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clan-cli: secrets: address CR feedback for sops encryption and key handling

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- Move public keys collection to a class method on `SopsKey`, and
  implement collection for each key type in `KeyType`, this helps make
  the code more generic ;
- Replace `Operation.__call__` by `run` (`sops.run` if you import the
  entire module), that allows us to dedent the code so that's cool ;
- Fix exception handling when trying to get a in-memory temporary file ;
- Make Executor cuter 😵🪦.
This commit is contained in:
Louis Opter
2024-11-19 16:34:50 -08:00
committed by Mic92
parent 1ba27196d8
commit 1e0db82827
2 changed files with 180 additions and 151 deletions
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12
pkgs/clan-cli/clan_cli/secrets/secrets.py
View File

@@ -94,7 +94,7 @@ def collect_keys_for_path(path: Path) -> set[tuple[str, sops.KeyType]]:
def encrypt_secret(
flake_dir: Path,
secret_path: Path,
value: IO[str] | str | bytes | None,
value: IO[bytes] | str | bytes | None,
add_users: list[str] | None = None,
add_machines: list[str] | None = None,
add_groups: list[str] | None = None,
@@ -305,10 +305,10 @@ def list_command(args: argparse.Namespace) -> None:
def decrypt_secret(flake_dir: Path, secret_path: Path) -> str:
# I can't think of a good way to ensure that we have the private key for
# the secret. I mean we could collect all private keys we could find and
# then make sure we have the one for the secret, but that seems
# complicated for little ux gain?
# lopter(2024-10): I can't think of a good way to ensure that we have the
# private key for the secret. I mean we could collect all private keys we
# could find and then make sure we have the one for the secret, but that
# seems complicated for little ux gain?
path = secret_path / "secret"
if not path.exists():
msg = f"Secret '{secret_path!s}' does not exist"
@@ -332,7 +332,7 @@ def is_tty_interactive() -> bool:
def set_command(args: argparse.Namespace) -> None:
env_value = os.environ.get("SOPS_NIX_SECRET")
secret_value: str | IO[str] | None = sys.stdin
secret_value: str | IO[bytes] | None = sys.stdin.buffer
if args.edit:
secret_value = None
elif env_value:

221
pkgs/clan-cli/clan_cli/secrets/sops.py
View File

@@ -11,10 +11,10 @@ from collections.abc import Iterable, Sequence
from contextlib import suppress
from pathlib import Path
from tempfile import NamedTemporaryFile
from typing import IO, Any, Protocol
from typing import IO, Protocol
import clan_cli.cmd
from clan_cli.api import API
from clan_cli.cmd import Log, run
from clan_cli.dirs import user_config_dir
from clan_cli.errors import ClanError, CmdOut
from clan_cli.nix import nix_shell
@@ -47,6 +47,56 @@ class KeyType(enum.Enum):
)
raise ClanError(msg)
def collect_public_keys(self) -> Sequence[str]:
keyring: Sequence[str] = []
if self == self.AGE:
if keys := os.environ.get("SOPS_AGE_KEY"):
# SOPS_AGE_KEY is fed into age.ParseIdentities by Sops, and
# reads identities line by line. See age/keysource.go in
# Sops, and age/parse.go in Age.
for private_key in keys.strip().splitlines():
public_key = get_public_age_key(private_key)
log.info(
f"Found age public key from a private key "
f"in the environment (SOPS_AGE_KEY): {public_key}"
)
keyring.append(public_key)
def maybe_read_from_path(key_path: Path) -> None:
try:
# as in parse.go in age:
lines = Path(key_path).read_text().strip().splitlines()
for private_key in filter(lambda ln: not ln.startswith("#"), lines):
public_key = get_public_age_key(private_key)
log.info(
f"Found age public key from a private key "
f"in {key_path}: {public_key}"
)
keyring.append(public_key)
except FileNotFoundError:
return
except Exception as ex:
log.warn(f"Could not read age keys from {key_path}: {ex}")
# Sops will try every location, see age/keysource.go
if key_path := os.environ.get("SOPS_AGE_KEY_FILE"):
maybe_read_from_path(Path(key_path))
maybe_read_from_path(user_config_dir() / "sops/age/keys.txt")
return keyring
if self == self.PGP:
if pgp_fingerprints := os.environ.get("SOPS_PGP_FP"):
for fp in pgp_fingerprints.strip().split(","):
msg = f"Found PGP public key in the environment (SOPS_PGP_FP): {fp}"
log.info(msg)
keyring.append(fp)
return keyring
msg = f"KeyType {self.name.lower()} is missing an implementation for collect_public_keys"
raise ClanError(msg)
@dataclasses.dataclass(frozen=True)
class SopsKey:
@@ -64,12 +114,20 @@ class SopsKey:
}
@classmethod
def load_dir(cls, dir: Path) -> "SopsKey": # noqa: ANN102
def load_dir(cls, folder: Path) -> "SopsKey": # noqa: ANN102
"""Load from the file named `keys.json` in the given directory."""
