251 lines
8.1 KiB
Python
251 lines
8.1 KiB
Python
|
# Copyright 2013 Donald Stufft and individual contributors
|
||
|
|
#
|
||
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
# you may not use this file except in compliance with the License.
|
||
|
|
# You may obtain a copy of the License at
|
||
|
|
#
|
||
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
#
|
||
|
|
# Unless required by applicable law or agreed to in writing, software
|
||
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
# See the License for the specific language governing permissions and
|
||
|
|
# limitations under the License.
|
||
|
|
from typing import Optional
|
||
|
|
|
||
|
|
import nacl.bindings
|
||
|
|
from nacl import encoding
|
||
|
|
from nacl import exceptions as exc
|
||
|
|
from nacl.public import (
|
||
|
|
PrivateKey as _Curve25519_PrivateKey,
|
||
|
|
PublicKey as _Curve25519_PublicKey,
|
||
|
|
)
|
||
|
|
from nacl.utils import StringFixer, random
|
||
|
|
|
||
|
|
|
||
|
|
class SignedMessage(bytes):
|
||
|
|
"""
|
||
|
|
A bytes subclass that holds a messaged that has been signed by a
|
||
|
|
:class:`SigningKey`.
|
||
|
|
"""
|
||
|
|
|
||
|
|
_signature: bytes
|
||
|
|
_message: bytes
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def _from_parts(
|
||
|
|
cls, signature: bytes, message: bytes, combined: bytes
|
||
|
|
) -> "SignedMessage":
|
||
|
|
obj = cls(combined)
|
||
|
|
obj._signature = signature
|
||
|
|
obj._message = message
|
||
|
|
return obj
|
||
|
|
|
||
|
|
@property
|
||
|
|
def signature(self) -> bytes:
|
||
|
|
"""
|
||
|
|
The signature contained within the :class:`SignedMessage`.
|
||
|
|
"""
|
||
|
|
return self._signature
|
||
|
|
|
||
|
|
@property
|
||
|
|
def message(self) -> bytes:
|
||
|
|
"""
|
||
|
|
The message contained within the :class:`SignedMessage`.
|
||
|
|
"""
|
||
|
|
return self._message
|
||
|
|
|
||
|
|
|
||
|
|
class VerifyKey(encoding.Encodable, StringFixer):
|
||
|
|
"""
|
||
|
|
The public key counterpart to an Ed25519 SigningKey for producing digital
|
||
|
|
signatures.
|
||
|
|
|
||
|
|
:param key: [:class:`bytes`] Serialized Ed25519 public key
|
||
|
|
:param encoder: A class that is able to decode the `key`
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(
|
||
|
|
self, key: bytes, encoder: encoding.Encoder = encoding.RawEncoder
|
||
|
|
):
|
||
|
|
# Decode the key
|
||
|
|
key = encoder.decode(key)
|
||
|
|
if not isinstance(key, bytes):
|
||
|
|
raise exc.TypeError("VerifyKey must be created from 32 bytes")
|
||
|
|
|
||
|
|
if len(key) != nacl.bindings.crypto_sign_PUBLICKEYBYTES:
|
||
|
|
raise exc.ValueError(
|
||
|
|
"The key must be exactly %s bytes long"
|
||
|
|
% nacl.bindings.crypto_sign_PUBLICKEYBYTES,
|
||
|
|
)
|
||
|
|
|
||
|
|
self._key = key
|
||
|
|
|
||
|
|
def __bytes__(self) -> bytes:
|
||
|
|
return self._key
|
||
|
|
|
||
|
|
def __hash__(self) -> int:
|
||
|
|
return hash(bytes(self))
|
||
|
|
|
||
|
|
def __eq__(self, other: object) -> bool:
|
||
|
|
if not isinstance(other, self.__class__):
|
||
|
|
return False
|
||
|
|
return nacl.bindings.sodium_memcmp(bytes(self), bytes(other))
|
||
|
|
|
||
|
|
def __ne__(self, other: object) -> bool:
|
||
|
|
return not (self == other)
|
||
|
|
|
||
|
|
def verify(
|
||
|
|
self,
|
||
|
|
smessage: bytes,
|
||
|
|
signature: Optional[bytes] = None,
|
||
|
|
encoder: encoding.Encoder = encoding.RawEncoder,
|
||
|
|
) -> bytes:
|
||
|
|
"""
|
||
|
|
Verifies the signature of a signed message, returning the message
|
||
|
|
if it has not been tampered with else raising
|
||
|
|
:class:`~nacl.signing.BadSignatureError`.
