Shift sq2/pow22523. Everything should be properly in FieldElement now.

src/ed25519/fe.rs

@@ -889,18 +889,19 @@ fn is_tests() {
     });
 }
 
-pub fn fe_sq2(h: &mut FieldElement, f: &FieldElement)
-{
-    let f0 = f.value[0];
-    let f1 = f.value[1];
-    let f2 = f.value[2];
-    let f3 = f.value[3];
-    let f4 = f.value[4];
-    let f5 = f.value[5];
-    let f6 = f.value[6];
-    let f7 = f.value[7];
-    let f8 = f.value[8];
-    let f9 = f.value[9];
+impl FieldElement {
+    pub fn sq2(&self) -> FieldElement
+    {
+        let f0 = self.value[0];
+        let f1 = self.value[1];
+        let f2 = self.value[2];
+        let f3 = self.value[3];
+        let f4 = self.value[4];
+        let f5 = self.value[5];
+        let f6 = self.value[6];
+        let f7 = self.value[7];
+        let f8 = self.value[8];
+        let f9 = self.value[9];
         let f0_2 = 2 * f0;
         let f1_2 = 2 * f1;
         let f2_2 = 2 * f2;
@@ -1020,16 +1021,14 @@ pub fn fe_sq2(h: &mut FieldElement, f: &FieldElement)
 
         carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & KTOP_38BITS;
 
-    h.value[0] = h0 as i32;
-    h.value[1] = h1 as i32;
-    h.value[2] = h2 as i32;
-    h.value[3] = h3 as i32;
-    h.value[4] = h4 as i32;
-    h.value[5] = h5 as i32;
-    h.value[6] = h6 as i32;
-    h.value[7] = h7 as i32;
-    h.value[8] = h8 as i32;
-    h.value[9] = h9 as i32;
+        FieldElement {
+            value: [ h0 as i32, h1 as i32,
+                     h2 as i32, h3 as i32,
+                     h4 as i32, h5 as i32,
+                     h6 as i32, h7 as i32,
+                     h8 as i32, h9 as i32, ]
+        }
+    }
 }
 
 #[cfg(test)]
@@ -1043,20 +1042,20 @@ fn square2() {
         assert!(!nega && !negc);
         let a = test_from_bytes(&abytes);
         let c = test_from_bytes(&cbytes);
-        let mut r = FieldElement::new();
-        fe_sq2(&mut r, &a);
+        let r = a.sq2();
         assert_eq!(r, c);
     });
 }
 
-pub fn fe_pow22523(z: &FieldElement) -> FieldElement
-{
-    let mut t0 = z.square();
+impl FieldElement {
+    pub fn pow22523(&self) -> FieldElement
+    {
+        let mut t0 = self.square();
         let mut t1 = t0.square();
         for _ in 1..2 {
             t1.square_mut();
         }
-    t1 *= &z;
+        t1 *= &self;
         t0 *= &t1;
         t0.square_mut();
         t0 *= &t1;
@@ -1099,7 +1098,8 @@ pub fn fe_pow22523(z: &FieldElement) -> FieldElement
         for _ in 1..2 {
             t0.square_mut();
         }
-    &t0 * &z
+        &t0 * &self
+    }
 }
 
 #[cfg(test)]
@@ -1113,7 +1113,7 @@ fn pow22523() {
         assert!(!nega && !negc);
         let a = test_from_bytes(&abytes);
         let c = test_from_bytes(&cbytes);
-        let r = fe_pow22523(&a);
+        let r = a.pow22523();
         assert_eq!(r, c);
     });
 }

src/ed25519/point.rs

@@ -51,7 +51,7 @@ impl Point {
       let mut hx = v3.square();
       hx *= &v;
       hx *= &u; /* x = uv^7 */
-      hx = fe_pow22523(&hx); /* x = (uv^7)^((q-5)/8) */
+      hx = hx.pow22523(); /* x = (uv^7)^((q-5)/8) */
       hx *= &v3;
       hx *= &u; /* x = uv^3(uv^7)^((q-5)/8) */
 
@@ -312,7 +312,7 @@ fn ge_p2_dbl(r: &mut PointP1P1, p: &Point2)
 {
   r.x = p.x.square();
   r.z = p.y.square();
-  fe_sq2(&mut r.t, &p.z);
+  r.t = p.z.sq2();
   r.y = &p.x + &p.y;
   let t0 = r.y.square();
   r.y = &r.z + &r.x;