chrome/browser/extensions/sandboxed_unpacker.h

   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 "content/public/browser/utility_process_host_client.h"
  15 #include "extensions/common/manifest.h"
  16
  17 class SkBitmap;
  18
  19 namespace base {
  20 class DictionaryValue;
  21 class SequencedTaskRunner;
  22 }
  23
  24 namespace extensions {
  25 class Extension;
  26
  27 class 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 base::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.
  76 class 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(
  82       const base::FilePath& crx_path,
  83       Manifest::Location location,
  84       int creation_flags,
  85       const base::FilePath& extensions_dir,
  86       const scoped_refptr<base::SequencedTaskRunner>& unpacker_io_task_runner,
  87       SandboxedUnpackerClient* client);
  88
  89   // Start unpacking the extension. The client is called with the results.
  90   void Start();
  91
  92  private:
  93   class ProcessHostClient;
  94
  95   // Enumerate all the ways unpacking can fail.  Calls to ReportFailure()
  96   // take a failure reason as an argument, and put it in histogram
  97   // Extensions.SandboxUnpackFailureReason.
  98   enum FailureReason {
  99     // SandboxedUnpacker::CreateTempDirectory()
 100     COULD_NOT_GET_TEMP_DIRECTORY,
 101     COULD_NOT_CREATE_TEMP_DIRECTORY,
 102
 103     // SandboxedUnpacker::Start()
 104     FAILED_TO_COPY_EXTENSION_FILE_TO_TEMP_DIRECTORY,
 105     COULD_NOT_GET_SANDBOX_FRIENDLY_PATH,
 106
 107     // SandboxedUnpacker::OnUnpackExtensionSucceeded()
 108     COULD_NOT_LOCALIZE_EXTENSION,
 109     INVALID_MANIFEST,
 110
 111     // SandboxedUnpacker::OnUnpackExtensionFailed()
 112     UNPACKER_CLIENT_FAILED,
 113
 114     // SandboxedUnpacker::OnProcessCrashed()
 115     UTILITY_PROCESS_CRASHED_WHILE_TRYING_TO_INSTALL,
 116
 117     // SandboxedUnpacker::ValidateSignature()
 118     CRX_FILE_NOT_READABLE,
 119     CRX_HEADER_INVALID,
 120     CRX_MAGIC_NUMBER_INVALID,
 121     CRX_VERSION_NUMBER_INVALID,
 122     CRX_EXCESSIVELY_LARGE_KEY_OR_SIGNATURE,
 123     CRX_ZERO_KEY_LENGTH,
 124     CRX_ZERO_SIGNATURE_LENGTH,
 125     CRX_PUBLIC_KEY_INVALID,
 126     CRX_SIGNATURE_INVALID,
 127     CRX_SIGNATURE_VERIFICATION_INITIALIZATION_FAILED,
 128     CRX_SIGNATURE_VERIFICATION_FAILED,
 129
 130     // SandboxedUnpacker::RewriteManifestFile()
 131     ERROR_SERIALIZING_MANIFEST_JSON,
 132     ERROR_SAVING_MANIFEST_JSON,
 133
 134     // SandboxedUnpacker::RewriteImageFiles()
 135     COULD_NOT_READ_IMAGE_DATA_FROM_DISK,
 136     DECODED_IMAGES_DO_NOT_MATCH_THE_MANIFEST,
 137     INVALID_PATH_FOR_BROWSER_IMAGE,
 138     ERROR_REMOVING_OLD_IMAGE_FILE,
 139     INVALID_PATH_FOR_BITMAP_IMAGE,
 140     ERROR_RE_ENCODING_THEME_IMAGE,
 141     ERROR_SAVING_THEME_IMAGE,
 142     ABORTED_DUE_TO_SHUTDOWN,
 143
 144     // SandboxedUnpacker::RewriteCatalogFiles()
 145     COULD_NOT_READ_CATALOG_DATA_FROM_DISK,
 146     INVALID_CATALOG_DATA,
 147     INVALID_PATH_FOR_CATALOG,
 148     ERROR_SERIALIZING_CATALOG,
 149     ERROR_SAVING_CATALOG,
 150
 151     NUM_FAILURE_REASONS
 152   };
 153
 154   friend class ProcessHostClient;
 155   friend class SandboxedUnpackerTest;
 156
 157   ~SandboxedUnpacker() override;
 158
 159   // Set |temp_dir_| as a temporary directory to unpack the extension in.
