def __eq__(self, other):
self_curve_nid = backend._elliptic_curve_to_nid(self.curve)
other_curve_nid = backend._elliptic_curve_to_nid(other.curve)
# TODO: This is not comparing the order, which currently is an OpenSSL pointer
self_attributes = self_curve_nid, self.g, self.CURVE_KEY_SIZE_BYTES, self.u
others_attributes = other_curve_nid, other.g, other.CURVE_KEY_SIZE_BYTES, other.u
return self_attributes == others_attributes
def gen_rand(cls, curve: ec.EllipticCurve = None):
"""
Returns a Point object with a cryptographically secure EC_POINT based
on the provided curve.
"""
curve = curve if curve is not None else default_curve()
curve_nid = backend._elliptic_curve_to_nid(curve)
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
generator = backend._lib.EC_GROUP_get0_generator(group)
backend.openssl_assert(generator != backend._ffi.NULL)
rand_point = backend._lib.EC_POINT_new(group)
backend.openssl_assert(rand_point != backend._ffi.NULL)
rand_point = backend._ffi.gc(rand_point,
backend._lib.EC_POINT_clear_free)
rand_bn = BigNum.gen_rand(curve).bignum
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_POINT_mul(group, rand_point,
backend._ffi.NULL, generator,
rand_bn, bn_ctx)
backend.openssl_assert(res == 1)
return Point(rand_point, curve_nid, group)
def from_affine(cls, coords, curve: ec.EllipticCurve = None):
"""
Returns a Point object from the given affine coordinates in a tuple in
the format of (x, y) and a given curve.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
affine_x, affine_y = coords
if type(affine_x) == int:
affine_x = openssl._int_to_bn(affine_x)
if type(affine_y) == int:
affine_y = openssl._int_to_bn(affine_y)
group = openssl._get_ec_group_by_curve_nid(curve_nid)
ec_point = openssl._get_EC_POINT_via_affine(affine_x,
affine_y,
ec_group=group)
return cls(ec_point, curve_nid, group)
def gen_rand(cls, curve: ec.EllipticCurve = None):
"""
Returns a BigNum object with a cryptographically secure BigNum based
on the given curve.
"""
curve = curve if curve is not None else default_curve()
curve_nid = backend._elliptic_curve_to_nid(curve)
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
order = backend._lib.BN_new()
backend.openssl_assert(order != backend._ffi.NULL)
order = backend._ffi.gc(order, backend._lib.BN_free)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_GROUP_get_order(group, order, bn_ctx)
backend.openssl_assert(res == 1)
order_int = backend._bn_to_int(order)
# Generate random number on curve
key_size = get_curve_keysize_bytes(curve)
rand_num = int.from_bytes(os.urandom(key_size), 'big')
while rand_num >= order_int or rand_num <= 0:
rand_num = int.from_bytes(os.urandom(key_size), 'big')
new_rand_bn = backend._int_to_bn(rand_num)
new_rand_bn = backend._ffi.gc(new_rand_bn, backend._lib.BN_free)
return cls(new_rand_bn, curve_nid, group, order)
def gen_rand(cls, curve: ec.EllipticCurve = None):
"""
Returns a BigNum object with a cryptographically secure BigNum based
on the given curve.
"""
curve = curve if curve is not None else default_curve()
curve_nid = backend._elliptic_curve_to_nid(curve)
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
order = backend._lib.BN_new()
backend.openssl_assert(order != backend._ffi.NULL)
order = backend._ffi.gc(order, backend._lib.BN_clear_free)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_GROUP_get_order(group, order, bn_ctx)
backend.openssl_assert(res == 1)
new_rand_bn = backend._lib.BN_new()
backend.openssl_assert(new_rand_bn != backend._ffi.NULL)
new_rand_bn = backend._ffi.gc(new_rand_bn, backend._lib.BN_clear_free)
rand_res = backend._lib.BN_rand_range(new_rand_bn, order)
backend.openssl_assert(rand_res == 1)
return cls(new_rand_bn, curve_nid, group, order)
def from_int(cls, num, curve: ec.EllipticCurve = None):
"""
Returns a BigNum object from a given integer on a curve.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
order = backend._lib.BN_new()
backend.openssl_assert(order != backend._ffi.NULL)
order = backend._ffi.gc(order, backend._lib.BN_clear_free)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_GROUP_get_order(group, order, bn_ctx)
backend.openssl_assert(res == 1)
order_int = backend._bn_to_int(order)
if num <= 0 or num >= order_int:
