java/com/google/gerrit/server/change/FileContentUtil.java - gerrit - Git at Google

 // Copyright (C) 2013 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 com.google.gerrit.server.change;

 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;

 import com.google.common.base.Strings;
 import com.google.common.hash.Hasher;
 import com.google.common.hash.Hashing;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.common.data.PatchScript.FileMode;
 import com.google.gerrit.entities.Patch;
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.BinaryResult;
 import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.mime.FileTypeRegistry;
 import com.google.gerrit.server.project.ProjectState;
 import com.google.gerrit.server.util.time.TimeUtil;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import eu.medsea.mimeutil.MimeType;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.security.SecureRandom;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 import org.eclipse.jgit.errors.LargeObjectException;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectLoader;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.util.NB;

 @Singleton
 public class FileContentUtil {
   public static final String TEXT_X_GERRIT_COMMIT_MESSAGE = "text/x-gerrit-commit-message";
   public static final String TEXT_X_GERRIT_MERGE_LIST = "text/x-gerrit-merge-list";
   private static final String X_GIT_SYMLINK = "x-git/symlink";
   private static final String X_GIT_GITLINK = "x-git/gitlink";
   private static final int MAX_SIZE = 5 << 20;
   private static final String ZIP_TYPE = "application/zip";
   private static final SecureRandom rng = new SecureRandom();

   private final GitRepositoryManager repoManager;
   private final FileTypeRegistry registry;

   @Inject
   FileContentUtil(GitRepositoryManager repoManager, FileTypeRegistry ftr) {
     this.repoManager = repoManager;
     this.registry = ftr;
   }

   /**
    * Get the content of a file at a specific commit or one of it's parent commits.
    *
    * @param project A {@code Project} that this request refers to.
    * @param revstr An {@code ObjectId} specifying the commit.
    * @param path A string specifying the filepath.
    * @param parent A 1-based parent index to get the content from instead. Null if the content
    *     should be obtained from {@code revstr} instead.
    * @return Content of the file as {@code BinaryResult}.
    * @throws ResourceNotFoundException
    * @throws IOException
    */
   public BinaryResult getContent(
       ProjectState project, ObjectId revstr, String path, @Nullable Integer parent)
       throws BadRequestException, ResourceNotFoundException, IOException {
     try (Repository repo = openRepository(project);
         RevWalk rw = new RevWalk(repo)) {
       if (parent != null) {
         RevCommit revCommit = rw.parseCommit(revstr);
         if (revCommit == null) {
           throw new ResourceNotFoundException("commit not found");
         }
         if (parent > revCommit.getParentCount()) {
           throw new BadRequestException("invalid parent");
         }
         revstr = rw.parseCommit(revstr).getParent(Integer.max(0, parent - 1)).toObjectId();
       }
       return getContent(repo, project, revstr, path);
     }
   }

   public BinaryResult getContent(
       Repository repo, ProjectState project, ObjectId revstr, String path)
       throws IOException, ResourceNotFoundException {
     try (RevWalk rw = new RevWalk(repo)) {
       RevCommit commit = rw.parseCommit(revstr);
       try (TreeWalk tw = TreeWalk.forPath(rw.getObjectReader(), path, commit.getTree())) {
         if (tw == null) {
           throw new ResourceNotFoundException();
         }

         org.eclipse.jgit.lib.FileMode mode = tw.getFileMode(0);
         ObjectId id = tw.getObjectId(0);
         if (mode == org.eclipse.jgit.lib.FileMode.GITLINK) {
           return BinaryResult.create(id.name()).setContentType(X_GIT_GITLINK).base64();
         }

         ObjectLoader obj = repo.open(id, OBJ_BLOB);
         byte[] raw;
         try {
           raw = obj.getCachedBytes(MAX_SIZE);
         } catch (LargeObjectException e) {
           raw = null;
         }