pubkey, key_type = read_key(dir)
pubkey, key_type = read_key(folder)
username = ""
return cls(pubkey, username, key_type)
@classmethod
def collect_public_keys(cls) -> Sequence["SopsKey"]: # noqa: ANN102
return [
cls(pubkey=key, username="", key_type=key_type)
for key_type in KeyType
for key in key_type.collect_public_keys()
]
class ExitStatus(enum.IntEnum): # see: cmd/sops/codes/codes.go
ERROR_GENERIC = 1
@@ -105,28 +163,34 @@ class ExitStatus(enum.IntEnum): # see: cmd/sops/codes/codes.go
return ExitStatus(code) if code in ExitStatus else None
class Executor(Protocol):
class Executer(Protocol):
def __call__(
self, cmd: list[str], *, env: dict[str, str] | None = None
) -> CmdOut: ...
class Operation(enum.StrEnum):
decrypt = "decrypt"
edit = "edit"
encrypt = "encrypt"
update_keys = "updatekeys"
DECRYPT = "decrypt"
EDIT = "edit"
ENCRYPT = "encrypt"
UPDATE_KEYS = "updatekeys"
def __call__(
self,
def run(
call: Operation,
secret_path: Path,
public_keys: Iterable[tuple[str, KeyType]],
executor: Executor,
executer: Executer,
) -> tuple[int, str]:
"""Call the sops binary for the given operation."""
# louis(2024-11-19): I regrouped the call into the sops binary into this
# one place because calling into sops needs to be done with a carefully
# setup context, and I don't feel good about the idea of having that logic
# exist in multiple places.
sops_cmd = ["sops"]
environ = os.environ.copy()
with NamedTemporaryFile(delete=False, mode="w") as manifest:
if self == Operation.decrypt:
if call == Operation.DECRYPT:
sops_cmd.append("decrypt")
else:
# When sops is used to edit a file the config is only used at
@@ -144,7 +208,7 @@ class Operation(enum.StrEnum):
json.dump(rules, manifest, indent=2)
manifest.flush()
if self == Operation.encrypt:
if call == Operation.ENCRYPT:
# Remove SOPS env vars used to specify public keys to force
# sops to use our config file [1]; so that the file gets
# encrypted with our keys and not something leaking out of
@@ -160,19 +224,19 @@ class Operation(enum.StrEnum):
}:
del environ[var]
sops_cmd.extend(["encrypt", "--in-place"])
elif self == Operation.update_keys:
elif call == Operation.UPDATE_KEYS:
sops_cmd.extend(["updatekeys", "--yes"])
elif self != Operation.edit:
elif call != Operation.EDIT:
known_operations = ",".join(Operation.__members__.values())
msg = (
f"Unsupported sops operation {self.value} "
f"Unsupported sops operation {call.value} "
f"(known operations: {known_operations})"
)
raise ClanError(msg)
sops_cmd.append(str(secret_path))
cmd = nix_shell(["nixpkgs#sops"], sops_cmd)
p = executor(cmd, env=environ)
p = executer(cmd, env=environ)
return p.returncode, p.stdout
@@ -191,7 +255,7 @@ def get_public_age_key(privkey: str) -> str:
def generate_private_key(out_file: Path | None = None) -> tuple[str, str]:
cmd = nix_shell(["nixpkgs#age"], ["age-keygen"])
try:
proc = run(cmd)
proc = clan_cli.cmd.run(cmd)
res = proc.stdout.strip()
pubkey = None
private_key = None
@@ -262,21 +326,17 @@ def default_admin_private_key_path() -> Path:
@API.register
def maybe_get_admin_public_key() -> None | SopsKey:
keyring = collect_public_keys()
keyring = SopsKey.collect_public_keys()
if len(keyring) == 0:
return None
if len(keyring) > 1:
# louis@(2024-10-22):
#
# This is confusing when it shows up and you have no information
# about where each key is going from, could we log the discovery
# of each key?
last_3 = [f"{key.key_type.name.lower()}:{key.pubkey}" for key in keyring[:3]]
msg = (
f"Found more than {len(keyring)} public keys in your "
f"environment/system and cannot decide which one to "
f"use, first three:\n\n"
f"- {'\n- '.join(str(key.as_dict()) for key in keyring[:3])}\n\n"
f"use, first {len(last_3)}:\n\n"
f"- {'\n- '.join(last_3)}\n\n"
f"Please set one of SOPS_AGE_KEY, SOPS_AGE_KEY_FILE or "
f"SOPS_PGP_FP appropriately"
)
@@ -285,48 +345,6 @@ def maybe_get_admin_public_key() -> None | SopsKey:
return keyring[0]
def collect_public_keys() -> Sequence[SopsKey]:
username = ""
keyring: list[SopsKey] = []
for private_key in collect_private_age_keys():
public_key = get_public_age_key(private_key)
keyring.append(SopsKey(public_key, username, KeyType.AGE))
if pgp_fingerprints := os.environ.get("SOPS_PGP_FP"):
for fp in pgp_fingerprints.strip().split(","):
keyring.append(SopsKey(fp, username, KeyType.PGP))
return keyring
def collect_private_age_keys() -> Sequence[str]:
private_age_keys: list[str] = []
if keys := os.environ.get("SOPS_AGE_KEY"):
# SOPS_AGE_KEY is fed into age.ParseIdentities by Sops, and reads
# identities line by line. See age/keysource.go in Sops, and
# age/parse.go in Age.
private_age_keys.extend(keys.strip().splitlines())
def maybe_read_from_path(key_path: Path) -> None:
try:
contents = Path(key_path).read_text().strip()
lines = contents.splitlines() # as in parse.go in age:
private_age_keys.extend(ln for ln in lines if ln and not ln.startswith("#"))
except FileNotFoundError:
return
except Exception as ex:
log.warn(f"Could not read age keys from {key_path}: {ex}")
# Sops will try every location, see age/keysource.go
if key_path := os.environ.get("SOPS_AGE_KEY_FILE"):
maybe_read_from_path(Path(key_path))
maybe_read_from_path(user_config_dir() / "sops/age/keys.txt")
return private_age_keys
def ensure_admin_public_key(flake_dir: Path) -> SopsKey:
key = maybe_get_admin_public_key()
if key:
@@ -338,15 +356,17 @@ def ensure_admin_public_key(flake_dir: Path) -> SopsKey:
def update_keys(secret_path: Path, keys: Iterable[tuple[str, KeyType]]) -> list[Path]:
secret_path = secret_path / "secret"
error_msg = f"Could not update keys for {secret_path}"
executor = functools.partial(run, log=Log.BOTH, error_msg=error_msg)
rc, _ = Operation.update_keys(secret_path, keys, executor)
executer = functools.partial(
clan_cli.cmd.run, log=clan_cli.cmd.Log.BOTH, error_msg=error_msg
)
rc, _ = run(Operation.UPDATE_KEYS, secret_path, keys, executer)
was_modified = ExitStatus.parse(rc) != ExitStatus.FILE_HAS_NOT_BEEN_MODIFIED
return [secret_path] if was_modified else []
def encrypt_file(
secret_path: Path,
content: IO[str] | str | bytes | None,
content: str | IO[bytes] | bytes | None,
pubkeys: list[tuple[str, KeyType]],
) -> None:
folder = secret_path.parent
@@ -355,7 +375,7 @@ def encrypt_file(
if not content:
# Don't use our `run` here, because it breaks editor integration.
# We never need this in our UI.
def executor(cmd: list[str], *, env: dict[str, str] | None = None) -> CmdOut:
def executer(cmd: list[str], *, env: dict[str, str] | None = None) -> CmdOut:
return CmdOut(
stdout="",
stderr="",
@@ -366,48 +386,57 @@ def encrypt_file(
msg=None,
)
rc, _ = Operation.edit(secret_path, pubkeys, executor)
rc, _ = run(Operation.EDIT, secret_path, pubkeys, executer)
status = ExitStatus.parse(rc)
if rc == 0 or status == ExitStatus.FILE_HAS_NOT_BEEN_MODIFIED:
return
msg = f"Failed to encrypt {secret_path}: sops exited with {status or rc}"
raise ClanError(msg)
def swap_secret(f: Any) -> None: # f's type is not exposed by tempfile
# lopter(2024-11-19): imo NamedTemporaryFile does RAII wrong since it
# creates the file in __init__, when really it should be created in
# __enter__ (that is in Python __enter__ is actually __init__ from a RAII
# perspective, and __init__ should just be thought off as syntax sugar to
# capture extra context), and now the linter is unhappy so hush it. Note
# that if NamedTemporaryFile created the file in __enter__ then we'd have
# to change exception handling:
try:
source = NamedTemporaryFile(dir="/dev/shm", delete=False) # noqa: SIM115
except (FileNotFoundError, PermissionError):
source = NamedTemporaryFile(delete=False) # noqa: SIM115
try: # swap the secret:
with source:
if isinstance(content, str):
Path(f.name).write_text(content)
source.file.write(content.encode())
elif isinstance(content, bytes):
Path(f.name).write_bytes(content)
elif isinstance(content, io.IOBase):
with Path(f.name).open("w") as fd:
shutil.copyfileobj(content, fd)
source.file.write(content)
elif isinstance(content, io.BufferedReader):
# lopter@(2024-11-19): mypy is freaking out on the 1st
# argument, idk why, it says:
#
# > Cannot infer type argument 1 of "copyfileobj"
shutil.copyfileobj(content, source.file) # type: ignore[misc]
else:
msg = f"Invalid content type: {type(content)}"
raise ClanError(msg)
Operation.encrypt(f.name, pubkeys, functools.partial(run, log=Log.BOTH))
executer = functools.partial(clan_cli.cmd.run, log=clan_cli.cmd.Log.BOTH)
run(Operation.ENCRYPT, Path(source.name), pubkeys, executer)
# atomic copy of the encrypted file
with NamedTemporaryFile(dir=folder, delete=False) as f2:
shutil.copyfile(f.name, f2.name)
Path(f2.name).rename(secret_path)
with NamedTemporaryFile(dir=folder, delete=False) as dest:
shutil.copyfile(source.name, dest.name)
Path(dest.name).rename(secret_path)
finally:
with suppress(OSError):
Path(f.name).unlink()
try:
with NamedTemporaryFile(dir="/dev/shm", delete=False) as f:
swap_secret(f)
except (FileNotFoundError, PermissionError):
# hopefully /tmp is written to an in-memory file to avoid leaking secrets
with NamedTemporaryFile(delete=False) as f:
swap_secret(f)
Path(source.name).unlink()
def decrypt_file(secret_path: Path) -> str:
# decryption uses private keys from the environment or default paths:
no_public_keys_needed: list[tuple[str, KeyType]] = []
executor = functools.partial(run, error_msg=f"Could not decrypt {secret_path}")
_, stdout = Operation.decrypt(secret_path, no_public_keys_needed, executor)
executer = functools.partial(
clan_cli.cmd.run, error_msg=f"Could not decrypt {secret_path}"
)
_, stdout = run(Operation.DECRYPT, secret_path, no_public_keys_needed, executer)
return stdout
@@ -420,7 +449,7 @@ def get_recipients(secret_path: Path) -> set[SopsKey]:
key_type=key_type,
)
for key_type in KeyType
for recipient in sops_attrs[key_type.name.lower()]
for recipient in sops_attrs[key_type.name.lower()] or []
}