1  # Constantine
 2  # Copyright (c) 2018-2019    Status Research & Development GmbH
 3  # Copyright (c) 2020-Present Mamy André-Ratsimbazafy
 4  # Licensed and distributed under either of
 5  #   * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
 6  #   * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
 7  # at your option. This file may not be copied, modified, or distributed except according to those terms.
 8  
 9  import  std/unittest,
10          ../../constantine/platforms/abstractions,
11          ../../constantine/math/arithmetic,
12          ../../constantine/math/io/io_fields,
13          ../../constantine/math/config/curves
14  
15  echo "\n------------------------------------------------------\n"
16  
17  proc main() =
18    suite "Finite field conditional arithmetic":
19      test "Conditional substraction borrow bug":
20        let a = FP[BN254_Snarks].fromHex"0x14ae3e4392eb3238968c7624ee3d041590392e289e4f0bdfac4b6e56ac8cf768"
21        let b = FP[BN254_Snarks].fromHex"0x24e810017b4c0630a0b35b5c63a377097533928b31fa95d58d0e08d1f98b16c6"
22  
23        let expected = FP[BN254_Snarks].fromHex"0x202a7cb4f8d0cc31ae29607f0c1ae569b287062ed4c640975b5df19b8b7edde9"
24  
25        var normalsub: Fp[BN254_Snarks]
26        normalsub.diff(a, b)
27  
28        var condsub = a
29        condsub.csub(b, CtTrue)
30  
31        check:
32          bool(normalsub == expected)
33          bool(condsub == expected)
34  
35  main()