         String type;
         if (mode == org.eclipse.jgit.lib.FileMode.SYMLINK) {
           type = X_GIT_SYMLINK;
         } else {
           type = registry.getMimeType(path, raw).toString();
           type = resolveContentType(project, path, FileMode.FILE, type);
         }

         return asBinaryResult(raw, obj).setContentType(type).base64();
       }
     }
   }

   private static BinaryResult asBinaryResult(byte[] raw, ObjectLoader obj) {
     if (raw != null) {
       return BinaryResult.create(raw);
     }
     BinaryResult result =
         new BinaryResult() {
           @Override
           public void writeTo(OutputStream os) throws IOException {
             obj.copyTo(os);
           }
         };
     result.setContentLength(obj.getSize());
     return result;
   }

   public BinaryResult downloadContent(
       ProjectState project, ObjectId revstr, String path, @Nullable Integer parent)
       throws ResourceNotFoundException, IOException {
     try (Repository repo = openRepository(project);
         RevWalk rw = new RevWalk(repo)) {
       String suffix = "new";
       RevCommit commit = rw.parseCommit(revstr);
       if (parent != null && parent > 0) {
         if (commit.getParentCount() == 1) {
           suffix = "old";
         } else {
           suffix = "old" + parent;
         }
         commit = rw.parseCommit(commit.getParent(parent - 1));
       }
       try (TreeWalk tw = TreeWalk.forPath(rw.getObjectReader(), path, commit.getTree())) {
         if (tw == null) {
           throw new ResourceNotFoundException();
         }

         int mode = tw.getFileMode(0).getObjectType();
         if (mode != Constants.OBJ_BLOB) {
           throw new ResourceNotFoundException();
         }

         ObjectId id = tw.getObjectId(0);
         ObjectLoader obj = repo.open(id, OBJ_BLOB);
         byte[] raw;
         try {
           raw = obj.getCachedBytes(MAX_SIZE);
         } catch (LargeObjectException e) {
           raw = null;
         }

         MimeType contentType = registry.getMimeType(path, raw);
         return registry.isSafeInline(contentType)
             ? wrapBlob(path, obj, raw, contentType, suffix)
             : zipBlob(path, obj, commit, suffix);
       }
     }
   }

   private BinaryResult wrapBlob(
       String path,
       final ObjectLoader obj,
       byte[] raw,
       MimeType contentType,
       @Nullable String suffix) {
     return asBinaryResult(raw, obj)
         .setContentType(contentType.toString())
         .setAttachmentName(safeFileName(path, suffix));
   }

   @SuppressWarnings("resource")
   private BinaryResult zipBlob(
       final String path, ObjectLoader obj, RevCommit commit, @Nullable final String suffix) {
     final String commitName = commit.getName();
     final long when = commit.getCommitTime() * 1000L;
     return new BinaryResult() {
       @Override
       public void writeTo(OutputStream os) throws IOException {
         try (ZipOutputStream zipOut = new ZipOutputStream(os)) {
           String decoration = randSuffix();
           if (!Strings.isNullOrEmpty(suffix)) {
             decoration = suffix + '-' + decoration;
           }
           ZipEntry e = new ZipEntry(safeFileName(path, decoration));
           e.setComment(commitName + ":" + path);
           e.setSize(obj.getSize());
           e.setTime(when);
           zipOut.putNextEntry(e);
           obj.copyTo(zipOut);
           zipOut.closeEntry();
         }
       }
     }.setContentType(ZIP_TYPE).setAttachmentName(safeFileName(path, suffix) + ".zip").disableGzip();
   }

   private static String safeFileName(String fileName, @Nullable String suffix) {
     // Convert a file path (e.g. "src/Init.c") to a safe file name with
     // no meta-characters that might be unsafe on any given platform.
     //
     int slash = fileName.lastIndexOf('/');
     if (slash >= 0) {
       fileName = fileName.substring(slash + 1);
     }

     StringBuilder r = new StringBuilder(fileName.length());
     for (int i = 0; i < fileName.length(); i++) {
       final char c = fileName.charAt(i);
       if (c == '_' || c == '-' || c == '.' || c == '@') {
         r.append(c);
       } else if ('0' <= c && c <= '9') {
         r.append(c);
       } else if ('A' <= c && c <= 'Z') {
         r.append(c);
       } else if ('a' <= c && c <= 'z') {
         r.append(c);
       } else if (c == ' ' || c == '\n' || c == '\r' || c == '\t') {
         r.append('-');
       } else {
         r.append('_');
       }
     }
     fileName = r.toString();

     int ext = fileName.lastIndexOf('.');
     if (suffix == null) {
       return fileName;
     } else if (ext <= 0) {
       return fileName + "_" + suffix;
     } else {
       return fileName.substring(0, ext) + "_" + suffix + fileName.substring(ext);
     }
   }

   private static String randSuffix() {
     // Produce a random suffix that is difficult (or nearly impossible)
     // for an attacker to guess in advance. This reduces the risk that
     // an attacker could upload a *.class file and have us send a ZIP
     // that can be invoked through an applet tag in the victim's browser.
     //
     Hasher h = Hashing.murmur3_128().newHasher();
     byte[] buf = new byte[8];

