def test_inversion():
s = SBox2([5, 6, 3, 2, 1, 7, 0, 4])
assert ~s == s**(-1) == [6, 4, 3, 2, 7, 0, 1, 5]
s = SBox2([3, 4, 7, 2, 1, 1, 6, 6], m=4)
assert s.image() == {1, 2, 3, 4, 6, 7}
assert s.preimage(2) == 3
assert s.preimage(1) == 4
assert s.preimage(6) == 6
assert s.preimages(2) == (3, )
assert s.preimages(1) == (4, 5)
assert s.preimages(6) == (6, 7)
assert sorted(s.preimage_structure().items()) == [(1, 4), (2, 2)]
def random_permutation(n, zero_zero=False):
s = list(range(2**n))
shuffle(s)
if zero_zero:
i = s.index(0)
s[0], s[i] = s[i], s[0]
return SBox2(s)
def concat(funcs):
assert len(set(f.input_size() for f in funcs)) == 1
sizes = tuple(f.output_size() for f in funcs)
return SBox2(
[Bin.concat(*Bin.array(ys, ns=sizes)) for ys in zip(*funcs)],
m=sum(sizes)
)
def random_minicipher(n, kn=None):
s = []
for k in range(2**kn):
p = list(range(2**n))
shuffle(p)
s.extend(p)
return SBox2(s)
def test_degrees():
s = SBox2([0] * 15 + [1])
assert s.degrees() == (4, )
assert str(s.anfs()) == "[x0*x1*x2*x3]"
s = SBox2([1] * 8 + [0] * 8)
assert s.degrees() == (1, )
assert str(s.anfs()) == "[x0 + 1]"
s = SBox2([0] * 16)
assert s.degrees() == ()
assert str(s.anfs()) == "[]"
s = SBox2([1] * 16)
assert s.degrees() == (0, )
assert str(s.anfs()) == "[1]"
def random_involution(n, allow_fixed_points=True):
s = list(range(2**n))
if not allow_fixed_points:
pairs = list(range(2**n))
shuffle(pairs)
else:
"""
Uniform?
n elements
a(k): number of involutions with k transpositions
a(k) / a(k-1) = (n-2*k+2) * (n-2*k+1) / (2*k)
approximate by floats to avoid bigints, should be ok
"""
ak = [1.0]
for k in range(1, 2**(n - 1) + 1):
ak.append(ak[-1] * (n - 2 * k + 2) * (n - 2 * k + 1) / (2 * k))
r = random() * sum(ak)
acc = 0
for k in range(2**(n - 1) + 1):
acc += ak[k]
if acc >= r:
break
pairs = list(range(2**n))
shuffle(pairs)
pairs = pairs[:2 * k]
for i in range(0, len(pairs), 2):
a, b = s[i:i + 2]
s[a] = b
s[b] = a
return SBox2(s)
def test_properties():
s = SBox2([5, 6, 3, 2, 1, 7, 0, 4])
assert props(s) == {s.is_permutation, s.is_balanced}
assert props(s.resize(4)) == set()
s = SBox2((0, 13, 14, 3, 8, 5, 6, 11, 12, 1, 2, 15, 4, 9, 10, 7))
assert props(s) == {
s.is_permutation, s.is_balanced, s.is_affine, s.is_linear
}
s = SBox2((14, 13, 6, 5, 0, 3, 8, 11, 15, 12, 7, 4, 1, 2, 9, 10))
assert props(s) == {s.is_permutation, s.is_balanced, s.is_affine}
s = SBox2([1] * 16)
assert props(s) == {s.is_affine, s.is_constant}
s = SBox2([0] * 16)
assert props(s) == {
s.is_affine, s.is_constant, s.is_linear, s.is_zero, s.is_balanced
}
s = SBox2([0] * 15 + [1])
assert props(s) == set()
s = SBox2(range(16))
assert props(s) == {
s.is_identity,
s.is_permutation,
s.is_balanced,
s.is_involution,
s.is_affine,
s.is_linear,
}
s = SBox2([0] * 8 + [1] * 8)
assert props(s) == {s.is_balanced, s.is_affine, s.is_linear}
s = SBox2([1] * 8 + [0] * 8)
assert props(s) == {s.is_balanced, s.is_affine}
s = SBox2(list(range(8, 16)) + list(range(8)))
assert props(s) == {
s.is_balanced,
s.is_permutation,
s.is_involution,
s.is_affine,
}
def make_transition(self, exp2, log2):
large_to_double = [0, 1]
for x in xrange(2, 2**self.N):
l = self.log1[x]
y = exp2[l]
large_to_double.append(y)
large_to_double = SBox2(large_to_double)
return large_to_double
def parallel(funcs):
input_sizes = [f.input_size() for f in funcs]
output_sizes = [f.output_size() for f in funcs]
s = []
for xs in ranges(list=[2**w for w in input_sizes]):