# TODO: Handle this better maybe? Ask David.
raise ValueError("Integer provided is not on the given curve.")
bignum = backend._int_to_bn(num)
bignum = backend._ffi.gc(bignum, backend._lib.BN_clear_free)
return cls(bignum, curve_nid, group, order)
def from_affine(cls, coords, curve: ec.EllipticCurve = None):
"""
Returns a Point object from the given affine coordinates in a tuple in
the format of (x, y) and a given curve.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
affine_x, affine_y = coords
if type(affine_x) == int:
affine_x = backend._int_to_bn(affine_x)
affine_x = backend._ffi.gc(affine_x, backend._lib.BN_clear_free)
if type(affine_y) == int:
affine_y = backend._int_to_bn(affine_y)
affine_y = backend._ffi.gc(affine_y, backend._lib.BN_clear_free)
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
ec_point = backend._lib.EC_POINT_new(group)
backend.openssl_assert(ec_point != backend._ffi.NULL)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_POINT_set_affine_coordinates_GFp(
group, ec_point, affine_x, affine_y, bn_ctx)
backend.openssl_assert(res == 1)
return Point(ec_point, curve_nid, group)
def get_order_from_curve(cls, curve: ec.EllipticCurve=None):
"""
Returns the order from the given curve as a CurveBN.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
group = openssl._get_ec_group_by_curve_nid(curve_nid)
order = openssl._get_ec_order_by_curve_nid(curve_nid)
return CurveBN(order, curve_nid, group, order)
def get_generator_from_curve(cls, curve: ec.EllipticCurve=None):
"""
Returns the generator Point from the given curve as a Point object.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
group = openssl._get_ec_group_by_curve_nid(curve_nid)
generator = openssl._get_ec_generator_by_curve_nid(curve_nid)
return cls(generator, curve_nid, group)
def __init__(self, curve: ec.EllipticCurve):
from umbral.point import Point, unsafe_hash_to_point
from umbral.utils import get_curve_keysize_bytes
self.curve = curve
curve_nid = backend._elliptic_curve_to_nid(curve)
self.g = Point.get_generator_from_curve(self.curve)
self.order = openssl._get_ec_order_by_curve_nid(curve_nid)
g_bytes = self.g.to_bytes(is_compressed=True)
self.CURVE_KEY_SIZE_BYTES = get_curve_keysize_bytes(self.curve)
parameters_seed = b'NuCypherKMS/UmbralParameters/'
self.u = unsafe_hash_to_point(g_bytes, self, parameters_seed + b'u')
def get_generator_from_curve(cls, curve: ec.EllipticCurve = None):
"""
Returns the generator Point from the given curve as a Point object.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
generator = backend._lib.EC_GROUP_get0_generator(group)
backend.openssl_assert(generator != backend._ffi.NULL)
return cls(generator, curve_nid, group)
def hash(cls, *crypto_items, params=None):
params = params if params is not None else default_params()
curve_nid = backend._elliptic_curve_to_nid(params.curve)
order = openssl._get_ec_order_by_curve_nid(curve_nid)
group = openssl._get_ec_group_by_curve_nid(curve_nid)
# TODO: Clean this in an upcoming cleanup of pyUmbral
blake2b = hashes.Hash(hashes.BLAKE2b(64), backend=backend)
for item in crypto_items:
try:
item_bytes = item.to_bytes()
except AttributeError:
if isinstance(item, bytes):
item_bytes = item
else:
raise TypeError(
"{} is not acceptable type, received {}".format(
item, type(item)))
blake2b.update(item_bytes)
hash_digest = blake2b.finalize()
hash_digest = int.from_bytes(hash_digest,
byteorder='big',
signed=False)
hash_digest = openssl._int_to_bn(hash_digest)
_1 = backend._lib.BN_value_one()
order_minus_1 = openssl._get_new_BN()
res = backend._lib.BN_sub(order_minus_1, order, _1)
backend.openssl_assert(res == 1)
bignum = openssl._get_new_BN()
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.BN_mod(bignum, hash_digest, order_minus_1,
bn_ctx)
backend.openssl_assert(res == 1)
res = backend._lib.BN_add(bignum, bignum, _1)
backend.openssl_assert(res == 1)
return cls(bignum, curve_nid, group, order)
def from_int(cls, num, curve: ec.EllipticCurve = None):
"""
Returns a CurveBN object from a given integer on a curve.