     NB.encodeInt64(buf, 0, TimeUtil.nowMs());
     h.putBytes(buf);

     rng.nextBytes(buf);
     h.putBytes(buf);

     return h.hash().toString();
   }

   public static String resolveContentType(
       ProjectState project, String path, FileMode fileMode, String mimeType) {
     switch (fileMode) {
       case FILE:
         if (Patch.COMMIT_MSG.equals(path)) {
           return TEXT_X_GERRIT_COMMIT_MESSAGE;
         }
         if (Patch.MERGE_LIST.equals(path)) {
           return TEXT_X_GERRIT_MERGE_LIST;
         }
         if (project != null) {
           for (ProjectState p : project.tree()) {
             String t = p.getConfig().getMimeTypes().getMimeType(path);
             if (t != null) {
               return t;
             }
           }
         }
         return mimeType;
       case GITLINK:
         return X_GIT_GITLINK;
       case SYMLINK:
         return X_GIT_SYMLINK;
       default:
         throw new IllegalStateException("file mode: " + fileMode);
     }
   }

   private Repository openRepository(ProjectState project)
       throws RepositoryNotFoundException, IOException {
     return repoManager.openRepository(project.getNameKey());
   }
 }
	// Copyright (C) 2013 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 com.google.gerrit.server.change;

	import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;

	import com.google.common.base.Strings;
	import com.google.common.hash.Hasher;
	import com.google.common.hash.Hashing;
	import com.google.gerrit.common.Nullable;
	import com.google.gerrit.common.data.PatchScript.FileMode;
	import com.google.gerrit.entities.Patch;
	import com.google.gerrit.extensions.restapi.BadRequestException;
	import com.google.gerrit.extensions.restapi.BinaryResult;
	import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
	import com.google.gerrit.server.git.GitRepositoryManager;
	import com.google.gerrit.server.mime.FileTypeRegistry;
	import com.google.gerrit.server.project.ProjectState;
	import com.google.gerrit.server.util.time.TimeUtil;
	import com.google.inject.Inject;
	import com.google.inject.Singleton;
	import eu.medsea.mimeutil.MimeType;
	import java.io.IOException;
	import java.io.OutputStream;
	import java.security.SecureRandom;
	import java.util.zip.ZipEntry;
	import java.util.zip.ZipOutputStream;
	import org.eclipse.jgit.errors.LargeObjectException;
	import org.eclipse.jgit.errors.RepositoryNotFoundException;
	import org.eclipse.jgit.lib.Constants;
	import org.eclipse.jgit.lib.ObjectId;
	import org.eclipse.jgit.lib.ObjectLoader;
	import org.eclipse.jgit.lib.Repository;
	import org.eclipse.jgit.revwalk.RevCommit;
	import org.eclipse.jgit.revwalk.RevWalk;
	import org.eclipse.jgit.treewalk.TreeWalk;
	import org.eclipse.jgit.util.NB;

	@Singleton
	public class FileContentUtil {
	public static final String TEXT_X_GERRIT_COMMIT_MESSAGE = "text/x-gerrit-commit-message";
	public static final String TEXT_X_GERRIT_MERGE_LIST = "text/x-gerrit-merge-list";
	private static final String X_GIT_SYMLINK = "x-git/symlink";
	private static final String X_GIT_GITLINK = "x-git/gitlink";
	private static final int MAX_SIZE = 5 << 20;
	private static final String ZIP_TYPE = "application/zip";
	private static final SecureRandom rng = new SecureRandom();

	private final GitRepositoryManager repoManager;
	private final FileTypeRegistry registry;

	@Inject
	FileContentUtil(GitRepositoryManager repoManager, FileTypeRegistry ftr) {
	this.repoManager = repoManager;
	this.registry = ftr;
	}

