1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CHROME_BROWSER_EXTENSIONS_SANDBOXED_UNPACKER_H_
6#define CHROME_BROWSER_EXTENSIONS_SANDBOXED_UNPACKER_H_
7
8#include <string>
9
10#include "base/files/file_path.h"
11#include "base/files/scoped_temp_dir.h"
12#include "base/memory/ref_counted.h"
13#include "base/time/time.h"
14#include "chrome/common/extensions/manifest.h"
15#include "content/public/browser/utility_process_host_client.h"
16
17class SkBitmap;
18
19namespace base {
20class DictionaryValue;
21class SequencedTaskRunner;
22}
23
24namespace extensions {
25class Extension;
26
27class SandboxedUnpackerClient
28    : public base::RefCountedThreadSafe<SandboxedUnpackerClient> {
29 public:
30  // temp_dir - A temporary directory containing the results of the extension
31  // unpacking. The client is responsible for deleting this directory.
32  //
33  // extension_root - The path to the extension root inside of temp_dir.
34  //
35  // original_manifest - The parsed but unmodified version of the manifest,
36  // with no modifications such as localization, etc.
37  //
38  // extension - The extension that was unpacked. The client is responsible
39  // for deleting this memory.
40  //
41  // install_icon - The icon we will display in the installation UI, if any.
42  virtual void OnUnpackSuccess(const base::FilePath& temp_dir,
43                               const base::FilePath& extension_root,
44                               const base::DictionaryValue* original_manifest,
45                               const Extension* extension,
46                               const SkBitmap& install_icon) = 0;
47  virtual void OnUnpackFailure(const string16& error) = 0;
48
49 protected:
50  friend class base::RefCountedThreadSafe<SandboxedUnpackerClient>;
51
52  virtual ~SandboxedUnpackerClient() {}
53};
54
55// SandboxedUnpacker unpacks extensions from the CRX format into a
56// directory. This is done in a sandboxed subprocess to protect the browser
57// process from parsing complex formats like JPEG or JSON from untrusted
58// sources.
59//
60// Unpacking an extension using this class makes minor changes to its source,
61// such as transcoding all images to PNG, parsing all message catalogs
62// and rewriting the manifest JSON. As such, it should not be used when the
63// output is not intended to be given back to the author.
64//
65//
66// Lifetime management:
67//
68// This class is ref-counted by each call it makes to itself on another thread,
69// and by UtilityProcessHost.
70//
71// Additionally, we hold a reference to our own client so that it lives at least
72// long enough to receive the result of unpacking.
73//
74//
75// NOTE: This class should only be used on the file thread.
76class SandboxedUnpacker : public content::UtilityProcessHostClient {
77 public:
78  // Unpacks the extension in |crx_path| into a temporary directory and calls
79  // |client| with the result. If |run_out_of_process| is provided, unpacking
80  // is done in a sandboxed subprocess. Otherwise, it is done in-process.
81  SandboxedUnpacker(const base::FilePath& crx_path,
82                    Manifest::Location location,
83                    int creation_flags,
84                    const base::FilePath& extensions_dir,
85                    base::SequencedTaskRunner* unpacker_io_task_runner,
86                    SandboxedUnpackerClient* client);
87
88  // Start unpacking the extension. The client is called with the results.
89  void Start();
90
91 private:
92  class ProcessHostClient;
93
94  // Enumerate all the ways unpacking can fail.  Calls to ReportFailure()
95  // take a failure reason as an argument, and put it in histogram
96  // Extensions.SandboxUnpackFailureReason.