|
||
|
|
|
||
|
|
:param smessage: [:class:`bytes`] Either the original messaged or a
|
||
|
|
signature and message concated together.
|
||
|
|
:param signature: [:class:`bytes`] If an unsigned message is given for
|
||
|
|
smessage then the detached signature must be provided.
|
||
|
|
:param encoder: A class that is able to decode the secret message and
|
||
|
|
signature.
|
||
|
|
:rtype: :class:`bytes`
|
||
|
|
"""
|
||
|
|
if signature is not None:
|
||
|
|
# If we were given the message and signature separately, validate
|
||
|
|
# signature size and combine them.
|
||
|
|
if not isinstance(signature, bytes):
|
||
|
|
raise exc.TypeError(
|
||
|
|
"Verification signature must be created from %d bytes"
|
||
|
|
% nacl.bindings.crypto_sign_BYTES,
|
||
|
|
)
|
||
|
|
|
||
|
|
if len(signature) != nacl.bindings.crypto_sign_BYTES:
|
||
|
|
raise exc.ValueError(
|
||
|
|
"The signature must be exactly %d bytes long"
|
||
|
|
% nacl.bindings.crypto_sign_BYTES,
|
||
|
|
)
|
||
|
|
|
||
|
|
smessage = signature + encoder.decode(smessage)
|
||
|
|
else:
|
||
|
|
# Decode the signed message
|
||
|
|
smessage = encoder.decode(smessage)
|
||
|
|
|
||
|
|
return nacl.bindings.crypto_sign_open(smessage, self._key)
|
||
|
|
|
||
|
|
def to_curve25519_public_key(self) -> _Curve25519_PublicKey:
|
||
|
|
"""
|
||
|
|
Converts a :class:`~nacl.signing.VerifyKey` to a
|
||
|
|
:class:`~nacl.public.PublicKey`
|
||
|
|
|
||
|
|
:rtype: :class:`~nacl.public.PublicKey`
|
||
|
|
"""
|
||
|
|
raw_pk = nacl.bindings.crypto_sign_ed25519_pk_to_curve25519(self._key)
|
||
|
|
return _Curve25519_PublicKey(raw_pk)
|
||
|
|
|
||
|
|
|
||
|
|
class SigningKey(encoding.Encodable, StringFixer):
|
||
|
|
"""
|
||
|
|
Private key for producing digital signatures using the Ed25519 algorithm.
|
||
|
|
|
||
|
|
Signing keys are produced from a 32-byte (256-bit) random seed value. This
|
||
|
|
value can be passed into the :class:`~nacl.signing.SigningKey` as a
|
||
|
|
:func:`bytes` whose length is 32.
|
||
|
|
|
||
|
|
.. warning:: This **must** be protected and remain secret. Anyone who knows
|
||
|
|
the value of your :class:`~nacl.signing.SigningKey` or it's seed can
|
||
|
|
masquerade as you.
|
||
|
|
|
||
|
|
:param seed: [:class:`bytes`] Random 32-byte value (i.e. private key)
|
||
|
|
:param encoder: A class that is able to decode the seed
|
||
|
|
|
||
|
|
:ivar: verify_key: [:class:`~nacl.signing.VerifyKey`] The verify
|
||
|
|
(i.e. public) key that corresponds with this signing key.
