Refactor threshold signer key loading and creation

cmd/horcrux/cmd/address.go

@@ -45,9 +45,9 @@ func addressCmd() *cobra.Command {
 					return err
 				}
 
-				key, err := signer.LoadCosignerEd25519Key(keyFile)
+				key, err := signer.LoadThresholdSignerEd25519Key(keyFile)
 				if err != nil {
-					return fmt.Errorf("error reading cosigner key: %w, check that key is present for chain Index: %s", err, chainID)
+					return fmt.Errorf("error reading threshold key: %w, check that key is present for chain id: %s", err, chainID)
 				}
 
 				pubKey = key.PubKey

cmd/horcrux/cmd/shards.go

@@ -112,7 +112,7 @@ func createCosignerEd25519ShardsCmd() *cobra.Command {
 				return nil
 			}
 
-			csKeys, err := signer.CreateCosignerEd25519ShardsFromFile(keyFile, threshold, shards)
+			csKeys, err := signer.CreateEd25519ThresholdSignShardsFromFile(keyFile, threshold, shards)
 			if err != nil {
 				return err
 			}

signer/cosigner_key.go

@@ -2,8 +2,6 @@ package signer
 
 import (
 	"encoding/json"
-	"os"
-
 	cometcrypto "github.com/cometbft/cometbft/crypto"
 	cometcryptoed25519 "github.com/cometbft/cometbft/crypto/ed25519"
 	cometcryptoencoding "github.com/cometbft/cometbft/crypto/encoding"
@@ -12,6 +10,7 @@ import (
 )
 
 // CosignerEd25519Key is a single Ed255219 key shard for an m-of-n threshold signer.
+// TODO: CosignerEd25519Key is almost a duplicate of ThresholdSignerEd25519Key
 type CosignerEd25519Key struct {
 	PubKey       cometcrypto.PubKey `json:"pubKey"`
 	PrivateShard []byte             `json:"privateShard"`
@@ -83,19 +82,3 @@ func (key *CosignerEd25519Key) UnmarshalJSON(data []byte) error {
 	key.PubKey = pubkey
 	return nil
 }
-
-// LoadCosignerEd25519Key loads a CosignerEd25519Key from file.
-func LoadCosignerEd25519Key(file string) (CosignerEd25519Key, error) {
-	pvKey := CosignerEd25519Key{}
-	keyJSONBytes, err := os.ReadFile(file)
-	if err != nil {
-		return pvKey, err
-	}
-
-	err = json.Unmarshal(keyJSONBytes, &pvKey)
-	if err != nil {
-		return pvKey, err
-	}
-
-	return pvKey, nil
-}

signer/cosigner_key_shares.go

@@ -10,33 +10,9 @@ import (
 	"github.com/cometbft/cometbft/privval"
 	"github.com/ethereum/go-ethereum/crypto/ecies"
 	"github.com/ethereum/go-ethereum/crypto/secp256k1"
-	tsed25519 "gitlab.com/unit410/threshold-ed25519/pkg"
 	"golang.org/x/sync/errgroup"
 )
 
-// CreateCosignerEd25519ShardsFromFile creates CosignerEd25519Key objects from a priv_validator_key.json file
-func CreateCosignerEd25519ShardsFromFile(priv string, threshold, shards uint8) ([]CosignerEd25519Key, error) {
-	pv, err := ReadPrivValidatorFile(priv)
-	if err != nil {
-		return nil, err
-	}
-	return CreateCosignerEd25519Shards(pv, threshold, shards), nil
-}
-
-// CreateCosignerEd25519Shards creates CosignerEd25519Key objects from a privval.FilePVKey
-func CreateCosignerEd25519Shards(pv privval.FilePVKey, threshold, shards uint8) []CosignerEd25519Key {
-	privShards := tsed25519.DealShares(tsed25519.ExpandSecret(pv.PrivKey.Bytes()[:32]), threshold, shards)
-	out := make([]CosignerEd25519Key, shards)
-	for i, shard := range privShards {
-		out[i] = CosignerEd25519Key{
-			PubKey:       pv.PubKey,
-			PrivateShard: shard,
-			ID:           i + 1,
-		}
-	}
-	return out
-}
-
 // CreateCosignerRSAShards generate  CosignerRSAKey objects.
 func CreateCosignerRSAShards(shards int) ([]CosignerRSAKey, error) {
 	rsaKeys, pubKeys, err := makeRSAKeys(shards)

signer/threshold_signer.go

@@ -1,7 +1,11 @@
 package signer
 
 import (
+	"encoding/json"
+	"github.com/cometbft/cometbft/privval"
 	"github.com/strangelove-ventures/horcrux/pkg/types"
+	tsed25519 "gitlab.com/unit410/threshold-ed25519/pkg"
+	"os"
 )
 
