/*

  * This file is part of dependency-check-core.

  *

  * 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.

  *

  * Copyright (c) 2013 Jeremy Long. All Rights Reserved.

  */

 package org.owasp.dependencycheck.analyzer;

 import java.io.BufferedInputStream;

 import java.io.Closeable;

 import java.io.File;

 import java.io.FileFilter;

 import java.io.FileInputStream;

 import java.io.FileNotFoundException;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.Enumeration;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Set;

 import org.apache.commons.compress.archivers.ArchiveEntry;

 import org.apache.commons.compress.archivers.ArchiveInputStream;

 import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;

 import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;

 import org.apache.commons.compress.archivers.zip.ZipArchiveInputStream;

 import org.apache.commons.compress.archivers.zip.ZipFile;

 import org.apache.commons.compress.compressors.CompressorInputStream;

 import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;

 import org.apache.commons.compress.compressors.bzip2.BZip2Utils;

 import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;

 import org.apache.commons.compress.compressors.gzip.GzipUtils;

 import org.apache.commons.compress.utils.IOUtils;

 import org.owasp.dependencycheck.Engine;

 import org.owasp.dependencycheck.analyzer.exception.AnalysisException;

 import org.owasp.dependencycheck.analyzer.exception.ArchiveExtractionException;

 import org.owasp.dependencycheck.dependency.Dependency;

 import org.owasp.dependencycheck.exception.InitializationException;

 import org.owasp.dependencycheck.utils.FileFilterBuilder;

 import org.owasp.dependencycheck.utils.FileUtils;

 import org.owasp.dependencycheck.utils.Settings;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * <p>

  * An analyzer that extracts files from archives and ensures any supported files

  * contained within the archive are added to the dependency list.</p>

  *

  * @author Jeremy Long

  */

 public class ArchiveAnalyzer extends AbstractFileTypeAnalyzer {

     /**

      * The logger.

      */

     private static final Logger LOGGER = LoggerFactory.getLogger(ArchiveAnalyzer.class);

     /**

      * The count of directories created during analysis. This is used for

      * creating temporary directories.

      */

     private static int dirCount = 0;

     /**

      * The parent directory for the individual directories per archive.

      */

     private File tempFileLocation = null;

     /**

      * The max scan depth that the analyzer will recursively extract nested

      * archives.

      */

     private static final int MAX_SCAN_DEPTH = Settings.getInt("archive.scan.depth", 3);

     /**

      * Tracks the current scan/extraction depth for nested archives.

      */

     private int scanDepth = 0;

     //<editor-fold defaultstate="collapsed" desc="All standard implementation details of Analyzer">

     /**

      * The name of the analyzer.

      */

     private static final String ANALYZER_NAME = "Archive Analyzer";

     /**

      * The phase that this analyzer is intended to run in.

      */

     private static final AnalysisPhase ANALYSIS_PHASE = AnalysisPhase.INITIAL;

     /**

      * The set of things we can handle with Zip methods

      */

     private static final Set<String> ZIPPABLES = newHashSet("zip", "ear", "war", "jar", "sar", "apk", "nupkg");

     /**

      * The set of file extensions supported by this analyzer. Note for

      * developers, any additions to this list will need to be explicitly handled

      * in {@link #extractFiles(File, File, Engine)}.

      */

     private static final Set<String> EXTENSIONS = newHashSet("tar", "gz", "tgz", "bz2", "tbz2");

     /**

      * Detects files with extensions to remove from the engine's collection of

      * dependencies.

      */

     private static final FileFilter REMOVE_FROM_ANALYSIS = FileFilterBuilder.newInstance().addExtensions("zip", "tar", "gz", "tgz", "bz2", "tbz2")

             .build();

     static {

         final String additionalZipExt = Settings.getString(Settings.KEYS.ADDITIONAL_ZIP_EXTENSIONS);

         if (additionalZipExt != null) {

             final String[] ext = additionalZipExt.split("\\s*,\\s*");

             Collections.addAll(ZIPPABLES, ext);

         }

         EXTENSIONS.addAll(ZIPPABLES);

     }

     /**

      * The file filter used to filter supported files.

