electron/shell/common/asar/archive.h

118 lines
3 KiB
C++

// Copyright (c) 2014 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#ifndef SHELL_COMMON_ASAR_ARCHIVE_H_
#define SHELL_COMMON_ASAR_ARCHIVE_H_
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>
#include "base/files/file.h"
#include "base/files/file_path.h"
#include "base/synchronization/lock.h"
#include "third_party/abseil-cpp/absl/types/optional.h"
namespace base {
class DictionaryValue;
}
namespace asar {
class ScopedTemporaryFile;
enum HashAlgorithm {
SHA256,
NONE,
};
struct IntegrityPayload {
IntegrityPayload();
~IntegrityPayload();
IntegrityPayload(const IntegrityPayload& other);
HashAlgorithm algorithm;
std::string hash;
uint32_t block_size;
std::vector<std::string> blocks;
};
// This class represents an asar package, and provides methods to read
// information from it. It is thread-safe after |Init| has been called.
class Archive {
public:
struct FileInfo {
FileInfo();
~FileInfo();
bool unpacked;
bool executable;
uint32_t size;
uint64_t offset;
absl::optional<IntegrityPayload> integrity;
};
struct Stats : public FileInfo {
Stats() : is_file(true), is_directory(false), is_link(false) {}
bool is_file;
bool is_directory;
bool is_link;
};
explicit Archive(const base::FilePath& path);
virtual ~Archive();
// disable copy
Archive(const Archive&) = delete;
Archive& operator=(const Archive&) = delete;
// Read and parse the header.
bool Init();
absl::optional<IntegrityPayload> HeaderIntegrity() const;
absl::optional<base::FilePath> RelativePath() const;
// Get the info of a file.
bool GetFileInfo(const base::FilePath& path, FileInfo* info) const;
// Fs.stat(path).
bool Stat(const base::FilePath& path, Stats* stats) const;
// Fs.readdir(path).
bool Readdir(const base::FilePath& path,
std::vector<base::FilePath>* files) const;
// Fs.realpath(path).
bool Realpath(const base::FilePath& path, base::FilePath* realpath) const;
// Copy the file into a temporary file, and return the new path.
// For unpacked file, this method will return its real path.
bool CopyFileOut(const base::FilePath& path, base::FilePath* out);
// Returns the file's fd.
// Using this fd will not validate the integrity of any files
// you read out of the ASAR manually. Callers are responsible
// for integrity validation after this fd is handed over.
int GetUnsafeFD() const;
base::FilePath path() const { return path_; }
private:
bool initialized_;
bool header_validated_ = false;
const base::FilePath path_;
base::File file_;
int fd_ = -1;
uint32_t header_size_ = 0;
std::unique_ptr<base::DictionaryValue> header_;
// Cached external temporary files.
base::Lock external_files_lock_;
std::unordered_map<base::FilePath::StringType,
std::unique_ptr<ScopedTemporaryFile>>
external_files_;
};
} // namespace asar
#endif // SHELL_COMMON_ASAR_ARCHIVE_H_