def point_to_share_string(point, charset):
""" Convert a point (a tuple of two integers) into a share string - that is,
a representation of the point that uses the charset provided.
"""
# point should be in the format (1, 4938573982723...)
if '-' in charset:
raise ValueError('The character "-" cannot be in the supplied charset.')
if not (isinstance(point, tuple) and len(point) == 2 and isinstance(point[0], integer_types) and isinstance(point[1], integer_types)):
raise ValueError('Point format is invalid. Must be a pair of integers.')
x, y = point
x_string = int_to_charset(x, charset)
y_string = int_to_charset(y, charset)
share_string = x_string + '-' + y_string
return share_string
def recover_secret(cls, shares):
points = []
for share in shares:
points.append(share_string_to_point(share, cls.share_charset))
secret_int = points_to_secret_int(points)
secret_string = int_to_charset(secret_int, cls.secret_charset)
return secret_string
def point_to_share_string(point, charset):
""" Convert a point (a tuple of two integers) into a share string - that is,
a representation of the point that uses the charset provided.
"""
# point should be in the format (1, 4938573982723...)
if '-' in charset:
raise ValueError(
'The character "-" cannot be in the supplied charset.')
if not (isinstance(point, tuple) and len(point) == 2 and
isinstance(point[0], (int, long)) and
isinstance(point[1], (int, long))):
raise ValueError(
'Point format is invalid. Must be a pair of integers.')
x, y = point
x_string = int_to_charset(x, charset)
y_string = int_to_charset(y, charset)
share_string = x_string + '-' + y_string
return share_string
def recover_secret(cls, shares, prime=None):
if not prime:
warnings.warn(
"Trying to recover secret without knowing the modulus! This might fail!"
)
points = []
for share in shares:
points.append(share_string_to_point(share, cls.share_charset))
secret_int = points_to_secret_int(points, prime)
secret_string = int_to_charset(secret_int, cls.secret_charset)
return secret_string
def test_long_to_hex(self):
i = int("985936198705846800453632448571546073741637651923621735932"
"00564555477131708560")
reference_value = hex(i).rstrip('L').lstrip('0x')
value = int_to_charset(i, base16_chars)
self.assertEqual(value, reference_value)
def test_int_to_deadbeef(self):
i = 3735928559
reference_value = ("%x" % i).replace('0x', '')
value = int_to_charset(i, base16_chars)
self.assertEqual(value, reference_value)
