def testSmallOrder(self):
O = (0, 1, 1, 0) # identity point
Q = ed.point_mul(8, O)
self.assertTrue(ed.point_equal(O, Q))
P = (38214883241950591754978413199355411911188925816896391856984770930832735035197, 0, 1, 0)
Q = ed.point_mul(8, P)
self.assertTrue(ed.point_equal(O, Q))
P = ed.G
Q = ed.point_mul(8, P)
self.assertFalse(ed.point_equal(O, Q))
#!/usr/bin/env python3
import base64
from itertools import cycle
from rfc8032 import point_add, point_compress, point_decompress, point_equal, point_mul, G
KEYLEN = 12
def catch(f, g, ty=Exception):
try:
return f()
except ty as e:
return g(e)
topoint = lambda n: point_mul(n, G)
frompoint = lambda p: catch(lambda: filter(lambda x: point_equal(p,topoint(x)), range(256)).__next__(), lambda _: None, StopIteration)
assert frompoint(topoint(42)) == 42
negate = lambda p: (p[0], -p[1], -p[2], p[3])
assert point_equal(point_add(negate(G), G), (0, 1, 1, 0))
def encrypt(key, ptxt):
print(repr((key, ptxt)))
points = [point_add(topoint(x), topoint(ord(y))) for (x,y) in zip(cycle(key), ptxt)]
return b';'.join(base64.b64encode(point_compress(p)) for p in points)
def decrypt(key, ctxt):
points = [point_decompress(base64.b64decode(p)) for p in ctxt.split(b';')]
ptxt = ''.join([chr(frompoint(point_add(negate(topoint(x)), y))) for (x,y) in zip(cycle(key), points)])
return ptxt
def testIsOnCurve(self):
self.assertTrue(ed.is_on_curve((0,1,1,0)))
self.assertFalse(ed.is_on_curve((1,0,1,0)))
self.assertTrue(ed.is_on_curve(ed.G))
self.assertTrue(ed.is_on_curve(ed.point_mul(5, ed.G)))