ec.c, field.c, group.c, mp.c: Fix conversions in `pow' and scalar mul.

[catacomb-python] / t / t-convert.py

### -*- mode: python, coding: utf-8 -*-
###
### Testing implicit conversions
###
### (c) 2019 Straylight/Edgeware
###

###----- Licensing notice ---------------------------------------------------
###
### This file is part of the Python interface to Catacomb.
###
### Catacomb/Python is free software: you can redistribute it and/or
### modify it under the terms of the GNU General Public License as
### published by the Free Software Foundation; either version 2 of the
### License, or (at your option) any later version.
###
### Catacomb/Python is distributed in the hope that it will be useful, but
### WITHOUT ANY WARRANTY; without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
### General Public License for more details.
###
### You should have received a copy of the GNU General Public License
### along with Catacomb/Python.  If not, write to the Free Software
### Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
### USA.

###--------------------------------------------------------------------------
### Imported modules.

import catacomb as C
import sys as SYS
import unittest as U
import testutils as T

###--------------------------------------------------------------------------
class TestConvert (U.TestCase):
  """Test implicit conversions between various mathematical types."""

  def test(me):

    k = C.PrimeField(17)
    E = k.ec(-3, 4)
    P = E(1) # order 15
    kk = C.BinPolyField(0x13)
    EE = kk.ec(1, 2)
    PP = E(9) # order 16

    ## `MP' asymmetric operations.
    me.assertEqual(pow(C.MP(5), 2), 25)
    me.assertEqual(pow(5, C.MP(2)), 25)
    me.assertEqual(pow(C.MP(5), 2, 7), 4)
    me.assertEqual(pow(5, C.MP(2), 7), 4)
    me.assertEqual(pow(5, 2, C.MP(7)), 4)
    for bad in [C.GF, k, kk, float, lambda x: [x]]:
      me.assertRaises(TypeError, pow, C.MP(5), bad(2))
      me.assertRaises(TypeError, pow, C.MP(5), bad(2), 7)
      if not (T.PY2 and T.DEBUGP):
        ## Debug builds of Python 2 crash here, and it's not our fault.  Run
        ##
        ## $ python2.7-dbg -c 'pow(long(5), 2, [7])'
        ##
        ## to confirm.  The `[7]' causes coercion to occur.  The first and
        ## second operands are coerced first, and successfully replaced by
        ## the results: the first operand (in this case) is unchanged, but
        ## has its refcount bumped, and the second operand is replaced by the
        ## result of coercion, which now has a refcount of 1.  Then the first
        ## and third operands are coerced, which fails.  Python decrements
        ## the refcounts of the results of the first coercion, so the second
        ## operand is now freed and, in debug builds, clobbered.  Python then
        ## tries to format an error message, quoting the types of the
        ## operands, but one of them has been lost.
        me.assertRaises(TypeError, pow, C.MP(5), 2, bad(7))
      me.assertRaises(TypeError, T.lsl, C.MP(5), bad(2))

    ## `GF' asymmetric operations.
    me.assertEqual(pow(C.GF(0x5), 2), C.GF(0x11))
    me.assertEqual(pow(C.GF(0x5), C.MP(2)), C.GF(0x11))
    me.assertEqual(pow(C.GF(5), 2, C.GF(0x13)), C.GF(0x2))
    for bad in [k, kk, float, lambda x: [x]]:
      me.assertRaises(TypeError, pow, C.GF(5), bad(2))
      me.assertRaises(TypeError, T.lsl, C.GF(5), bad(2))
    for bad in [C.MP, k, kk, float, lambda x: [x]]:
      me.assertRaises(TypeError, pow, bad(5), C.GF(2))
      me.assertRaises(TypeError, pow, bad(5), C.GF(2), bad(7))
      me.assertRaises(TypeError, pow, bad(5), bad(2), C.GF(7))
      me.assertRaises(TypeError, pow, C.GF(5), bad(2), bad(7))
      if not (T.PY2 and T.DEBUGP):
        ## Python bug: see above.
        me.assertRaises(TypeError, pow, C.GF(5), 2, bad(7))

    ## `MP' and `GF'.
    me.assertEqual(C.MP(5), 5)
    me.assertEqual(5, C.MP(5))

    me.assertEqual(C.MP(5) + 3, 8)
    me.assertEqual(3 + C.MP(5), 8)
    me.assertRaises(TypeError, T.add, C.MP(5), C.GF(3))
    me.assertRaises(TypeError, T.add, C.GF(3), C.MP(5))

    ## Field elements.
    me.assertEqual(k(3) + 4, 7)
    me.assertEqual(4 + k(3), 7)
    me.assertEqual(k(3) + C.MP(4), 7)
    me.assertEqual(C.MP(4) + k(3), 7)
    me.assertEqual(k(3) + 4, 7)
    me.assertEqual(C.GF(7) + kk(3), C.GF(4))
    me.assertEqual(kk(3) + C.GF(7), C.GF(4))

    me.assertRaises(TypeError, T.add, k(3), 3.0)
    me.assertRaises(TypeError, T.add, k(3), kk(3))
    me.assertRaises(TypeError, T.add, kk(3), k(3))
    me.assertRaises(TypeError, T.add, k(3), C.GF(7))
    me.assertRaises(TypeError, T.add, C.GF(7), k(3))
    me.assertRaises(TypeError, T.add, kk(3), 7.0)
    me.assertRaises(TypeError, T.add, kk(3), C.MP(7))
    me.assertRaises(TypeError, T.add, C.MP(7), kk(3))

###----- That's all, folks --------------------------------------------------

if __name__ == "__main__": U.main()