dash/test/functional/test_framework/key.py
Wladimir J. van der Laan 4ae641ca18
Partial merge #8499: Add several policy limits and disable uncompressed keys for segwit scripts
67d6ee1 remove redundant tests in p2p-segwit.py (Johnson Lau)
9260085 test segwit uncompressed key fixes (Johnson Lau)
248f3a7 Fix ismine and addwitnessaddress: no uncompressed keys in segwit (Pieter Wuille)
b811124 [qa] Add tests for uncompressed pubkeys in segwit (Suhas Daftuar)
9f0397a Make test framework produce lowS signatures (Johnson Lau)
4c0c25a Require compressed keys in segwit as policy and disable signing with uncompressed keys for segwit scripts (Johnson Lau)
3ade2f6 Add standard limits for P2WSH with tests (Johnson Lau)
2021-06-05 22:12:55 +03:00

227 lines
8.0 KiB
Python

# Copyright (c) 2011 Sam Rushing
"""ECC secp256k1 OpenSSL wrapper.
WARNING: This module does not mlock() secrets; your private keys may end up on
disk in swap! Use with caution!
This file is modified from python-bitcoinlib.
"""
import ctypes
import ctypes.util
import hashlib
ssl = ctypes.cdll.LoadLibrary(ctypes.util.find_library ('ssl') or 'libeay32')
ssl.BN_new.restype = ctypes.c_void_p
ssl.BN_new.argtypes = []
ssl.BN_bin2bn.restype = ctypes.c_void_p
ssl.BN_bin2bn.argtypes = [ctypes.c_char_p, ctypes.c_int, ctypes.c_void_p]
ssl.BN_CTX_free.restype = None
ssl.BN_CTX_free.argtypes = [ctypes.c_void_p]
ssl.BN_CTX_new.restype = ctypes.c_void_p
ssl.BN_CTX_new.argtypes = []
ssl.ECDH_compute_key.restype = ctypes.c_int
ssl.ECDH_compute_key.argtypes = [ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_void_p]
ssl.ECDSA_sign.restype = ctypes.c_int
ssl.ECDSA_sign.argtypes = [ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
ssl.ECDSA_verify.restype = ctypes.c_int
ssl.ECDSA_verify.argtypes = [ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p]
ssl.EC_KEY_free.restype = None
ssl.EC_KEY_free.argtypes = [ctypes.c_void_p]
ssl.EC_KEY_new_by_curve_name.restype = ctypes.c_void_p
ssl.EC_KEY_new_by_curve_name.argtypes = [ctypes.c_int]
ssl.EC_KEY_get0_group.restype = ctypes.c_void_p
ssl.EC_KEY_get0_group.argtypes = [ctypes.c_void_p]
ssl.EC_KEY_get0_public_key.restype = ctypes.c_void_p
ssl.EC_KEY_get0_public_key.argtypes = [ctypes.c_void_p]
ssl.EC_KEY_set_private_key.restype = ctypes.c_int
ssl.EC_KEY_set_private_key.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ssl.EC_KEY_set_conv_form.restype = None
ssl.EC_KEY_set_conv_form.argtypes = [ctypes.c_void_p, ctypes.c_int]
ssl.EC_KEY_set_public_key.restype = ctypes.c_int
ssl.EC_KEY_set_public_key.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ssl.i2o_ECPublicKey.restype = ctypes.c_void_p
ssl.i2o_ECPublicKey.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ssl.EC_POINT_new.restype = ctypes.c_void_p
ssl.EC_POINT_new.argtypes = [ctypes.c_void_p]
ssl.EC_POINT_free.restype = None
ssl.EC_POINT_free.argtypes = [ctypes.c_void_p]
ssl.EC_POINT_mul.restype = ctypes.c_int
ssl.EC_POINT_mul.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
# this specifies the curve used with ECDSA.
NID_secp256k1 = 714 # from openssl/obj_mac.h
SECP256K1_ORDER = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141
SECP256K1_ORDER_HALF = SECP256K1_ORDER // 2
# Thx to Sam Devlin for the ctypes magic 64-bit fix.
def _check_result(val, func, args):
if val == 0:
raise ValueError
else:
return ctypes.c_void_p (val)
ssl.EC_KEY_new_by_curve_name.restype = ctypes.c_void_p
ssl.EC_KEY_new_by_curve_name.errcheck = _check_result
class CECKey():
"""Wrapper around OpenSSL's EC_KEY"""
POINT_CONVERSION_COMPRESSED = 2
POINT_CONVERSION_UNCOMPRESSED = 4
def __init__(self):
self.k = ssl.EC_KEY_new_by_curve_name(NID_secp256k1)
def __del__(self):
if ssl:
ssl.EC_KEY_free(self.k)
self.k = None
def set_secretbytes(self, secret):
priv_key = ssl.BN_bin2bn(secret, 32, ssl.BN_new())
group = ssl.EC_KEY_get0_group(self.k)
pub_key = ssl.EC_POINT_new(group)
ctx = ssl.BN_CTX_new()
if not ssl.EC_POINT_mul(group, pub_key, priv_key, None, None, ctx):
raise ValueError("Could not derive public key from the supplied secret.")
