From 9dcfc927bcc76ac68b179ce0dac4a75e8b5f6d2f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20N=C3=A1jera?= <hi@oscarnajera.com>
Date: Tue, 6 Jul 2021 20:51:59 +0200
Subject: refactor binary expansion

---
 ecc.hs | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/ecc.hs b/ecc.hs
index 17029b6..0bdbf02 100644
--- a/ecc.hs
+++ b/ecc.hs
@@ -94,14 +94,15 @@ add p q
         new_y = slope * (x p - new_x) - y p
     in  ECPoint new_x new_y (a p) (b p)
 
-binex :: (Eq a, Fractional a) => Integer -> ECPoint a -> ECPoint a -> ECPoint a
-binex m value result | m == 0       = result
-                     | m .&. 1 == 1 = loop (add result value)
-                     | otherwise    = loop result
-  where loop = binex (m `shiftR` 1) (add value value)
 
-crmul :: (Eq a, Fractional a) => Integer -> ECPoint a -> ECPoint a
-crmul m ec = binex m ec Infinity
+binaryExpansion :: (Eq a, Fractional a) => Integer -> ECPoint a -> ECPoint a -> ECPoint a
+binaryExpansion m value result | m == 0    = result
+                               | otherwise = binaryExpansion (m `shiftR` 1) (add value value) accumulator
+      where
+        accumulator = if m .&. 1 == 1 then add result value else result
+
+scalarProduct :: (Eq a, Fractional a) => Integer -> ECPoint a -> ECPoint a
+scalarProduct m ec = binaryExpansion m ec Infinity
 
 tre = FieldElement 3 :: FieldElement 31
 cc =
@@ -120,14 +121,18 @@ cc =
       )
 
 dd =
-  let prime = 223
-      a     = FieldElement 0 :: FieldElement prime
+  let a     = FieldElement 0 :: FieldElement 223
       b     = FieldElement 7
       x     = FieldElement 192
       y     = FieldElement 105
-      point = ECPoint x y a b
-  in  point
+  in ECPoint x y a b
+ee = ECPoint 192 105 (FieldElement 0 :: FieldElement 223) 7
+ff = ECPoint 192 105 0 7 :: ECPoint (FieldElement 223)
+
+aPoint = ECPoint 192 105 0 7 :: ECPoint (FieldElement 223)
+total = add aPoint $ add aPoint $ add aPoint $ add aPoint aPoint
 
+totalfold=foldr add Infinity $ replicate 5 aPoint
 
 type S256Field = FieldElement (2 ^ 256- 2^ 32 - 977)
 type S256Point = ECPoint S256Field
@@ -135,6 +140,8 @@ s256point :: S256Field -> S256Field -> S256Point
 s256point x y = ECPoint x y 0 7
 li :: S256Field
 li = 12
+ll :: ECPoint ( FieldElement 31)
+ll = Infinity
 ri= ECPoint 3 7 5 7 :: S256Point
 
 
-- 
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