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PaddingScheme |
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| 1.0;1 |
1 | /* | |
2 | * Licensed to the Apache Software Foundation (ASF) under one | |
3 | * or more contributor license agreements. See the NOTICE file | |
4 | * distributed with this work for additional information | |
5 | * regarding copyright ownership. The ASF licenses this file | |
6 | * to you under the Apache License, Version 2.0 (the | |
7 | * "License"); you may not use this file except in compliance | |
8 | * with the License. You may obtain a copy of the License at | |
9 | * | |
10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
11 | * | |
12 | * Unless required by applicable law or agreed to in writing, | |
13 | * software distributed under the License is distributed on an | |
14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
15 | * KIND, either express or implied. See the License for the | |
16 | * specific language governing permissions and limitations | |
17 | * under the License. | |
18 | */ | |
19 | package org.apache.shiro.crypto; | |
20 | ||
21 | /** | |
22 | * A {@code CipherPaddingScheme} represents well-known | |
23 | * <a href="http://en.wikipedia.org/wiki/Padding_(cryptography)">padding schemes</a> supported by JPA providers in a | |
24 | * type-safe manner. | |
25 | * <p/> | |
26 | * When encrypted data is transferred, it is usually desirable to ensure that all 'chunks' transferred are a fixed-length: | |
27 | * different length blocks might give cryptanalysts clues about what the data might be, among other reasons. Of course | |
28 | * not all data will convert to neat fixed-length blocks, so padding schemes are used to 'fill in' (pad) any remaining | |
29 | * space with unintelligible data. | |
30 | * <p/> | |
31 | * Padding schemes can be used in both asymmetric key ciphers as well as symmetric key ciphers (e.g. block ciphers). | |
32 | * Block-ciphers especially regularly use padding schemes as they are based on the notion of fixed-length block sizes. | |
33 | * | |
34 | * @see <a href="http://en.wikipedia.org/wiki/Padding_(cryptography)">Wikipedia: Cryptographic Padding</a> | |
35 | * @since 1.0 | |
36 | */ | |
37 | 1 | public enum PaddingScheme { |
38 | ||
39 | /** | |
40 | * No padding. Useful when the block size is 8 bits for block cipher streaming operations. (Because | |
41 | * a byte is the most primitive block size, there is nothing to pad). | |
42 | */ | |
43 | 1 | NONE("NoPadding"), |
44 | ||
45 | /** | |
46 | * Padding scheme as defined in the W3C's "XML Encryption Syntax and Processing" document, | |
47 | * <a href="http://www.w3.org/TR/xmlenc-core/#sec-Alg-Block">Section 5.2 - Block Encryption Algorithms</a>. | |
48 | */ | |
49 | 1 | ISO10126("ISO10126Padding"), |
50 | ||
51 | /** | |
52 | * Optimal Asymmetric Encryption Padding defined in RSA's <a href="http://en.wikipedia.org/wiki/PKCS1">PKSC#1 | |
53 | * standard</a> (aka <a href="http://tools.ietf.org/html/rfc3447">RFC 3447</a>). | |
54 | * <p/> | |
55 | * <b>NOTE:</b> using this padding requires initializing {@link javax.crypto.Cipher Cipher} instances with a | |
56 | * {@link javax.crypto.spec.OAEPParameterSpec OAEPParameterSpec} object which provides the 1) message digest and | |
57 | * 2) mask generation function to use for the scheme. | |
58 | * <h3>Convenient Alternatives</h3> | |
59 | * While using this scheme enables you full customization of the message digest + mask generation function | |
60 | * combination, it does require the extra burden of providing your own {@code OAEPParameterSpec} object. This is | |
61 | * often unnecessary, because most combinations are fairly standard. These common combinations are pre-defined | |
62 | * in this enum in the {@code OAEP}* variants. | |
63 | * <p/> | |
64 | * If you find that these common combinations still do not meet your needs, then you will need to | |
65 | * specify your own message digest and mask generation function, either as an {@code OAEPParameterSpec} object | |
66 | * during Cipher initialization or, maybe more easily, in the scheme name directly. If you want to use scheme name | |
67 | * approach, the name format is specified in the | |
68 | * <a href="http://java.sun.com/javase/6/docs/technotes/guides/security/StandardNames.html">Standard Names</a> | |
69 | * document in the <code>Cipher Algorithm Padding</code> section. | |
70 | * | |
71 | * @see #OAEPWithMd5AndMgf1 | |
72 | * @see #OAEPWithSha1AndMgf1 | |
73 | * @see #OAEPWithSha256AndMgf1 | |
74 | * @see #OAEPWithSha384AndMgf1 | |
75 | * @see #OAEPWithSha512AndMgf1 | |
76 | */ | |
77 | 1 | OAEP("OAEPPadding"), |
78 | ||
79 | /** | |
80 | * Optimal Asymmetric Encryption Padding with {@code MD5} message digest and {@code MGF1} mask generation function. | |
81 | * <p/> | |
