Refactor cosigner package and add ted25519SignerSoft type

pkg/cosigner/cosigner.go

@@ -17,6 +17,7 @@ import (
 	"github.com/strangelove-ventures/horcrux/signer/proto"
 )
 
+/*
 // threshold-ed25519
 type MPC struct {
 	// our own cosigner
@@ -33,7 +34,7 @@ type Localcosigner interface {
 type Remotecosigner interface {
 	// TODO - add methods
 }
-
+*/
 // CosignerSignRequest is sent to a co-signer to obtain their signature for the SignBytes
 // The SignBytes should be a serialized block
 type CosignerSignRequest struct {

pkg/cosigner/remote_cosigner.go → pkg/cosigner/remote.go

@@ -16,7 +16,8 @@ import (
 // var _ Cosigner = &RemoteCosigner{}
 
 // RemoteCosigner uses CosignerGRPC to request signing from a remote cosigner
-// Remote Cosigner are the CLIENT!
+// Remote Cosigner are CLIENTS! to every other cosigner, including the the nodes local cosigner
+// It calls the GRPC server of the other cosigner
 type RemoteCosigner struct {
 	id      int
 	address string
@@ -28,7 +29,7 @@ type RemoteCosigner struct {
 func InitRemoteCosigner(id int, address string, client proto.CosignerClient) *RemoteCosigner {
 	cosigner := &RemoteCosigner{
 		id:      id,
-		address: address,
+		address: address, // address is the P2P URL of the remote cosigner
 		Client:  client,
 	}
 
@@ -37,7 +38,7 @@ func InitRemoteCosigner(id int, address string, client proto.CosignerClient) *Re
 
 // NewRemoteCosigner returns a newly initialized RemoteCosigner
 func NewRemoteCosigner(id int, address string) (*RemoteCosigner, error) {
-	client, err := getGRPCClient(address)
+	client, err := getGRPCClient(address) // address is the P2P URL of the cosigner server to dial
 	if err != nil {
 		return nil, err
 	}

pkg/tss/threshold-ed25519_signer_soft.go

@@ -31,15 +31,18 @@ func CreateEd25519ThresholdSignShards(pv privval.FilePVKey, threshold, shards ui
 	return out
 }
 
-type ThresholdSignerSoft struct {
+// ted25519SignerSoft is a threshold signer that uses the threshold-ed25519 library
+// to perform the signing operations.
+// Its only responsibility is to sign a payload and combine signatures
+type ted25519SignerSoft struct {
 	privateKeyShard []byte
 	pubKey          []byte
 	threshold       uint8
 	total           uint8
 	id              uint8
 }
 
-func NewThresholdEd25519SignerSoft(config *config.RuntimeConfig, id int, chainID string) (*ThresholdSignerSoft, error) {
+func NewThresholdEd25519SignerSoft(config *config.RuntimeConfig, id int, chainID string) (*ted25519SignerSoft, error) {
 	keyFile, err := config.KeyFileExistsCosigner(chainID)
 	if err != nil {
 		return nil, err
@@ -54,7 +57,7 @@ func NewThresholdEd25519SignerSoft(config *config.RuntimeConfig, id int, chainID
 		return nil, fmt.Errorf("key shard Index (%d) in (%s) does not match cosigner Index (%d)", key.ID, keyFile, id)
 	}
 
-	s := ThresholdSignerSoft{
+	s := ted25519SignerSoft{
 		privateKeyShard: key.PrivateShard,
 		pubKey:          key.PubKey.Bytes(),
 		threshold:       uint8(config.Config.ThresholdModeConfig.Threshold),
@@ -65,12 +68,13 @@ func NewThresholdEd25519SignerSoft(config *config.RuntimeConfig, id int, chainID
 	return &s, nil
 }
 
-func (s *ThresholdSignerSoft) GetPubKey() []byte {
+func (s *ted25519SignerSoft) GetPubKey() []byte {
 	return s.pubKey
 }
 
-func (s *ThresholdSignerSoft) Sign(nonces []types.Nonce, payload []byte) ([]byte, error) {
-	nonceShare, noncePub, err := s.sumNonces(nonces)
+func (s *ted25519SignerSoft) Sign(nonces []types.Nonce, payload []byte) ([]byte, error) {
+	// sum the nonces to get the ephemeral public key and share
+	nonceShare, noncePub, err := sumNonces(nonces)
 	if err != nil {
 		return nil, fmt.Errorf("failed to combine nonces: %w", err)
 	}
@@ -80,7 +84,7 @@ func (s *ThresholdSignerSoft) Sign(nonces []types.Nonce, payload []byte) ([]byte
 	return append(noncePub, sig...), nil
 }
 
-func (s *ThresholdSignerSoft) sumNonces(nonces []types.Nonce) (tsed25519.Scalar, tsed25519.Element, error) {
+func sumNonces(nonces []types.Nonce) (tsed25519.Scalar, tsed25519.Element, error) {
 	shareParts := make([]tsed25519.Scalar, len(nonces))
 	publicKeys := make([]tsed25519.Element, len(nonces))
 
@@ -132,7 +136,7 @@ func (ng NonceGenerator) GenerateNonces(threshold, total uint8) (types.Nonces, e
 }
 
 // CombineSignatures combines partial signatures into a full signature
-func (s *ThresholdSignerSoft) CombineSignatures(signatures []types.PartialSignature) ([]byte, error) {
+func (s *ted25519SignerSoft) CombineSignatures(signatures []types.PartialSignature) ([]byte, error) {
 	sigIds := make([]int, len(signatures))
 	shareSigs := make([][]byte, len(signatures))
 	var ephPub []byte

signer/threshold_validator.go

@@ -651,6 +651,7 @@ func (pv *ThresholdValidator) Sign(ctx context.Context, chainID string, block ty
 	numPeers := len(pv.peerCosigners)
 	total := uint8(numPeers + 1)
 
+	// More or less everything belov here shoud be moved to a "cosigners"
 	peerStartTime := time.Now()
 
 	cosignersOrderedByFastest := pv.cosignerHealth.GetFastest()