def _evp_pkey_to_public_key(self, evp_pkey):
"""
Return the appropriate type of PublicKey given an evp_pkey cdata
pointer.
"""
type = evp_pkey.type
if type == self._lib.EVP_PKEY_RSA:
rsa_cdata = self._lib.EVP_PKEY_get1_RSA(evp_pkey)
assert rsa_cdata != self._ffi.NULL
rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
return _RSAPublicKey(self, rsa_cdata)
elif type == self._lib.EVP_PKEY_DSA:
dsa_cdata = self._lib.EVP_PKEY_get1_DSA(evp_pkey)
assert dsa_cdata != self._ffi.NULL
dsa_cdata = self._ffi.gc(dsa_cdata, self._lib.DSA_free)
return _DSAPublicKey(self, dsa_cdata)
elif (self._lib.Cryptography_HAS_EC == 1
and type == self._lib.EVP_PKEY_EC):
ec_cdata = self._lib.EVP_PKEY_get1_EC_KEY(evp_pkey)
assert ec_cdata != self._ffi.NULL
ec_cdata = self._ffi.gc(ec_cdata, self._lib.EC_KEY_free)
return _EllipticCurvePublicKey(self, ec_cdata)
else:
raise UnsupportedAlgorithm("Unsupported key type.")
def _evp_pkey_to_public_key(self, evp_pkey):
"""
Return the appropriate type of PublicKey given an evp_pkey cdata
pointer.
"""
type = evp_pkey.type
if type == self._lib.EVP_PKEY_RSA:
rsa_cdata = self._lib.EVP_PKEY_get1_RSA(evp_pkey)
assert rsa_cdata != self._ffi.NULL
rsa_cdata = self._ffi.gc(rsa_cdata, self._lib.RSA_free)
return _RSAPublicKey(self, rsa_cdata)
elif type == self._lib.EVP_PKEY_DSA:
dsa_cdata = self._lib.EVP_PKEY_get1_DSA(evp_pkey)
assert dsa_cdata != self._ffi.NULL
dsa_cdata = self._ffi.gc(dsa_cdata, self._lib.DSA_free)
return _DSAPublicKey(self, dsa_cdata)
elif (self._lib.Cryptography_HAS_EC == 1 and
type == self._lib.EVP_PKEY_EC):
ec_cdata = self._lib.EVP_PKEY_get1_EC_KEY(evp_pkey)
assert ec_cdata != self._ffi.NULL
ec_cdata = self._ffi.gc(ec_cdata, self._lib.EC_KEY_free)
return _EllipticCurvePublicKey(self, ec_cdata)
else:
raise UnsupportedAlgorithm("Unsupported key type.")
def to_cryptography_pubkey(self) -> _EllipticCurvePublicKey:
"""
Returns a cryptography.io EllipticCurvePublicKey from the Umbral key.
"""
backend = default_backend()
backend.openssl_assert(self.point_key.curve.ec_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)
set_group_result = backend._lib.EC_KEY_set_group(
ec_key, self.point_key.curve.ec_group
)
backend.openssl_assert(set_group_result == 1)
set_pubkey_result = backend._lib.EC_KEY_set_public_key(
ec_key, self.point_key.ec_point
)
backend.openssl_assert(set_pubkey_result == 1)
evp_pkey = backend._ec_cdata_to_evp_pkey(ec_key)
return _EllipticCurvePublicKey(backend, ec_key, evp_pkey)
def elliptic_curve_public_key_from_numbers(self, numbers):
curve_nid = self._elliptic_curve_to_nid(numbers.curve)
ctx = self._lib.EC_KEY_new_by_curve_name(curve_nid)
assert ctx != self._ffi.NULL
ctx = self._ffi.gc(ctx, self._lib.EC_KEY_free)
ctx = self._ec_key_set_public_key_affine_coordinates(
ctx, numbers.x, numbers.y)
return _EllipticCurvePublicKey(self, ctx, numbers.curve)
def load_elliptic_curve_public_numbers(self, numbers):
curve_nid = self._elliptic_curve_to_nid(numbers.curve)
ec_cdata = self._lib.EC_KEY_new_by_curve_name(curve_nid)
assert ec_cdata != self._ffi.NULL
ec_cdata = self._ffi.gc(ec_cdata, self._lib.EC_KEY_free)
ec_cdata = self._ec_key_set_public_key_affine_coordinates(
ec_cdata, numbers.x, numbers.y)
return _EllipticCurvePublicKey(self, ec_cdata)
def load_elliptic_curve_public_numbers(self, numbers):
curve_nid = self._elliptic_curve_to_nid(numbers.curve)
ec_cdata = self._lib.EC_KEY_new_by_curve_name(curve_nid)
assert ec_cdata != self._ffi.NULL
ec_cdata = self._ffi.gc(ec_cdata, self._lib.EC_KEY_free)
ec_cdata = self._ec_key_set_public_key_affine_coordinates(
ec_cdata, numbers.x, numbers.y)
return _EllipticCurvePublicKey(self, ec_cdata)
def elliptic_curve_public_key_from_numbers(self, numbers):
curve_nid = self._elliptic_curve_to_nid(numbers.curve)
ctx = self._lib.EC_KEY_new_by_curve_name(curve_nid)
assert ctx != self._ffi.NULL
ctx = self._ffi.gc(ctx, self._lib.EC_KEY_free)
ctx = self._ec_key_set_public_key_affine_coordinates(
ctx, numbers.x, numbers.y)
return _EllipticCurvePublicKey(self, ctx, numbers.curve)
def point_to_pubkey(curve: Curve, point):
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)
set_group_result = BACKEND_LIB.EC_KEY_set_group(ec_key, curve.ec_group)
backend.openssl_assert(set_group_result == 1)
set_pubkey_result = BACKEND_LIB.EC_KEY_set_public_key(ec_key, point)
backend.openssl_assert(set_pubkey_result == 1)
evp_pkey = backend._ec_cdata_to_evp_pkey(ec_key)
return _EllipticCurvePublicKey(backend, ec_key, evp_pkey)
def to_cryptography_pub_key(self):
"""
Converts the Point object to a cryptography.io EllipticCurvePublicKey
"""
backend.openssl_assert(self.group != backend._ffi.NULL)
backend.openssl_assert(self.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.group)
backend.openssl_assert(res == 1)
res = backend._lib.EC_KEY_set_public_key(ec_key, self.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 _point_to_public_key(backend, group, point) -> _EllipticCurvePublicKey:
"""
Converts an EC_POINT to an EllipticCurvePublicKey.
