/*

  * 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.BufferedOutputStream;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileNotFoundException;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.Collections;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Set;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 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.ZipArchiveInputStream;

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

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

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

 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.utils.FileUtils;

 import org.owasp.dependencycheck.utils.Settings;

 /**

  * <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 <jeremy.long@owasp.org>

  */

 public class ArchiveAnalyzer extends AbstractAnalyzer implements Analyzer {

     /**

      * The buffer size to use when extracting files from the archive.

      */

     private static final int BUFFER_SIZE = 4096;

     /**

      * 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", "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 extractFiles().

      */

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

     static {

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

         if (additionalZipExt != null) {

             final HashSet ext = new HashSet<String>(Arrays.asList(additionalZipExt));

             ZIPPABLES.addAll(ext);

         }

         EXTENSIONS.addAll(ZIPPABLES);

     }

     /**

      * Returns a list of file EXTENSIONS supported by this analyzer.

      *

      * @return a list of file EXTENSIONS supported by this analyzer.

      */

     public Set<String> getSupportedExtensions() {

         return EXTENSIONS;

     }

     /**

      * Returns the name of the analyzer.

      *

      * @return the name of the analyzer.

      */

     public String getName() {

         return ANALYZER_NAME;

     }

     /**

      * Returns whether or not this analyzer can process the given extension.

      *

      * @param extension the file extension to test for support.

      * @return whether or not the specified file extension is supported by this analyzer.

      */

     public boolean supportsExtension(String extension) {

         return EXTENSIONS.contains(extension);

     }

     /**

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

      *

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

      */

     public AnalysisPhase getAnalysisPhase() {

         return ANALYSIS_PHASE;

     }

     //</editor-fold>

     /**

      * The initialize method does nothing for this Analyzer.

      *

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

      */

     @Override

     public void initialize() throws Exception {

         final File baseDir = Settings.getTempDirectory();

         if (!baseDir.exists()) {

             if (!baseDir.mkdirs()) {

                 final String msg = String.format("Unable to make a temporary folder '%s'", baseDir.getPath());

                 throw new AnalysisException(msg);

             }

         }

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

         if (!tempFileLocation.delete()) {

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

             throw new AnalysisException(msg);

         }

         if (!tempFileLocation.mkdirs()) {

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

             throw new AnalysisException(msg);

         }

     }

     /**

      * 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.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINE, "Attempting to delete temporary files");

             final boolean success = FileUtils.delete(tempFileLocation);

             if (!success) {

                 Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.WARNING,

                         "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 analyze(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 List<Dependency> dependencies = new ArrayList<Dependency>(engine.getDependencies());

         engine.scan(tmpDir);

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

         if (dependencies.size() != newDependencies.size()) {

             //get the new dependencies

             final Set<Dependency> dependencySet = new HashSet<Dependency>();

             dependencySet.addAll(newDependencies);

             dependencySet.removeAll(dependencies);

             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%s",

                         dependency.getFileName(),

                         File.separator,

                         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.supportsExtension(d.getFileExtension()) && scanDepth < MAX_SCAN_DEPTH) {

                     scanDepth += 1;

                     analyze(d, engine);

                     scanDepth -= 1;

                 }

             }

         }

         Collections.sort(engine.getDependencies());

     }

     /**

      * 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) {

             return;

         }

         FileInputStream fis = null;

         try {

             fis = new FileInputStream(archive);

         } catch (FileNotFoundException ex) {

             Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINE, null, ex);

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

         }

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

         try {

             if (ZIPPABLES.contains(archiveExt)) {

                 extractArchive(new ZipArchiveInputStream(new BufferedInputStream(fis)), 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 String uncompressedExt = FileUtils.getFileExtension(uncompressedName).toLowerCase();

                 if (engine.supportsExtension(uncompressedExt)) {

                     decompressFile(new GzipCompressorInputStream(new BufferedInputStream(fis)), new File(destination, uncompressedName));

                 }

             }

         } catch (ArchiveExtractionException ex) {

             final String msg = String.format("Exception extracting archive '%s'.", archive.getName());

             Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.WARNING, msg);

             Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINE, null, ex);

         } catch (IOException ex) {

             final String msg = String.format("Exception reading archive '%s'.", archive.getName());

             Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.WARNING, msg);

             Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINE, null, ex);

         } finally {

             try {

                 fis.close();

             } catch (IOException ex) {

                 Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINEST, null, ex);

             }

         }

     }

     /**

      * 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) {

                 if (entry.isDirectory()) {

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

                     if (!d.exists()) {

                         if (!d.mkdirs()) {

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

                             throw new AnalysisException(msg);

                         }

                     }

                 } else {

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

                     final String ext = FileUtils.getFileExtension(file.getName());

                     if (engine.supportsExtension(ext)) {

                         BufferedOutputStream bos = null;

                         FileOutputStream fos;

                         try {

                             final File parent = file.getParentFile();

                             if (!parent.isDirectory()) {

                                 if (!parent.mkdirs()) {

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

                                     throw new AnalysisException(msg);

                                 }

                             }

                             fos = new FileOutputStream(file);

                             bos = new BufferedOutputStream(fos, BUFFER_SIZE);

                             int count;

                             final byte data[] = new byte[BUFFER_SIZE];

                             while ((count = input.read(data, 0, BUFFER_SIZE)) != -1) {

                                 bos.write(data, 0, count);

                             }

                             bos.flush();

                         } catch (FileNotFoundException ex) {

                             Logger.getLogger(ArchiveAnalyzer.class

                                     .getName()).log(Level.FINE, null, ex);

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

                             throw new AnalysisException(msg, ex);

                         } catch (IOException ex) {

                             Logger.getLogger(ArchiveAnalyzer.class

                                     .getName()).log(Level.FINE, null, ex);

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

                             throw new AnalysisException(msg, ex);

                         } finally {

                             if (bos != null) {

                                 try {

                                     bos.close();

                                 } catch (IOException ex) {

                                     Logger.getLogger(ArchiveAnalyzer.class

                                             .getName()).log(Level.FINEST, null, ex);

                                 }

                             }

                         }

                     }

                 }

             }

         } catch (IOException ex) {

             throw new ArchiveExtractionException(ex);

         } catch (Throwable ex) {

             throw new ArchiveExtractionException(ex);

         } finally {

             if (input != null) {

                 try {

                     input.close();

                 } catch (IOException ex) {

                     Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINEST, null, ex);

                 }

             }

         }

     }

     /**

      * 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 {

         FileOutputStream out = null;

         try {

             out = new FileOutputStream(outputFile);

             final byte[] buffer = new byte[BUFFER_SIZE];

             int n = 0;

             while (-1 != (n = inputStream.read(buffer))) {

                 out.write(buffer, 0, n);

             }

         } catch (FileNotFoundException ex) {

             Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINE, null, ex);

             throw new ArchiveExtractionException(ex);

         } catch (IOException ex) {

             Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINE, null, ex);

             throw new ArchiveExtractionException(ex);

         } finally {

             if (out != null) {

                 try {

                     out.close();

                 } catch (IOException ex) {

                     Logger.getLogger(ArchiveAnalyzer.class.getName()).log(Level.FINEST, null, ex);

                 }

             }

         }

     }

 }