M7350/base/core/java/android/security/MessageDigest.java

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2024-09-09 08:52:07 +00:00
/*
* Copyright (C) 2007 The Android Open Source Project
*
* 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 android.security;
import java.security.NoSuchAlgorithmException;
/**
* Base class for producing a message digest from different hash encryptions.
*/
public abstract class MessageDigest
{
/**
* Returns a digest object of the specified type.
*
* @param algorithm The type of hash function to use. Valid values are
* <em>SHA-1</em> and <em>MD5</em>.
* @return The respective MessageDigest object. Either a
* {@link android.security.Sha1MessageDigest} or
* {@link android.security.Md5MessageDigest} object.
* @throws NoSuchAlgorithmException If an invalid <var>algorithm</var>
* is given.
*/
public static MessageDigest getInstance(String algorithm)
throws NoSuchAlgorithmException
{
if (algorithm == null) {
return null;
}
if (algorithm.equals("SHA-1")) {
return new Sha1MessageDigest();
}
else if (algorithm.equals("MD5")) {
return new Md5MessageDigest();
}
throw new NoSuchAlgorithmException();
}
public abstract void update(byte[] input);
public abstract byte[] digest();
/**
* Produces a message digest for the given input.
*
* @param input The message to encrypt.
* @return The digest (hash sum).
*/
public abstract byte[] digest(byte[] input);
}