| /* |
| * Copyright 2010 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| * use this file except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| package java.security; |
| |
| /** |
| * Message Digest Service Provider Interface - <a |
| * href="http://java.sun.com/j2se/1.4.2/docs/api/java/security/MessageDigestSpi.html">[Sun's |
| * docs]</a>. |
| */ |
| public abstract class MessageDigestSpi { |
| |
| protected abstract byte[] engineDigest(); |
| |
| protected int engineDigest(byte[] buf, int offset, int len) |
| throws DigestException { |
| byte[] digest = engineDigest(); |
| if (buf.length < digest.length + offset) { |
| throw new DigestException("Insufficient buffer space for digest"); |
| } |
| if (len < digest.length) { |
| throw new DigestException("Length not large enough to hold digest"); |
| } |
| System.arraycopy(digest, 0, buf, offset, digest.length); |
| return digest.length; |
| } |
| |
| protected int engineGetDigestLength() { |
| return 0; |
| } |
| |
| protected abstract void engineReset(); |
| |
| protected abstract void engineUpdate(byte input); |
| |
| protected abstract void engineUpdate(byte[] input, int offset, int len); |
| } |