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pyUmbral
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Implement to_cryptography_pubkey/privkey in keys.py

pull/85/head
tuxxy 2018-03-07 18:29:41 -07:00
parent 4feca68bd7
commit aada52b392
1 changed files with 63 additions and 1 deletions
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64
umbral/keys.py
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@ -3,10 +3,13 @@ import base64
from typing import Union
from nacl.secret import SecretBox
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives.kdf.scrypt import Scrypt
from cryptography.hazmat.backends import default_backend
from nacl.secret import SecretBox
from cryptography.hazmat.backends.openssl.ec import (
_EllipticCurvePublicKey, _EllipticCurvePrivateKey
)
from umbral.config import default_params
from umbral.point import Point, BigNum
@ -108,6 +111,43 @@ class UmbralPrivateKey(object):
"""
return UmbralPublicKey(self.bn_key * self.params.g)
def to_cryptography_privkey(self):
"""
Returns a cryptography.io EllipticCurvePrivateKey from the Umbral key.
"""
backend = default_backend()
backend.openssl_assert(self.bn_key.group != backend._ffi.NULL)
backend.openssl_assert(self.bn_key.bignum != backend._ffi.NULL)
ec_key = backend._lib.EC_KEY_new()
backend.openssl_assert(ec_key != backend._ffi.NULL)
ec_key = backend._ffi.gc(ec_key, backend._lib.EC_KEY_free)
res = backend._lib.EC_KEY_set_group(ec_key, self.bn_key.group)
backend.openssl_assert(res == 1)
res = backend._lib.EC_KEY_set_private_key(ec_key, self.bn_key.bignum)
backend.openssl_assert(res == 1)
# Get public key
point = backend._lib.EC_POINT_new(self.bn_key.group)
backend.openssl_assert(point != backend._ffi.NULL)
point = backend._ffi.gc(point, backend._lib.EC_POINT_free)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_POINT_mul(
self.bn_key.group, point, self.bn_key.bignum, backend._ffi.NULL,
backend._ffi.NULL, bn_ctx
)
backend.openssl_assert(res == 1)
res = backend._lib.EC_KEY_set_public_key(ec_key, point)
backend.openssl_assert(res == 1)
evp_pkey = backend._ec_cdata_to_evp_pkey(ec_key)
return _EllipticCurvePrivateKey(backend, ec_key, evp_pkey)
class UmbralPublicKey(object):
def __init__(self, point_key, params: UmbralParameters=None):
@ -152,6 +192,28 @@ class UmbralPublicKey(object):
def get_pubkey(self):
raise NotImplementedError
def to_cryptography_pubkey(self):
"""
Returns a cryptography.io EllipticCurvePublicKey from the Umbral key.
"""
backend = default_backend()
backend.openssl_assert(self.point_key.group != backend._ffi.NULL)
backend.openssl_assert(self.point_key.ec_point != backend._ffi.NULL)
ec_key = backend._lib.EC_KEY_new()
backend.openssl_assert(ec_key != backend._ffi.NULL)
ec_key = backend._ffi.gc(ec_key, backend._lib.EC_KEY_free)
res = backend._lib.EC_KEY_set_group(ec_key, self.point_key.group)
backend.openssl_assert(res == 1)
res = backend._lib.EC_KEY_set_public_key(ec_key, self.point_key.ec_point)
backend.openssl_assert(res == 1)
evp_pkey = backend._ec_cdata_to_evp_pkey(ec_key)
return _EllipticCurvePublicKey(backend, ec_key, evp_pkey)
def __bytes__(self):
"""
Returns an Umbral Public key as a bytestring.