 160   // Return true on success.
 161   virtual bool CreateTempDirectory();
 162
 163   // Validates the signature of the extension and extract the key to
 164   // |public_key_|. Returns true if the signature validates, false otherwise.
 165   //
 166   // NOTE: Having this method here is a bit ugly. This code should really live
 167   // in extensions::Unpacker as it is not specific to sandboxed unpacking. It
 168   // was put here because we cannot run windows crypto code in the sandbox. But
 169   // we could still have this method statically on extensions::Unpacker so that
 170   // code just for unpacking is there and code just for sandboxing of unpacking
 171   // is here.
 172   bool ValidateSignature();
 173
 174   // Starts the utility process that unpacks our extension.
 175   void StartProcessOnIOThread(const base::FilePath& temp_crx_path);
 176
 177   // UtilityProcessHostClient
 178   bool OnMessageReceived(const IPC::Message& message) override;
 179   void OnProcessCrashed(int exit_code) override;
 180
 181   // IPC message handlers.
 182   void OnUnpackExtensionSucceeded(const base::DictionaryValue& manifest);
 183   void OnUnpackExtensionFailed(const base::string16& error_message);
 184
 185   void ReportFailure(FailureReason reason, const base::string16& message);
 186   void ReportSuccess(const base::DictionaryValue& original_manifest,
 187                      const SkBitmap& install_icon);
 188
 189   // Overwrites original manifest with safe result from utility process.
 190   // Returns NULL on error. Caller owns the returned object.
 191   base::DictionaryValue* RewriteManifestFile(
 192       const base::DictionaryValue& manifest);
 193
 194   // Overwrites original files with safe results from utility process.
 195   // Reports error and returns false if it fails.
 196   bool RewriteImageFiles(SkBitmap* install_icon);
 197   bool RewriteCatalogFiles();
 198
 199   // Cleans up temp directory artifacts.
 200   void Cleanup();
 201
 202   // The path to the CRX to unpack.
 203   base::FilePath crx_path_;
 204
 205   // Our client.
 206   scoped_refptr<SandboxedUnpackerClient> client_;
 207
 208   // The Extensions directory inside the profile.
 209   base::FilePath extensions_dir_;
 210
 211   // A temporary directory to use for unpacking.
 212   base::ScopedTempDir temp_dir_;
 213
 214   // The root directory of the unpacked extension. This is a child of temp_dir_.
 215   base::FilePath extension_root_;
 216
 217   // Represents the extension we're unpacking.
 218   scoped_refptr<Extension> extension_;
 219
 220   // Whether we've received a response from the utility process yet.
 221   bool got_response_;
 222
 223   // The public key that was extracted from the CRX header.
 224   std::string public_key_;
 225
 226   // The extension's ID. This will be calculated from the public key in the crx
 227   // header.
 228   std::string extension_id_;
 229
 230   // Time at which unpacking started. Used to compute the time unpacking takes.
 231   base::TimeTicks unpack_start_time_;
 232
 233   // Location to use for the unpacked extension.
 234   Manifest::Location location_;
 235
 236   // Creation flags to use for the extension.  These flags will be used
 237   // when calling Extenion::Create() by the crx installer.
 238   int creation_flags_;
 239
 240   // Sequenced task runner where file I/O operations will be performed at.
 241   scoped_refptr<base::SequencedTaskRunner> unpacker_io_task_runner_;
 242 };
 243
 244 }  // namespace extensions
 245
 246 #endif  // CHROME_BROWSER_EXTENSIONS_SANDBOXED_UNPACKER_H_