"""
backend.openssl_assert(group != backend._ffi.NULL)
backend.openssl_assert(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, group)
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 _EllipticCurvePublicKey(backend, ec_key, evp_pkey)
def elliptic_curve_public_key_from_numbers(self, numbers):
ec_key = self._ec_key_cdata_from_public_numbers(numbers)
return _EllipticCurvePublicKey(self, ec_key, numbers.curve)
def recover_pubkey(cls,
signature,
data,
check=None,
backend=None,
curve=ec.SECP256K1()):
from cryptography.hazmat.backends.openssl.ec import _EllipticCurvePublicKey
backend = backend or default_backend()
curve_nid = backend._elliptic_curve_to_nid(curve)
with backend._tmp_bn_ctx() as ctx:
ec_cdata = backend._lib.EC_KEY_new_by_curve_name(curve_nid)
backend.openssl_assert(ec_cdata != backend._ffi.NULL)
ec_cdata = backend._ffi.gc(ec_cdata, backend._lib.EC_KEY_free)
group = backend._lib.EC_KEY_get0_group(ec_cdata)
backend.openssl_assert(group != backend._ffi.NULL)
z_data = BlcSha.sha256(data)
z_len = (backend._lib.EC_GROUP_get_degree(group) + 7) // 8
backend.openssl_assert(z_len > 0)
z_buf = backend._ffi.new("unsigned char[]", z_data[-z_len:])
z = backend._lib.BN_CTX_get(ctx)
backend._lib.BN_bin2bn(z_buf, z_len, z)
# print(f'z: {backend._bn_to_int(z)}')
sigbuf = backend._ffi.new("unsigned char[]", signature)
psigbuf = backend._ffi.new("unsigned char **", sigbuf)
sig = backend._lib.d2i_ECDSA_SIG(backend._ffi.NULL, psigbuf,
len(signature))
backend.openssl_assert(sig != backend._ffi.NULL)
pr = backend._ffi.new("BIGNUM **")
ps = backend._ffi.new("BIGNUM **")
backend._lib.ECDSA_SIG_get0(sig, pr, ps)
r = backend._bn_to_int(pr[0])
s = backend._bn_to_int(ps[0])
# print(f'sig: {r}\n {s}')
for y in [0, 1]:
point = backend._lib.EC_POINT_new(group)
backend._lib.EC_POINT_set_compressed_coordinates_GFp(
group, point, pr[0], y, ctx)
bnx = backend._lib.BN_CTX_get(ctx)
bny = backend._lib.BN_CTX_get(ctx)
backend._lib.EC_POINT_get_affine_coordinates_GFp(
group, point, bnx, bny, ctx)
# print(f'point: {backend._bn_to_int(bnx)}\n {backend._bn_to_int(bny)}')
order = backend._lib.BN_CTX_get(ctx)
backend._lib.EC_GROUP_get_order(group, order, ctx)
# print(f'order: {backend._bn_to_int(order)}')
inv = backend._lib.BN_CTX_get(ctx)
backend._lib.BN_mod_inverse(inv, pr[0], order, ctx)
# print(f'r inv: {backend._bn_to_int(inv)}')
rs = backend._lib.BN_CTX_get(ctx)
backend._lib.BN_mod_mul(rs, inv, ps[0], order, ctx)
# print(f'r1 s: {backend._bn_to_int(rs)}')
rz = backend._lib.BN_CTX_get(ctx)
rzn = backend._lib.BN_CTX_get(ctx)
zero = backend._lib.BN_CTX_get(ctx)
backend._lib.BN_mod_mul(rz, inv, z, order, ctx)
backend._lib.BN_mod_sub(rzn, zero, rz, order, ctx)
# print(f'r1 z: {backend._bn_to_int(rz)}')
# print(f'-r1 z: {backend._bn_to_int(rzn)}')
zn = backend._lib.BN_CTX_get(ctx)
backend._lib.BN_mod_sub(zn, zero, z, order, ctx)
res = backend._lib.EC_POINT_new(group)
backend._lib.EC_POINT_mul(group, res, rzn, point, rs, ctx)
bnx = backend._lib.BN_CTX_get(ctx)
bny = backend._lib.BN_CTX_get(ctx)
backend._lib.EC_POINT_get_affine_coordinates_GFp(
group, res, bnx, bny, ctx)
# print(f'pkey: {backend._bn_to_int(bnx)}\n {backend._bn_to_int(bny)}')
ec_cdata = backend._ec_key_set_public_key_affine_coordinates(
ec_cdata, backend._bn_to_int(bnx), backend._bn_to_int(bny))
evp_pkey = backend._ec_cdata_to_evp_pkey(ec_cdata)
pkey = _EllipticCurvePublicKey(backend, ec_cdata, evp_pkey)
if not check or check(pkey):
return pkey
