Fix issue #14.

Not really an issue, the prime in the test did not satisfy the
formula assumption so it should have failed.

2 files changed, 17 insertions, 5 deletions

diff --git a/test/ec/test_mult.py b/test/ec/test_mult.py
index 24306ad..5e0b514 100644
--- a/test/ec/test_mult.py
+++ b/test/ec/test_mult.py
@@ -292,8 +292,7 @@ def test_basic_multipliers(secp128r1, num, add, dbl):
     ladder_options = {"complete": (True, False)}
     ladders = [SimpleLadderMultiplier(add, dbl, scale, **dict(zip(ladder_options.keys(), combination))) for combination in product(*ladder_options.values())]
     fixed_options = {"m": (5, 8)}
-    fixeds = [FixedWindowLTRMultiplier(add, dbl, scl=scale, **dict(zip(fixed_options.keys(), combination))) for
-             combination in product(*fixed_options.values())]
+    fixeds = [FixedWindowLTRMultiplier(add, dbl, scl=scale, **dict(zip(fixed_options.keys(), combination))) for combination in product(*fixed_options.values())]
 
     mults: Sequence[ScalarMultiplier] = ltrs + rtls + bnafs + wnafs + [CoronMultiplier(add, dbl, scale)] + ladders + fixeds
     results = []
@@ -303,7 +302,6 @@ def test_basic_multipliers(secp128r1, num, add, dbl):
         if results:
             assert res == results[-1], f"Points not equal {res} != {results[-1]} for mult = {mult}"
         results.append(res)
-    print(len(results))
 
 
 def test_init_fail(curve25519, secp128r1):
diff --git a/test/ec/test_regress.py b/test/ec/test_regress.py
index f032de2..886d7cc 100644
--- a/test/ec/test_regress.py
+++ b/test/ec/test_regress.py
@@ -6,6 +6,7 @@ from sympy import symbols
 
 from pyecsca.ec.coordinates import AffineCoordinateModel
 from pyecsca.ec.curve import EllipticCurve
+from pyecsca.ec.error import UnsatisfiedAssumptionError
 from pyecsca.ec.formula import AdditionFormula, DoublingFormula, ScalingFormula
 from pyecsca.ec.mod import Mod, SymbolicMod
 from pyecsca.ec.model import MontgomeryModel, EdwardsModel
@@ -94,13 +95,26 @@ def test_issue_13():
     formula(p, PmQ, P, Q, c=c, r=r, d=d)
 
 
-@pytest.mark.xfail(reason="Unresolved issue currently.")
 def test_issue_14():
     model = EdwardsModel()
     coords = model.coordinates["projective"]
     affine = AffineCoordinateModel(model)
     formula = coords.formulas["add-2007-bl-4"]
-    p = 19
+
+    with pytest.raises(UnsatisfiedAssumptionError):
+        # p is 3 mod 4, so there is no square root of -1
+        p = 19
+        c = Mod(2, p)
+        d = Mod(10, p)
+        curve = EllipticCurve(model, coords, p, InfinityPoint(coords), {"c": c, "d": d})
+        Paff = Point(affine, x=Mod(0xD, p), y=Mod(0x9, p))
+        P = Paff.to_model(coords, curve)
+        Qaff = Point(affine, x=Mod(0x4, p), y=Mod(0x12, p))
+        Q = Qaff.to_model(coords, curve)
+        formula(p, P, Q, **curve.parameters)[0]
+
+    # p is 1 mod 4, so there is a square root of -1
+    p = 29
     c = Mod(2, p)
     d = Mod(10, p)
     curve = EllipticCurve(model, coords, p, InfinityPoint(coords), {"c": c, "d": d})