From 47e4d26e698aff51a3963ac498483a21a5adc9c8 Mon Sep 17 00:00:00 2001
From: David Florness <david@florness.com>
Date: Mon, 8 Jun 2020 18:34:01 -0600
Subject: [PATCH] Simplify big int code and keep track of a voter's input after
 eval

---
 poly.go  | 12 ++++--------
 voter.go | 16 ++++++++++------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/poly.go b/poly.go
index 559a1e3..855072c 100644
--- a/poly.go
+++ b/poly.go
@@ -17,8 +17,7 @@ func RandomBigInt(numBytes uint, allowAllZeros bool) (*big.Int, error) {
 	if err != nil {
 		return nil, err
 	}
-	bi := big.Int{}
-	bi.SetBytes(randBytes)
+	bi := new(big.Int).SetBytes(randBytes)
 	if bi.Cmp(big.NewInt(0)) == 0 {
 		return RandomBigInt(numBytes, allowAllZeros)
 	}
@@ -29,8 +28,7 @@ func RandomBigInt(numBytes uint, allowAllZeros bool) (*big.Int, error) {
 // of entropy for the random coefficients, and assigns the ballot to the
 // constant term
 func NewRandomPoly(degree uint, entropy uint, ballot []byte) *Poly {
-	constant := &big.Int{}
-	constant.SetBytes(ballot)
+	constant := new(big.Int).SetBytes(ballot)
 	p := &Poly{constant, make([]*big.Int, degree)}
 
 	// number of bits per coefficient
@@ -54,13 +52,11 @@ func NewRandomPoly(degree uint, entropy uint, ballot []byte) *Poly {
 }
 
 func (p *Poly) Eval(input *big.Int) *big.Int {
-	res := &big.Int{}
-	res.Set(p.constant)
+	res := new(big.Int).Set(p.constant)
 
 	for i, coef := range p.coefs {
 		degree := big.NewInt(int64(i + 1))
-		term := &big.Int{}
-		term.Exp(input, degree, nil)
+		term := new(big.Int).Exp(input, degree, nil)
 		term.Mul(term, coef)
 		res.Add(res, term)
 	}
diff --git a/voter.go b/voter.go
index aedf05e..1dbe809 100644
--- a/voter.go
+++ b/voter.go
@@ -130,9 +130,15 @@ func handleCmd(cmd string, rw *bufio.ReadWriter, stream network.Stream) {
 				stream.Conn().RemotePeer())
 			return
 		}
-		input := &big.Int{}
-		input.SetBytes(inputBytes)
-		output := me.poly.Eval(input)
+		peer, exists := election.remoteVoters[stream.Conn().RemotePeer()]
+		if !exists {
+			logger.Warning("receiving eval command from unrecognized peer")
+			return
+		}
+		peer.Lock()
+		peer.input = new(big.Int).SetBytes(inputBytes)
+		peer.Unlock()
+		output := me.poly.Eval(peer.input)
 		rw.WriteString(base58.Encode(output.Bytes()))
 		rw.Flush()
 	case "sum":
@@ -257,9 +263,7 @@ retry:
 		printErr(err, "couldn't base58-decode contents from stream")
 		goto retry
 	}
-	bi := &big.Int{}
-	bi.SetBytes(retBytes)
-	return bi
+	return new(big.Int).SetBytes(retBytes)
 }
 
 func startVoting() {
-- 
2.38.4