fully = 0
for f, x, w in zip(funcs, xs, output_sizes):
fully = (fully << w) | f(x)
s.append(fully)
return SBox2(s, m=sum(output_sizes))
def test_main():
from cry.sbox2 import SBox2
s = SBox2([3, 4, 7, 2, 1, 1, 6, 6], m=4)
assert s.n == s.input_size() == 3
assert s.m == s.output_size() == 4
assert len(s) == 8
assert list(s.input_range()) == list(range(8))
assert list(s.output_range()) == list(range(16))
assert list(s.graph()) == [(0, 3), (1, 4), (2, 7), (3, 2), (4, 1), (5, 1),
(6, 6), (7, 6)]
assert s.as_hex(sep=":") == "3:4:7:2:1:1:6:6"
assert s.as_hex(sep="") == "34721166"
ss = SBox2([3, 4, 7, 2, 1, 1, 6, 6])
assert s != ss
assert s == ss.resize(4)
ss = SBox2([3, 4, 7, 2, 1, 1, 6, 6], 4)
assert s == ss
ss = SBox2([2, 4, 7, 2, 1, 1, 6, 6], 4)
assert s != ss
assert s == [3, 4, 7, 2, 1, 1, 6, 6]
assert s == (3, 4, 7, 2, 1, 1, 6, 6)
assert s != (2, 4, 7, 2, 1, 1, 6, 6)
assert hash(s) != 0
assert s ^ 1 == s ^ 1 == s ^ Integer(1) == s ^ SBox2([1] * 8, m=4) \
== (2, 5, 6, 3, 0, 0, 7, 7)
assert s ^ s == [0] * 8
assert s[0] == s(0) == s[0, 0, 0] == 3
assert s[3] == s(3) == s[0, 1, 1] == 2
assert s[7] == s(7) == s[1, 1, 1] == 6
assert tuple(s)[1:3] == (4, 7)
assert tuple(s)[-3:] == (1, 6, 6)
def try_good():
A = SBox2.new.random_linear_permutation(N)
B = SBox2.new.random_linear_permutation(N)
s1 = gen()
s2 = B * s1 * A
At, Bt = SBox2.are_linear_equivalent(s1, s2)
assert Bt * s1 * At == s2
assert At.is_linear()
assert Bt.is_linear()
assert At.is_permutation()
assert Bt.is_permutation()
def feistel_round_xor(func, swap=False):
func = SBox2(func)
n = func.in_bits
res = []
for al in range(2**n):
for ar in range(2**n):
l, r = al, ar
l ^= func(r)
if swap:
l, r = r, l
res.append((l << n) | r)
return res
def random_function_of_degree(
n, m, d, zero_zero=False,
force_all_maxterms=False
):
anf = [0] * m
mindeg = 1 if zero_zero else 0
for deg in range(mindeg, d + 1):
for mask in hamming_masks(m, deg):
for out_bit in range(m):
take = int(randint(0, 1) or (force_all_maxterms and deg == d))
anf[mask] = (anf[mask] << 1) | take
return SBox2(anf, m=m).mobius()
def feistel_round_add(func, swap=False):
func = SBox2.new(func)
n = func.in_bits
mask = (1 << n) - 1
res = []
for al in range(2**n):
for ar in range(2**n):
l, r = al, ar
l = (l + func(r)) & mask
if swap:
l, r = r, l
res.append((l << n) | r)
return res
def from_matrix(mat):
s = []
for x in range(2**mat.ncols()):
s.append(matrix_mult_int(mat, x))
return SBox2(s, m=mat.nrows())
def power(e, n=None, field=None):
assert (n is not None) ^ (field is not None)
field = field or GF(2**n, name='a')
x = PolynomialRing(field, names='x').gen()
return SBox2(x**e)
def id(n):
return SBox2(range(2**n))
def const(c, n):
return SBox2([c] * 2**n)
def swap(h):
s = []
for l, r in ranges(2**h, 2**h):
s.append((r << h) | l)
return SBox2(s)
def test_transform():
s = SBox2([5, 6, 3, 2, 1, 7, 0, 4])
assert s.xor(0, 3) == s ^ 3
assert s.mobius().mobius() == s
def try_bad():
s1 = gen()
s2 = gen()
res = SBox2.are_linear_equivalent(s1, s2)
assert res is False
def random_affine_permutation(n):
xor = randint(0, 2**n - 1)
return SBox2(y ^ xor for y in from_matrix(random_invertible_matrix(n)))
def random_affine(*args):
lin = random_linear(*args)
xor = randint(0, max(lin))
return SBox2(y ^ xor for y in lin)
def random_function(n, m=None, zero_zero=False):
m = m or n
s = [randint(0, 2**m - 1) for i in range(2**n)]
if zero_zero:
s[0] = 0
return SBox2(s, m=m)
