Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.eclipse.aether.internal.impl.checksum;
020
021import javax.inject.Inject;
022import javax.inject.Named;
023import javax.inject.Singleton;
024
025import java.io.BufferedReader;
026import java.io.IOException;
027import java.io.UncheckedIOException;
028import java.nio.charset.StandardCharsets;
029import java.nio.file.Files;
030import java.nio.file.Path;
031import java.util.ArrayList;
032import java.util.HashMap;
033import java.util.List;
034import java.util.Map;
035import java.util.Objects;
036import java.util.concurrent.ConcurrentHashMap;
037import java.util.concurrent.atomic.AtomicBoolean;
038
039import org.eclipse.aether.MultiRuntimeException;
040import org.eclipse.aether.RepositorySystemSession;
041import org.eclipse.aether.artifact.Artifact;
042import org.eclipse.aether.impl.RepositorySystemLifecycle;
043import org.eclipse.aether.internal.impl.LocalPathComposer;
044import org.eclipse.aether.repository.ArtifactRepository;
045import org.eclipse.aether.spi.connector.checksum.ChecksumAlgorithmFactory;
046import org.eclipse.aether.util.FileUtils;
047import org.slf4j.Logger;
048import org.slf4j.LoggerFactory;
049
050import static java.util.Objects.requireNonNull;
051import static java.util.stream.Collectors.toList;
052
053/**
054 * Compact file {@link FileTrustedChecksumsSourceSupport} implementation that use specified directory as base
055 * directory, where it expects a "summary" file named as "checksums.${checksumExt}" for each checksum algorithm.
056 * File format is GNU Coreutils compatible: each line holds checksum followed by two spaces and artifact relative path
057 * (from local repository root, without leading "./"). This means that trusted checksums summary file can be used to
058 * validate artifacts or generate it using standard GNU tools like GNU {@code sha1sum} is (for BSD derivatives same
059 * file can be used with {@code -r} switch).
060 * <p>
061 * The format supports comments "#" (hash) and empty lines for easier structuring the file content, and both are
062 * ignored. Also, their presence makes the summary file incompatible with GNU Coreutils format. On save of the
063 * summary file, the comments and empty lines are lost, and file is sorted by path names for easier diffing
064 * (2nd column in file).
065 * <p>
066 * The source by default is "origin aware", and it will factor in origin repository ID as well into summary file name,
067 * for example "checksums-central.sha256".
068 * <p>
069 * Example commands for managing summary file (in examples will use repository ID "central"):
070 * <ul>
071 *     <li>To create summary file: {@code find * -not -name "checksums-central.sha256" -type f -print0 |
072 *       xargs -0 sha256sum | sort -k 2 > checksums-central.sha256}</li>
073 *     <li>To verify artifacts using summary file: {@code sha256sum --quiet -c checksums-central.sha256}</li>
074 * </ul>
075 * <p>
076 * The checksums summary file is lazily loaded and remains cached during lifetime of the component, so file changes
077 * during lifecycle of the component are not picked up. This implementation can be simultaneously used to lookup and
078 * also record checksums. The recorded checksums will become visible for every session, and will be flushed
079 * at repository system shutdown, merged with existing ones on disk.
080 * <p>
081 * The name of this implementation is "summaryFile".
