Init bls only once before serving api (#37)

* init bls only once before serving api

* change bls init to main

listener/cmd/listener/main.go

@@ -4,6 +4,7 @@ import (
 	"github.com/dappnode/validator-monitoring/listener/internal/api"
 	"github.com/dappnode/validator-monitoring/listener/internal/config"
 	"github.com/dappnode/validator-monitoring/listener/internal/logger"
+	"github.com/herumi/bls-eth-go-binary/bls"
 )
 
 func main() {
@@ -15,6 +16,15 @@ func main() {
 	}
 	logger.SetLogLevelFromString(config.LogLevel)
 
+	// This is a configuration of the BLS library at the process level. Notice how bls.Init() does not return an initialized BLS object.
+	// Any call to bls functions within the process will use this configuration. We initialize bls before starting the api.
+	if err := bls.Init(bls.BLS12_381); err != nil {
+		logger.Fatal("Failed to initialize BLS: " + err.Error())
+	}
+	if err := bls.SetETHmode(bls.EthModeDraft07); err != nil {
+		logger.Fatal("Failed to set BLS ETH mode: " + err.Error())
+	}
+
 	s := api.NewApi(
 		config.Port,
 		config.MongoDBURI,

listener/internal/api/validation/VerifySignature.go

@@ -11,17 +11,6 @@ import (
 )
 
 func VerifySignature(req types.SignatureRequestDecoded) (bool, error) {
-	// Initialize the BLS system
-	if err := bls.Init(bls.BLS12_381); err != nil {
-		logger.Error("Failed to initialize BLS system: " + err.Error())
-		return false, err
-	}
-	// Set the BLS mode to ETH draft 07
-	if err := bls.SetETHmode(bls.EthModeDraft07); err != nil {
-		logger.Error("Failed to set BLS mode to ETH draft 07: " + err.Error())
-		return false, err
-	}
-
 	// Decode the public key from hex, remove the 0x prefix ONLY if exists from req.Pubkey
 	req.Pubkey = strings.TrimPrefix(req.Pubkey, "0x")
 	req.Pubkey = strings.TrimSpace(req.Pubkey)