def ecdsa_sign(curve_obj, hash_int, hash_num_bits, private_key, message, k=None):
"""Sign message using the private key.
Returns the signature (r, s).
@param hash_int: a hash function mapping to an integer, for example
lambda m: util.be2int(hashlib.sha256(m).digest())
@param hash_num_bits: the number of bits in the digest above, for
example 256.
"""
n = curve_obj.order
if k is None:
k = util.randint(1, n - 1)
e = hash_int(message)
L_n = util.count_bits(n)
z = e >> max(hash_num_bits - L_n, 0)
while True:
(x1, y1) = curve.mul(k, curve_obj.base_point, curve_obj.curve)
r = x1 % curve_obj.order
if r == 0:
continue
k_neg = numbertheory.inverse_of(k, n)
s = (k_neg * (z + r * private_key)) % n
if s == 0:
continue
break
return (r, s)
def _test_with_vector(self, PUB, REPR, PRIV, VALID):
Repr = ref_ed.decodeint(''.join(map(chr, REPR)))
X = ref_ed.decodeint(''.join(map(chr, PUB)))
Priv = ref_ed.decodeint(''.join(map(chr, PRIV)))
Pub = curvemod.mul(Priv, self.curve25519.base_point,
self.curve25519.curve)
# Check valid
valid = True
try:
P1, P2 = self.curve25519.curve.get_y(X)
except:
valid = False
self.assertEquals(valid, VALID)
# Check mappings back and forth
if valid:
"""
print
print 'P1', P1
print 'P2', P2
print 'XXX', self.ell2.map_random_to_point(Repr)
print
self.assertEquals(Repr, self.ell2.map_point_to_random(P1))
self.assertEquals(Repr, self.ell2.map_point_to_random(P2))
"""
self.assertEquals(Repr, self.ell2.map_point_to_random(Pub))
self.assertEquals(X, self.ell2.map_random_to_point(Repr)[0])
def _test_with_vector(self, PUB, REPR, PRIV, VALID):
Repr = ref_ed.decodeint("".join(map(chr, REPR)))
X = ref_ed.decodeint("".join(map(chr, PUB)))
Priv = ref_ed.decodeint("".join(map(chr, PRIV)))
Pub = curvemod.mul(Priv, self.curve25519.base_point, self.curve25519.curve)
# Check valid
valid = True
try:
P1, P2 = self.curve25519.curve.get_y(X)
except:
valid = False
self.assertEquals(valid, VALID)
# Check mappings back and forth
if valid:
"""
print
print 'P1', P1
print 'P2', P2
print 'XXX', self.ell2.map_random_to_point(Repr)
print
self.assertEquals(Repr, self.ell2.map_point_to_random(P1))
self.assertEquals(Repr, self.ell2.map_point_to_random(P2))
"""
self.assertEquals(Repr, self.ell2.map_point_to_random(Pub))
self.assertEquals(X, self.ell2.map_random_to_point(Repr)[0])
def ecdsa_verify(curve_obj, hash_int, hash_num_bits, public_key, message,
signature):
"""Verify that signature is over the message using the public key.
Returns True if so, False otherwise.
Otherwise similar to ecdsa_sign() in usage.
"""
n = curve_obj.order
# Verify
if public_key == curve_obj.base_point or \
curve_obj.curve.invert_point(public_key) == curve_obj.base_point: # XXX: Check inverted too?
return False
if not curve_obj.curve.point_on_curve(public_key):
return False
if not curve.mul(curve_obj.order, public_key,
curve_obj.curve) == curve_obj.curve.neutral_point():
return False
(r, s) = signature
if not 1 <= r <= n - 1:
return False
if not 1 <= s <= n - 1:
return False
e = hash_int(message)
L_n = util.count_bits(n)
z = e >> max(hash_num_bits - L_n, 0)
# Verify
w = numbertheory.inverse_of(s, curve_obj.order) % n
u_1 = (z * w) % n
u_2 = (r * w) % n
(x1, y1) = curve_obj.curve.add_points(
curve.mul(u_1, curve_obj.base_point, curve_obj.curve),
curve.mul(u_2, public_key, curve_obj.curve))
return (r % n) == (x1 % n)
def ecdsa_verify(curve_obj, hash_int, hash_num_bits, public_key, message, signature):
"""Verify that signature is over the message using the public key.
Returns True if so, False otherwise.
Otherwise similar to ecdsa_sign() in usage.