82 | * This is a convenient pre-defined OAEP padding scheme that embeds the message digest and mask generation function. | |
83 | * When using this padding scheme, there is no need to init the {@code Cipher} instance with an | |
84 | * {@link javax.crypto.spec.OAEPParameterSpec OAEPParameterSpec} object, as it is already 'built in' to the scheme | |
85 | * name (unlike the {@link #OAEP OAEP} scheme, which requires a bit more work). | |
86 | */ | |
87 | 1 | OAEPWithMd5AndMgf1("OAEPWithMD5AndMGF1Padding"), |
88 | ||
89 | /** | |
90 | * Optimal Asymmetric Encryption Padding with {@code SHA-1} message digest and {@code MGF1} mask generation function. | |
91 | * <p/> | |
92 | * This is a convenient pre-defined OAEP padding scheme that embeds the message digest and mask generation function. | |
93 | * When using this padding scheme, there is no need to init the {@code Cipher} instance with an | |
94 | * {@link javax.crypto.spec.OAEPParameterSpec OAEPParameterSpec} object, as it is already 'built in' to the scheme | |
95 | * name (unlike the {@link #OAEP OAEP} scheme, which requires a bit more work). | |
96 | */ | |
97 | 1 | OAEPWithSha1AndMgf1("OAEPWithSHA-1AndMGF1Padding"), |
98 | ||
99 | /** | |
100 | * Optimal Asymmetric Encryption Padding with {@code SHA-256} message digest and {@code MGF1} mask generation function. | |
101 | * <p/> | |
102 | * This is a convenient pre-defined OAEP padding scheme that embeds the message digest and mask generation function. | |
103 | * When using this padding scheme, there is no need to init the {@code Cipher} instance with an | |
104 | * {@link javax.crypto.spec.OAEPParameterSpec OAEPParameterSpec} object, as it is already 'built in' to the scheme | |
105 | * name (unlike the {@link #OAEP OAEP} scheme, which requires a bit more work). | |
106 | */ | |
107 | 1 | OAEPWithSha256AndMgf1("OAEPWithSHA-256AndMGF1Padding"), |
108 | ||
109 | /** | |
110 | * Optimal Asymmetric Encryption Padding with {@code SHA-384} message digest and {@code MGF1} mask generation function. | |
111 | * <p/> | |
112 | * This is a convenient pre-defined OAEP padding scheme that embeds the message digest and mask generation function. | |
113 | * When using this padding scheme, there is no need to init the {@code Cipher} instance with an | |
114 | * {@link javax.crypto.spec.OAEPParameterSpec OAEPParameterSpec} object, as it is already 'built in' to the scheme | |
115 | * name (unlike the {@link #OAEP OAEP} scheme, which requires a bit more work). | |
116 | */ | |
117 | 1 | OAEPWithSha384AndMgf1("OAEPWithSHA-384AndMGF1Padding"), |
118 | ||
119 | /** | |
120 | * Optimal Asymmetric Encryption Padding with {@code SHA-512} message digest and {@code MGF1} mask generation function. | |
121 | * <p/> | |
122 | * This is a convenient pre-defined OAEP padding scheme that embeds the message digest and mask generation function. | |
123 | * When using this padding scheme, there is no need to init the {@code Cipher} instance with an | |
124 | * {@link javax.crypto.spec.OAEPParameterSpec OAEPParameterSpec} object, as it is already 'built in' to the scheme | |
125 | * name (unlike the {@link #OAEP OAEP} scheme, which requires a bit more work). | |
126 | */ | |
127 | 1 | OAEPWithSha512AndMgf1("OAEPWithSHA-512AndMGF1Padding"), |
128 | ||
129 | /** | |
130 | * Padding scheme used with the {@code RSA} algorithm defined in RSA's | |
131 | * <a href="http://en.wikipedia.org/wiki/PKCS1">PKSC#1 standard</a> (aka | |
132 | * <a href="http://tools.ietf.org/html/rfc3447">RFC 3447</a>). | |
133 | */ | |
134 | 1 | PKCS1("PKCS1Padding"), |
135 | ||
136 | /** | |
137 | * Padding scheme defined in RSA's <a href="http://www.rsa.com/rsalabs/node.asp?id=2127">Password-Based | |
138 | * Cryptography Standard</a>. | |
139 | */ | |
140 | 1 | PKCS5("PKCS5Padding"), |
141 | ||
142 | /** | |
143 | * Padding scheme defined in the <a href="http://www.mozilla.org/projects/security/pki/nss/ssl/draft302.txt">SSL | |
144 | * 3.0 specification</a>, section <code>5.2.3.2 (CBC block cipher)</code>. | |
145 | */ | |
146 | 1 | SSL3("SSL3Padding"); |
147 | ||
148 | private final String transformationName; | |
149 | ||
150 | 11 | private PaddingScheme(String transformationName) { |
151 | 11 | this.transformationName = transformationName; |
152 | 11 | } |
153 | ||
154 | /** | |
155 | * Returns the actual string name to use when building the {@link javax.crypto.Cipher Cipher} | |
156 | * {@code transformation string}. | |
157 | * | |
158 | * @return the actual string name to use when building the {@link javax.crypto.Cipher Cipher} | |
159 | * {@code transformation string}. | |
160 | * @see javax.crypto.Cipher#getInstance(String) | |
161 | */ | |
162 | public String getTransformationName() { | |
163 | 12 | return this.transformationName; |
164 | } | |
165 | } |