalsIgnoreCase("DiffieHellman")) {
148 aliases = new String[] {"DH", "DiffieHellman"};
149 } else {
150 aliases = new String[] {algorithm};
151 }
152
153 return Arrays.asList(aliases);
154 }
155
156 private static void hasLoop(Set<String> elements, String find, String replace) {
157 if (elements.contains(find)) {
158 if (!elements.contains(replace)) {
159 elements.add(replace);
160 }
161 elements.remove(find);
162 }
163 }
164
165 /*
166 * This decomposes a standard name into sub-elements with a consistent
167 * message digest algorithm name to avoid overly complicated checking.
168 */
169 public static Set<String> decomposeOneHash(String algorithm) {
170 if (algorithm == null || algorithm.length() == 0) {
171 return new HashSet<>();
172 }
173
174 Set<String> elements = decomposeImpl(algorithm);
175
176 hasLoop(elements, "SHA-1", "SHA1");
177 hasLoop(elements, "SHA-224", "SHA224");
178 hasLoop(elements, "SHA-256", "SHA256");
179 hasLoop(elements, "SHA-384", "SHA384");
180 hasLoop(elements, "SHA-512", "SHA512");
181
182 return elements;
183 }
184
185 /*
186 * The provided message digest algorithm name will return a consistent
187 * naming scheme.
188 */
189 public static String hashName(String algorithm) {
190 return algorithm.replace("-", "");
191 }
192 }