60 lines
1.8 KiB
Python
60 lines
1.8 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 import exceptions as exc
|
|
from nacl._sodium import ffi, lib
|
|
from nacl.exceptions import ensure
|
|
|
|
|
|
crypto_scalarmult_BYTES = lib.crypto_scalarmult_bytes()
|
|
crypto_scalarmult_SCALARBYTES = lib.crypto_scalarmult_scalarbytes()
|
|
|
|
|
|
def crypto_scalarmult_base(n):
|
|
"""
|
|
Computes and returns the scalar product of a standard group element and an
|
|
integer ``n``.
|
|
|
|
:param n: bytes
|
|
:rtype: bytes
|
|
"""
|
|
q = ffi.new("unsigned char[]", crypto_scalarmult_BYTES)
|
|
|
|
rc = lib.crypto_scalarmult_base(q, n)
|
|
ensure(rc == 0,
|
|
'Unexpected library error',
|
|
raising=exc.RuntimeError)
|
|
|
|
return ffi.buffer(q, crypto_scalarmult_SCALARBYTES)[:]
|
|
|
|
|
|
def crypto_scalarmult(n, p):
|
|
"""
|
|
Computes and returns the scalar product of the given group element and an
|
|
integer ``n``.
|
|
|
|
:param p: bytes
|
|
:param n: bytes
|
|
:rtype: bytes
|
|
"""
|
|
q = ffi.new("unsigned char[]", crypto_scalarmult_BYTES)
|
|
|
|
rc = lib.crypto_scalarmult(q, n, p)
|
|
ensure(rc == 0,
|
|
'Unexpected library error',
|
|
raising=exc.RuntimeError)
|
|
|
|
return ffi.buffer(q, crypto_scalarmult_SCALARBYTES)[:]
|