082 *
083 * @see <a href="https://man7.org/linux/man-pages/man1/sha1sum.1.html">sha1sum man page</a>
084 * @see <a href="https://www.gnu.org/software/coreutils/manual/coreutils.html#md5sum-invocation">GNU Coreutils: md5sum</a>
085 * @since 1.9.0
086 */
087@Singleton
088@Named(SummaryFileTrustedChecksumsSource.NAME)
089public final class SummaryFileTrustedChecksumsSource extends FileTrustedChecksumsSourceSupport {
090    public static final String NAME = "summaryFile";
091
092    private static final String CHECKSUMS_FILE_PREFIX = "checksums";
093
094    private static final Logger LOGGER = LoggerFactory.getLogger(SummaryFileTrustedChecksumsSource.class);
095
096    private final LocalPathComposer localPathComposer;
097
098    private final RepositorySystemLifecycle repositorySystemLifecycle;
099
100    private final ConcurrentHashMap<Path, ConcurrentHashMap<String, String>> checksums;
101
102    private final ConcurrentHashMap<Path, Boolean> changedChecksums;
103
104    private final AtomicBoolean onShutdownHandlerRegistered;
105
106    @Inject
107    public SummaryFileTrustedChecksumsSource(
108            LocalPathComposer localPathComposer, RepositorySystemLifecycle repositorySystemLifecycle) {
109        super(NAME);
110        this.localPathComposer = requireNonNull(localPathComposer);
111        this.repositorySystemLifecycle = requireNonNull(repositorySystemLifecycle);
112        this.checksums = new ConcurrentHashMap<>();
113        this.changedChecksums = new ConcurrentHashMap<>();
114        this.onShutdownHandlerRegistered = new AtomicBoolean(false);
115    }
116
117    @Override
118    protected Map<String, String> doGetTrustedArtifactChecksums(
119            RepositorySystemSession session,
120            Artifact artifact,
121            ArtifactRepository artifactRepository,
122            List<ChecksumAlgorithmFactory> checksumAlgorithmFactories) {
123        final HashMap<String, String> result = new HashMap<>();
124        final Path basedir = getBasedir(session, false);
125        if (Files.isDirectory(basedir)) {
126            final String artifactPath = localPathComposer.getPathForArtifact(artifact, false);
127            final boolean originAware = isOriginAware(session);
128            for (ChecksumAlgorithmFactory checksumAlgorithmFactory : checksumAlgorithmFactories) {
129                Path summaryFile = summaryFile(
130                        basedir, originAware, artifactRepository.getId(), checksumAlgorithmFactory.getFileExtension());
131                ConcurrentHashMap<String, String> algorithmChecksums =
132                        checksums.computeIfAbsent(summaryFile, f -> loadProvidedChecksums(summaryFile));
133                String checksum = algorithmChecksums.get(artifactPath);
134                if (checksum != null) {
135                    result.put(checksumAlgorithmFactory.getName(), checksum);
136                }
137            }
138        }
139        return result;
140    }
141
142    @Override
143    protected SummaryFileWriter doGetTrustedArtifactChecksumsWriter(RepositorySystemSession session) {
144        if (onShutdownHandlerRegistered.compareAndSet(false, true)) {
145            repositorySystemLifecycle.addOnSystemEndedHandler(this::saveRecordedLines);
146        }
147        return new SummaryFileWriter(checksums, getBasedir(session, true), isOriginAware(session));
148    }
149
150    /**
151     * Returns the summary file path. The file itself and its parent directories may not exist, this method merely
152     * calculate the path.
153     */
154    private Path summaryFile(Path basedir, boolean originAware, String repositoryId, String checksumExtension) {
155        String fileName = CHECKSUMS_FILE_PREFIX;
156        if (originAware) {
157            fileName += "-" + repositoryId;
158        }
159        return basedir.resolve(fileName + "." + checksumExtension);
160    }
161
162    private ConcurrentHashMap<String, String> loadProvidedChecksums(Path summaryFile) {
163        ConcurrentHashMap<String, String> result = new ConcurrentHashMap<>();
164        if (Files.isRegularFile(summaryFile)) {
165            try (BufferedReader reader = Files.newBufferedReader(summaryFile, StandardCharsets.UTF_8)) {
166                String line;
167                while ((line = reader.readLine()) != null) {
168                    if (!line.startsWith("#") && !line.isEmpty()) {
169                        String[] parts = line.split("  ", 2);
170                        if (parts.length == 2) {
171                            String newChecksum = parts[0];
172                            String artifactPath = parts[1];
173                            String oldChecksum = result.put(artifactPath, newChecksum);
174                            if (oldChecksum != null) {
175                                if (Objects.equals(oldChecksum, newChecksum)) {
176                                    LOGGER.warn(
177                                            "Checksums file '{}' contains duplicate checksums for artifact {}: {}",
178                                            summaryFile,