	/**
	* Get the content of a file at a specific commit or one of it's parent commits.
	*
	* @param project A {@code Project} that this request refers to.
	* @param revstr An {@code ObjectId} specifying the commit.
	* @param path A string specifying the filepath.
	* @param parent A 1-based parent index to get the content from instead. Null if the content
	* should be obtained from {@code revstr} instead.
	* @return Content of the file as {@code BinaryResult}.
	* @throws ResourceNotFoundException
	* @throws IOException
	*/
	public BinaryResult getContent(
	ProjectState project, ObjectId revstr, String path, @Nullable Integer parent)
	throws BadRequestException, ResourceNotFoundException, IOException {
	try (Repository repo = openRepository(project);
	RevWalk rw = new RevWalk(repo)) {
	if (parent != null) {
	RevCommit revCommit = rw.parseCommit(revstr);
	if (revCommit == null) {
	throw new ResourceNotFoundException("commit not found");
	}
	if (parent > revCommit.getParentCount()) {
	throw new BadRequestException("invalid parent");
	}
	revstr = rw.parseCommit(revstr).getParent(Integer.max(0, parent - 1)).toObjectId();
	}
	return getContent(repo, project, revstr, path);
	}
	}

	public BinaryResult getContent(
	Repository repo, ProjectState project, ObjectId revstr, String path)
	throws IOException, ResourceNotFoundException {
	try (RevWalk rw = new RevWalk(repo)) {
	RevCommit commit = rw.parseCommit(revstr);
	try (TreeWalk tw = TreeWalk.forPath(rw.getObjectReader(), path, commit.getTree())) {
	if (tw == null) {
	throw new ResourceNotFoundException();
	}

	org.eclipse.jgit.lib.FileMode mode = tw.getFileMode(0);
	ObjectId id = tw.getObjectId(0);
	if (mode == org.eclipse.jgit.lib.FileMode.GITLINK) {
	return BinaryResult.create(id.name()).setContentType(X_GIT_GITLINK).base64();
	}

	ObjectLoader obj = repo.open(id, OBJ_BLOB);
	byte[] raw;
	try {
	raw = obj.getCachedBytes(MAX_SIZE);
	} catch (LargeObjectException e) {
	raw = null;
	}

	String type;
	if (mode == org.eclipse.jgit.lib.FileMode.SYMLINK) {
	type = X_GIT_SYMLINK;
	} else {
	type = registry.getMimeType(path, raw).toString();
	type = resolveContentType(project, path, FileMode.FILE, type);
	}

	return asBinaryResult(raw, obj).setContentType(type).base64();
	}
	}
	}

	private static BinaryResult asBinaryResult(byte[] raw, ObjectLoader obj) {
	if (raw != null) {
	return BinaryResult.create(raw);
	}
	BinaryResult result =
	new BinaryResult() {
	@Override
	public void writeTo(OutputStream os) throws IOException {
	obj.copyTo(os);
	}
	};
	result.setContentLength(obj.getSize());
	return result;
	}

	public BinaryResult downloadContent(
	ProjectState project, ObjectId revstr, String path, @Nullable Integer parent)
	throws ResourceNotFoundException, IOException {
	try (Repository repo = openRepository(project);
	RevWalk rw = new RevWalk(repo)) {
	String suffix = "new";
	RevCommit commit = rw.parseCommit(revstr);
	if (parent != null && parent > 0) {
	if (commit.getParentCount() == 1) {
	suffix = "old";
	} else {
	suffix = "old" + parent;
	}
	commit = rw.parseCommit(commit.getParent(parent - 1));
	}
	try (TreeWalk tw = TreeWalk.forPath(rw.getObjectReader(), path, commit.getTree())) {
	if (tw == null) {
	throw new ResourceNotFoundException();
	}

	int mode = tw.getFileMode(0).getObjectType();
	if (mode != Constants.OBJ_BLOB) {
	throw new ResourceNotFoundException();
	}

	ObjectId id = tw.getObjectId(0);
	ObjectLoader obj = repo.open(id, OBJ_BLOB);
	byte[] raw;
	try {
	raw = obj.getCachedBytes(MAX_SIZE);
	} catch (LargeObjectException e) {
	raw = null;
	}

