def _decrypt(self, ciphertext):
if not 0 < ciphertext < self._n:
raise ValueError("Ciphertext too large")
if not self.has_private():
raise TypeError("This is not a private key")
# Blinded RSA decryption (to prevent timing attacks):
# Step 1: Generate random secret blinding factor r,
# such that 0 < r < n-1
r = Integer.random_range(min_inclusive=1, max_exclusive=self._n)
# Step 2: Compute c' = c * r**e mod n
cp = Integer(ciphertext) * pow(r, self._e, self._n) % self._n
# Step 3: Compute m' = c'**d mod n (ordinary RSA decryption)
m1 = pow(cp, self._d % (self._p - 1), self._p)
m2 = pow(cp, self._d % (self._q - 1), self._q)
h = m2 - m1
while h < 0:
h += self._q
h = (h * self._u) % self._q
mp = h * self._p + m1
# Step 4: Compute m = m**(r-1) mod n
result = (r.inverse(self._n) * mp) % self._n
# Verify no faults occured
if ciphertext != pow(result, self._e, self._n):
raise ValueError("Fault detected in RSA decryption")
return result
def _import_openssh_private_ecc(data, password):
from ._openssh import (import_openssh_private_generic, read_bytes,
read_string, check_padding)
ssh_name, decrypted = import_openssh_private_generic(data, password)
name, decrypted = read_string(decrypted)
if name not in _curves:
raise UnsupportedEccFeature("Unsupported ECC curve %s" % name)
curve = _curves[name]
modulus_bytes = (curve.modulus_bits + 7) // 8
public_key, decrypted = read_bytes(decrypted)
if bord(public_key[0]) != 4:
raise ValueError("Only uncompressed OpenSSH EC keys are supported")
if len(public_key) != 2 * modulus_bytes + 1:
raise ValueError("Incorrect public key length")
point_x = Integer.from_bytes(public_key[1:1 + modulus_bytes])
point_y = Integer.from_bytes(public_key[1 + modulus_bytes:])
point = EccPoint(point_x, point_y, curve=name)
private_key, decrypted = read_bytes(decrypted)
d = Integer.from_bytes(private_key)
_, padded = read_string(decrypted) # Comment
check_padding(padded)
return EccKey(curve=name, d=d, point=point)
def test_several_lengths(self):
prng = SHAKE128.new().update(b('Test'))
for length in range(1, 100):
base = Integer.from_bytes(prng.read(length))
modulus2 = Integer.from_bytes(prng.read(length)) | 1
exponent2 = Integer.from_bytes(prng.read(length))
expected = pow(base, exponent2, modulus2)
result = monty_pow(base, exponent2, modulus2)
self.assertEqual(result, expected)
def test_probable_prime(candidate, randfunc=None):
"""Test if a number is prime.
A number is qualified as prime if it passes a certain
number of Miller-Rabin tests (dependent on the size
of the number, but such that probability of a false
positive is less than 10^-30) and a single Lucas test.
For instance, a 1024-bit candidate will need to pass
4 Miller-Rabin tests.
:Parameters:
candidate : integer
The number to test for primality.
randfunc : callable
The routine to draw random bytes from to select Miller-Rabin bases.
:Returns:
``PROBABLE_PRIME`` if the number if prime with very high probability.
``COMPOSITE`` if the number is a composite.
For efficiency reasons, ``COMPOSITE`` is also returned for small primes.
"""
if randfunc is None:
randfunc = Random.new().read
if not isinstance(candidate, Integer):
candidate = Integer(candidate)
# First, check trial division by the smallest primes
if int(candidate) in _sieve_base:
return PROBABLY_PRIME
try:
map(candidate.fail_if_divisible_by, _sieve_base)
except ValueError:
