NewNat().setBig(big.NewInt(1)).ExpandFor(N) if A.Mul(I, N).Equal(one) != 1 { t.Error("a * inv(a) mod b != 1") } } func TestMul(t *testing.T) { t.Run("small", func(t *testing.T) { testMul(t, 760/8) }) t.Run("1024", func(t *testing.T) { testMul(t, 1024/8) }) t.Run("1536", func(t *testing.T) { testMul(t, 1536/8) }) t.Run("2048", func(t *testing.T) { testMul(t, 2048/8) }) } func testMul(t *testing.T, n int) { a, b, m := make([]byte, n), make([]byte, n), make([]byte, n) cryptorand.Read(a) cryptorand.Read(b)...