1 /*
2 * Copyright (c) 1997, 2013, 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
150 * engine implementor.
151 *
152 * This method should be abstract, but we leave it concrete for
153 * binary compatibility. Knowledgeable providers should override this
154 * method.
155 *
156 * @param buf the output buffer in which to store the digest
157 *
158 * @param offset offset to start from in the output buffer
159 *
160 * @param len number of bytes within buf allotted for the digest.
161 * Both this default implementation and the SUN provider do not
162 * return partial digests. The presence of this parameter is solely
163 * for consistency in our API's. If the value of this parameter is less
164 * than the actual digest length, the method will throw a DigestException.
165 * This parameter is ignored if its value is greater than or equal to
166 * the actual digest length.
167 *
168 * @return the length of the digest stored in the output buffer.
169 *
170 * @exception DigestException if an error occurs.
171 *
172 * @since 1.2
173 */
174 protected int engineDigest(byte[] buf, int offset, int len)
175 throws DigestException {
176
177 byte[] digest = engineDigest();
178 if (len < digest.length)
179 throw new DigestException("partial digests not returned");
180 if (buf.length - offset < digest.length)
181 throw new DigestException("insufficient space in the output "
182 + "buffer to store the digest");
183 System.arraycopy(digest, 0, buf, offset, digest.length);
184 return digest.length;
185 }
186
187 /**
188 * Resets the digest for further use.
189 */
190 protected abstract void engineReset();
191
192 /**
193 * Returns a clone if the implementation is cloneable.
194 *
195 * @return a clone if the implementation is cloneable.
196 *
197 * @exception CloneNotSupportedException if this is called on an
198 * implementation that does not support {@code Cloneable}.
199 */
200 public Object clone() throws CloneNotSupportedException {
201 if (this instanceof Cloneable) {
202 return super.clone();
203 } else {
204 throw new CloneNotSupportedException();
205 }
206 }
207 }
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1 /*
2 * Copyright (c) 1997, 2019, 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
150 * engine implementor.
151 *
152 * This method should be abstract, but we leave it concrete for
153 * binary compatibility. Knowledgeable providers should override this
154 * method.
155 *
156 * @param buf the output buffer in which to store the digest
157 *
158 * @param offset offset to start from in the output buffer
159 *
160 * @param len number of bytes within buf allotted for the digest.
161 * Both this default implementation and the SUN provider do not
162 * return partial digests. The presence of this parameter is solely
163 * for consistency in our API's. If the value of this parameter is less
164 * than the actual digest length, the method will throw a DigestException.
165 * This parameter is ignored if its value is greater than or equal to
166 * the actual digest length.
167 *
168 * @return the length of the digest stored in the output buffer.
169 *
170 * @throws DigestException if an error occurs.
171 *
172 * @since 1.2
173 */
174 protected int engineDigest(byte[] buf, int offset, int len)
175 throws DigestException {
176
177 byte[] digest = engineDigest();
178 if (len < digest.length)
179 throw new DigestException("partial digests not returned");
180 if (buf.length - offset < digest.length)
181 throw new DigestException("insufficient space in the output "
182 + "buffer to store the digest");
183 System.arraycopy(digest, 0, buf, offset, digest.length);
184 return digest.length;
185 }
186
187 /**
188 * Resets the digest for further use.
189 */
190 protected abstract void engineReset();
191
192 /**
193 * Returns a clone if the implementation is cloneable.
194 *
195 * @return a clone if the implementation is cloneable.
196 *
197 * @throws CloneNotSupportedException if this is called on an
198 * implementation that does not support {@code Cloneable}.
199 */
200 public Object clone() throws CloneNotSupportedException {
201 if (this instanceof Cloneable) {
202 return super.clone();
203 } else {
204 throw new CloneNotSupportedException();
205 }
206 }
207 }
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