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(
|
||
|
|
self,
|
||
|
|
seed: bytes,
|
||
|
|
encoder: encoding.Encoder = encoding.RawEncoder,
|
||
|
|
):
|
||
|
|
# Decode the seed
|
||
|
|
seed = encoder.decode(seed)
|
||
|
|
if not isinstance(seed, bytes):
|
||
|
|
raise exc.TypeError(
|
||
|
|
"SigningKey must be created from a 32 byte seed"
|
||
|
|
)
|
||
|
|
|
||
|
|
# Verify that our seed is the proper size
|
||
|
|
if len(seed) != nacl.bindings.crypto_sign_SEEDBYTES:
|
||
|
|
raise exc.ValueError(
|
||
|
|
"The seed must be exactly %d bytes long"
|
||
|
|
% nacl.bindings.crypto_sign_SEEDBYTES
|
||
|
|
)
|
||
|
|
|
||
|
|
public_key, secret_key = nacl.bindings.crypto_sign_seed_keypair(seed)
|
||
|
|
|
||
|
|
self._seed = seed
|
||
|
|
self._signing_key = secret_key
|
||
|
|
self.verify_key = VerifyKey(public_key)
|
||
|
|
|
||
|
|
def __bytes__(self) -> bytes:
|
||
|
|
return self._seed
|
||
|
|
|
||
|
|
def __hash__(self) -> int:
|
||
|
|
return hash(bytes(self))
|
||
|
|
|
||
|
|
def __eq__(self, other: object) -> bool:
|
||
|
|
if not isinstance(other, self.__class__):
|
||
|
|
return False
|
||
|
|
return nacl.bindings.sodium_memcmp(bytes(self), bytes(other))
|
||
|
|
|
||
|
|
def __ne__(self, other: object) -> bool:
|
||
|
|
return not (self == other)
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def generate(cls) -> "SigningKey":
|
||
|
|
"""
|
||
|
|
Generates a random :class:`~nacl.signing.SigningKey` object.
|
||
|
|
|
||
|
|
:rtype: :class:`~nacl.signing.SigningKey`
|
||
|
|
"""
|
||
|
|
return cls(
|
||
|
|
random(nacl.bindings.crypto_sign_SEEDBYTES),
|
||
|
|
encoder=encoding.RawEncoder,
|
||
|
|
)
|
||
|
|
|
||
|
|
def sign(
|
||
|
|
self,
|
||
|
|
message: bytes,
|
||
|
|
encoder: encoding.Encoder = encoding.RawEncoder,
|
||
|
|
) -> SignedMessage:
|
||
|
|
"""
|
||
|
|
Sign a message using this key.
|
||
|
|
|
||
|
|
:param message: [:class:`bytes`] The data to be signed.
|
||
|
|
:param encoder: A class that is used to encode the signed message.
|
||
|
|
:rtype: :class:`~nacl.signing.SignedMessage`
|
||
|
|
"""
|
||
|
|
raw_signed = nacl.bindings.crypto_sign(message, self._signing_key)
|
||
|
|
|
||
|
|
crypto_sign_BYTES = nacl.bindings.crypto_sign_BYTES
|
||
|
|
signature = encoder.encode(raw_signed[:crypto_sign_BYTES])
|
||
|
|
message = encoder.encode(raw_signed[crypto_sign_BYTES:])
|
||
|
|
signed = encoder.encode(raw_signed)
|
||
|
|
|
||
|
|
return SignedMessage._from_parts(signature, message, signed)
|
||
|
|
|
||
|
|
def to_curve25519_private_key(self) -> _Curve25519_PrivateKey:
|
||
|
|
"""
|
||
|
|
Converts a :class:`~nacl.signing.SigningKey` to a
|
||
|
|
:class:`~nacl.public.PrivateKey`
|
||
|
|
|
||
|
|
:rtype: :class:`~nacl.public.PrivateKey`
|
||
|
|
"""
|
||
|
|
sk = self._signing_key
|
||
|
|
raw_private = nacl.bindings.crypto_sign_ed25519_sk_to_curve25519(sk)
|
||
|
|
return _Curve25519_PrivateKey(raw_private)
|