return COMPOSITE
# These are the number of Miller-Rabin iterations s.t. p(k, t) < 1E-30,
# with p(k, t) being the probability that a randomly chosen k-bit number
# is composite but still survives t MR iterations.
mr_ranges = ((220, 30), (280, 20), (390, 15), (512, 10), (620, 7),
(740, 6), (890, 5), (1200, 4), (1700, 3), (3700, 2))
bit_size = candidate.size_in_bits()
try:
mr_iterations = list(filter(lambda x: bit_size < x[0],
mr_ranges))[0][1]
except IndexError:
mr_iterations = 1
if miller_rabin_test(candidate, mr_iterations,
randfunc=randfunc) == COMPOSITE:
return COMPOSITE
if lucas_test(candidate) == COMPOSITE:
return COMPOSITE
return PROBABLY_PRIME
def xy(self):
modulus_bytes = self.size_in_bytes()
xb = bytearray(modulus_bytes)
yb = bytearray(modulus_bytes)
result = _ec_lib.ec_ws_get_xy(c_uint8_ptr(xb), c_uint8_ptr(yb),
c_size_t(modulus_bytes),
self._point.get())
if result:
raise ValueError("Error %d while encoding an EC point" % result)
return (Integer(bytes_to_long(xb)), Integer(bytes_to_long(yb)))
def _sign(self, M, K):
if (not hasattr(self, 'x')):
raise TypeError('Private key not available in this object')
p1 = self.p - 1
K = Integer(K)
if (K.gcd(p1) != 1):
raise ValueError('Bad K value: GCD(K,p-1)!=1')
a = pow(self.g, K, self.p)
t = (Integer(M) - self.x * a) % p1
while t < 0:
t = t + p1
b = (t * K.inverse(p1)) % p1
return list(map(int, (a, b)))
def construct(**kwargs):
"""Build a new ECC key (private or public) starting
from some base components.
Args:
curve (string):
Mandatory. It must be "P-256", "prime256v1" or "secp256r1".
d (integer):
Only for a private key. It must be in the range ``[1..order-1]``.
point_x (integer):
Mandatory for a public key. X coordinate (affine) of the ECC point.
point_y (integer):
Mandatory for a public key. Y coordinate (affine) of the ECC point.
Returns:
:class:`EccKey` : a new ECC key object
"""
point_x = kwargs.pop("point_x", None)
point_y = kwargs.pop("point_y", None)
if "point" in kwargs:
raise TypeError("Unknown keyword: point")
if None not in (point_x, point_y):
kwargs["point"] = EccPoint(point_x, point_y)
# Validate that the point is on the P-256 curve
eq1 = pow(Integer(point_y), 2, _curve.p)
x = Integer(point_x)
eq2 = pow(x, 3, _curve.p)
x *= -3
eq2 += x
eq2 += _curve.b
eq2 %= _curve.p
if eq1 != eq2:
raise ValueError("The point is not on the curve")
# Validate that the private key matches the public one
d = kwargs.get("d", None)
if d is not None and "point" in kwargs:
pub_key = _curve.G * d
if pub_key.x != point_x or pub_key.y != point_y:
raise ValueError("Private and public ECC keys do not match")
return EccKey(**kwargs)
def verify(self, msg_hash, signature):
"""Check if a certain (EC)DSA signature is authentic.
:parameter msg_hash:
The hash that was carried out over the message.
This is an object belonging to the :mod:`crypto.Hash` module.
Under mode *'fips-186-3'*, the hash must be a FIPS
approved secure hash (SHA-1 or a member of the SHA-2 family),
of cryptographic strength appropriate for the DSA key.
For instance, a 3072/256 DSA key can only be used in
combination with SHA-512.
