File size: 5,227 Bytes
bb9e896 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 | # This file is licensed under the BSD 2-Clause License.
# See https://opensource.org/licenses/BSD-2-Clause for details.
from ._curve import _Curve
from Crypto.Math.Numbers import Integer
from Crypto.Util._raw_api import (load_pycryptodome_raw_lib, VoidPointer,
SmartPointer)
def curve25519_curve():
p = 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed # 2**255 - 19
order = 0x1000000000000000000000000000000014def9dea2f79cd65812631a5cf5d3ed
_curve25519_lib = load_pycryptodome_raw_lib("Crypto.PublicKey._curve25519", """
typedef void Point;
int curve25519_new_point(Point **out,
const uint8_t x[32],
size_t modsize,
const void* context);
int curve25519_clone(Point **P, const Point *Q);
void curve25519_free_point(Point *p);
int curve25519_get_x(uint8_t *xb, size_t modsize, Point *p);
int curve25519_scalar(Point *P, const uint8_t *scalar, size_t scalar_len, uint64_t seed);
int curve25519_cmp(const Point *ecp1, const Point *ecp2);
""")
class EcLib(object):
new_point = _curve25519_lib.curve25519_new_point
clone = _curve25519_lib.curve25519_clone
free_point = _curve25519_lib.curve25519_free_point
get_x = _curve25519_lib.curve25519_get_x
scalar = _curve25519_lib.curve25519_scalar
cmp = _curve25519_lib.curve25519_cmp
def _validate_x25519_point(point):
p2 = p * 2
x1 = 325606250916557431795983626356110631294008115727848805560023387167927233504
x2 = 39382357235489614581723060781553021112529911719440698176882885853963445705823
# http://cr.yp.to/ecdh.html#validate
deny_list = (
0,
1,
x1,
x2,
p - 1,
p,
p + 1,
p + x1,
p + x2,
p2 - 1,
p2,
p2 + 1,
)
try:
valid = point.x not in deny_list
except ValueError:
valid = False
if not valid:
raise ValueError("Invalid Curve25519 public key")
curve25519 = _Curve(Integer(p),
None,
Integer(order),
Integer(9),
None,
None,
255,
"1.3.101.110", # RFC8410
None,
"Curve25519",
None,
EcLib,
_validate_x25519_point,
)
return curve25519
def curve448_curve():
p = 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffeffffffffffffffffffffffffffffffffffffffffffffffffffffffff # 2**448 - 2**224 - 1
order = 0x3fffffffffffffffffffffffffffffffffffffffffffffffffffffff7cca23e9c44edb49aed63690216cc2728dc58f552378c292ab5844f3
_curve448_lib = load_pycryptodome_raw_lib("Crypto.PublicKey._curve448", """
typedef void Curve448Context;
typedef void Curve448Point;
int curve448_new_context(Curve448Context **pec_ctx);
void curve448_free_context(Curve448Context *ec_ctx);
int curve448_new_point(Curve448Point **out,
const uint8_t *x,
size_t len,
const Curve448Context *ec_ctx);
void curve448_free_point(Curve448Point *p);
int curve448_clone(Curve448Point **P, const Curve448Point *Q);
int curve448_get_x(uint8_t *xb, size_t modsize, const Curve448Point *p);
int curve448_scalar(Curve448Point *P, const uint8_t *scalar, size_t scalar_len, uint64_t seed);
int curve448_cmp(const Curve448Point *ecp1, const Curve448Point *ecp2);
""")
class EcLib(object):
new_context = _curve448_lib.curve448_new_context
free_context = _curve448_lib.curve448_free_context
new_point = _curve448_lib.curve448_new_point
clone = _curve448_lib.curve448_clone
free_point = _curve448_lib.curve448_free_point
get_x = _curve448_lib.curve448_get_x
scalar = _curve448_lib.curve448_scalar
cmp = _curve448_lib.curve448_cmp
curve448_context = VoidPointer()
result = EcLib.new_context(curve448_context.address_of())
if result:
raise ImportError("Error %d initializing Curve448 context" % result)
def _validate_x448_point(point):
deny_list = (
0,
1,
p - 1,
p,
p + 1,
)
try:
valid = point.x not in deny_list
except ValueError:
valid = False
if not valid:
raise ValueError("Invalid Curve448 public key")
curve448 = _Curve(Integer(p),
None,
Integer(order),
Integer(5),
None,
None,
448,
"1.3.101.111", # RFC8410
SmartPointer(curve448_context.get(), EcLib.free_context),
"Curve448",
None,
EcLib,
_validate_x448_point,
)
return curve448
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