| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 |
| * |
| * https://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 org.apache.tools.ant.types.selectors.modifiedselector; |
| |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.file.Files; |
| import java.security.DigestInputStream; |
| import java.security.MessageDigest; |
| import java.security.NoSuchAlgorithmException; |
| import java.security.NoSuchProviderException; |
| import java.util.Locale; |
| |
| import org.apache.tools.ant.BuildException; |
| |
| |
| /** |
| * Computes a 'hashvalue' for the content of file using |
| * java.security.MessageDigest. |
| * Use of this algorithm doesn't require any additional nested <param>s. |
| * Supported <param>s are: |
| * <table> |
| * <caption>Digest algorithm parameters</caption> |
| * <tr> |
| * <th>name</th><th>values</th><th>description</th><th>required</th> |
| * </tr> |
| * <tr> |
| * <td>algorithm.algorithm</td> |
| * <td>MD5 | SHA (default provider)</td> |
| * <td>name of the algorithm the provider should use</td> |
| * <td>no, defaults to MD5</td> |
| * </tr> |
| * <tr> |
| * <td> algorithm.provider</td> |
| * <td></td> |
| * <td>name of the provider to use</td> |
| * <td>no, defaults to <i>null</i></td> |
| * </tr> |
| * </table> |
| * |
| * @version 2004-07-08 |
| * @since Ant 1.6 |
| */ |
| public class DigestAlgorithm implements Algorithm { |
| |
| private static final int BYTE_MASK = 0xFF; |
| private static final int BUFFER_SIZE = 8192; |
| |
| // ----- member variables ----- |
| |
| |
| /** |
| * MessageDigest algorithm to be used. |
| */ |
| private String algorithm = "MD5"; |
| |
| /** |
| * MessageDigest Algorithm provider |
| */ |
| private String provider = null; |
| |
| /** |
| * Message Digest instance |
| */ |
| private MessageDigest messageDigest = null; |
| |
| /** |
| * Size of the read buffer to use. |
| */ |
| private int readBufferSize = BUFFER_SIZE; |
| |
| |
| // ----- Algorithm-Configuration ----- |
| |
| |
| /** |
| * Specifies the algorithm to be used to compute the checksum. |
| * Defaults to "MD5". Other popular algorithms like "SHA" may be used as well. |
| * @param algorithm the digest algorithm to use |
| */ |
| public void setAlgorithm(String algorithm) { |
| this.algorithm = algorithm != null |
| ? algorithm.toUpperCase(Locale.ENGLISH) : null; |
| } |
| |
| |
| /** |
| * Sets the MessageDigest algorithm provider to be used |
| * to calculate the checksum. |
| * @param provider provider to use |
| */ |
| public void setProvider(String provider) { |
| this.provider = provider; |
| } |
| |
| |
| /** Initialize the security message digest. */ |
| public void initMessageDigest() { |
| if (messageDigest != null) { |
| return; |
| } |
| |
| if (provider != null && !provider.isEmpty() && !"null".equals(provider)) { |
| try { |
| messageDigest = MessageDigest.getInstance(algorithm, provider); |
| } catch (NoSuchAlgorithmException | NoSuchProviderException e) { |
| throw new BuildException(e); |
| } |
| } else { |
| try { |
| messageDigest = MessageDigest.getInstance(algorithm); |
| } catch (NoSuchAlgorithmException noalgo) { |
| throw new BuildException(noalgo); |
| } |
| } |
| } |
| |
| |
| // ----- Logic ----- |
| |
| |
| /** |
| * This algorithm supports only MD5 and SHA. |
| * @return <i>true</i> if all is ok, otherwise <i>false</i>. |
| */ |
| @Override |
| public boolean isValid() { |
| return "SHA".equals(algorithm) || "MD5".equals(algorithm); |
| } |
| |
| /** |
| * Computes a value for a file content with the specified digest algorithm. |
| * @param file File object for which the value should be evaluated. |
| * @return The value for that file |
| */ |
| // implementation adapted from ...taskdefs.Checksum, thanks to Magesh for hint |
| @Override |
| public String getValue(File file) { |
| if (!file.canRead()) { |
| return null; |
| } |
| initMessageDigest(); |
| byte[] buf = new byte[readBufferSize]; |
| messageDigest.reset(); |
| try (DigestInputStream dis = new DigestInputStream(Files.newInputStream(file.toPath()), |
| messageDigest)) { |
| // read the whole stream |
| while (dis.read(buf, 0, readBufferSize) != -1) { |
| } |
| StringBuilder checksumSb = new StringBuilder(); |
| for (byte digestByte : messageDigest.digest()) { |
| checksumSb.append(String.format("%02x", BYTE_MASK & digestByte)); |
| } |
| return checksumSb.toString(); |
| } catch (IOException ignored) { |
| return null; |
| } |
| } |
| |
| /** |
| * Override Object.toString(). |
| * @return some information about this algorithm. |
| */ |
| @Override |
| public String toString() { |
| return String.format("<DigestAlgorithm:algorithm=%s;provider=%s>", |
| algorithm, provider); |
| } |
| } |