:type msg_hash: hash object
:parameter signature:
The signature that needs to be validated
:type signature: byte string
:raise ValueError: if the signature is not authentic
"""
if not self._valid_hash(msg_hash):
raise ValueError("Hash is not sufficiently strong")
if self._encoding == 'binary':
if len(signature) != (2 * self._order_bytes):
raise ValueError("The signature is not authentic (length)")
r_prime, s_prime = [
Integer.from_bytes(x) for x in (signature[:self._order_bytes],
signature[self._order_bytes:])
]
else:
try:
der_seq = DerSequence().decode(signature, strict=True)
except (ValueError, IndexError):
raise ValueError("The signature is not authentic (DER)")
if len(der_seq) != 2 or not der_seq.hasOnlyInts():
raise ValueError(
"The signature is not authentic (DER content)")
r_prime, s_prime = Integer(der_seq[0]), Integer(der_seq[1])
if not (0 < r_prime < self._order) or not (0 < s_prime < self._order):
raise ValueError("The signature is not authentic (d)")
z = Integer.from_bytes(msg_hash.digest()[:self._order_bytes])
result = self._key._verify(z, (r_prime, s_prime))
if not result:
raise ValueError("The signature is not authentic")
# Make PyCrypto code to fail
return False
def __mul__(self, scalar):
"""Return a new point, the scalar product of this one"""
if scalar < 0:
raise ValueError("Scalar multiplication only defined for non-negative integers")
# Trivial results
if scalar == 0 or self.is_point_at_infinity():
return self.point_at_infinity()
elif scalar == 1:
return self.copy()
# Scalar randomization
scalar_blind = Integer.random(exact_bits=64) * _curve.order + scalar
# Montgomery key ladder
r = [self.point_at_infinity().copy(), self.copy()]
bit_size = int(scalar_blind.size_in_bits())
scalar_int = int(scalar_blind)
for i in range(bit_size, -1, -1):
di = scalar_int >> i & 1
r[di ^ 1] += r[di]
r[di].double()
return r[0]
def __init__(self, **kwargs):
"""Create a new ECC key
Keywords:
curve : string
It must be *"P-256"*, *"prime256v1"* or *"secp256r1"*.
d : integer
Only for a private key. It must be in the range ``[1..order-1]``.
point : EccPoint
Mandatory for a public key. If provided for a private key,
the implementation will NOT check whether it matches ``d``.
"""
kwargs_ = dict(kwargs)
self.curve = kwargs_.pop("curve", None)
self._d = kwargs_.pop("d", None)
self._point = kwargs_.pop("point", None)
if kwargs_:
raise TypeError("Unknown parameters: " + str(kwargs_))
if self.curve not in _curve.names:
raise ValueError("Unsupported curve (%s)", self.curve)
if self._d is None:
if self._point is None:
raise ValueError("Either private or public ECC component must be specified")
else:
self._d = Integer(self._d)
if not 1 <= self._d < _curve.order:
raise ValueError("Invalid ECC private component")
def __init__(self, x, y):
self._x = Integer(x)
self._y = Integer(y)
# Buffers
self._common = Integer(0)
self._tmp1 = Integer(0)
self._x3 = Integer(0)
self._y3 = Integer(0)
def _import_public_der(curve_oid, ec_point):
"""Convert an encoded EC point into an EccKey object
curve_name: string with the OID of the curve
ec_point: byte string with the EC point (not DER encoded)
"""
for curve_name, curve in _curves.items():
if curve.oid == curve_oid:
break
else:
raise UnsupportedEccFeature("Unsupported ECC curve (OID: %s)" %
curve_oid)
# See 2.2 in RFC5480 and 2.3.3 in SEC1
# The first byte is:
# - 0x02: compressed, only X-coordinate, Y-coordinate is even
# - 0x03: compressed, only X-coordinate, Y-coordinate is odd
# - 0x04: uncompressed, X-coordinate is followed by Y-coordinate
#
# PAI is in theory encoded as 0x00.
modulus_bytes = curve.p.size_in_bytes()
point_type = bord(ec_point[0])
# Uncompressed point
if point_type == 0x04:
if len(ec_point) != (1 + 2 * modulus_bytes):
raise ValueError("Incorrect EC point length")
x = Integer.from_bytes(ec_point[1:modulus_bytes + 1])
y = Integer.from_bytes(ec_point[modulus_bytes + 1:])
# Compressed point
elif point_type in (0x02, 0x3):
if len(ec_point) != (1 + modulus_bytes):
raise ValueError("Incorrect EC point length")
x = Integer.from_bytes(ec_point[1:])
y = (x**3 - x * 3 + curve.b).sqrt(curve.p) # Short Weierstrass
if point_type == 0x02 and y.is_odd():
y = curve.p - y
if point_type == 0x03 and y.is_even():
y = curve.p - y
else:
raise ValueError("Incorrect EC point encoding")
return construct(curve=curve_name, point_x=x, point_y=y)
def _bits2int(self, bstr):
"""See 2.3.2 in RFC6979"""
result = Integer.from_bytes(bstr)
q_len = self._order.size_in_bits()
b_len = len(bstr) * 8
if b_len > q_len:
result >>= (b_len - q_len)
return result
def __init__(self, key, encoding, order, randfunc):
super(FipsDsaSigScheme, self).__init__(key, encoding, order)
self._randfunc = randfunc
L = Integer(key.p).size_in_bits()
if (L, self._order_bits) not in self._fips_186_3_L_N:
error = ("L/N (%d, %d) is not compliant to FIPS 186-3" %
(L, self._order_bits))
raise ValueError(error)
def generate_probable_prime(**kwargs):
"""Generate a random probable prime.
