Fix panic when BLS key is nothing & support multiple keys

cmd/geth/main.go

@@ -150,6 +150,7 @@ var (
 		utils.BLSPasswordFileFlag,
 		utils.BLSWalletDirFlag,
 		utils.VoteJournalDirFlag,
+		utils.VoteKeyNameFlag,
 		utils.LogDebugFlag,
 		utils.LogBacktraceAtFlag,
 	}, utils.NetworkFlags, utils.DatabaseFlags)

cmd/utils/flags.go

@@ -944,6 +944,11 @@ Please note that --` + MetricsHTTPFlag.Name + ` must be set to start the server.
 		Usage:    "Path for the voteJournal dir in fast finality feature (default = inside the datadir)",
 		Category: flags.FastFinalityCategory,
 	}
+	VoteKeyNameFlag = &cli.StringFlag{
+		Name:     "vote-key-name",
+		Usage:    "Name of the BLS public key used for voting (default = first found key)",
+		Category: flags.FastFinalityCategory,
+	}
 )
 
 var (
@@ -1450,6 +1455,9 @@ func SetNodeConfig(ctx *cli.Context, cfg *node.Config) {
 	if ctx.IsSet(BLSPasswordFileFlag.Name) {
 		cfg.BLSPasswordFile = ctx.String(BLSPasswordFileFlag.Name)
 	}
+	if ctx.IsSet(VoteKeyNameFlag.Name) {
+		cfg.VoteKeyName = ctx.String(VoteKeyNameFlag.Name)
+	}
 	if ctx.IsSet(DBEngineFlag.Name) {
 		dbEngine := ctx.String(DBEngineFlag.Name)
 		if dbEngine != "leveldb" && dbEngine != "pebble" {

core/vote/vote_manager.go

@@ -44,7 +44,7 @@ type VoteManager struct {
 	engine consensus.PoS
 }
 
-func NewVoteManager(eth Backend, chain *core.BlockChain, pool *VotePool, journalPath, blsPasswordPath, blsWalletPath string, engine consensus.PoS) (*VoteManager, error) {
+func NewVoteManager(eth Backend, chain *core.BlockChain, pool *VotePool, journalPath, blsPasswordPath, blsWalletPath, blsAccountName string, engine consensus.PoS) (*VoteManager, error) {
 	voteManager := &VoteManager{
 		eth:         eth,
 		chain:       chain,
@@ -55,7 +55,7 @@ func NewVoteManager(eth Backend, chain *core.BlockChain, pool *VotePool, journal
 	}
 
 	// Create voteSigner.
-	voteSigner, err := NewVoteSigner(blsPasswordPath, blsWalletPath)
+	voteSigner, err := NewVoteSigner(blsPasswordPath, blsWalletPath, blsAccountName)
 	if err != nil {
 		return nil, err
 	}

core/vote/vote_signer.go

@@ -12,6 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/validator/accounts/iface"
 	"github.com/prysmaticlabs/prysm/v5/validator/accounts/wallet"
 	"github.com/prysmaticlabs/prysm/v5/validator/keymanager"
+	"github.com/prysmaticlabs/prysm/v5/validator/keymanager/local"
 
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
@@ -29,7 +30,7 @@ type VoteSigner struct {
 	PubKey [48]byte
 }
 
-func NewVoteSigner(blsPasswordPath, blsWalletPath string) (*VoteSigner, error) {
+func NewVoteSigner(blsPasswordPath, blsWalletPath, blsAccountName string) (*VoteSigner, error) {
 	dirExists, err := wallet.Exists(blsWalletPath)
 	if err != nil {
 		log.Error("Check BLS wallet exists", "err", err)
@@ -71,10 +72,39 @@ func NewVoteSigner(blsPasswordPath, blsWalletPath string) (*VoteSigner, error) {
 	if err != nil {
 		return nil, errors.Wrap(err, "could not fetch validating public keys")
 	}
+	if len(pubKeys) == 0 {
+		return nil, errors.New("no public keys in the BLS wallet")
+	}
+
+	// The default uses the first found key.
+	pubKey := pubKeys[0]
+
+	// If a key name is specified, find for it, but use the first key if not found.
+	if blsAccountName != "" {
+		ikm, ok := km.(*local.Keymanager)
+		if !ok {
+			return nil, errors.New("could not assert BLS keymanager interface to concrete type")
+		}
+		accountNames, err := ikm.ValidatingAccountNames()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not fetch BLS account names")
+		}
+		var found bool
+		for i := 0; i < len(accountNames) && !found; i++ {
+			found = accountNames[i] == blsAccountName
+			if found {
+				pubKey = pubKeys[i]
+			}
+		}
+		if !found {
+			log.Warn("Configured voting BLS public key was not found, so the default key will be used",
+				"configured", blsAccountName, "default", accountNames[0])
+		}
+	}
 
 	return &VoteSigner{
 		km:     &km,
-		PubKey: pubKeys[0],
+		PubKey: pubKey,
 	}, nil
 }
 

eth/backend.go

@@ -290,8 +290,9 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 			conf := stack.Config()
 			blsPasswordPath := stack.ResolvePath(conf.BLSPasswordFile)
 			blsWalletPath := stack.ResolvePath(conf.BLSWalletDir)
+			blsAccountName := conf.VoteKeyName
 			voteJournalPath := stack.ResolvePath(conf.VoteJournalDir)
-			if _, err := vote.NewVoteManager(eth, eth.blockchain, votePool, voteJournalPath, blsPasswordPath, blsWalletPath, posa); err != nil {
+			if _, err := vote.NewVoteManager(eth, eth.blockchain, votePool, voteJournalPath, blsPasswordPath, blsWalletPath, blsAccountName, posa); err != nil {
 				log.Error("Failed to Initialize voteManager", "err", err)
 				return nil, err
 			}

node/config.go

@@ -212,6 +212,9 @@ type Config struct {
 	// VoteJournalDir is the directory to store votes in the fast finality feature.
 	VoteJournalDir string `toml:",omitempty"`
 
+	// VoteKeyName is name of the BLS public key used for voting
+	VoteKeyName string `toml:",omitempty"`
+
 	// BatchRequestLimit is the maximum number of requests in a batch.
 	BatchRequestLimit int `toml:",omitempty"`