ssl.EC_POINT_mul(group, pub_key, priv_key, None, None, ctx)
ssl.EC_KEY_set_private_key(self.k, priv_key)
ssl.EC_KEY_set_public_key(self.k, pub_key)
ssl.EC_POINT_free(pub_key)
ssl.BN_CTX_free(ctx)
return self.k
def set_privkey(self, key):
self.mb = ctypes.create_string_buffer(key)
return ssl.d2i_ECPrivateKey(ctypes.byref(self.k), ctypes.byref(ctypes.pointer(self.mb)), len(key))
def set_pubkey(self, key):
self.mb = ctypes.create_string_buffer(key)
return ssl.o2i_ECPublicKey(ctypes.byref(self.k), ctypes.byref(ctypes.pointer(self.mb)), len(key))
def get_privkey(self):
size = ssl.i2d_ECPrivateKey(self.k, 0)
mb_pri = ctypes.create_string_buffer(size)
ssl.i2d_ECPrivateKey(self.k, ctypes.byref(ctypes.pointer(mb_pri)))
return mb_pri.raw
def get_pubkey(self):
size = ssl.i2o_ECPublicKey(self.k, 0)
mb = ctypes.create_string_buffer(size)
ssl.i2o_ECPublicKey(self.k, ctypes.byref(ctypes.pointer(mb)))
return mb.raw
def get_raw_ecdh_key(self, other_pubkey):
ecdh_keybuffer = ctypes.create_string_buffer(32)
r = ssl.ECDH_compute_key(ctypes.pointer(ecdh_keybuffer), 32,
ssl.EC_KEY_get0_public_key(other_pubkey.k),
self.k, 0)
if r != 32:
raise Exception('CKey.get_ecdh_key(): ECDH_compute_key() failed')
return ecdh_keybuffer.raw
def get_ecdh_key(self, other_pubkey, kdf=lambda k: hashlib.sha256(k).digest()):
# FIXME: be warned it's not clear what the kdf should be as a default
r = self.get_raw_ecdh_key(other_pubkey)
return kdf(r)
def sign(self, hash, low_s = True):
# FIXME: need unit tests for below cases
if not isinstance(hash, bytes):
raise TypeError('Hash must be bytes instance; got %r' % hash.__class__)
if len(hash) != 32:
raise ValueError('Hash must be exactly 32 bytes long')
sig_size0 = ctypes.c_uint32()
sig_size0.value = ssl.ECDSA_size(self.k)
mb_sig = ctypes.create_string_buffer(sig_size0.value)
result = ssl.ECDSA_sign(0, hash, len(hash), mb_sig, ctypes.byref(sig_size0), self.k)
assert 1 == result
assert mb_sig.raw[0] == 0x30
assert mb_sig.raw[1] == sig_size0.value - 2
total_size = mb_sig.raw[1]
assert mb_sig.raw[2] == 2
r_size = mb_sig.raw[3]
assert mb_sig.raw[4 + r_size] == 2
s_size = mb_sig.raw[5 + r_size]
s_value = int.from_bytes(mb_sig.raw[6+r_size:6+r_size+s_size], byteorder='big')
if (not low_s) or s_value <= SECP256K1_ORDER_HALF:
return mb_sig.raw[:sig_size0.value]
else:
low_s_value = SECP256K1_ORDER - s_value
low_s_bytes = (low_s_value).to_bytes(33, byteorder='big')
while len(low_s_bytes) > 1 and low_s_bytes[0] == 0 and low_s_bytes[1] < 0x80:
low_s_bytes = low_s_bytes[1:]
new_s_size = len(low_s_bytes)
new_total_size_byte = (total_size + new_s_size - s_size).to_bytes(1,byteorder='big')
new_s_size_byte = (new_s_size).to_bytes(1,byteorder='big')
return b'\x30' + new_total_size_byte + mb_sig.raw[2:5+r_size] + new_s_size_byte + low_s_bytes
def verify(self, hash, sig):
"""Verify a DER signature"""
return ssl.ECDSA_verify(0, hash, len(hash), sig, len(sig), self.k) == 1
def set_compressed(self, compressed):
if compressed:
form = self.POINT_CONVERSION_COMPRESSED
else:
form = self.POINT_CONVERSION_UNCOMPRESSED
ssl.EC_KEY_set_conv_form(self.k, form)
class CPubKey(bytes):
"""An encapsulated public key
Attributes:
is_valid - Corresponds to CPubKey.IsValid()
is_fullyvalid - Corresponds to CPubKey.IsFullyValid()
is_compressed - Corresponds to CPubKey.IsCompressed()
"""
def __new__(cls, buf, _cec_key=None):
self = super(CPubKey, cls).__new__(cls, buf)
if _cec_key is None:
_cec_key = CECKey()
self._cec_key = _cec_key
self.is_fullyvalid = _cec_key.set_pubkey(self) != 0
return self
@property
def is_valid(self):
return len(self) > 0
@property
def is_compressed(self):
return len(self) == 33
def verify(self, hash, sig):
return self._cec_key.verify(hash, sig)
def __str__(self):
return repr(self)
def __repr__(self):
return '%s(%s)' % (self.__class__.__name__, super(CPubKey, self).__repr__())