153 lines
4.7 KiB
Python
153 lines
4.7 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 __future__ import absolute_import, division, print_function
|
|
|
|
from nacl._sodium import ffi, lib
|
|
from nacl.exceptions import BadSignatureError
|
|
|
|
|
|
crypto_sign_BYTES = lib.crypto_sign_bytes()
|
|
# crypto_sign_SEEDBYTES = lib.crypto_sign_seedbytes()
|
|
crypto_sign_SEEDBYTES = lib.crypto_sign_secretkeybytes() // 2
|
|
crypto_sign_PUBLICKEYBYTES = lib.crypto_sign_publickeybytes()
|
|
crypto_sign_SECRETKEYBYTES = lib.crypto_sign_secretkeybytes()
|
|
|
|
crypto_sign_curve25519_BYTES = lib.crypto_box_secretkeybytes()
|
|
|
|
|
|
def crypto_sign_keypair():
|
|
"""
|
|
Returns a randomly generated public key and secret key.
|
|
|
|
:rtype: (bytes(public_key), bytes(secret_key))
|
|
"""
|
|
pk = ffi.new("unsigned char[]", crypto_sign_PUBLICKEYBYTES)
|
|
sk = ffi.new("unsigned char[]", crypto_sign_SECRETKEYBYTES)
|
|
|
|
rc = lib.crypto_sign_keypair(pk, sk)
|
|
assert rc == 0
|
|
|
|
return (
|
|
ffi.buffer(pk, crypto_sign_PUBLICKEYBYTES)[:],
|
|
ffi.buffer(sk, crypto_sign_SECRETKEYBYTES)[:],
|
|
)
|
|
|
|
|
|
def crypto_sign_seed_keypair(seed):
|
|
"""
|
|
Computes and returns the public key and secret key using the seed ``seed``.
|
|
|
|
:param seed: bytes
|
|
:rtype: (bytes(public_key), bytes(secret_key))
|
|
"""
|
|
if len(seed) != crypto_sign_SEEDBYTES:
|
|
raise ValueError("Invalid seed")
|
|
|
|
pk = ffi.new("unsigned char[]", crypto_sign_PUBLICKEYBYTES)
|
|
sk = ffi.new("unsigned char[]", crypto_sign_SECRETKEYBYTES)
|
|
|
|
rc = lib.crypto_sign_seed_keypair(pk, sk, seed)
|
|
assert rc == 0
|
|
|
|
return (
|
|
ffi.buffer(pk, crypto_sign_PUBLICKEYBYTES)[:],
|
|
ffi.buffer(sk, crypto_sign_SECRETKEYBYTES)[:],
|
|
)
|
|
|
|
|
|
def crypto_sign(message, sk):
|
|
"""
|
|
Signs the message ``message`` using the secret key ``sk`` and returns the
|
|
signed message.
|
|
|
|
:param message: bytes
|
|
:param sk: bytes
|
|
:rtype: bytes
|
|
"""
|
|
signed = ffi.new("unsigned char[]", len(message) + crypto_sign_BYTES)
|
|
signed_len = ffi.new("unsigned long long *")
|
|
|
|
rc = lib.crypto_sign(signed, signed_len, message, len(message), sk)
|
|
assert rc == 0
|
|
|
|
return ffi.buffer(signed, signed_len[0])[:]
|
|
|
|
|
|
def crypto_sign_open(signed, pk):
|
|
"""
|
|
Verifies the signature of the signed message ``signed`` using the public
|
|
key ``pk`` and returns the unsigned message.
|
|
|
|
:param signed: bytes
|
|
:param pk: bytes
|
|
:rtype: bytes
|
|
"""
|
|
message = ffi.new("unsigned char[]", len(signed))
|
|
message_len = ffi.new("unsigned long long *")
|
|
|
|
if lib.crypto_sign_open(
|
|
message, message_len, signed, len(signed), pk) != 0:
|
|
raise BadSignatureError("Signature was forged or corrupt")
|
|
|
|
return ffi.buffer(message, message_len[0])[:]
|
|
|
|
|
|
def crypto_sign_ed25519_pk_to_curve25519(public_key_bytes):
|
|
"""
|
|
Converts a public Ed25519 key (encoded as bytes ``public_key_bytes``) to
|
|
a public Curve25519 key as bytes.
|
|
|
|
Raises a ValueError if ``public_key_bytes`` is not of length
|
|
``crypto_sign_PUBLICKEYBYTES``
|
|
|
|
:param public_key_bytes: bytes
|
|
:rtype: bytes
|
|
"""
|
|
if len(public_key_bytes) != crypto_sign_PUBLICKEYBYTES:
|
|
raise ValueError("Invalid curve public key")
|
|
|
|
curve_public_key_len = crypto_sign_curve25519_BYTES
|
|
curve_public_key = ffi.new("unsigned char[]", curve_public_key_len)
|
|
|
|
rc = lib.crypto_sign_ed25519_pk_to_curve25519(curve_public_key,
|
|
public_key_bytes)
|
|
assert rc == 0
|
|
|
|
return ffi.buffer(curve_public_key, curve_public_key_len)[:]
|
|
|
|
|
|
def crypto_sign_ed25519_sk_to_curve25519(secret_key_bytes):
|
|
"""
|
|
Converts a secret Ed25519 key (encoded as bytes ``secret_key_bytes``) to
|
|
a secret Curve25519 key as bytes.
|
|
|
|
Raises a ValueError if ``secret_key_bytes``is not of length
|
|
``crypto_sign_SECRETKEYBYTES``
|
|
|
|
:param public_key_bytes: bytes
|
|
:rtype: bytes
|
|
"""
|
|
if len(secret_key_bytes) != crypto_sign_SECRETKEYBYTES:
|
|
raise ValueError("Invalid curve public key")
|
|
|
|
curve_secret_key_len = crypto_sign_curve25519_BYTES
|
|
curve_secret_key = ffi.new("unsigned char[]", curve_secret_key_len)
|
|
|
|
rc = lib.crypto_sign_ed25519_sk_to_curve25519(curve_secret_key,
|
|
secret_key_bytes)
|
|
assert rc == 0
|
|
|
|
return ffi.buffer(curve_secret_key, curve_secret_key_len)[:]
|