ssgx::filesystem_t Namespace Reference

This module is designed to operate directly on files and directories in enclave. More...

Classes
class	FileStatus
	A class to store file type and permissions. More...
class	FileSystemException
	Exception about filesystem. More...
class	Path
	A class for storing path. More...
class	PlainFileReader
	Read a plaintext file (file size <= 100 KB) More...
class	PlainFileWriter
	Write a plaintext file (file size <= 100 KB) More...
class	ProtectedFileReader
	A ProtectedFileReader for reading from the Intel SGX Protected File System. More...
class	ProtectedFileWriter
	A ProtectedFileWriter for writing to the Intel SGX Protected File System. More...

Enumerations
enum class	FileType {   None = 0 , NotFound , Regular , Directory ,   Symlink , Block , Character , Fifo ,   Socket , Unknown }
	File type enum. More...
enum class	Perms : unsigned {   None = 0 , OwnerRead = 0400 , OwnerWrite = 0200 , OwnerExec = 0100 ,   OwnerAll = 0700 , GroupRead = 040 , GroupWrite = 020 , GroupExec = 010 ,   GroupAll = 070 , OthersRead = 04 , OthersWrite = 02 , OthersExec = 01 ,   OthersAll = 07 , All = 0777 , SetUid = 04000 , SetGid = 02000 ,   StickyBit = 01000 , Mask = 07777 , Unknown = 0xFFFF }
	File permissions (Octal) More...
enum class	FileMode { CreateNew = 1 , OpenOrCreate = 2 , Append = 3 }
	The mode for file writing operation. More...

Functions
bool	CreateDirectory (const Path &p)
	Create a directory (attribute default 0755)
FileStatus	Status (const Path &p)
	Retrieve file type and permissions; If the file is a symbolic link, the retrieved file type and permissions correspond to those of the target file it references.
FileStatus	SymlinkStatus (const Path &p)
	Retrieve file type and permissions; This function can retrieve the type and permissions of the symbolic link file itself, distinct from its target file.
bool	Exists (const FileStatus &s) noexcept
	Check if a file exists.
bool	Exists (const Path &p)
	Check if a file exists.
bool	Remove (const Path &p)
	Remove a file.
bool	RemoveProtectedFile (const Path &file_name)
	Remove a protected file.
uintmax_t	FileSize (const Path &p)
	Check the size of the file.
bool	IsDirectory (const FileStatus &s) noexcept
	Check if the file is a directory.
bool	IsDirectory (const Path &p)
	Check if the file is a directory.
bool	IsEmpty (const Path &p)
	If the path is a directory, check whether it is empty; If the path is a regular file, check whether its size is 0.
bool	IsRegularFile (const FileStatus &s) noexcept
	Check if the file is a regular file.
bool	IsRegularFile (const Path &p)
	Check if the file is a regular file.

Detailed Description

This module is designed to operate directly on files and directories in enclave.

Enumeration Type Documentation

FileMode

enum class ssgx::filesystem_t::FileMode

strong

The mode for file writing operation.

Enumerator
CreateNew	Specifies that the operating system should create a new file. If the file already exists, an FileSystemException exception is thrown.
OpenOrCreate	Specifies that the operating system should open a file if it exists; otherwise, a new file will be created.
Append	Opens the file if it exists and seeks to the end of the file, or creates a new file.

FileType

enum class ssgx::filesystem_t::FileType

strong

File type enum.

Enumerator
None	default value
NotFound	the file is not exist
Regular	the file is a regular file
Directory	the file is a directory file
Symlink	the file is a symlink file
Block	the file is a block file
Character	the file is a character file
Fifo	the file is a fifo file
Socket	the file is a socket file
Unknown	the type of file is unknown

Perms

enum class ssgx::filesystem_t::Perms : unsigned

strong

File permissions (Octal)

Enumerator
None	No permissions.
OwnerRead	The file owner has read permission.
OwnerWrite	The file owner has write permission.
OwnerExec	The file owner has execute permission.
OwnerAll	The file owner has read, write and execute permission.
GroupRead	The file owner's user group has read permissions.
GroupWrite	The file owner's user group has write permissions.
GroupExec	The file owner's user group has execute permissions.
GroupAll	The file owner's user group has read, write and execute permission
OthersRead	Others have read permission.
OthersWrite	Others have write permission.
OthersExec	Others have execute permission.
OthersAll	Others have read, write and execute permission.
All	All users have read, write and execute permission.
SetUid	When this bit is set, the file has the file owner's permissions during execution
SetGid	When this bit is set, files created in this directory belong to the same group as the directory.
StickyBit	When this bit is set, only the owner of the file in the directory or root can delete or move the file.
Mask	The file permissions represent the bits.
Unknown	Invalid permission.

Function Documentation

CreateDirectory()

bool ssgx::filesystem_t::CreateDirectory

(

const Path &

p

)

Create a directory (attribute default 0755)

Parameters

[in]

p

Dir path

Returns

Return true if created successfully; return false if the directory already exists

Exceptions

FileSystemException

Example

Path file_path("/root/main.cpp");
try {
    bool result = CreateDirectory(file_path);
} catch (FileSystemException& e) {
    ...
}

Exists() [1/2]

bool ssgx::filesystem_t::Exists ( const FileStatus & s )

noexcept

Check if a file exists.