      */

     private static final FileFilter FILTER = FileFilterBuilder.newInstance().addExtensions(EXTENSIONS).build();

     @Override

     protected FileFilter getFileFilter() {

         return FILTER;

     }

     /**

      * Detects files with .zip extension.

      */

     private static final FileFilter ZIP_FILTER = FileFilterBuilder.newInstance().addExtensions("zip").build();

     /**

      * Returns the name of the analyzer.

      *

      * @return the name of the analyzer.

      */

     @Override

     public String getName() {

         return ANALYZER_NAME;

     }

     /**

      * Returns the phase that the analyzer is intended to run in.

      *

      * @return the phase that the analyzer is intended to run in.

      */

     @Override

     public AnalysisPhase getAnalysisPhase() {

         return ANALYSIS_PHASE;

     }

     //</editor-fold>

     /**

      * Returns the key used in the properties file to reference the analyzer's

      * enabled property.

      *

      * @return the analyzer's enabled property setting key

      */

     @Override

     protected String getAnalyzerEnabledSettingKey() {

         return Settings.KEYS.ANALYZER_ARCHIVE_ENABLED;

     }

     /**

      * The initialize method does nothing for this Analyzer.

      *

      * @throws InitializationException is thrown if there is an exception

      * deleting or creating temporary files

      */

     @Override

     public void initializeFileTypeAnalyzer() throws InitializationException {

         try {

             final File baseDir = Settings.getTempDirectory();

             tempFileLocation = File.createTempFile("check", "tmp", baseDir);

             if (!tempFileLocation.delete()) {

                 setEnabled(false);

                 final String msg = String.format("Unable to delete temporary file '%s'.", tempFileLocation.getAbsolutePath());

                 throw new InitializationException(msg);

             }

             if (!tempFileLocation.mkdirs()) {

                 setEnabled(false);

                 final String msg = String.format("Unable to create directory '%s'.", tempFileLocation.getAbsolutePath());

                 throw new InitializationException(msg);

             }

         } catch (IOException ex) {

             setEnabled(false);

             throw new InitializationException("Unable to create a temporary file", ex);

         }

     }

     /**

      * The close method deletes any temporary files and directories created

      * during analysis.

      *

      * @throws Exception thrown if there is an exception deleting temporary

      * files

      */

     @Override

     public void close() throws Exception {

         if (tempFileLocation != null && tempFileLocation.exists()) {

             LOGGER.debug("Attempting to delete temporary files");

             final boolean success = FileUtils.delete(tempFileLocation);

             if (!success && tempFileLocation.exists()) {

                 final String[] l = tempFileLocation.list();

                 if (l != null && l.length > 0) {

                     LOGGER.warn("Failed to delete some temporary files, see the log for more details");

                 }

             }

         }

     }

     /**

      * Analyzes a given dependency. If the dependency is an archive, such as a

      * WAR or EAR, the contents are extracted, scanned, and added to the list of

      * dependencies within the engine.

      *

      * @param dependency the dependency to analyze

      * @param engine the engine scanning

      * @throws AnalysisException thrown if there is an analysis exception

      */

     @Override

     public void analyzeFileType(Dependency dependency, Engine engine) throws AnalysisException {

         final File f = new File(dependency.getActualFilePath());

         final File tmpDir = getNextTempDirectory();

         extractFiles(f, tmpDir, engine);

         //make a copy

         final Set<Dependency> dependencySet = findMoreDependencies(engine, tmpDir);

         if (!dependencySet.isEmpty()) {

             for (Dependency d : dependencySet) {

                 //fix the dependency's display name and path

                 final String displayPath = String.format("%s%s",

                         dependency.getFilePath(),

                         d.getActualFilePath().substring(tmpDir.getAbsolutePath().length()));

                 final String displayName = String.format("%s: %s",

                         dependency.getFileName(),

                         d.getFileName());

                 d.setFilePath(displayPath);

                 d.setFileName(displayName);

                 //TODO - can we get more evidence from the parent? EAR contains module name, etc.

