1// Copyright 2014 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 COMPONENTS_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_
6#define COMPONENTS_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_
7
8#include <stdint.h>
9#include <string>
10#include <vector>
11
12#include "base/callback.h"
13#include "base/files/file_path.h"
14#include "base/json/json_file_value_serializer.h"
15#include "base/macros.h"
16#include "base/memory/ref_counted.h"
17#include "base/memory/scoped_ptr.h"
18#include "base/sequenced_task_runner.h"
19
20namespace component_updater {
21
22class ComponentInstaller;
23class ComponentPatcher;
24class OutOfProcessPatcher;
25
26// Deserializes the CRX manifest. The top level must be a dictionary.
27scoped_ptr<base::DictionaryValue> ReadManifest(
28    const base::FilePath& unpack_path);
29
30// In charge of unpacking the component CRX package and verifying that it is
31// well formed and the cryptographic signature is correct. If there is no
32// error the component specific installer will be invoked to proceed with
33// the component installation or update.
34//
35// This class should be used only by the component updater. It is inspired by
36// and overlaps with code in the extension's SandboxedUnpacker.
37// The main differences are:
38// - The public key hash is full SHA256.
39// - Does not use a sandboxed unpacker. A valid component is fully trusted.
40// - The manifest can have different attributes and resources are not
41//   transcoded.
42//
43// If the CRX is a delta CRX, the flow is:
44//   [ComponentUpdater]      [ComponentPatcher]
45//   Unpack
46//     \_ Verify
47//     \_ Unzip
48//     \_ BeginPatching ---> DifferentialUpdatePatch
49//                             ...
50//   EndPatching <------------ ...
51//     \_ Install
52//     \_ Finish
53//
54// For a full CRX, the flow is:
55//   [ComponentUpdater]
56//   Unpack
57//     \_ Verify
58//     \_ Unzip
59//     \_ BeginPatching
60//          |
61//          V
62//   EndPatching
63//     \_ Install
64//     \_ Finish
65//
66// In both cases, if there is an error at any point, the remaining steps will
67// be skipped and Finish will be called.
68class ComponentUnpacker : public base::RefCountedThreadSafe<ComponentUnpacker> {
69 public:
70  // Possible error conditions.
71  // Add only to the bottom of this enum; the order must be kept stable.
72  enum Error {
73    kNone,
74    kInvalidParams,
75    kInvalidFile,
76    kUnzipPathError,
77    kUnzipFailed,
78    kNoManifest,
79    kBadManifest,
80    kBadExtension,
81    kInvalidId,
82    kInstallerError,
83    kIoError,
84    kDeltaVerificationFailure,
85    kDeltaBadCommands,
86    kDeltaUnsupportedCommand,
87    kDeltaOperationFailure,
88    kDeltaPatchProcessFailure,
89    kDeltaMissingExistingFile,
90    kFingerprintWriteFailed,
91  };
92
93  typedef base::Callback<void(Error, int)> Callback;
94
95  // Constructs an unpacker for a specific component unpacking operation.
96  // |pk_hash| is the expected/ public key SHA256 hash. |path| is the current
97  // location of the CRX.
98  ComponentUnpacker(const std::vector<uint8_t>& pk_hash,
99                    const base::FilePath& path,
100                    const std::string& fingerprint,
101                    ComponentInstaller* installer,
102                    scoped_refptr<OutOfProcessPatcher> out_of_process_patcher,
103                    scoped_refptr<base::SequencedTaskRunner> task_runner);
104
105  // Begins the actual unpacking of the files. May invoke a patcher if the
106  // package is a differential update. Calls |callback| with the result.
107  void Unpack(const Callback& callback);
108
109 private:
110  friend class base::RefCountedThreadSafe<ComponentUnpacker>;
111
112  virtual ~ComponentUnpacker();
113
114  bool UnpackInternal();
115
116  // The first step of unpacking is to verify the file. Returns false if an
117  // error is encountered, the file is malformed, or the file is incorrectly
118  // signed.
119  bool Verify();
120
121  // The second step of unpacking is to unzip. Returns false if an error
122  // occurs as part of unzipping.
123  bool Unzip();
124
125  // The third step is to optionally patch files - this is a no-op for full
126  // (non-differential) updates. This step is asynchronous. Returns false if an
127  // error is encountered.
128  bool BeginPatching();
129
130  // When patching is complete, EndPatching is called before moving on to step
131  // four.
132  void EndPatching(Error error, int extended_error);
133
134  // The fourth step is to install the unpacked component.
135  void Install();
136
137  // The final step is to do clean-up for things that can't be tidied as we go.
138  // If there is an error at any step, the remaining steps are skipped and
139  // and Finish is called.
140  // Finish is responsible for calling the callback provided in Start().
141  void Finish();
142
143  std::vector<uint8_t> pk_hash_;
144  base::FilePath path_;
145  base::FilePath unpack_path_;
146  base::FilePath unpack_diff_path_;
147  bool is_delta_;
148  std::string fingerprint_;
149  scoped_refptr<ComponentPatcher> patcher_;
150  ComponentInstaller* installer_;
151  Callback callback_;
152  scoped_refptr<OutOfProcessPatcher> out_of_process_patcher_;
153  Error error_;
154  int extended_error_;
155  scoped_refptr<base::SequencedTaskRunner> task_runner_;
156
157  DISALLOW_COPY_AND_ASSIGN(ComponentUnpacker);
158};
159
160}  // namespace component_updater
161
162#endif  // COMPONENTS_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_
163