 // Interface for the local signer whether it's a soft sign or HSM
@@ -15,3 +19,42 @@ type ThresholdSigner interface {
 	// CombineSignatures combines multiple partial signatures to a full signature.
 	CombineSignatures([]types.PartialSignature) ([]byte, error)
 }
+
+// LoadThresholdSignerEd25519Key loads the persistent ThresholdSignerEd25519Key from file.
+func LoadThresholdSignerEd25519Key(file string) (CosignerEd25519Key, error) {
+	pvKey := CosignerEd25519Key{}
+	keyJSONBytes, err := os.ReadFile(file)
+	if err != nil {
+		return pvKey, err
+	}
+
+	err = json.Unmarshal(keyJSONBytes, &pvKey)
+	if err != nil {
+		return pvKey, err
+	}
+
+	return pvKey, nil
+}
+
+// CreateEd25519ThresholdSignShardsFromFile creates CosignerEd25519Key objects from a priv_validator_key.json file
+func CreateEd25519ThresholdSignShardsFromFile(priv string, threshold, shards uint8) ([]CosignerEd25519Key, error) {
+	pv, err := ReadPrivValidatorFile(priv)
+	if err != nil {
+		return nil, err
+	}
+	return CreateEd25519ThresholdSignShards(pv, threshold, shards), nil
+}
+
+// CreateEd25519ThresholdSignShards creates CosignerEd25519Key objects from a privval.FilePVKey
+func CreateEd25519ThresholdSignShards(pv privval.FilePVKey, threshold, shards uint8) []CosignerEd25519Key {
+	privShards := tsed25519.DealShares(tsed25519.ExpandSecret(pv.PrivKey.Bytes()[:32]), threshold, shards)
+	out := make([]CosignerEd25519Key, shards)
+	for i, shard := range privShards {
+		out[i] = CosignerEd25519Key{
+			PubKey:       pv.PubKey,
+			PrivateShard: shard,
+			ID:           i + 1,
+		}
+	}
+	return out
+}

signer/threshold_signer_bls.go

@@ -26,7 +26,7 @@ func NewThresholdSignerSoftBLS(config *RuntimeConfig, id int, chainID string) (*
 		return nil, err
 	}
 
-	key, err := LoadCosignerEd25519Key(keyFile)
+	key, err := LoadThresholdSignerEd25519Key(keyFile)
 	if err != nil {
 		return nil, fmt.Errorf("error reading cosigner key: %s", err)
 	}

signer/threshold_signer_soft.go

@@ -27,7 +27,7 @@ func NewThresholdSignerSoft(config *RuntimeConfig, id int, chainID string) (*Thr
 		return nil, err
 	}
 
-	key, err := LoadCosignerEd25519Key(keyFile)
+	key, err := LoadThresholdSignerEd25519Key(keyFile)
 	if err != nil {
 		return nil, fmt.Errorf("error reading cosigner key: %s", err)
 	}
@@ -87,6 +87,7 @@ func (s *ThresholdSignerSoft) sumNonces(nonces []types.Nonce) (tsed25519.Scalar,
 	return nonceShare, noncePub, nil
 }
 
+// GenerateNonces is a function that generates Nonces to be used in the MPC
 func GenerateNonces(threshold, total uint8) (types.Nonces, error) {
 	secret := make([]byte, 32)
 	if _, err := rand.Read(secret); err != nil {

test/validator_threshold.go

@@ -257,7 +257,7 @@ func getShardedPrivvalKey(ctx context.Context, node *cosmos.ChainNode, threshold
 		return nil, nil, err
 	}
 
-	ed25519Shards := signer.CreateCosignerEd25519Shards(pvKey, threshold, shards)
+	ed25519Shards := signer.CreateEd25519ThresholdSignShards(pvKey, threshold, shards)
 
 	return ed25519Shards, pvKey.PubKey, nil
 }