179                                            artifactPath,
180                                            oldChecksum);
181                                } else {
182                                    LOGGER.warn(
183                                            "Checksums file '{}' contains different checksums for artifact {}: "
184                                                    + "old '{}' replaced by new '{}'",
185                                            summaryFile,
186                                            artifactPath,
187                                            oldChecksum,
188                                            newChecksum);
189                                }
190                            }
191                        } else {
192                            LOGGER.warn("Checksums file '{}' ignored malformed line '{}'", summaryFile, line);
193                        }
194                    }
195                }
196            } catch (IOException e) {
197                throw new UncheckedIOException(e);
198            }
199            LOGGER.info("Loaded {} trusted checksums from {}", result.size(), summaryFile);
200        }
201        return result;
202    }
203
204    private class SummaryFileWriter implements Writer {
205        private final ConcurrentHashMap<Path, ConcurrentHashMap<String, String>> cache;
206
207        private final Path basedir;
208
209        private final boolean originAware;
210
211        private SummaryFileWriter(
212                ConcurrentHashMap<Path, ConcurrentHashMap<String, String>> cache, Path basedir, boolean originAware) {
213            this.cache = cache;
214            this.basedir = basedir;
215            this.originAware = originAware;
216        }
217
218        @Override
219        public void addTrustedArtifactChecksums(
220                Artifact artifact,
221                ArtifactRepository artifactRepository,
222                List<ChecksumAlgorithmFactory> checksumAlgorithmFactories,
223                Map<String, String> trustedArtifactChecksums) {
224            String artifactPath = localPathComposer.getPathForArtifact(artifact, false);
225            for (ChecksumAlgorithmFactory checksumAlgorithmFactory : checksumAlgorithmFactories) {
226                Path summaryFile = summaryFile(
227                        basedir, originAware, artifactRepository.getId(), checksumAlgorithmFactory.getFileExtension());
228                String checksum = requireNonNull(trustedArtifactChecksums.get(checksumAlgorithmFactory.getName()));
229
230                String oldChecksum = cache.computeIfAbsent(summaryFile, k -> loadProvidedChecksums(summaryFile))
231                        .put(artifactPath, checksum);
232
233                if (oldChecksum == null) {
234                    changedChecksums.put(summaryFile, Boolean.TRUE); // new
235                } else if (!Objects.equals(oldChecksum, checksum)) {
236                    changedChecksums.put(summaryFile, Boolean.TRUE); // replaced
237                    LOGGER.info(
238                            "Trusted checksum for artifact {} replaced: old {}, new {}",
239                            artifact,
240                            oldChecksum,
241                            checksum);
242                }
243            }
244        }
245    }
246
247    /**
248     * On-close handler that saves recorded checksums, if any.
249     */
250    private void saveRecordedLines() {
251        if (changedChecksums.isEmpty()) {
252            return;
253        }
254
255        ArrayList<Exception> exceptions = new ArrayList<>();
256        for (Map.Entry<Path, ConcurrentHashMap<String, String>> entry : checksums.entrySet()) {
257            Path summaryFile = entry.getKey();
258            if (changedChecksums.get(summaryFile) != Boolean.TRUE) {
259                continue;
260            }
261            ConcurrentHashMap<String, String> recordedLines = entry.getValue();
262            if (!recordedLines.isEmpty()) {
263                try {
264                    ConcurrentHashMap<String, String> result = new ConcurrentHashMap<>();
265                    result.putAll(loadProvidedChecksums(summaryFile));
266                    result.putAll(recordedLines);
267
268                    LOGGER.info("Saving {} checksums to '{}'", result.size(), summaryFile);
269                    FileUtils.writeFileWithBackup(
270                            summaryFile,
271                            p -> Files.write(
272                                    p,
273                                    result.entrySet().stream()
274                                            .sorted(Map.Entry.comparingByValue())
275                                            .map(e -> e.getValue() + "  " + e.getKey())
276                                            .collect(toList())));
277                } catch (IOException e) {
278                    exceptions.add(e);
279                }
280            }
281        }
282        MultiRuntimeException.mayThrow("session save checksums failure", exceptions);
283    }
284}