By default, the underlying OpenSSL BIGNUM has BN_FLG_CONSTTIME set for
constant time operations.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
group = openssl._get_ec_group_by_curve_nid(curve_nid)
order = openssl._get_ec_order_by_curve_nid(curve_nid)
conv_bn = openssl._int_to_bn(num, curve_nid)
return cls(conv_bn, curve_nid, group, order)
def CURVE_GET_ORDER(curve) -> _EllipticCurvePrivateKey:
"""
Returns the order of the curve provided.
This returns it as a private key to use in the above operations, if needed.
"""
curve_nid = backend._elliptic_curve_to_nid(curve)
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
order = backend._lib.BN_new()
backend.openssl_assert(order != backend._ffi.NULL)
order = backend._ffi.gc(order, backend._lib.BN_free)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_GROUP_get_order(group, order, bn_ctx)
backend.openssl_assert(res == 1)
return _bignum_to_private_key(backend, group, order)
def from_bytes(cls, data, curve: ec.EllipticCurve = None):
"""
Returns a Point object from the given byte data on the curve provided.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
# Check if compressed
if data[0] in [2, 3]:
type_y = data[0] - 2
if len(data[1:]) > get_curve_keysize_bytes(curve):
raise ValueError("X coordinate too large for curve.")
affine_x = BigNum.from_bytes(data[1:], curve)
ec_point = backend._lib.EC_POINT_new(affine_x.group)
backend.openssl_assert(ec_point != backend._ffi.NULL)
ec_point = backend._ffi.gc(ec_point,
backend._lib.EC_POINT_clear_free)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_POINT_set_compressed_coordinates_GFp(
affine_x.group, ec_point, affine_x.bignum, type_y, bn_ctx)
backend.openssl_assert(res == 1)
return cls(ec_point, curve_nid, affine_x.group)
# Handle uncompressed point
elif data[0] == 4:
key_size = get_curve_keysize_bytes(curve)
affine_x = int.from_bytes(data[1:key_size + 1], 'big')
affine_y = int.from_bytes(data[1 + key_size:], 'big')
return Point.from_affine((affine_x, affine_y), curve)
else:
raise ValueError("Invalid point serialization.")
def gen_rand(cls, curve: ec.EllipticCurve=None):
"""
Returns a Point object with a cryptographically secure EC_POINT based
on the provided curve.
"""
curve = curve if curve is not None else default_curve()
curve_nid = backend._elliptic_curve_to_nid(curve)
group = openssl._get_ec_group_by_curve_nid(curve_nid)
generator = openssl._get_ec_generator_by_curve_nid(curve_nid)
rand_point = openssl._get_new_EC_POINT(ec_group=group)
rand_bn = CurveBN.gen_rand(curve).bignum
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_POINT_mul(
group, rand_point, backend._ffi.NULL, generator, rand_bn, bn_ctx
)
backend.openssl_assert(res == 1)
return Point(rand_point, curve_nid, group)
def CURVE_GET_GENERATOR(curve) -> _EllipticCurvePublicKey:
"""
Returns the generator point of the curve provided.
