oops forgot macros.rs

src/macros.rs

@@ -0,0 +1,52 @@
+#[macro_export]
+macro_rules! ladder_impl {
+    ($point:ident, $swap_fn:ident) => {
+        impl<N> $point<N>
+        where
+            N: AddMod
+                + SubMod
+                + MulMod<Output = N>
+                + InvMod<Output = N>
+                + Copy
+                + Integer
+                + Div<Output = N>,
+        {
+            pub fn ladder(&self, rhs: &N) -> $point<N> {
+                let mut x_0 = *self;
+                let mut x_1 = x_0.double();
+
+                for i in (0..rhs.bits() - 1).rev() {
+                    if !bool::from(rhs.bit(i)) {
+                        x_1 = x_0.add(&x_1, &self);
+                        x_0 = x_0.double();
+                    } else {
+                        x_0 = x_0.add(&x_1, &self);
+                        x_1 = x_1.double();
+                    }
+                }
+
+                x_0
+            }
+
+            pub fn ct_ladder(&self, rhs: &N) -> $point<N> {
+                let max = N::zero().wrapping_sub(&N::one());
+
+                let mut x_0 = *self;
+                let mut x_1 = x_0.double();
+
+                let mut prev: u8 = 0;
+                for i in (0..rhs.bits() - 1).rev() {
+                    let curr: u8 = bool::from(rhs.bit(i)).into();
+                    $swap_fn(&mut x_0, &mut x_1, curr ^ prev, max);
+                    prev = curr;
+
+                    x_1 = x_0.add(&x_1, &self);
+                    x_0 = x_0.double();
+                }
+                $swap_fn(&mut x_0, &mut x_1, prev, max);
+
+                x_0
+            }
+        }
+    };
+}