Blue account

CHANGELOG.md

@@ -1,6 +1,9 @@
 # Changelog
 
 ## HEAD
+- `gconf`: allow to provide an optional authentication address that will be
+  used to authenticate a configuration creation message. This solves a
+  chicken-egg problem of when the confgiuration was not created via genesis.
 - `migrations`: when upgrading the schema version an explicit version must be
   provided. This is required to ensure at most one delivery.
 - `cmd/bnscli` can create a schema upgrade transaction.

cmd/bnsd/x/blueaccount/handler.go

@@ -61,7 +61,7 @@ func RegisterRoutes(r weave.Registry, auth x.Authenticator) {
 	})
 
 	r.Handle(&UpdateConfigurationMsg{}, gconf.NewUpdateConfigurationHandler(
-		"blueaccount", &Configuration{}, auth))
+		"blueaccount", &Configuration{}, auth, migration.CurrentAdmin))
 }
 
 type registerDomainHandler struct {

cmd/bnsd/x/username/handlers.go

@@ -180,5 +180,5 @@ func (h *changeTokenTargetsHandler) validate(ctx weave.Context, db weave.KVStore
 
 func NewConfigHandler(auth x.Authenticator) weave.Handler {
 	var conf Configuration
-	return gconf.NewUpdateConfigurationHandler("username", &conf, auth)
+	return gconf.NewUpdateConfigurationHandler("username", &conf, auth, migration.CurrentAdmin)
 }

gconf/handler.go

@@ -20,17 +20,42 @@ type OwnedConfig interface {
 type UpdateConfigurationHandler struct {
 	pkg string
 	// We require this type to load the data.
-	config OwnedConfig
-	auth   x.Authenticator
+	config    OwnedConfig
+	auth      x.Authenticator
+	initAdmin func(weave.ReadOnlyKVStore) (weave.Address, error)
 }
 
 var _ weave.Handler = (*UpdateConfigurationHandler)(nil)
 
-func NewUpdateConfigurationHandler(pkg string, config OwnedConfig, auth x.Authenticator) UpdateConfigurationHandler {
+// NewUpdateConfigurationHandler returns a message handler that process
+// configuration patch message.
+//
+// To pass authentication step, each message must be signed by the current
+// configuration owner.
+//
+// A special chicken-egg problem appears when the configuration does not exist
+// (it was not created via genesis). This is an issue, because without
+// configuration we cannot configure configuration owner that can update the
+// configuration. This means that the configuration cannot be created as well.
+// A configuration is needed to create a configuration.
+// To address the above issue, an optional `initConfAdmin` argument can be
+// given to provide a creation only admin address. A good deafult is to use
+// `migration.CurrentAdmin` function.
+// `initConfAdmin` is used to authenticate the tranaction only when no
+// configuration exist. Once a configuration is created, `initConfAdmin` is not
+// used anymore and the autentication relies only on configuration's owner
+// declaration.
+func NewUpdateConfigurationHandler(
+	pkg string,
+	config OwnedConfig,
+	auth x.Authenticator,
+	initConfAdmin func(weave.ReadOnlyKVStore) (weave.Address, error),
+) UpdateConfigurationHandler {
 	return UpdateConfigurationHandler{
-		pkg:    pkg,
-		config: config,
-		auth:   auth,
+		pkg:       pkg,
+		config:    config,
+		auth:      auth,
+		initAdmin: initConfAdmin,
 	}
 }
 
@@ -64,8 +89,16 @@ func (h UpdateConfigurationHandler) applyTx(ctx weave.Context, store weave.KVSto
 		// Configuration entity does not exist. It was not initialized
 		// during via the genesis and will be created for the first
 		// time now.
-
-		// TODO - because of lack of a better idea, anyone can do this right now
+		if h.initAdmin == nil {
+			return errors.Wrap(errors.ErrUnauthorized, "configuration does not exist and cannot be initialized")
+		}
+		admin, err := h.initAdmin(store)
+		if err != nil {
+			return errors.Wrap(err, "get init admin")
+		}
+		if !h.auth.HasAddress(ctx, admin) {
+			return errors.Wrap(errors.ErrUnauthorized, "initialization admin signature required")
+		}
 	default:
 		return errors.Wrap(err, "load current configuration")
 	}

migration/configuration.go

@@ -1,6 +1,7 @@
 package migration
 
 import (
+	weave "github.com/iov-one/weave"
 	"github.com/iov-one/weave/errors"
 	"github.com/iov-one/weave/gconf"
 )
@@ -12,11 +13,24 @@ func (c *Configuration) Validate() error {
 	return nil
 }
 
-func mustLoadConf(db gconf.Store) Configuration {
+func loadConf(db gconf.ReadStore) (*Configuration, error) {
 	var conf Configuration
 	if err := gconf.Load(db, "migration", &conf); err != nil {
-		err = errors.Wrap(err, "load configuration")
-		panic(err)
+		return nil, errors.Wrap(err, "gconf")
 	}
-	return conf
+	return &conf, nil
+}
+
+// CurrentAdmin returns migration extension admin address as currently
+// configured.
+//
+// This function is useful for the `gconf` package users to provide a one time
+// authentication address during configuration initialization. See
+// `gconf.NewUpdateConfigurationHandler` for more details.
+func CurrentAdmin(db weave.ReadOnlyKVStore) (weave.Address, error) {
+	conf, err := loadConf(db)
+	if err != nil {
+		return nil, errors.Wrap(err, "load configuration")
+	}
+	return conf.Admin, nil
 }

migration/handler.go

@@ -133,7 +133,10 @@ func (h *upgradeSchemaHandler) validate(ctx weave.Context, db weave.KVStore, tx
 		return nil, errors.Wrap(err, "load msg")
 	}
 
-	conf := mustLoadConf(db)
+	conf, err := loadConf(db)
+	if err != nil {
+		return nil, errors.Wrap(err, "load configuration")
+	}
 	if !h.auth.HasAddress(ctx, conf.Admin) {
 		return nil, errors.Wrap(errors.ErrUnauthorized, "admin signature required")
 	}

x/cash/handler.go

@@ -78,5 +78,5 @@ func (h SendHandler) Deliver(ctx weave.Context, store weave.KVStore, tx weave.Tx
 
 func NewConfigHandler(auth x.Authenticator) weave.Handler {
 	var conf Configuration
-	return gconf.NewUpdateConfigurationHandler("cash", &conf, auth)
+	return gconf.NewUpdateConfigurationHandler("cash", &conf, auth, migration.CurrentAdmin)
 }

x/msgfee/handler.go

@@ -78,5 +78,5 @@ func (h *setMsgFeeHandler) validate(ctx weave.Context, db weave.KVStore, tx weav
 
 func NewConfigHandler(auth x.Authenticator) weave.Handler {
 	var conf Configuration
-	return gconf.NewUpdateConfigurationHandler("cash", &conf, auth)
+	return gconf.NewUpdateConfigurationHandler("cash", &conf, auth, migration.CurrentAdmin)
 }