def get_pos_y_for_x(pubkey_x, yneg=0):
key = pub_key = pub_key_x = pub_key_y = None
try:
key = OpenSSL.EC_KEY_new_by_curve_name(OpenSSL.get_curve('secp256k1'))
group = OpenSSL.EC_KEY_get0_group(key)
pub_key_x = OpenSSL.BN_bin2bn(pubkey_x, len(pubkey_x), 0)
pub_key = OpenSSL.EC_POINT_new(group)
if OpenSSL.EC_POINT_set_compressed_coordinates_GFp(group, pub_key,
pub_key_x, yneg, 0) == 0:
raise Exception("[OpenSSL] EC_POINT_set_compressed_coordinates_GFp FAIL ... " + OpenSSL.get_error())
pub_key_y = OpenSSL.BN_new()
if (OpenSSL.EC_POINT_get_affine_coordinates_GFp(group, pub_key,
pub_key_x,
pub_key_y, 0
)) == 0:
raise Exception("[OpenSSL] EC_POINT_get_affine_coordinates_GFp FAIL ... " + OpenSSL.get_error())
pubkeyy = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(pub_key_y))
OpenSSL.BN_bn2bin(pub_key_y, pubkeyy)
pubkeyy = pubkeyy.raw
field_size = OpenSSL.EC_GROUP_get_degree(OpenSSL.EC_KEY_get0_group(key))
secret_len = int((field_size + 7) / 8)
if len(pubkeyy) < secret_len:
pubkeyy = pubkeyy.rjust(secret_len, b'\0')
return pubkeyy
finally:
if key is not None: OpenSSL.EC_KEY_free(key)
if pub_key is not None: OpenSSL.EC_POINT_free(pub_key)
if pub_key_x is not None: OpenSSL.BN_free(pub_key_x)
if pub_key_y is not None: OpenSSL.BN_free(pub_key_y)
def _generate(self):
try:
pub_key_x = OpenSSL.BN_new()
pub_key_y = OpenSSL.BN_new()
key = OpenSSL.EC_KEY_new_by_curve_name(self.curve)
if key == 0:
raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ...")
if (OpenSSL.EC_KEY_generate_key(key)) == 0:
raise Exception("[OpenSSL] EC_KEY_generate_key FAIL ...")
if (OpenSSL.EC_KEY_check_key(key)) == 0:
raise Exception("[OpenSSL] EC_KEY_check_key FAIL ...")
priv_key = OpenSSL.EC_KEY_get0_private_key(key)
group = OpenSSL.EC_KEY_get0_group(key)
pub_key = OpenSSL.EC_KEY_get0_public_key(key)
if (OpenSSL.EC_POINT_get_affine_coordinates_GFp(
group, pub_key, pub_key_x, pub_key_y, 0)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_get_affine_coordinates_GFp FAIL ...")
privkey = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(priv_key))
pubkeyx = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(pub_key_x))
pubkeyy = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(pub_key_y))
OpenSSL.BN_bn2bin(priv_key, privkey)
privkey = privkey.raw
OpenSSL.BN_bn2bin(pub_key_x, pubkeyx)
pubkeyx = pubkeyx.raw
OpenSSL.BN_bn2bin(pub_key_y, pubkeyy)
pubkeyy = pubkeyy.raw
self.raw_check_key(privkey, pubkeyx, pubkeyy)
return privkey, pubkeyx, pubkeyy
finally:
OpenSSL.EC_KEY_free(key)
OpenSSL.BN_free(pub_key_x)
OpenSSL.BN_free(pub_key_y)
def __init__(self, os_bn=None,decval=None,binval=None):
"""
Constructs a new BN object
and fills it with the value given.
"""
if os_bn is not None:
self.bn = os_bn
self.__created_bn = False
else:
self.bn = OpenSSL.BN_new()
self.__created_bn = True
if decval is None and binval is None:
decval = 0
if decval is not None:
binval = ECHelper.int2bin( decval )
if binval is not None:
OpenSSL.BN_bin2bn( binval, len( binval ), self.bn )
def ecc_ecdh_key(sec, pub):
assert isinstance(sec, ecc.ECC)
if isinstance(pub, ecc.ECC):
pub = pub.get_pubkey()
#return sec.get_ecdh_key(pub)
pubkey_x, pubkey_y = ecc.ECC._decode_pubkey(pub, 'binary')
other_key = other_pub_key_x = other_pub_key_y = other_pub_key = None
own_priv_key = res = res_x = res_y = None
try:
other_key = OpenSSL.EC_KEY_new_by_curve_name(sec.curve)
if other_key == 0:
raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ... " + OpenSSL.get_error())
other_pub_key_x = OpenSSL.BN_bin2bn(pubkey_x, len(pubkey_x), 0)
other_pub_key_y = OpenSSL.BN_bin2bn(pubkey_y, len(pubkey_y), 0)
other_group = OpenSSL.EC_KEY_get0_group(other_key)
other_pub_key = OpenSSL.EC_POINT_new(other_group)
if (other_pub_key == None):
raise Exception("[OpenSSl] EC_POINT_new FAIL ... " + OpenSSL.get_error())
if (OpenSSL.EC_POINT_set_affine_coordinates_GFp(other_group,
other_pub_key,
other_pub_key_x,
other_pub_key_y,
0)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_set_affine_coordinates_GFp FAIL ..." + OpenSSL.get_error())
own_priv_key = OpenSSL.BN_bin2bn(sec.privkey, len(sec.privkey), 0)
res = OpenSSL.EC_POINT_new(other_group)
if (OpenSSL.EC_POINT_mul(other_group, res, 0, other_pub_key, own_priv_key, 0)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_mul FAIL ..." + OpenSSL.get_error())
res_x = OpenSSL.BN_new()
res_y = OpenSSL.BN_new()
if (OpenSSL.EC_POINT_get_affine_coordinates_GFp(other_group, res,
res_x,
res_y, 0
)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_get_affine_coordinates_GFp FAIL ... " + OpenSSL.get_error())
resx = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(res_x))
resy = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(res_y))
OpenSSL.BN_bn2bin(res_x, resx)
resx = resx.raw
OpenSSL.BN_bn2bin(res_y, resy)
resy = resy.raw
return resx, resy
finally:
if other_key: OpenSSL.EC_KEY_free(other_key)
if other_pub_key_x: OpenSSL.BN_free(other_pub_key_x)
if other_pub_key_y: OpenSSL.BN_free(other_pub_key_y)
if other_pub_key: OpenSSL.EC_POINT_free(other_pub_key)
if own_priv_key: OpenSSL.BN_free(own_priv_key)
if res: OpenSSL.EC_POINT_free(res)
if res_x: OpenSSL.BN_free(res_x)
if res_y: OpenSSL.BN_free(res_y)