The prime will not have any specific properties
(e.g. it will not be a *strong* prime).
Random numbers are evaluated for primality until one
passes all tests, consisting of a certain number of
Miller-Rabin tests with random bases followed by
a single Lucas test.
The number of Miller-Rabin iterations is chosen such that
the probability that the output number is a non-prime is
less than 1E-30 (roughly 2^{-100}).
This approach is compliant to `FIPS PUB 186-4`__.
:Keywords:
exact_bits : integer
The desired size in bits of the probable prime.
It must be at least 160.
randfunc : callable
An RNG function where candidate primes are taken from.
prime_filter : callable
A function that takes an Integer as parameter and returns
True if the number can be passed to further primality tests,
False if it should be immediately discarded.
:Return:
A probable prime in the range 2^exact_bits > p > 2^(exact_bits-1).
.. __: http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf
"""
exact_bits = kwargs.pop("exact_bits", None)
randfunc = kwargs.pop("randfunc", None)
prime_filter = kwargs.pop("prime_filter", lambda x: True)
if kwargs:
raise ValueError("Unknown parameters: " + kwargs.keys())
if exact_bits is None:
raise ValueError("Missing exact_bits parameter")
if exact_bits < 160:
raise ValueError("Prime number is not big enough.")
if randfunc is None:
randfunc = Random.new().read
result = COMPOSITE
while result == COMPOSITE:
candidate = Integer.random(exact_bits=exact_bits,
randfunc=randfunc) | 1
if not prime_filter(candidate):
continue
result = test_probable_prime(candidate, randfunc)
return candidate
def _verify(self, m, sig):
r, s = sig
y, q, p, g = [self._key[comp] for comp in ['y', 'q', 'p', 'g']]
if not (0 < r < q) or not (0 < s < q):
return False
w = Integer(s).inverse(q)
u1 = (w * m) % q
u2 = (w * r) % q
v = (pow(g, u1, p) * pow(y, u2, p) % p) % q
return v == r
def _decrypt(self, M):
if (not hasattr(self, 'x')):
raise TypeError('Private key not available in this object')
r = Integer.random_range(min_inclusive=2,
max_exclusive=self.p - 1,
randfunc=self._randfunc)
a_blind = (pow(self.g, r, self.p) * M[0]) % self.p
ax = pow(a_blind, self.x, self.p)
plaintext_blind = (ax.inverse(self.p) * M[1]) % self.p
plaintext = (plaintext_blind * pow(self.y, r, self.p)) % self.p
return int(plaintext)
def _sign(self, z, k):
assert 0 < k < _curve.order
blind = Integer.random_range(min_inclusive=1,
max_exclusive=_curve.order)
blind_d = self._d * blind
inv_blind_k = (blind * k).inverse(_curve.order)
r = (_curve.G * k).x % _curve.order
s = inv_blind_k * (blind * z + blind_d * r) % _curve.order
return (r, s)
def __repr__(self):
attrs = []
for k in self._keydata:
if k == 'p':
bits = Integer(self.p).size_in_bits()
attrs.append("p(%d)" % (bits, ))
elif hasattr(self, k):
attrs.append(k)
if self.has_private():
attrs.append("private")
# PY3K: This is meant to be text, do not change to bytes (data)
return "<%s @0x%x %s>" % (self.__class__.__name__, id(self),
",".join(attrs))
def construct(tup):
r"""Construct an ElGamal key from a tuple of valid ElGamal components.
The modulus *p* must be a prime.