                 //analyze the dependency (i.e. extract files) if it is a supported type.

                 if (this.accept(d.getActualFile()) && scanDepth < MAX_SCAN_DEPTH) {

                     scanDepth += 1;

                     analyze(d, engine);

                     scanDepth -= 1;

                 }

             }

         }

         if (REMOVE_FROM_ANALYSIS.accept(dependency.getActualFile())) {

             addDisguisedJarsToDependencies(dependency, engine);

             engine.getDependencies().remove(dependency);

         }

         Collections.sort(engine.getDependencies());

     }

     /**

      * If a zip file was identified as a possible JAR, this method will add the

      * zip to the list of dependencies.

      *

      * @param dependency the zip file

      * @param engine the engine

      * @throws AnalysisException thrown if there is an issue

      */

     private void addDisguisedJarsToDependencies(Dependency dependency, Engine engine) throws AnalysisException {

         if (ZIP_FILTER.accept(dependency.getActualFile()) && isZipFileActuallyJarFile(dependency)) {

             final File tdir = getNextTempDirectory();

             final String fileName = dependency.getFileName();

             LOGGER.info("The zip file '{}' appears to be a JAR file, making a copy and analyzing it as a JAR.", fileName);

             final File tmpLoc = new File(tdir, fileName.substring(0, fileName.length() - 3) + "jar");

             try {

                 org.apache.commons.io.FileUtils.copyFile(tdir, tmpLoc);

                 final Set<Dependency> dependencySet = findMoreDependencies(engine, tmpLoc);

                 if (!dependencySet.isEmpty()) {

                     if (dependencySet.size() != 1) {

                         LOGGER.info("Deep copy of ZIP to JAR file resulted in more than one dependency?");

                     }

                     for (Dependency d : dependencySet) {

                         //fix the dependency's display name and path

                         d.setFilePath(dependency.getFilePath());

                         d.setDisplayFileName(dependency.getFileName());

                     }

                 }

             } catch (IOException ex) {

                 LOGGER.debug("Unable to perform deep copy on '{}'", dependency.getActualFile().getPath(), ex);

             }

         }

     }

     /**

      * An empty dependency set.

      */

     private static final Set<Dependency> EMPTY_DEPENDENCY_SET = Collections.emptySet();

     /**

      * Scan the given file/folder, and return any new dependencies found.

      *

      * @param engine used to scan

      * @param file target of scanning

      * @return any dependencies that weren't known to the engine before

      */

     private static Set<Dependency> findMoreDependencies(Engine engine, File file) {

         final List<Dependency> before = new ArrayList<Dependency>(engine.getDependencies());

         engine.scan(file);

         final List<Dependency> after = engine.getDependencies();

         final boolean sizeChanged = before.size() != after.size();

         final Set<Dependency> newDependencies;

         if (sizeChanged) {

             //get the new dependencies

             newDependencies = new HashSet<Dependency>(after);

             newDependencies.removeAll(before);

         } else {

             newDependencies = EMPTY_DEPENDENCY_SET;

         }

         return newDependencies;

     }

     /**

      * Retrieves the next temporary directory to extract an archive too.

      *

      * @return a directory

      * @throws AnalysisException thrown if unable to create temporary directory

      */

     private File getNextTempDirectory() throws AnalysisException {

         dirCount += 1;

         final File directory = new File(tempFileLocation, String.valueOf(dirCount));

         //getting an exception for some directories not being able to be created; might be because the directory already exists?

         if (directory.exists()) {

             return getNextTempDirectory();

         }

         if (!directory.mkdirs()) {

             final String msg = String.format("Unable to create temp directory '%s'.", directory.getAbsolutePath());

             throw new AnalysisException(msg);

         }

         return directory;

     }

     /**

      * Extracts the contents of an archive into the specified directory.

