Files
Borealis-Github-Replica/Data/Engine/services/crypto/signing.py

76 lines
2.5 KiB
Python

"""Script signing utilities for the Engine."""
from __future__ import annotations
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import ed25519
from Data.Engine.integrations.crypto.keys import base64_from_spki_der
from Data.Engine.runtime import ensure_server_certificates_dir, runtime_path, server_certificates_path
__all__ = ["ScriptSigner", "load_signer"]
_KEY_DIR = server_certificates_path("Code-Signing")
_SIGNING_KEY_FILE = _KEY_DIR / "engine-script-ed25519.key"
_SIGNING_PUB_FILE = _KEY_DIR / "engine-script-ed25519.pub"
_LEGACY_KEY_FILE = runtime_path("keys") / "borealis-script-ed25519.key"
_LEGACY_PUB_FILE = runtime_path("keys") / "borealis-script-ed25519.pub"
class ScriptSigner:
def __init__(self, private_key: ed25519.Ed25519PrivateKey) -> None:
self._private = private_key
self._public = private_key.public_key()
def sign(self, payload: bytes) -> bytes:
return self._private.sign(payload)
def public_spki_der(self) -> bytes:
return self._public.public_bytes(
encoding=serialization.Encoding.DER,
format=serialization.PublicFormat.SubjectPublicKeyInfo,
)
def public_base64_spki(self) -> str:
return base64_from_spki_der(self.public_spki_der())
def load_signer() -> ScriptSigner:
private_key = _load_or_create()
return ScriptSigner(private_key)
def _load_or_create() -> ed25519.Ed25519PrivateKey:
ensure_server_certificates_dir("Code-Signing")
if _SIGNING_KEY_FILE.exists():
with _SIGNING_KEY_FILE.open("rb") as fh:
return serialization.load_pem_private_key(fh.read(), password=None)
if _LEGACY_KEY_FILE.exists():
with _LEGACY_KEY_FILE.open("rb") as fh:
return serialization.load_pem_private_key(fh.read(), password=None)
private_key = ed25519.Ed25519PrivateKey.generate()
pem = private_key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.PKCS8,
encryption_algorithm=serialization.NoEncryption(),
)
_KEY_DIR.mkdir(parents=True, exist_ok=True)
_SIGNING_KEY_FILE.write_bytes(pem)
try:
if hasattr(_SIGNING_KEY_FILE, "chmod"):
_SIGNING_KEY_FILE.chmod(0o600)
except Exception:
pass
pub_der = private_key.public_key().public_bytes(
encoding=serialization.Encoding.DER,
format=serialization.PublicFormat.SubjectPublicKeyInfo,
)
_SIGNING_PUB_FILE.write_bytes(pub_der)
return private_key