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File Settings

Source code in src/desfire/schemas/file_settings.py 
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class FileSettings:
    def __init__(
        self,
        encryption: DESFireCommunicationMode | None = None,
        file_type: DESFireFileType | None = None,
        permissions: FilePermissions | None = None,
        file_size: int = 0,
    ):
        """
        Initialize the FileSettings object

        Args:
            encryption (DESFireCommunicationMode | None, optional): Encryption mode that should be applied
                to the file. Can be plain (anyone can read/write), MACed (only authenticated users can read/write)
                or encrypted (only authenticated users can read/write).
            file_type (DESFireFileType | None, optional): Type of the file. Currently only standard files are supported.
            permissions (FilePermissions | None, optional): Permissions that should be applied to the file.
                Refer to the FilePermissions class for more information.
            file_size (int, optional): File size in bytes. Only used for standard data files.
        """
        self.encryption = encryption
        self.file_type = file_type
        self.permissions = permissions

        # used only for MDFT_STANDARD_DATA_FILE and MDFT_BACKUP_DATA_FILE, uint32_t
        self.file_size = file_size

    def parse(self, data):
        """
        Takes raw data from command 0xF5 (get file settings) and parses it into a FileSettings object.

        Example of a raw data from command 0xF5 (get file settings on a standard data file):

        ```
        00 03 00 23 08 00 00
        ^^ ^^ ^^^^^ ^^^^^^^^
        |  |  |     |
        |  |  |     ^ File Size (3 bytes)
        |  |  ^ File Permissions (2 bytes)
        |  ^ Communication / Encryption mode (1 byte)
        ^ File Type (1 byte)
        ```

        File permissions are 4 bits each:
            - 0b - 3b: Change Permission key
            - 4b - 7b: Read-Write Permission key
            - 8b - 11b: Write Permission key
            - 12b - 15b: Read Permission key

        There are four other file types that are not implemented yet.
        """

        self.file_type = DESFireFileType(data[0])
        self.encryption = DESFireCommunicationMode(data[1])
        self.permissions = FilePermissions()
        self.permissions.parse(data[2:4])

        if self.file_type == DESFireFileType.MDFT_STANDARD_DATA_FILE:
            # Standard data file, parse file size in bytes. <I is little-endian unsigned int
            self.file_size = struct.unpack("<I", bytes(data[4:7] + [0x00]))[0]
        else:
            # TODO: We currently only support standard data files
            raise NotImplementedError(f"Filetype {data[0]:02X} is currently not supported.")

    def __repr__(self):
        """
        Returns a human readable representation of the file settings.
        """
        temp = " ----- FileSettings ----\r\n"
        temp += f"File type: {self.file_type.name}\r\n"
        temp += f"Encryption: {self.encryption.name}\r\n"
        temp += f"Permissions: {repr(self.permissions)}\r\n"
        if self.file_type == DESFireFileType.MDFT_STANDARD_DATA_FILE:
            temp += f"File size: {self.file_size}\r\n"

        return temp

__init__ 

__init__(
    encryption: DESFireCommunicationMode | None = None,
    file_type: DESFireFileType | None = None,
    permissions: FilePermissions | None = None,
    file_size: int = 0,
)

Initialize the FileSettings object

Parameters:

Name Type Description Default
encryption DESFireCommunicationMode | None

Encryption mode that should be applied to the file. Can be plain (anyone can read/write), MACed (only authenticated users can read/write) or encrypted (only authenticated users can read/write).

 None
file_type DESFireFileType | None

Type of the file. Currently only standard files are supported.

 None
permissions FilePermissions | None

Permissions that should be applied to the file. Refer to the FilePermissions class for more information.

 None
file_size int

File size in bytes. Only used for standard data files.

 0
Source code in src/desfire/schemas/file_settings.py 
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def __init__(
    self,
    encryption: DESFireCommunicationMode | None = None,
    file_type: DESFireFileType | None = None,
    permissions: FilePermissions | None = None,
    file_size: int = 0,
):
    """
    Initialize the FileSettings object

    Args:
        encryption (DESFireCommunicationMode | None, optional): Encryption mode that should be applied
            to the file. Can be plain (anyone can read/write), MACed (only authenticated users can read/write)
            or encrypted (only authenticated users can read/write).
        file_type (DESFireFileType | None, optional): Type of the file. Currently only standard files are supported.
        permissions (FilePermissions | None, optional): Permissions that should be applied to the file.
            Refer to the FilePermissions class for more information.
        file_size (int, optional): File size in bytes. Only used for standard data files.
    """
    self.encryption = encryption
    self.file_type = file_type
    self.permissions = permissions

    # used only for MDFT_STANDARD_DATA_FILE and MDFT_BACKUP_DATA_FILE, uint32_t
    self.file_size = file_size

__repr__ 

__repr__()

Returns a human readable representation of the file settings.

Source code in src/desfire/schemas/file_settings.py 
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def __repr__(self):
    """
    Returns a human readable representation of the file settings.
    """
    temp = " ----- FileSettings ----\r\n"
    temp += f"File type: {self.file_type.name}\r\n"
    temp += f"Encryption: {self.encryption.name}\r\n"
    temp += f"Permissions: {repr(self.permissions)}\r\n"
    if self.file_type == DESFireFileType.MDFT_STANDARD_DATA_FILE:
        temp += f"File size: {self.file_size}\r\n"

    return temp

parse 

parse(data)

Takes raw data from command 0xF5 (get file settings) and parses it into a FileSettings object.

Example of a raw data from command 0xF5 (get file settings on a standard data file):

00 03 00 23 08 00 00
^^ ^^ ^^^^^ ^^^^^^^^
|  |  |     |
|  |  |     ^ File Size (3 bytes)
|  |  ^ File Permissions (2 bytes)
|  ^ Communication / Encryption mode (1 byte)
^ File Type (1 byte)
File permissions are 4 bits each
  • 0b - 3b: Change Permission key
  • 4b - 7b: Read-Write Permission key
  • 8b - 11b: Write Permission key
  • 12b - 15b: Read Permission key

There are four other file types that are not implemented yet.

Source code in src/desfire/schemas/file_settings.py 
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def parse(self, data):
    """
    Takes raw data from command 0xF5 (get file settings) and parses it into a FileSettings object.

    Example of a raw data from command 0xF5 (get file settings on a standard data file):

    ```
    00 03 00 23 08 00 00
    ^^ ^^ ^^^^^ ^^^^^^^^
    |  |  |     |
    |  |  |     ^ File Size (3 bytes)
    |  |  ^ File Permissions (2 bytes)
    |  ^ Communication / Encryption mode (1 byte)
    ^ File Type (1 byte)
    ```

    File permissions are 4 bits each:
        - 0b - 3b: Change Permission key
        - 4b - 7b: Read-Write Permission key
        - 8b - 11b: Write Permission key
        - 12b - 15b: Read Permission key

    There are four other file types that are not implemented yet.
    """

    self.file_type = DESFireFileType(data[0])
    self.encryption = DESFireCommunicationMode(data[1])
    self.permissions = FilePermissions()
    self.permissions.parse(data[2:4])

    if self.file_type == DESFireFileType.MDFT_STANDARD_DATA_FILE:
        # Standard data file, parse file size in bytes. <I is little-endian unsigned int
        self.file_size = struct.unpack("<I", bytes(data[4:7] + [0x00]))[0]
    else:
        # TODO: We currently only support standard data files
        raise NotImplementedError(f"Filetype {data[0]:02X} is currently not supported.")