1 |
769 |
jeremybenn |
/* IMac.java --
|
2 |
|
|
Copyright (C) 2001, 2002, 2006 Free Software Foundation, Inc.
|
3 |
|
|
|
4 |
|
|
This file is a part of GNU Classpath.
|
5 |
|
|
|
6 |
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
7 |
|
|
it under the terms of the GNU General Public License as published by
|
8 |
|
|
the Free Software Foundation; either version 2 of the License, or (at
|
9 |
|
|
your option) any later version.
|
10 |
|
|
|
11 |
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
12 |
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
|
|
General Public License for more details.
|
15 |
|
|
|
16 |
|
|
You should have received a copy of the GNU General Public License
|
17 |
|
|
along with GNU Classpath; if not, write to the Free Software
|
18 |
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
|
19 |
|
|
USA
|
20 |
|
|
|
21 |
|
|
Linking this library statically or dynamically with other modules is
|
22 |
|
|
making a combined work based on this library. Thus, the terms and
|
23 |
|
|
conditions of the GNU General Public License cover the whole
|
24 |
|
|
combination.
|
25 |
|
|
|
26 |
|
|
As a special exception, the copyright holders of this library give you
|
27 |
|
|
permission to link this library with independent modules to produce an
|
28 |
|
|
executable, regardless of the license terms of these independent
|
29 |
|
|
modules, and to copy and distribute the resulting executable under
|
30 |
|
|
terms of your choice, provided that you also meet, for each linked
|
31 |
|
|
independent module, the terms and conditions of the license of that
|
32 |
|
|
module. An independent module is a module which is not derived from
|
33 |
|
|
or based on this library. If you modify this library, you may extend
|
34 |
|
|
this exception to your version of the library, but you are not
|
35 |
|
|
obligated to do so. If you do not wish to do so, delete this
|
36 |
|
|
exception statement from your version. */
|
37 |
|
|
|
38 |
|
|
|
39 |
|
|
package gnu.javax.crypto.mac;
|
40 |
|
|
|
41 |
|
|
import java.security.InvalidKeyException;
|
42 |
|
|
import java.util.Map;
|
43 |
|
|
|
44 |
|
|
/**
|
45 |
|
|
* The basic visible methods of any MAC (Message Authentication Code) algorithm.
|
46 |
|
|
* <p>
|
47 |
|
|
* A <i>MAC</i> provides a way to check the integrity of information
|
48 |
|
|
* transmitted over, or stored in, an unreliable medium, based on a secret key.
|
49 |
|
|
* Typically, <i>MAC</i>s are used between two parties, that share a common
|
50 |
|
|
* secret key, in order to validate information transmitted between them.
|
51 |
|
|
* <p>
|
52 |
|
|
* When a <i>MAC</i> algorithm is based on a cryptographic hash function, it is
|
53 |
|
|
* then called to a <i>HMAC</i> (Hashed Message Authentication Code) --see <a
|
54 |
|
|
* href="http://www.ietf.org/rfc/rfc-2104.txt">RFC-2104</a>.
|
55 |
|
|
* <p>
|
56 |
|
|
* Another type of <i>MAC</i> algorithms exist: UMAC or <i>Universal Message
|
57 |
|
|
* Authentication Code</i>, described in <a
|
58 |
|
|
* href="http://www.ietf.org/internet-drafts/draft-krovetz-umac-01.txt">
|
59 |
|
|
* draft-krovetz-umac-01.txt</a>.
|
60 |
|
|
* <p>
|
61 |
|
|
* With <i>UMAC</i>s, the sender and receiver share a common secret key (the
|
62 |
|
|
* <i>MAC</i> key) which determines:
|
63 |
|
|
* <ul>
|
64 |
|
|
* <li>The key for a <i>universal hash function</i>. This hash function is
|
65 |
|
|
* <i>non-cryptographic</i>, in the sense that it does not need to have any
|
66 |
|
|
* cryptographic <i>hardness</i> property. Rather, it needs to satisfy some
|
67 |
|
|
* combinatorial property, which can be proven to hold without relying on
|
68 |
|
|
* unproven hardness assumptions.</li>
|
69 |
|
|
* <li>The key for a <i>pseudorandom function</i>. This is where one needs a
|
70 |
|
|
* cryptographic hardness assumption. The pseudorandom function may be obtained
|
71 |
|
|
* from a <i>block cipher</i> or a <i>cryptographic hash function</i>. </li>
|
72 |
|
|
* </ul>
|
73 |
|
|
* <p>
|
74 |
|
|
* References:
|
75 |
|
|
* <ol>
|
76 |
|
|
* <li><a href="http://www.ietf.org/rfc/rfc-2104.txt">RFC 2104</a>HMAC:
|
77 |
|
|
* Keyed-Hashing for Message Authentication.<br>
|
78 |
|
|
* H. Krawczyk, M. Bellare, and R. Canetti.</li>
|
79 |
|
|
* <li><a href="http://www.ietf.org/internet-drafts/draft-krovetz-umac-01.txt">
|
80 |
|
|
* UMAC</a>: Message Authentication Code using Universal Hashing.<br>
|
81 |
|
|
* T. Krovetz, J. Black, S. Halevi, A. Hevia, H. Krawczyk, and P. Rogaway.</li>
|
82 |
|
|
* </ol>
|
83 |
|
|
*/
|
84 |
|
|
public interface IMac
|
85 |
|
|
{
|
86 |
|
|
/**
|
87 |
|
|
* Property name of the user-supplied key material. The value associated to
|
88 |
|
|
* this property name is taken to be a byte array.
