ensure IBC light client existence upon IBC handshake

x/btcstkconsumer/keeper/consumer_registry.go

@@ -9,6 +9,7 @@ import (
 	"github.com/babylonlabs-io/babylon/x/btcstkconsumer/types"
 )
 
+// RegisterConsumer registers a new consumer
 func (k Keeper) RegisterConsumer(ctx context.Context, consumerRegister *types.ConsumerRegister) error {
 	if k.IsConsumerRegistered(ctx, consumerRegister.ConsumerId) {
 		return types.ErrConsumerAlreadyRegistered
@@ -17,6 +18,15 @@ func (k Keeper) RegisterConsumer(ctx context.Context, consumerRegister *types.Co
 	return nil
 }
 
+// UpdateConsumer updates the consumer register for a given consumer ID
+func (k Keeper) UpdateConsumer(ctx context.Context, consumerRegister *types.ConsumerRegister) error {
+	if !k.IsConsumerRegistered(ctx, consumerRegister.ConsumerId) {
+		return types.ErrConsumerNotRegistered
+	}
+	k.setConsumerRegister(ctx, consumerRegister)
+	return nil
+}
+
 func (k Keeper) setConsumerRegister(ctx context.Context, consumerRegister *types.ConsumerRegister) {
 	store := k.consumerRegistryStore(ctx)
 	store.Set([]byte(consumerRegister.ConsumerId), k.cdc.MustMarshal(consumerRegister))

x/zoneconcierge/keeper/ibc_packet_btc_staking_consumer_event.go

@@ -53,13 +53,46 @@ func (k Keeper) BroadcastBTCStakingConsumerEvents(
 	}
 }
 
+// HandleIBCChannelCreation processes the IBC handshake request. The handshake is successful
+// only if the client ID is registered as a consumer in the ZoneConcierge
+func (k Keeper) HandleIBCChannelCreation(
+	ctx sdk.Context,
+	portID string,
+	channelID string,
+) error {
+	clientID, _, err := k.channelKeeper.GetChannelClientState(ctx, portID, channelID)
+	if err != nil {
+		return fmt.Errorf("failed to get client state: %w", err)
+	}
+
+	// Check if the client ID is registered as a consumer
+	consumerRegister, err := k.btcStkKeeper.GetConsumerRegister(ctx, clientID)
+	if err != nil {
+		return fmt.Errorf("client ID %s is not registered as a consumer: %w", clientID, err)
+	}
+
+	// Update the consumer metadata with the new channel ID
+	cosmosMetadata := consumerRegister.GetCosmosConsumerMetadata()
+	if cosmosMetadata == nil {
+		return fmt.Errorf("consumer %s is not a Cosmos consumer", clientID)
+	}
+
+	// all good, update the channel ID
+	cosmosMetadata.ChannelId = channelID
+	if err := k.btcStkKeeper.UpdateConsumer(ctx, consumerRegister); err != nil {
+		return fmt.Errorf("failed to update consumer register: %w", err)
+	}
+
+	return nil
+}
+
 func (k Keeper) HandleConsumerSlashing(
 	ctx sdk.Context,
-	destinationPort string,
-	destinationChannel string,
+	portID string,
+	channelID string,
 	consumerSlashing *types.ConsumerSlashingIBCPacket,
 ) error {
-	clientID, _, err := k.channelKeeper.GetChannelClientState(ctx, destinationPort, destinationChannel)
+	clientID, _, err := k.channelKeeper.GetChannelClientState(ctx, portID, channelID)
 	if err != nil {
 		return fmt.Errorf("failed to get client state: %w", err)
 	}

x/zoneconcierge/module_ibc.go

@@ -52,6 +52,12 @@ func (im IBCModule) OnChanOpenInit(
 		return "", errorsmod.Wrapf(types.ErrInvalidVersion, "got %s, expected %s", version, types.Version)
 	}
 
+	// Handle the IBC handshake request, i.e., ensuring the client ID is registered as
+	// a Cosmos consumer
+	if err := im.keeper.HandleIBCChannelCreation(ctx, portID, channelID); err != nil {
+		return "", err
+	}
+
 	// Claim channel capability passed back by IBC module
 	if err := im.keeper.ClaimCapability(ctx, chanCap, host.ChannelCapabilityPath(portID, channelID)); err != nil {
 		return "", err
@@ -87,6 +93,12 @@ func (im IBCModule) OnChanOpenTry(
 		return "", errorsmod.Wrapf(types.ErrInvalidVersion, "invalid counterparty version: got: %s, expected %s", counterpartyVersion, types.Version)
 	}
 
+	// Handle the IBC handshake request, i.e., ensuring the client ID is registered as
+	// a Cosmos consumer
+	if err := im.keeper.HandleIBCChannelCreation(ctx, portID, channelID); err != nil {
+		return "", err
+	}
+
 	// Module may have already claimed capability in OnChanOpenInit in the case of crossing hellos
 	// (ie chainA and chainB both call ChanOpenInit before one of them calls ChanOpenTry)
 	// If module can already authenticate the capability then module already owns it so we don't need to claim

x/zoneconcierge/types/expected_keepers.go

@@ -115,6 +115,8 @@ type BTCStakingKeeper interface {
 
 type BTCStkConsumerKeeper interface {
 	RegisterConsumer(ctx context.Context, consumerRegister *btcstkconsumertypes.ConsumerRegister) error
+	UpdateConsumer(ctx context.Context, consumerRegister *btcstkconsumertypes.ConsumerRegister) error
+	GetConsumerRegister(ctx context.Context, consumerID string) (*btcstkconsumertypes.ConsumerRegister, error)
 	GetConsumerOfFinalityProvider(ctx context.Context, fpBTCPK *bbn.BIP340PubKey) (string, error)
 	GetConsumerFinalityProvider(ctx context.Context, consumerID string, fpBTCPK *bbn.BIP340PubKey) (*bstypes.FinalityProvider, error)
 	SetConsumerFinalityProvider(ctx context.Context, fp *bstypes.FinalityProvider)