"""
n = curve_obj.order
# Verify
if public_key == curve_obj.base_point or \
curve_obj.curve.invert_point(public_key) == curve_obj.base_point: # XXX: Check inverted too?
return False
if not curve_obj.curve.point_on_curve(public_key):
return False
if not curve.mul(curve_obj.order, public_key, curve_obj.curve) == curve_obj.curve.neutral_point():
return False
(r, s) = signature
if not 1 <= r <= n - 1:
return False
if not 1 <= s <= n - 1:
return False
e = hash_int(message)
L_n = util.count_bits(n)
z = e >> max(hash_num_bits - L_n, 0)
# Verify
w = numbertheory.inverse_of(s, curve_obj.order) % n
u_1 = (z * w) % n
u_2 = (r * w) % n
(x1, y1) = curve_obj.curve.add_points(
curve.mul(u_1, curve_obj.base_point, curve_obj.curve),
curve.mul(u_2, public_key, curve_obj.curve)
)
return (r % n) == (x1 % n)
def _test_with_vector(self, PUB, REPR, PRIV, VALID):
Repr = ref_ed.decodeint(''.join(map(chr, REPR)))
X = ref_ed.decodeint(''.join(map(chr, PUB)))
Priv = ref_ed.decodeint(''.join(map(chr, PRIV)))
Pub = curvemod.mul(Priv, self.curve25519.base_point, self.curve25519.curve)
self.assertEquals(arr2str(PRIV), self.curve25519.canonical_binary_form_private(Priv))
self.assertEquals(arr2str(PUB), self.curve25519.canonical_binary_form_public(Pub))
self.assertEquals(Priv, self.curve25519.binary_to_private(arr2str(PRIV)))
def _test_with_vector(self, PUB, REPR, PRIV, VALID):
Repr = ref_ed.decodeint(''.join(map(chr, REPR)))
X = ref_ed.decodeint(''.join(map(chr, PUB)))
Priv = ref_ed.decodeint(''.join(map(chr, PRIV)))
Pub = curvemod.mul(Priv, self.curve25519.base_point,
self.curve25519.curve)
self.assertEquals(arr2str(PRIV),
self.curve25519.canonical_binary_form_private(Priv))
self.assertEquals(arr2str(PUB),
self.curve25519.canonical_binary_form_public(Pub))
self.assertEquals(Priv,
self.curve25519.binary_to_private(arr2str(PRIV)))
def ecdsa_sign(curve_obj,
hash_int,
hash_num_bits,
private_key,
message,
k=None):
"""Sign message using the private key.
Returns the signature (r, s).
@param hash_int: a hash function mapping to an integer, for example
lambda m: util.be2int(hashlib.sha256(m).digest())
@param hash_num_bits: the number of bits in the digest above, for
example 256.
"""
n = curve_obj.order
if k is None:
k = util.randint(1, n - 1)
e = hash_int(message)
L_n = util.count_bits(n)
z = e >> max(hash_num_bits - L_n, 0)
while True:
(x1, y1) = curve.mul(k, curve_obj.base_point, curve_obj.curve)
r = x1 % curve_obj.order
if r == 0:
continue
k_neg = numbertheory.inverse_of(k, n)
s = (k_neg * (z + r * private_key)) % n
if s == 0:
continue
break
return (r, s)
def test_multiplication_by_0(self):
self.assertEquals(self.curve.neutral_point(),
mul(0, self.A, self.curve))
def generate_key_pair(self, seed):
private = self.generate_private_key(seed)
public = curve.mul(private, self.base_point, self.curve)
return (public, private)
def test_generator(self):
self.assertEquals(self.curve.neutral_point(), mul(self.bp_order, self.bp, self.curve))
def test_multiplication(self):
self.assertEquals(self.MUL_P_1, mul(self.MUL_K_1, self.bp, self.curve))
self.assertEquals(self.MUL_P_2, mul(self.MUL_K_2, self.bp, self.curve))
def test_multiplication_by_1(self):
self.assertEquals(self.A, mul(1, self.A, self.curve))
def test_multiplication_by_2_equals_doubling(self):
self.assertEquals(self.curve.double_point(self.A), mul(2, self.A, self.curve))
def test_multiplication_by_0(self):
self.assertEquals(self.curve.neutral_point(), mul(0, self.A, self.curve))
def test_generator(self):
self.assertEquals(self.curve.neutral_point(),
mul(self.bp_order, self.bp, self.curve))
def test_multiplication(self):
self.assertEquals(self.MUL_P_1, mul(self.MUL_K_1, self.bp, self.curve))
self.assertEquals(self.MUL_P_2, mul(self.MUL_K_2, self.bp, self.curve))
def test_multiplication_by_1(self):
self.assertEquals(self.A, mul(1, self.A, self.curve))
def test_multiplication_by_2_equals_doubling(self):
self.assertEquals(self.curve.double_point(self.A),
mul(2, self.A, self.curve))
def derive_public_key(self, private):
return curve.mul(private, self.base_point, self.curve)
def ecdh(curve_obj, my_private, other_public):
"""Derive the shared secret in ECDH."""
# here curve_obj is from asymmetric.ECCBase
return curve.mul(my_private, other_public, curve_obj.curve)
def generate_key_pair(self, seed):
private = self.generate_private_key(seed)
public = curve.mul(private, self.base_point, self.curve)
return (public, private)
def derive_public_key(self, private):
return curve.mul(private, self.base_point, self.curve)