Parameters

[in]

s

File status

Returns

Return true if it exists; return false if it does not exist

See also

ssgx::filesystem::Status(const Path& p)

Example

Path file_path("/root/main.cpp");
try {
    FileStatus file_status = Status(file_path);
} catch (FileSystemException& e) {
    ...
}
bool result = Exists(file_status);

Exists() [2/2]

bool ssgx::filesystem_t::Exists

(

const Path &

p

)

Check if a file exists.

Parameters

[in]

p

File path

Returns

Return true if it exists; return false if it does not exist

Exceptions

FileSystemException

Example

Path file_path("/root/main.cpp");
try {
    bool result = Exists(file_path);
} catch (FileSystemException& e) {
    ...
}

FileSize()

uintmax_t ssgx::filesystem_t::FileSize

(

const Path &

p

)

Check the size of the file.

Parameters

[in]

p

File path

Returns

File size

Exceptions

FileSystemException

Example

Path file_path("/root/main.cpp");
try {
    uint64_t result = FileSize(file_path);
} catch (FileSystemException& e) {
    ...
}

IsDirectory() [1/2]

bool ssgx::filesystem_t::IsDirectory ( const FileStatus & s )

noexcept

Check if the file is a directory.

Parameters

[in]

s

File status

Returns

Return true if the file type is a directory; otherwise return false

See also

Status(const Path& p)

Example

Path file_path("/root/main.cpp");
try {
    FileStatus file_status = Status(file_path);
} catch (FileSystemException& e) {
    ...
}
bool result = IsDirectory(file_status);

IsDirectory() [2/2]

bool ssgx::filesystem_t::IsDirectory

(

const Path &

p

)

Check if the file is a directory.

Parameters

[in]

p

File path

Returns

Return true if the file type is a directory; otherwise return false

Exceptions

FileSystemException

Example

Path file_path("/root/main.cpp");
try {
    bool result = IsDirectory(file_path);
} catch (FileSystemException& e) {
    ...
}

IsEmpty()

bool ssgx::filesystem_t::IsEmpty

(

const Path &

p

)

If the path is a directory, check whether it is empty; If the path is a regular file, check whether its size is 0.

Parameters

[in]

p

Path

Returns

If the path is a directory: return true if the directory is empty; otherwise return false;
If the path is a regular file: returns true if its size is 0; otherwise return false

Exceptions

FileSystemException

Example

Path file_path("/root");
try {
    bool result = IsEmpty(file_path);
} catch (FileSystemException& e) {
    ...
}

IsRegularFile() [1/2]

bool ssgx::filesystem_t::IsRegularFile ( const FileStatus & s )

noexcept

Check if the file is a regular file.

Parameters

[in]

s

File status

Returns

Return true if the file type is a regular file; otherwise return false

See also

Status(const Path& p)

Example

Path file_path("/root/main.cpp");
try {
    FileStatus file_status = Status(file_path);
} catch (FileSystemException& e) {
    ...
}
bool result = IsRegularFile(file_status);

IsRegularFile() [2/2]

bool ssgx::filesystem_t::IsRegularFile

(

const Path &

p

)

Check if the file is a regular file.

Parameters

[in]

p

File path

Returns

Return true if the file type is a regular file; otherwise return false

Exceptions

FileSystemException

Example

Path file_path("/root/main.cpp");
try {
    bool result = IsRegularFile(file_path);
} catch (FileSystemException& e) {
    ...
}

Remove()

bool ssgx::filesystem_t::Remove

(

const Path &

p

)

Remove a file.

Parameters

[in]

p

File path

Returns

Return true if removed successfully; return false if the file does not exist

Exceptions

FileSystemException

Example

Path file_path("/root/main.cpp");
try {
    bool result = Remove(file_path);
} catch (FileSystemException& e) {
    ...
}

RemoveProtectedFile()

bool ssgx::filesystem_t::RemoveProtectedFile

(

const Path &

file_name

)

Remove a protected file.

Parameters

[in]

The

protected file name

Returns

Return true if removed successfully; return false if the file does not exist

Exceptions

FileSystemException

Example

Path file_path("/root/sealed_file");
try {
    bool result = RemoveProtectedFile(file_path);
} catch (FileSystemException& e) {
    ...
}

Status()

FileStatus ssgx::filesystem_t::Status

(

const Path &

p

)

Retrieve file type and permissions; If the file is a symbolic link, the retrieved file type and permissions correspond to those of the target file it references.

Parameters

[in]

p

File path

Returns

File status

Exceptions

FileSystemException

Example

Path file_path("/root/main.cpp");
try {
    FileStatus file_status = Status(file_path);
} catch (FileSystemException& e) {
    ...
}

SymlinkStatus()

FileStatus ssgx::filesystem_t::SymlinkStatus

(

const Path &

p

)

Retrieve file type and permissions; This function can retrieve the type and permissions of the symbolic link file itself, distinct from its target file.

Parameters

[in]

p

File path

Returns

File status

Exceptions

FileSystemException

Example

Path file_path("/root/main.cpp");
try {
    FileStatus file_status = SymlinkStatus(file_path);
} catch (FileSystemException& e) {
    ...
}