From 22f4c1287850b79638e290df67c397b5f6fb6e10 Mon Sep 17 00:00:00 2001
From: David Florness <david@florness.com>
Date: Thu, 6 Aug 2020 16:12:13 -0600
Subject: [PATCH] Include candidates and rendezvous nonce in election info

---
 config.go   | 38 ++++++++++++++++++++++++++++----------
 election.go | 21 ++++++++++++++-------
 2 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/config.go b/config.go
index 5a68989..953ae51 100644
--- a/config.go
+++ b/config.go
@@ -23,19 +23,23 @@ type ElectionInfos map[string]*ElectionInfo
 
 // an entry of an election's cached info
 type ElectionInfo struct{
-	PrivKey crypto.PrivKey
-	PubKey  crypto.PubKey
+	Candidates      []Candidate
+	PrivKey         crypto.PrivKey
+	PubKey          crypto.PubKey
+	RendezvousNonce Nonce
 }
 
 // used for JSON {en,de}coding
 type RawElectionInfos map[string]RawElectionInfo
 
 type RawElectionInfo struct{
+	Candidates      []string
 	// Our private key in base58. TODO: encrypt
-	PrivKey string
+	PrivKey         string
 	// Our public key in base58. Kept in addition to the private key to
 	// check against when the private key is later encrypted
-	PubKey  string
+	PubKey          string
+	RendezvousNonce string
 }
 
 // Saves an election's info into a file that can later be easily retrieved, even
@@ -57,8 +61,10 @@ func (e *Election) saveInfo() error {
 	defer file.Close()
 	localVoter := e.localVoter
 	infos[e.electionKey] = &ElectionInfo{
-		PrivKey: localVoter.Peerstore().PrivKey(localVoter.ID()),
-		PubKey:  localVoter.Peerstore().PubKey(localVoter.ID()),
+		e.Candidates,
+		localVoter.Peerstore().PrivKey(localVoter.ID()),
+		localVoter.Peerstore().PubKey(localVoter.ID()),
+		e.rendezvousNonce,
 	}
 	raw, err := marshalElectionInfos(infos)
 	if err != nil {
@@ -128,6 +134,10 @@ func decodeElectionInfos(reader io.Reader) (rawElections RawElectionInfos, err e
 func marshalElectionInfos(electionConfigs ElectionInfos) (rawElections RawElectionInfos, err error) {
 	rawElections = make(RawElectionInfos)
 	for electionKey, electionConfig := range electionConfigs {
+		candidates := make([]string, 0, len(electionConfig.Candidates))
+		for _, c := range electionConfig.Candidates {
+			candidates = append(candidates, string(c))
+		}
 		privKeyBytes, err := crypto.MarshalPrivateKey(electionConfig.PrivKey)
 		if err != nil {
 			return nil, err
@@ -139,8 +149,10 @@ func marshalElectionInfos(electionConfigs ElectionInfos) (rawElections RawElecti
 		}
 		pubKeyStr := base58.Encode(pubKeyBytes)
 		rawElections[electionKey] = RawElectionInfo{
-			PrivKey: privKeyStr,
-			PubKey:  pubKeyStr,
+			candidates,
+			privKeyStr,
+			pubKeyStr,
+			string(electionConfig.RendezvousNonce),
 		}
 	}
 	return rawElections, nil
@@ -149,6 +161,10 @@ func marshalElectionInfos(electionConfigs ElectionInfos) (rawElections RawElecti
 func unmarshalRawElectionInfos(rawElections RawElectionInfos) (electionConfigs ElectionInfos, err error) {
 	electionConfigs = make(ElectionInfos)
 	for electionKey, info := range rawElections {
+		candidates := make([]Candidate, 0, len(info.Candidates))
+		for _, s := range info.Candidates {
+			candidates = append(candidates, Candidate(s))
+		}
 		privKeyBytes, err := base58.Decode(info.PrivKey)
 		if err != nil {
 			return nil, err
@@ -166,8 +182,10 @@ func unmarshalRawElectionInfos(rawElections RawElectionInfos) (electionConfigs E
 			return nil, err
 		}
 		electionConfigs[electionKey] = &ElectionInfo{
-			PrivKey: privKey,
-			PubKey:  pubKey,
+			candidates,
+			privKey,
+			pubKey,
+			Nonce(info.RendezvousNonce),
 		}
 	}
 	return electionConfigs, nil
diff --git a/election.go b/election.go
index 64b9ba0..4d2d8b1 100644
--- a/election.go
+++ b/election.go
@@ -56,7 +56,11 @@ func NewElectionWithCandidates(candidates []Candidate) *Election {
 }
 
 func NewElectionWithElectionKey(electionKey string) *Election {
-	var localVoter *LocalVoter
+	var (
+		candidates      []Candidate
+		localVoter      *LocalVoter
+		rendezvousNonce Nonce
+	)
 	// try to recover info from elections file to see if we've
 	// joined/created this election before
 	electionInfo, err := getElectionInfo(electionKey)
@@ -64,21 +68,24 @@ func NewElectionWithElectionKey(electionKey string) *Election {
 		panic(err)
 	}
 	if electionInfo != nil { // we've joined this election before
-		// ensure public key from config is same as one derived
-		// from private key
+		// ensure public key from config is same as one derived from
+		// private key
+		candidates = electionInfo.Candidates
 		if !electionInfo.PrivKey.GetPublic().Equals(electionInfo.PubKey) {
 			// TODO: handle properly
 			panic("loaded public key does not match derived one from private key")
 		}
 		localVoter = NewLocalVoter(libp2p.Identity(electionInfo.PrivKey))
+		rendezvousNonce = electionInfo.RendezvousNonce
 	} else { // we've never joined this election before
 		localVoter = NewLocalVoter(libp2p.RandomIdentity)
 	}
-
 	e := &Election{
-		electionKey:  electionKey,
-		localVoter:   localVoter,
-		remoteVoters: make(map[peer.ID]*Voter),
+		Candidates:      candidates,
+		electionKey:     electionKey,
+		localVoter:      localVoter,
+		remoteVoters:    make(map[peer.ID]*Voter),
+		rendezvousNonce: rendezvousNonce,
 	}
 	zeroi := strings.IndexByte(electionKey, '0')
 	if zeroi == -1 {
-- 
2.38.4