      *

      * @param archive an archive file such as a WAR or EAR

      * @param destination a directory to extract the contents to

      * @param engine the scanning engine

      * @throws AnalysisException thrown if the archive is not found

      */

     private void extractFiles(File archive, File destination, Engine engine) throws AnalysisException {

         if (archive != null && destination != null) {

             FileInputStream fis;

             try {

                 fis = new FileInputStream(archive);

             } catch (FileNotFoundException ex) {

                 LOGGER.debug("", ex);

                 throw new AnalysisException("Archive file was not found.", ex);

             }

             final String archiveExt = FileUtils.getFileExtension(archive.getName()).toLowerCase();

             try {

                 if (ZIPPABLES.contains(archiveExt)) {

                     final BufferedInputStream in = new BufferedInputStream(fis);

                     ensureReadableJar(archiveExt, in);

                     extractArchive(new ZipArchiveInputStream(in), destination, engine);

                 } else if ("tar".equals(archiveExt)) {

                     extractArchive(new TarArchiveInputStream(new BufferedInputStream(fis)), destination, engine);

                 } else if ("gz".equals(archiveExt) || "tgz".equals(archiveExt)) {

                     final String uncompressedName = GzipUtils.getUncompressedFilename(archive.getName());

                     final File f = new File(destination, uncompressedName);

                     if (engine.accept(f)) {

                         decompressFile(new GzipCompressorInputStream(new BufferedInputStream(fis)), f);

                     }

                 } else if ("bz2".equals(archiveExt) || "tbz2".equals(archiveExt)) {

                     final String uncompressedName = BZip2Utils.getUncompressedFilename(archive.getName());

                     final File f = new File(destination, uncompressedName);

                     if (engine.accept(f)) {

                         decompressFile(new BZip2CompressorInputStream(new BufferedInputStream(fis)), f);

                     }

                 }

             } catch (ArchiveExtractionException ex) {

                 LOGGER.warn("Exception extracting archive '{}'.", archive.getName());

                 LOGGER.debug("", ex);

             } catch (IOException ex) {

                 LOGGER.warn("Exception reading archive '{}'.", archive.getName());

                 LOGGER.debug("", ex);

             } finally {

                 close(fis);

             }

         }

     }

     /**

      * Checks if the file being scanned is a JAR that begins with '#!/bin' which

      * indicates it is a fully executable jar. If a fully executable JAR is

      * identified the input stream will be advanced to the start of the actual

      * JAR file ( skipping the script).

      *

      * @see

      * <a href="http://docs.spring.io/spring-boot/docs/1.3.0.BUILD-SNAPSHOT/reference/htmlsingle/#deployment-install">Installing

      * Spring Boot Applications</a>

      * @param archiveExt the file extension

      * @param in the input stream

      * @throws IOException thrown if there is an error reading the stream

      */

     private void ensureReadableJar(final String archiveExt, BufferedInputStream in) throws IOException {

         if ("jar".equals(archiveExt) && in.markSupported()) {

             in.mark(7);

             final byte[] b = new byte[7];

             in.read(b);

             if (b[0] == '#'

                     && b[1] == '!'

                     && b[2] == '/'

                     && b[3] == 'b'

                     && b[4] == 'i'

                     && b[5] == 'n'

                     && b[6] == '/') {

                 boolean stillLooking = true;

                 int chr, nxtChr;

                 while (stillLooking && (chr = in.read()) != -1) {

                     if (chr == '\n' || chr == '\r') {

                         in.mark(4);

                         if ((chr = in.read()) != -1) {

                             if (chr == 'P' && (chr = in.read()) != -1) {

                                 if (chr == 'K' && (chr = in.read()) != -1) {

                                     if ((chr == 3 || chr == 5 || chr == 7) && (nxtChr = in.read()) != -1) {

                                         if (nxtChr == chr + 1) {

                                             stillLooking = false;

                                             in.reset();

                                         }

                                     }

                                 }

                             }

                         }

                     }

                 }

             }

         }

     }

     /**

      * Extracts files from an archive.

