[curve25519] add some simple code comment

typed-io · Jan 26, 2022 · 1050ee1 · 1050ee1
1 parent 78c3828
commit 1050ee1
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/src/curve25519/scalar/scalar64.rs b/src/curve25519/scalar/scalar64.rs
@@ -168,12 +168,14 @@ impl Scalar {
     pub(crate) fn nibbles(&self) -> [i8; 64] {
         let mut es: [i8; 64] = [0; 64];
 
+        // contract limbs
         let mut c = [0; 4];
         c[0] = self.0[1] << 56 | self.0[0];
         c[1] = self.0[2] << 48 | self.0[1] >> 8;
         c[2] = self.0[3] << 40 | self.0[2] >> 16;
         c[3] = self.0[4] << 32 | self.0[3] >> 24;
 
+        // write 16 nibbles for each saturated limbs, for 64 nibbles
         for b in 0..4 {
             es[16 * b + 0] = ((c[b] >> 0) & 0b1111) as i8;
             es[16 * b + 1] = ((c[b] >> 4) & 0b1111) as i8;