dissect.fve.crypto

Submodules

Package Contents

Classes

Cipher

Plain

Plain64

Plain64BE

Functions

create_cipher

Create a cipher object according to a given cipher specification and key.

parse_cipher_spec

Parse a cipher specification into a tuple of (cipher, mode, key size, iv mode, iv options).

Attributes

IV_MODE_MAP

class dissect.fve.crypto.Cipher(key: bytes, key_size: int, block_size: int, iv_mode: type[IV], iv_options: str, sector_size: int = 512, iv_sector_size: int = 512)
key
key_size
key_size_bytes
block_size
sector_size = 512
iv_sector_size = 512
iv_mode
encrypt(ciphertext: bytes, sector: int = 0, output: bytearray | None = None) → bytes | None
decrypt(ciphertext: bytes, sector: int = 0, output: bytearray | None = None) → bytes | None
class dissect.fve.crypto.Plain(cipher: Cipher, key: bytes, iv_options: str | None = None)

Bases: IV

generate(mode: int, iv: bytearray, data: bytearray, sector: int = 0) → None
class dissect.fve.crypto.Plain64(cipher: Cipher, key: bytes, iv_options: str | None = None)

Bases: IV

generate(mode: int, iv: bytearray, data: bytearray, sector: int = 0) → None
class dissect.fve.crypto.Plain64BE(cipher: Cipher, key: bytes, iv_options: str | None = None)

Bases: IV

generate(mode: int, iv: bytearray, data: bytearray, sector: int = 0) → None
dissect.fve.crypto.IV_MODE_MAP
dissect.fve.crypto.create_cipher(spec: str, key: bytes, key_size: int | None = None, sector_size: int = 512, iv_sector_size: int = 512) → base.Cipher

Create a cipher object according to a given cipher specification and key.

For more information on the cipher specification, read the documentation on parse_cipher_spec().

Parameters:

  • spec – The cipher specification to parse.

  • key – The key to initialize the cipher with.

  • key_size – Optional key size that overrides the specification key size.

  • sector_size – Optional sector size.

dissect.fve.crypto.parse_cipher_spec(spec: str, key_size: int | None = None, key_size_hint: int | None = None) → tuple[str, str, int, str, str | None]

Parse a cipher specification into a tuple of (cipher, mode, key size, iv mode, iv options).

Inspired by and accepts LUKS/dm-crypt-like cipher specifications in the form of:

cipher-mode-keysize-iv:ivopts

The mode, keysize, iv and ivopts are optional and will default to cbc, the key_size argument and plain respectively.

Parameters:

  • spec – The cipher specification to parse.

  • key_size – Optional key size that overrides the specification key size.

  • key_size_hint – Optional key size hint for the amount of bits that the key actually has.