This returns it as a public key to use in the above operations, if needed.
"""
curve_nid = backend._elliptic_curve_to_nid(curve)
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
gen_point = backend._lib.EC_POINT_new(group)
backend.openssl_assert(gen_point != backend._ffi.NULL)
gen_point = backend._ffi.gc(gen_point, backend._lib.EC_POINT_free)
generator = backend._lib.EC_GROUP_get0_generator(group)
backend.openssl_assert(generator != backend._ffi.NULL)
res = backend._lib.EC_POINT_copy(gen_point, generator)
backend.openssl_assert(res == 1)
return _point_to_public_key(backend, group, generator)
def from_bytes(cls, data, curve: ec.EllipticCurve = None):
"""
Returns a Point object from the given byte data on the curve provided.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
compressed_size = cls.expected_bytes_length(curve)
# Check if compressed
if data[0] in [2, 3]:
if len(data) != compressed_size:
raise ValueError("X coordinate too large for curve.")
affine_x = CurveBN.from_bytes(data[1:], curve)
type_y = data[0] - 2
ec_point = openssl._get_new_EC_POINT(ec_group=affine_x.group)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_POINT_set_compressed_coordinates_GFp(
affine_x.group, ec_point, affine_x.bignum, type_y, bn_ctx)
backend.openssl_assert(res == 1)
return cls(ec_point, curve_nid, affine_x.group)
# Handle uncompressed point
elif data[0] == 4:
coord_size = compressed_size - 1
uncompressed_size = 1 + 2 * coord_size
if len(data) != uncompressed_size:
raise ValueError(
"uncompressed point does not have right size.")
affine_x = int.from_bytes(data[1:coord_size + 1], 'big')
affine_y = int.from_bytes(data[1 + coord_size:], 'big')
return cls.from_affine((affine_x, affine_y), curve)
else:
raise ValueError("Invalid point serialization.")
def gen_rand(cls, curve: ec.EllipticCurve = None):
"""
Returns a CurveBN object with a cryptographically secure OpenSSL BIGNUM
based on the given curve.
By default, the underlying OpenSSL BIGNUM has BN_FLG_CONSTTIME set for
constant time operations.
"""
curve = curve if curve is not None else default_curve()
curve_nid = backend._elliptic_curve_to_nid(curve)
group = openssl._get_ec_group_by_curve_nid(curve_nid)
order = openssl._get_ec_order_by_curve_nid(curve_nid)
new_rand_bn = openssl._get_new_BN()
rand_res = backend._lib.BN_rand_range(new_rand_bn, order)
backend.openssl_assert(rand_res == 1)
if not openssl._bn_is_on_curve(new_rand_bn, curve_nid):
new_rand_bn = cls.gen_rand(curve=curve)
return new_rand_bn
return cls(new_rand_bn, curve_nid, group, order)
def get_order_from_curve(cls, curve: ec.EllipticCurve = None):
"""
Returns the order from the given curve as a BigNum.
"""
curve = curve if curve is not None else default_curve()
try:
curve_nid = backend._elliptic_curve_to_nid(curve)
except AttributeError:
# Presume that the user passed in the curve_nid
curve_nid = curve
group = backend._lib.EC_GROUP_new_by_curve_name(curve_nid)
backend.openssl_assert(group != backend._ffi.NULL)
order = backend._lib.BN_new()
backend.openssl_assert(order != backend._ffi.NULL)
order = backend._ffi.gc(order, backend._lib.BN_clear_free)
with backend._tmp_bn_ctx() as bn_ctx:
res = backend._lib.EC_GROUP_get_order(group, order, bn_ctx)
backend.openssl_assert(res == 1)
return BigNum(order, curve_nid, group, order)