97  enum FailureReason {
98    // SandboxedUnpacker::CreateTempDirectory()
99    COULD_NOT_GET_TEMP_DIRECTORY,
100    COULD_NOT_CREATE_TEMP_DIRECTORY,
101
102    // SandboxedUnpacker::Start()
103    FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY,
104    COULD_NOT_GET_SANDBOX_FRIENDLY_PATH,
105
106    // SandboxedUnpacker::OnUnpackExtensionSucceeded()
107    COULD_NOT_LOCALIZE_EXTENSION,
108    INVALID_MANIFEST,
109
110    // SandboxedUnpacker::OnUnpackExtensionFailed()
111    UNPACKER_CLIENT_FAILED,
112
113    // SandboxedUnpacker::OnProcessCrashed()
114    UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL,
115
116    // SandboxedUnpacker::ValidateSignature()
117    CRX_FILE_NOT_READABLE,
118    CRX_HEADER_INVALID,
119    CRX_MAGIC_NUMBER_INVALID,
120    CRX_VERSION_NUMBER_INVALID,
121    CRX_EXCESSIVELY_LARGE_KEY_OR_SIGNATURE,
122    CRX_ZERO_KEY_LENGTH,
123    CRX_ZERO_SIGNATURE_LENGTH,
124    CRX_PUBLIC_KEY_INVALID,
125    CRX_SIGNATURE_INVALID,
126    CRX_SIGNATURE_VERIFICATION_INITIALIZATION_FAILED,
127    CRX_SIGNATURE_VERIFICATION_FAILED,
128
129    // SandboxedUnpacker::RewriteManifestFile()
130    ERROR_SERIALIZING_MANIFEST_JSON,
131    ERROR_SAVING_MANIFEST_JSON,
132
133    // SandboxedUnpacker::RewriteImageFiles()
134    COULD_NOT_READ_IMAGE_DATA_FROM_DISK,
135    DECODED_IMAGES_DO_NOT_MATCH_THE_MANIFEST,
136    INVALID_PATH_FOR_BROWSER_IMAGE,
137    ERROR_REMOVING_OLD_IMAGE_FILE,
138    INVALID_PATH_FOR_BITMAP_IMAGE,
139    ERROR_RE_ENCODING_THEME_IMAGE,
140    ERROR_SAVING_THEME_IMAGE,
141    ABORTED_DUE_TO_SHUTDOWN,
142
143    // SandboxedUnpacker::RewriteCatalogFiles()
144    COULD_NOT_READ_CATALOG_DATA_FROM_DISK,
145    INVALID_CATALOG_DATA,
146    INVALID_PATH_FOR_CATALOG,
147    ERROR_SERIALIZING_CATALOG,
148    ERROR_SAVING_CATALOG,
149
150    NUM_FAILURE_REASONS
151  };
152
153  friend class ProcessHostClient;
154  friend class SandboxedUnpackerTest;
155
156  virtual ~SandboxedUnpacker();
157
158  // Set |temp_dir_| as a temporary directory to unpack the extension in.
159  // Return true on success.
160  virtual bool CreateTempDirectory();
161
162  // Validates the signature of the extension and extract the key to
163  // |public_key_|. Returns true if the signature validates, false otherwise.
164  //
165  // NOTE: Having this method here is a bit ugly. This code should really live
166  // in extensions::Unpacker as it is not specific to sandboxed unpacking. It
167  // was put here because we cannot run windows crypto code in the sandbox. But
168  // we could still have this method statically on extensions::Unpacker so that
169  // code just for unpacking is there and code just for sandboxing of unpacking
170  // is here.
171  bool ValidateSignature();
172
173  // Starts the utility process that unpacks our extension.
174  void StartProcessOnIOThread(const base::FilePath& temp_crx_path);
175
176  // UtilityProcessHostClient
177  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
178  virtual void OnProcessCrashed(int exit_code) OVERRIDE;
179
180  // IPC message handlers.
181  void OnUnpackExtensionSucceeded(const base::DictionaryValue& manifest);
182  void OnUnpackExtensionFailed(const string16& error_message);
183
184  void ReportFailure(FailureReason reason, const string16& message);
185  void ReportSuccess(const base::DictionaryValue& original_manifest,
186                     const SkBitmap& install_icon);
187
188  // Overwrites original manifest with safe result from utility process.
189  // Returns NULL on error. Caller owns the returned object.
190  base::DictionaryValue* RewriteManifestFile(
191      const base::DictionaryValue& manifest);
192
193  // Overwrites original files with safe results from utility process.
194  // Reports error and returns false if it fails.
195  bool RewriteImageFiles(SkBitmap* install_icon);
196  bool RewriteCatalogFiles();
197
198  // Cleans up temp directory artifacts.
199  void Cleanup();
200
201  // The path to the CRX to unpack.
202  base::FilePath crx_path_;
203
204  // Our client.
205  scoped_refptr<SandboxedUnpackerClient> client_;
206
207  // The Extensions directory inside the profile.
208  base::FilePath extensions_dir_;
209
210  // A temporary directory to use for unpacking.
211  base::ScopedTempDir temp_dir_;
212
213  // The root directory of the unpacked extension. This is a child of temp_dir_.
214  base::FilePath extension_root_;
215
216  // Represents the extension we're unpacking.
217  scoped_refptr<Extension> extension_;
218
219  // Whether we've received a response from the utility process yet.
220  bool got_response_;
221
222  // The public key that was extracted from the CRX header.
223  std::string public_key_;
224
225  // The extension's ID. This will be calculated from the public key in the crx
226  // header.
227  std::string extension_id_;
228
229  // Time at which unpacking started. Used to compute the time unpacking takes.
230  base::TimeTicks unpack_start_time_;
231
232  // Location to use for the unpacked extension.
233  Manifest::Location location_;
234
235  // Creation flags to use for the extension.  These flags will be used
236  // when calling Extenion::Create() by the crx installer.
237  int creation_flags_;
238
239  // Sequenced task runner where file I/O operations will be performed at.
240  scoped_refptr<base::SequencedTaskRunner> unpacker_io_task_runner_;
241};
242
243}  // namespace extensions
244
245#endif  // CHROME_BROWSER_EXTENSIONS_SANDBOXED_UNPACKER_H_
246