Add cryptography fallback when PyCryptodome (Crypto) is unavailable#1725
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Home Assistant OS environments may not provide a working `Crypto.*` module (PyCryptodome), causing SonoffLAN to fail at startup with: "cannot import name 'AES' from 'Crypto.Cipher'". This change wraps the PyCryptodome imports in a try/except and provides a drop-in fallback implementation using the `cryptography` package (already bundled with Home Assistant) plus `hashlib`/`os`: - AES-CBC cipher wrapper compatible with `AES.new(..., AES.MODE_CBC, iv=...)` - `AES.block_size` constant - `MD5.new()` compatible helper backed by `hashlib.md5` - `get_random_bytes()` backed by `os.urandom` The existing local `pad()`/`unpad()` functions are kept unchanged.
AlexxIT
approved these changes
Mar 3, 2026
Owner
|
Thanks! I don't think there's any point in supporting pycryptodome if cryptography is already included in HA by default. |
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Summary
On Home Assistant OS (and some other HA Python environments), SonoffLAN can fail to load due to missing/incompatible PyCryptodome imports:
from Crypto.Cipher import AESfrom Crypto.Hash import MD5from Crypto.Random import get_random_bytesThis results in a startup error such as:
cannot import name 'AES' from 'Crypto.Cipher'What changed
Crypto.*) imports intry/except.cryptography(HA already ships it)hashlibfor MD5os.urandomfor random bytesThe fallback preserves the existing API used by
local.py:AES.new(key, AES.MODE_CBC, iv=iv)returning an object withencrypt()/decrypt()AES.block_sizeMD5.new().update(...).digest()get_random_bytes(n)No behavior changes when PyCryptodome is available.
Why
HAOS users cannot install Python dependencies with pip inside the HA container,
so SonoffLAN should degrade gracefully when PyCryptodome is not present.
Testing