// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_
#define CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_
#include <string>
#include <vector>
#include "base/basictypes.h"
#include "base/callback.h"
#include "base/files/file_path.h"
#include "base/json/json_file_value_serializer.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/sequenced_task_runner.h"
namespace component_updater {
class ComponentInstaller;
class ComponentPatcher;
// Deserializes the CRX manifest. The top level must be a dictionary.
scoped_ptr<base::DictionaryValue> ReadManifest(
const base::FilePath& unpack_path);
// In charge of unpacking the component CRX package and verifying that it is
// well formed and the cryptographic signature is correct. If there is no
// error the component specific installer will be invoked to proceed with
// the component installation or update.
//
// This class should be used only by the component updater. It is inspired by
// and overlaps with code in the extension's SandboxedUnpacker.
// The main differences are:
// - The public key hash is full SHA256.
// - Does not use a sandboxed unpacker. A valid component is fully trusted.
// - The manifest can have different attributes and resources are not
// transcoded.
//
// If the CRX is a delta CRX, the flow is:
// [ComponentUpdater] [ComponentPatcher]
// Unpack
// \_ Verify
// \_ Unzip
// \_ BeginPatching ---> DifferentialUpdatePatch
// ...
// EndPatching <------------ ...
// \_ Install
// \_ Finish
//
// For a full CRX, the flow is:
// [ComponentUpdater]
// Unpack
// \_ Verify
// \_ Unzip
// \_ BeginPatching
// |
// V
// EndPatching
// \_ Install
// \_ Finish
//
// In both cases, if there is an error at any point, the remaining steps will
// be skipped and Finish will be called.
class ComponentUnpacker : public base::RefCountedThreadSafe<ComponentUnpacker> {
public:
// Possible error conditions.
// Add only to the bottom of this enum; the order must be kept stable.
enum Error {
kNone,
kInvalidParams,
kInvalidFile,
kUnzipPathError,
kUnzipFailed,
kNoManifest,
kBadManifest,
kBadExtension,
kInvalidId,
kInstallerError,
kIoError,
kDeltaVerificationFailure,
kDeltaBadCommands,
kDeltaUnsupportedCommand,
kDeltaOperationFailure,
kDeltaPatchProcessFailure,
kDeltaMissingExistingFile,
kFingerprintWriteFailed,
};
typedef base::Callback<void(Error, int)> Callback;
// Constructs an unpacker for a specific component unpacking operation.
// |pk_hash| is the expected/ public key SHA256 hash. |path| is the current
// location of the CRX.
ComponentUnpacker(const std::vector<uint8>& pk_hash,
const base::FilePath& path,
const std::string& fingerprint,
ComponentInstaller* installer,
bool in_process,
scoped_refptr<base::SequencedTaskRunner> task_runner);
// Begins the actual unpacking of the files. May invoke a patcher if the
// package is a differential update. Calls |callback| with the result.
void Unpack(const Callback& callback);
private:
friend class base::RefCountedThreadSafe<ComponentUnpacker>;
virtual ~ComponentUnpacker();
bool UnpackInternal();
// The first step of unpacking is to verify the file. Returns false if an
// error is encountered, the file is malformed, or the file is incorrectly
// signed.
bool Verify();
// The second step of unpacking is to unzip. Returns false if an error
// occurs as part of unzipping.
bool Unzip();
// The third step is to optionally patch files - this is a no-op for full
// (non-differential) updates. This step is asynchronous. Returns false if an
// error is encountered.
bool BeginPatching();
// When patching is complete, EndPatching is called before moving on to step
// four.
void EndPatching(Error error, int extended_error);
// The fourth step is to install the unpacked component.
void Install();
// The final step is to do clean-up for things that can't be tidied as we go.
// If there is an error at any step, the remaining steps are skipped and
// and Finish is called.
// Finish is responsible for calling the callback provided in Start().
void Finish();
std::vector<uint8> pk_hash_;
base::FilePath path_;
base::FilePath unpack_path_;
base::FilePath unpack_diff_path_;
bool is_delta_;
std::string fingerprint_;
scoped_refptr<ComponentPatcher> patcher_;
ComponentInstaller* installer_;
Callback callback_;
const bool in_process_;
Error error_;
int extended_error_;
scoped_refptr<base::SequencedTaskRunner> task_runner_;
DISALLOW_COPY_AND_ASSIGN(ComponentUnpacker);
};
} // namespace component_updater
#endif // CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UNPACKER_H_