The following conditions must apply:
.. math::
\begin{align}
&1 < g < p-1 \\
&g^{p-1} = 1 \text{ mod } 1 \\
&1 < x < p-1 \\
&g^x = y \text{ mod } p
\end{align}
Args:
tup (tuple):
A tuple with either 3 or 4 integers,
in the following order:
1. Modulus (*p*).
2. Generator (*g*).
3. Public key (*y*).
4. Private key (*x*). Optional.
Raises:
ValueError: when the key being imported fails the most basic ElGamal validity checks.
Returns:
an :class:`ElGamalKey` object
"""
obj = ElGamalKey()
if len(tup) not in [3, 4]:
raise ValueError('argument for construct() wrong length')
for i in range(len(tup)):
field = obj._keydata[i]
setattr(obj, field, Integer(tup[i]))
fmt_error = test_probable_prime(obj.p) == COMPOSITE
fmt_error |= obj.g <= 1 or obj.g >= obj.p
fmt_error |= pow(obj.g, obj.p - 1, obj.p) != 1
fmt_error |= obj.y < 1 or obj.y >= obj.p
if len(tup) == 4:
fmt_error |= obj.x <= 1 or obj.x >= obj.p
fmt_error |= pow(obj.g, obj.x, obj.p) != obj.y
if fmt_error:
raise ValueError("Invalid ElGamal key components")
return obj
def _import_private_der(encoded, passphrase, curve_oid=None):
# See RFC5915 https://tools.ietf.org/html/rfc5915
#
# ECPrivateKey ::= SEQUENCE {
# version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
# privateKey OCTET STRING,
# parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
# publicKey [1] BIT STRING OPTIONAL
# }
private_key = DerSequence().decode(encoded, nr_elements=(3, 4))
if private_key[0] != 1:
raise ValueError("Incorrect ECC private key version")
try:
parameters = DerObjectId(explicit=0).decode(private_key[2]).value
if curve_oid is not None and parameters != curve_oid:
raise ValueError("Curve mismatch")
curve_oid = parameters
except ValueError:
pass
if curve_oid is None:
raise ValueError("No curve found")
for curve_name, curve in _curves.items():
if curve.oid == curve_oid:
break
else:
raise UnsupportedEccFeature("Unsupported ECC curve (OID: %s)" %
curve_oid)
scalar_bytes = DerOctetString().decode(private_key[1]).payload
modulus_bytes = curve.p.size_in_bytes()
if len(scalar_bytes) != modulus_bytes:
raise ValueError("Private key is too small")
d = Integer.from_bytes(scalar_bytes)
# Decode public key (if any)
if len(private_key) == 4:
public_key_enc = DerBitString(explicit=1).decode(private_key[3]).value
public_key = _import_public_der(curve_oid, public_key_enc)
point_x = public_key.pointQ.x
point_y = public_key.pointQ.y
else:
point_x = point_y = None
return construct(curve=curve_name, d=d, point_x=point_x, point_y=point_y)
def _sign(self, m, k):
if not self.has_private():
raise TypeError("DSA public key cannot be used for signing")
if not (1 < k < self.q):
raise ValueError("k is not between 2 and q-1")
x, q, p, g = [self._key[comp] for comp in ['x', 'q', 'p', 'g']]
blind_factor = Integer.random_range(min_inclusive=1, max_exclusive=q)
inv_blind_k = (blind_factor * k).inverse(q)
blind_x = x * blind_factor
r = pow(g, k, p) % q # r = (g**k mod p) mod q
s = (inv_blind_k * (blind_factor * m + blind_x * r)) % q
return map(int, (r, s))
def _check_private_key(self, rsaObj):
from crypto.Math.Numbers import Integer
# Check capabilities
self.assertEqual(1, rsaObj.has_private())
# Sanity check key data
self.assertEqual(rsaObj.n, rsaObj.p * rsaObj.q) # n = pq
lcm = int(Integer(rsaObj.p-1).lcm(rsaObj.q-1))
self.assertEqual(1, rsaObj.d * rsaObj.e % lcm) # ed = 1 (mod LCM(p-1, q-1))
self.assertEqual(1, rsaObj.p * rsaObj.u % rsaObj.q) # pu = 1 (mod q)
self.assertEqual(1, rsaObj.p > 1) # p > 1
self.assertEqual(1, rsaObj.q > 1) # q > 1
self.assertEqual(1, rsaObj.e > 1) # e > 1
self.assertEqual(1, rsaObj.d > 1) # d > 1
def init_p256():
p = 0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff
b = 0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b
order = 0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551
Gx = 0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296
Gy = 0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5
p256_modulus = long_to_bytes(p, 32)
p256_b = long_to_bytes(b, 32)
p256_order = long_to_bytes(order, 32)
ec_p256_context = VoidPointer()
result = _ec_lib.ec_ws_new_context(ec_p256_context.address_of(),
c_uint8_ptr(p256_modulus),
c_uint8_ptr(p256_b),
c_uint8_ptr(p256_order),
c_size_t(len(p256_modulus)),
c_ulonglong(getrandbits(64)))
if result:
raise ImportError("Error %d initializing P-256 context" % result)
context = SmartPointer(ec_p256_context.get(), _ec_lib.ec_free_context)
p256 = _Curve(
Integer(p),
Integer(b),
Integer(order),
Integer(Gx),
Integer(Gy),
None,
256,
"1.2.840.10045.3.1.7", # ANSI X9.62
context,
"NIST P-256",
"ecdsa-sha2-nistp256")
global p256_names
_curves.update(dict.fromkeys(p256_names, p256))
def init_p384():
p = 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffeffffffff0000000000000000ffffffff
b = 0xb3312fa7e23ee7e4988e056be3f82d19181d9c6efe8141120314088f5013875ac656398d8a2ed19d2a85c8edd3ec2aef
order = 0xffffffffffffffffffffffffffffffffffffffffffffffffc7634d81f4372ddf581a0db248b0a77aecec196accc52973
Gx = 0xaa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a385502f25dbf55296c3a545e3872760aB7
Gy = 0x3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c00a60b1ce1d7e819d7a431d7c90ea0e5F
p384_modulus = long_to_bytes(p, 48)
p384_b = long_to_bytes(b, 48)
p384_order = long_to_bytes(order, 48)
ec_p384_context = VoidPointer()
result = _ec_lib.ec_ws_new_context(ec_p384_context.address_of(),
c_uint8_ptr(p384_modulus),
c_uint8_ptr(p384_b),
c_uint8_ptr(p384_order),
c_size_t(len(p384_modulus)),
c_ulonglong(getrandbits(64)))
if result:
raise ImportError("Error %d initializing P-384 context" % result)
context = SmartPointer(ec_p384_context.get(), _ec_lib.ec_free_context)
p384 = _Curve(
Integer(p),
Integer(b),
Integer(order),
Integer(Gx),
Integer(Gy),
None,
384,
"1.3.132.0.34", # SEC 2
context,
"NIST P-384",
"ecdsa-sha2-nistp384")
global p384_names
_curves.update(dict.fromkeys(p384_names, p384))
def init_p521():
p = 0x000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
b = 0x00000051953eb9618e1c9a1f929a21a0b68540eea2da725b99b315f3b8b489918ef109e156193951ec7e937b1652c0bd3bb1bf073573df883d2c34f1ef451fd46b503f00
order = 0x000001fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffa51868783bf2f966b7fcc0148f709a5d03bb5c9b8899c47aebb6fb71e91386409
Gx = 0x000000c6858e06b70404e9cd9e3ecb662395b4429c648139053fb521f828af606b4d3dbaa14b5e77efe75928fe1dc127a2ffa8de3348b3c1856a429bf97e7e31c2e5bd66
Gy = 0x0000011839296a789a3bc0045c8a5fb42c7d1bd998f54449579b446817afbd17273e662c97ee72995ef42640c550b9013fad0761353c7086a272c24088be94769fd16650
p521_modulus = long_to_bytes(p, 66)
p521_b = long_to_bytes(b, 66)
p521_order = long_to_bytes(order, 66)
ec_p521_context = VoidPointer()
result = _ec_lib.ec_ws_new_context(ec_p521_context.address_of(),
c_uint8_ptr(p521_modulus),
c_uint8_ptr(p521_b),
c_uint8_ptr(p521_order),
c_size_t(len(p521_modulus)),
c_ulonglong(getrandbits(64)))
if result:
raise ImportError("Error %d initializing P-521 context" % result)
context = SmartPointer(ec_p521_context.get(), _ec_lib.ec_free_context)
p521 = _Curve(
Integer(p),
Integer(b),
Integer(order),
Integer(Gx),
Integer(Gy),
None,
521,
"1.3.132.0.35", # SEC 2
context,
"NIST P-521",
"ecdsa-sha2-nistp521")
global p521_names
_curves.update(dict.fromkeys(p521_names, p521))
def sign(self, msg_hash):
"""Produce the DSA/ECDSA signature of a message.