|
89 |
|
|
*/
|
90 |
|
|
String MAC_KEY_MATERIAL = "gnu.crypto.mac.key.material";
|
91 |
|
|
/**
|
92 |
|
|
* Property name of the desired truncated output size in bytes. The value
|
93 |
|
|
* associated to this property name is taken to be an integer. If no value is
|
94 |
|
|
* specified in the attributes map at initialisation time, then all bytes of
|
95 |
|
|
* the underlying hash algorithm's output are emitted.
|
96 |
|
|
* <p>
|
97 |
|
|
* This implementation, follows the recommendation of the <i>RFC 2104</i>
|
98 |
|
|
* authors; specifically:
|
99 |
|
|
* <pre>
|
100 |
|
|
* We recommend that the output length t be not less than half the
|
101 |
|
|
* length of the hash output (to match the birthday attack bound)
|
102 |
|
|
* and not less than 80 bits (a suitable lower bound on the number
|
103 |
|
|
* of bits that need to be predicted by an attacker).
|
104 |
|
|
* </pre>
|
105 |
|
|
*/
|
106 |
|
|
String TRUNCATED_SIZE = "gnu.crypto.mac.truncated.size";
|
107 |
|
|
|
108 |
|
|
/**
|
109 |
|
|
* Returns the canonical name of this algorithm.
|
110 |
|
|
*
|
111 |
|
|
* @return the canonical name of this algorithm.
|
112 |
|
|
*/
|
113 |
|
|
String name();
|
114 |
|
|
|
115 |
|
|
/**
|
116 |
|
|
* Returns the output length in bytes of this <i>MAC</i> algorithm.
|
117 |
|
|
*
|
118 |
|
|
* @return the output length in bytes of this <i>MAC</i> algorithm.
|
119 |
|
|
*/
|
120 |
|
|
int macSize();
|
121 |
|
|
|
122 |
|
|
/**
|
123 |
|
|
* Initialises the algorithm with designated attributes. Permissible names and
|
124 |
|
|
* values are described in the class documentation above.
|
125 |
|
|
*
|
126 |
|
|
* @param attributes a set of name-value pairs that describe the desired
|
127 |
|
|
* future instance behaviour.
|
128 |
|
|
* @exception InvalidKeyException if the key data is invalid.
|
129 |
|
|
* @exception IllegalStateException if the instance is already initialised.
|
130 |
|
|
* @see #MAC_KEY_MATERIAL
|
131 |
|
|
*/
|
132 |
|
|
void init(Map attributes) throws InvalidKeyException, IllegalStateException;
|
133 |
|
|
|
134 |
|
|
/**
|
135 |
|
|
* Continues a <i>MAC</i> operation using the input byte.
|
136 |
|
|
*
|
137 |
|
|
* @param b the input byte to digest.
|
138 |
|
|
*/
|
139 |
|
|
void update(byte b);
|
140 |
|
|
|
141 |
|
|
/**
|
142 |
|
|
* Continues a <i>MAC</i> operation, by filling the buffer, processing data
|
143 |
|
|
* in the algorithm's MAC_SIZE-bit block(s), updating the context and count,
|
144 |
|
|
* and buffering the remaining bytes in buffer for the next operation.
|
145 |
|
|
*
|
146 |
|
|
* @param in the input block.
|
147 |
|
|
* @param offset start of meaningful bytes in input block.
|
148 |
|
|
* @param length number of bytes, in input block, to consider.
|
149 |
|
|
*/
|
150 |
|
|
void update(byte[] in, int offset, int length);
|
151 |
|
|
|
152 |
|
|
/**
|
153 |
|
|
* Completes the <i>MAC</i> by performing final operations such as padding
|
154 |
|
|
* and resetting the instance.
|
155 |
|
|
*
|
156 |
|
|
* @return the array of bytes representing the <i>MAC</i> value.
|
157 |
|
|
*/
|
158 |
|
|
byte[] digest();
|
159 |
|
|
|
160 |
|
|
/**
|
161 |
|
|
* Resets the algorithm instance for re-initialisation and use with other
|
162 |
|
|
* characteristics. This method always succeeds.
|
163 |
|
|
*/
|
164 |
|
|
void reset();
|
165 |
|
|
|
166 |
|
|
/**
|
167 |
|
|
* A basic test. Ensures that the MAC of a pre-determined message is equal to
|
168 |
|
|
* a known pre-computed value.
|
169 |
|
|
*
|
170 |
|
|
* @return <code>true</code> if the implementation passes a basic self-test.
|
171 |
|
|
* Returns <code>false</code> otherwise.
|
172 |
|
|
*/
|
173 |
|
|
boolean selfTest();
|
174 |
|
|
|
175 |
|
|
/**
|
176 |
|
|
* Returns a clone copy of this instance.
|
177 |
|
|
*
|
178 |
|
|
* @return a clone copy of this instance.
|
179 |
|
|
*/
|
180 |
|
|
Object clone() throws CloneNotSupportedException;
|
181 |
|
|
}
|