      *

      * @param input the archive to extract files from

      * @param destination the location to write the files too

      * @param engine the dependency-check engine

      * @throws ArchiveExtractionException thrown if there is an exception

      * extracting files from the archive

      */

     private void extractArchive(ArchiveInputStream input, File destination, Engine engine) throws ArchiveExtractionException {

         ArchiveEntry entry;

         try {

             while ((entry = input.getNextEntry()) != null) {

                 final File file = new File(destination, entry.getName());

                 if (entry.isDirectory()) {

                     if (!file.exists() && !file.mkdirs()) {

                         final String msg = String.format("Unable to create directory '%s'.", file.getAbsolutePath());

                         throw new AnalysisException(msg);

                     }

                 } else if (engine.accept(file)) {

                     extractAcceptedFile(input, file);

                 }

             }

         } catch (Throwable ex) {

             throw new ArchiveExtractionException(ex);

         } finally {

             close(input);

         }

     }

     /**

      * Extracts a file from an archive.

      *

      * @param input the archives input stream

      * @param file the file to extract

      * @throws AnalysisException thrown if there is an error

      */

     private static void extractAcceptedFile(ArchiveInputStream input, File file) throws AnalysisException {

         LOGGER.debug("Extracting '{}'", file.getPath());

         FileOutputStream fos = null;

         try {

             final File parent = file.getParentFile();

             if (!parent.isDirectory() && !parent.mkdirs()) {

                 final String msg = String.format("Unable to build directory '%s'.", parent.getAbsolutePath());

                 throw new AnalysisException(msg);

             }

             fos = new FileOutputStream(file);

             IOUtils.copy(input, fos);

         } catch (FileNotFoundException ex) {

             LOGGER.debug("", ex);

             final String msg = String.format("Unable to find file '%s'.", file.getName());

             throw new AnalysisException(msg, ex);

         } catch (IOException ex) {

             LOGGER.debug("", ex);

             final String msg = String.format("IO Exception while parsing file '%s'.", file.getName());

             throw new AnalysisException(msg, ex);

         } finally {

             close(fos);

         }

     }

     /**

      * Decompresses a file.

      *

      * @param inputStream the compressed file

      * @param outputFile the location to write the decompressed file

      * @throws ArchiveExtractionException thrown if there is an exception

      * decompressing the file

      */

     private void decompressFile(CompressorInputStream inputStream, File outputFile) throws ArchiveExtractionException {

         LOGGER.debug("Decompressing '{}'", outputFile.getPath());

         FileOutputStream out = null;

         try {

             out = new FileOutputStream(outputFile);

             IOUtils.copy(inputStream, out);

         } catch (FileNotFoundException ex) {

             LOGGER.debug("", ex);

             throw new ArchiveExtractionException(ex);

         } catch (IOException ex) {

             LOGGER.debug("", ex);

             throw new ArchiveExtractionException(ex);

         } finally {

             close(out);

         }

     }

     /**

      * Close the given {@link Closeable} instance, ignoring nulls, and logging

      * any thrown {@link IOException}.

      *

      * @param closeable to be closed

      */

     private static void close(Closeable closeable) {

         if (null != closeable) {

             try {

                 closeable.close();

             } catch (IOException ex) {

                 LOGGER.trace("", ex);

             }

         }

     }

     /**

      * Attempts to determine if a zip file is actually a JAR file.

      *

      * @param dependency the dependency to check

      * @return true if the dependency appears to be a JAR file; otherwise false

      */

     private boolean isZipFileActuallyJarFile(Dependency dependency) {

         boolean isJar = false;

         ZipFile zip = null;

         try {

             zip = new ZipFile(dependency.getActualFilePath());

             if (zip.getEntry("META-INF/MANIFEST.MF") != null

                     || zip.getEntry("META-INF/maven") != null) {

                 final Enumeration<ZipArchiveEntry> entries = zip.getEntries();

                 while (entries.hasMoreElements()) {

                     final ZipArchiveEntry entry = entries.nextElement();

                     if (!entry.isDirectory()) {

                         final String name = entry.getName().toLowerCase();

                         if (name.endsWith(".class")) {

                             isJar = true;

                             break;

                         }

                     }

                 }

             }

         } catch (IOException ex) {

             LOGGER.debug("Unable to unzip zip file '{}'", dependency.getFilePath(), ex);

         } finally {

             ZipFile.closeQuietly(zip);

         }

         return isJar;

     }

 }