:parameter msg_hash:
The hash that was carried out over the message.
The object belongs to the :mod:`crypto.Hash` package.
Under mode *'fips-186-3'*, the hash must be a FIPS
approved secure hash (SHA-1 or a member of the SHA-2 family),
of cryptographic strength appropriate for the DSA key.
For instance, a 3072/256 DSA key can only be used
in combination with SHA-512.
:type msg_hash: hash object
:return: The signature as a *byte string*
:raise ValueError: if the hash algorithm is incompatible to the (EC)DSA key
:raise TypeError: if the (EC)DSA key has no private half
"""
if not self._valid_hash(msg_hash):
raise ValueError("Hash is not sufficiently strong")
# Generate the nonce k (critical!)
nonce = self._compute_nonce(msg_hash)
# Perform signature using the raw API
z = Integer.from_bytes(msg_hash.digest()[:self._order_bytes])
sig_pair = self._key._sign(z, nonce)
# Encode the signature into a single byte string
if self._encoding == 'binary':
output = b"".join(
[long_to_bytes(x, self._order_bytes) for x in sig_pair])
else:
# Dss-sig ::= SEQUENCE {
# r INTEGER,
# s INTEGER
# }
# Ecdsa-Sig-Value ::= SEQUENCE {
# r INTEGER,
# s INTEGER
# }
output = DerSequence(sig_pair).encode()
return output
def _import_pkcs1_private(encoded, *kwargs):
# RSAPrivateKey ::= SEQUENCE {
# version Version,
# modulus INTEGER, -- n
# publicExponent INTEGER, -- e
# privateExponent INTEGER, -- d
# prime1 INTEGER, -- p
# prime2 INTEGER, -- q
# exponent1 INTEGER, -- d mod (p-1)
# exponent2 INTEGER, -- d mod (q-1)
# coefficient INTEGER -- (inverse of q) mod p
# }
#
# Version ::= INTEGER
der = DerSequence().decode(encoded, nr_elements=9, only_ints_expected=True)
if der[0] != 0:
raise ValueError("No PKCS#1 encoding of an RSA private key")
return construct(der[1:6] + [Integer(der[4]).inverse(der[5])])
def _import_openssh_private_rsa(data, password):
from ._openssh import (import_openssh_private_generic, read_bytes,
read_string, check_padding)
ssh_name, decrypted = import_openssh_private_generic(data, password)
if ssh_name != "ssh-rsa":
raise ValueError("This SSH key is not RSA")
n, decrypted = read_bytes(decrypted)
e, decrypted = read_bytes(decrypted)
d, decrypted = read_bytes(decrypted)
iqmp, decrypted = read_bytes(decrypted)
p, decrypted = read_bytes(decrypted)
q, decrypted = read_bytes(decrypted)
_, padded = read_string(decrypted) # Comment
check_padding(padded)
build = [Integer.from_bytes(x) for x in (n, e, d, q, p, iqmp)]
return construct(build)
def _get_weak_domain(self):
from crypto.Math.Numbers import Integer
from crypto.Math import Primality
p = Integer(4)
while p.size_in_bits() != 1024 or Primality.test_probable_prime(
p) != Primality.PROBABLY_PRIME:
q1 = Integer.random(exact_bits=80)
q2 = Integer.random(exact_bits=80)
q = q1 * q2
z = Integer.random(exact_bits=1024 - 160)
p = z * q + 1
h = Integer(2)
g = 1
while g == 1:
g = pow(h, z, p)
h += 1
return (p, q, g)