	MimeType contentType = registry.getMimeType(path, raw);
	return registry.isSafeInline(contentType)
	? wrapBlob(path, obj, raw, contentType, suffix)
	: zipBlob(path, obj, commit, suffix);
	}
	}
	}

	private BinaryResult wrapBlob(
	String path,
	final ObjectLoader obj,
	byte[] raw,
	MimeType contentType,
	@Nullable String suffix) {
	return asBinaryResult(raw, obj)
	.setContentType(contentType.toString())
	.setAttachmentName(safeFileName(path, suffix));
	}

	@SuppressWarnings("resource")
	private BinaryResult zipBlob(
	final String path, ObjectLoader obj, RevCommit commit, @Nullable final String suffix) {
	final String commitName = commit.getName();
	final long when = commit.getCommitTime() * 1000L;
	return new BinaryResult() {
	@Override
	public void writeTo(OutputStream os) throws IOException {
	try (ZipOutputStream zipOut = new ZipOutputStream(os)) {
	String decoration = randSuffix();
	if (!Strings.isNullOrEmpty(suffix)) {
	decoration = suffix + '-' + decoration;
	}
	ZipEntry e = new ZipEntry(safeFileName(path, decoration));
	e.setComment(commitName + ":" + path);
	e.setSize(obj.getSize());
	e.setTime(when);
	zipOut.putNextEntry(e);
	obj.copyTo(zipOut);
	zipOut.closeEntry();
	}
	}
	}.setContentType(ZIP_TYPE).setAttachmentName(safeFileName(path, suffix) + ".zip").disableGzip();
	}

	private static String safeFileName(String fileName, @Nullable String suffix) {
	// Convert a file path (e.g. "src/Init.c") to a safe file name with
	// no meta-characters that might be unsafe on any given platform.
	//
	int slash = fileName.lastIndexOf('/');
	if (slash >= 0) {
	fileName = fileName.substring(slash + 1);
	}

	StringBuilder r = new StringBuilder(fileName.length());
	for (int i = 0; i < fileName.length(); i++) {
	final char c = fileName.charAt(i);
	if (c == '_' \|\| c == '-' \|\| c == '.' \|\| c == '@') {
	r.append(c);
	} else if ('0' <= c && c <= '9') {
	r.append(c);
	} else if ('A' <= c && c <= 'Z') {
	r.append(c);
	} else if ('a' <= c && c <= 'z') {
	r.append(c);
	} else if (c == ' ' \|\| c == '\n' \|\| c == '\r' \|\| c == '\t') {
	r.append('-');
	} else {
	r.append('_');
	}
	}
	fileName = r.toString();

	int ext = fileName.lastIndexOf('.');
	if (suffix == null) {
	return fileName;
	} else if (ext <= 0) {
	return fileName + "_" + suffix;
	} else {
	return fileName.substring(0, ext) + "_" + suffix + fileName.substring(ext);
	}
	}

	private static String randSuffix() {
	// Produce a random suffix that is difficult (or nearly impossible)
	// for an attacker to guess in advance. This reduces the risk that
	// an attacker could upload a *.class file and have us send a ZIP
	// that can be invoked through an applet tag in the victim's browser.
	//
	Hasher h = Hashing.murmur3_128().newHasher();
	byte[] buf = new byte[8];

	NB.encodeInt64(buf, 0, TimeUtil.nowMs());
	h.putBytes(buf);

	rng.nextBytes(buf);
	h.putBytes(buf);

	return h.hash().toString();
	}

	public static String resolveContentType(
	ProjectState project, String path, FileMode fileMode, String mimeType) {
	switch (fileMode) {
	case FILE:
	if (Patch.COMMIT_MSG.equals(path)) {
	return TEXT_X_GERRIT_COMMIT_MESSAGE;
	}
	if (Patch.MERGE_LIST.equals(path)) {
	return TEXT_X_GERRIT_MERGE_LIST;
	}
	if (project != null) {
	for (ProjectState p : project.tree()) {
	String t = p.getConfig().getMimeTypes().getMimeType(path);
	if (t != null) {
	return t;
	}
	}
	}
	return mimeType;
	case GITLINK:
	return X_GIT_GITLINK;
	case SYMLINK:
	return X_GIT_SYMLINK;
	default:
	throw new IllegalStateException("file mode: " + fileMode);
	}
	}

	private Repository openRepository(ProjectState project)
	throws RepositoryNotFoundException, IOException {
	return repoManager.openRepository(project.getNameKey());
	}
	}