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My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

Showing the changes to java/pkg/java/security/MessageDigestSpi.java (1 of 18352 files). Show all

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java/pkg/java/security/MessageDigestSpi.java+206−0
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1+/*
2+ * Copyright (c) 1997, 2006, 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 java.security;
27+
28+import java.nio.ByteBuffer;
29+
30+import sun.security.jca.JCAUtil;
31+
32+/**
33+ * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
34+ * for the <code>MessageDigest</code> class, which provides the functionality
35+ * of a message digest algorithm, such as MD5 or SHA. Message digests are
36+ * secure one-way hash functions that take arbitrary-sized data and output a
37+ * fixed-length hash value.
38+ *
39+ * <p> All the abstract methods in this class must be implemented by a
40+ * cryptographic service provider who wishes to supply the implementation
41+ * of a particular message digest algorithm.
42+ *
43+ * <p> Implementations are free to implement the Cloneable interface.
44+ *
45+ * @author Benjamin Renaud
46+ *
47+ *
48+ * @see MessageDigest
49+ */
50+
51+public abstract class MessageDigestSpi {
52+
53+ // for re-use in engineUpdate(ByteBuffer input)
54+ private byte[] tempArray;
55+
56+ /**
57+ * Returns the digest length in bytes.
58+ *
59+ * <p>This concrete method has been added to this previously-defined
60+ * abstract class. (For backwards compatibility, it cannot be abstract.)
61+ *
62+ * <p>The default behavior is to return 0.
63+ *
64+ * <p>This method may be overridden by a provider to return the digest
65+ * length.
66+ *
67+ * @return the digest length in bytes.
68+ *
69+ * @since 1.2
70+ */
71+ protected int engineGetDigestLength() {
72+ return 0;
73+ }
74+
75+ /**
76+ * Updates the digest using the specified byte.
77+ *
78+ * @param input the byte to use for the update.
79+ */
80+ protected abstract void engineUpdate(byte input);
81+
82+ /**
83+ * Updates the digest using the specified array of bytes,
84+ * starting at the specified offset.
85+ *
86+ * @param input the array of bytes to use for the update.
87+ *
88+ * @param offset the offset to start from in the array of bytes.
89+ *
90+ * @param len the number of bytes to use, starting at
91+ * <code>offset</code>.
92+ */
93+ protected abstract void engineUpdate(byte[] input, int offset, int len);
94+
95+ /**
96+ * Update the digest using the specified ByteBuffer. The digest is
97+ * updated using the <code>input.remaining()</code> bytes starting
98+ * at <code>input.position()</code>.
99+ * Upon return, the buffer's position will be equal to its limit;
100+ * its limit will not have changed.
101+ *
102+ * @param input the ByteBuffer
103+ * @since 1.5
104+ */
105+ protected void engineUpdate(ByteBuffer input) {
106+ if (input.hasRemaining() == false) {
107+ return;
108+ }
109+ if (input.hasArray()) {
110+ byte[] b = input.array();
111+ int ofs = input.arrayOffset();
112+ int pos = input.position();
113+ int lim = input.limit();
114+ engineUpdate(b, ofs + pos, lim - pos);
115+ input.position(lim);
116+ } else {
117+ int len = input.remaining();
118+ int n = JCAUtil.getTempArraySize(len);
119+ if ((tempArray == null) || (n > tempArray.length)) {
120+ tempArray = new byte[n];
121+ }
122+ while (len > 0) {
123+ int chunk = Math.min(len, tempArray.length);
124+ input.get(tempArray, 0, chunk);
125+ engineUpdate(tempArray, 0, chunk);
126+ len -= chunk;
127+ }
128+ }
129+ }
130+
131+ /**
132+ * Completes the hash computation by performing final
133+ * operations such as padding. Once <code>engineDigest</code> has
134+ * been called, the engine should be reset (see
135+ * {@link #engineReset() engineReset}).
136+ * Resetting is the responsibility of the
137+ * engine implementor.
138+ *
139+ * @return the array of bytes for the resulting hash value.
140+ */
141+ protected abstract byte[] engineDigest();
142+
143+ /**
144+ * Completes the hash computation by performing final
145+ * operations such as padding. Once <code>engineDigest</code> has
146+ * been called, the engine should be reset (see
147+ * {@link #engineReset() engineReset}).
148+ * Resetting is the responsibility of the
149+ * engine implementor.
150+ *
151+ * This method should be abstract, but we leave it concrete for
152+ * binary compatibility. Knowledgeable providers should override this
153+ * method.
154+ *
155+ * @param buf the output buffer in which to store the digest
156+ *
157+ * @param offset offset to start from in the output buffer
158+ *
159+ * @param len number of bytes within buf allotted for the digest.
160+ * Both this default implementation and the SUN provider do not
161+ * return partial digests. The presence of this parameter is solely
162+ * for consistency in our API's. If the value of this parameter is less
163+ * than the actual digest length, the method will throw a DigestException.
164+ * This parameter is ignored if its value is greater than or equal to
165+ * the actual digest length.
166+ *
167+ * @return the length of the digest stored in the output buffer.
168+ *
169+ * @exception DigestException if an error occurs.
170+ *
171+ * @since 1.2
172+ */
173+ protected int engineDigest(byte[] buf, int offset, int len)
174+ throws DigestException {
175+
176+ byte[] digest = engineDigest();
177+ if (len < digest.length)
178+ throw new DigestException("partial digests not returned");
179+ if (buf.length - offset < digest.length)
180+ throw new DigestException("insufficient space in the output "
181+ + "buffer to store the digest");
182+ System.arraycopy(digest, 0, buf, offset, digest.length);
183+ return digest.length;
184+ }
185+
186+ /**
187+ * Resets the digest for further use.
188+ */
189+ protected abstract void engineReset();
190+
191+ /**
192+ * Returns a clone if the implementation is cloneable.
193+ *
194+ * @return a clone if the implementation is cloneable.
195+ *
196+ * @exception CloneNotSupportedException if this is called on an
197+ * implementation that does not support <code>Cloneable</code>.
198+ */
199+ public Object clone() throws CloneNotSupportedException {
200+ if (this instanceof Cloneable) {
201+ return super.clone();
202+ } else {
203+ throw new CloneNotSupportedException();
204+ }
205+ }
206+}