feat(lite): counterparty client logic (#6307)

* imp: added counterparty client store

* imp: added provide counterparty to proto

* imp: ran 'make proto-all'

* imp: added logic to counterparty client

* imp: fix proto

* imp: fix proto

* imp: ran 'make proto-all'

* feat: finished counterparty client logic

modules/core/02-client/keeper/keeper.go

@@ -322,6 +322,31 @@ func (k *Keeper) GetSelfConsensusState(ctx sdk.Context, height exported.Height)
 	return k.consensusHost.GetSelfConsensusState(ctx, height)
 }
 
+// GetCounterparty returns the counterparty client's identifier for a given client identifier.
+// If the counterparty client identifier is not found, an empty string is returned.
+func (k *Keeper) GetCounterparty(ctx sdk.Context, clientID string) string {
+	return string(k.ClientStore(ctx, clientID).Get(host.CounterpartyKey()))
+}
+
+// SetCounterparty sets the counterparty client's identifier for a given client identifier.
+func (k *Keeper) SetCounterparty(ctx sdk.Context, clientID, counterpartyClientID string) {
+	k.ClientStore(ctx, clientID).Set(host.CounterpartyKey(), []byte(counterpartyClientID))
+}
+
+// GetCreator returns the creator of the client.
+func (k *Keeper) GetCreator(ctx sdk.Context, clientID string) string {
+	// the creator key is imported from types instead of host because
+	// the creator key is not a part of the ics-24 host specification
+	return string(k.ClientStore(ctx, clientID).Get([]byte(types.CreatorKey)))
+}
+
+// SetCreator sets the creator of the client.
+func (k *Keeper) SetCreator(ctx sdk.Context, clientID, creator string) {
+	// the creator key is imported from types instead of host because
+	// the creator key is not a part of the ics-24 host specification
+	k.ClientStore(ctx, clientID).Set([]byte(types.CreatorKey), []byte(creator))
+}
+
 // ValidateSelfClient validates the client parameters for a client of the running chain.
 // This function is only used to validate the client state the counterparty stores for this chain.
 // NOTE: If the client type is not of type Tendermint then delegate to a custom client validator function.

modules/core/02-client/keeper/keeper_test.go

@@ -129,6 +129,17 @@ func (suite *KeeperTestSuite) TestSetClientState() {
 	suite.Require().Equal(clientState, retrievedState, "Client states are not equal")
 }
 
+func (suite *KeeperTestSuite) TestSetCounterparty() {
+	counterpartyClientID := suite.keeper.GetCounterparty(suite.ctx, testClientID)
+	suite.Require().Equal("", counterpartyClientID, "Counterparty client ID is not empty")
+
+	testCounterpartyID := "counterparty-1"
+	suite.keeper.SetCounterparty(suite.ctx, testClientID, testCounterpartyID)
+
+	counterpartyClientID = suite.keeper.GetCounterparty(suite.ctx, testClientID)
+	suite.Require().Equal(testCounterpartyID, counterpartyClientID, "Counterparty client ID is not equal")
+}
+
 func (suite *KeeperTestSuite) TestSetClientConsensusState() {
 	suite.keeper.SetClientConsensusState(suite.ctx, testClientID, testClientHeight, suite.consensusState)
 

modules/core/02-client/types/errors.go

@@ -38,4 +38,5 @@ var (
 	ErrFailedNonMembershipVerification        = errorsmod.Register(SubModuleName, 31, "non-membership verification failed")
 	ErrRouteNotFound                          = errorsmod.Register(SubModuleName, 32, "light client module route not found")
 	ErrClientTypeNotSupported                 = errorsmod.Register(SubModuleName, 33, "client type not supported")
+	ErrInvalidCounterparty                    = errorsmod.Register(SubModuleName, 34, "invalid counterparty identifier")
 )

modules/core/02-client/types/keys.go

@@ -32,6 +32,9 @@ const (
 	// AllowAllClients is the value that if set in AllowedClients param
 	// would allow any wired up light client modules to be allowed
 	AllowAllClients = "*"
+
+	// CreatorKey is the key used to store the client creator in the client store
+	CreatorKey = "creator"
 )
 
 // FormatClientIdentifier returns the client identifier with the sequence appended.

modules/core/02-client/types/msgs.go

@@ -1,6 +1,8 @@
 package types
 
 import (
+	"strings"
+
 	errorsmod "cosmossdk.io/errors"
 	upgradetypes "cosmossdk.io/x/upgrade/types"
 
@@ -20,6 +22,7 @@ var (
 	_ sdk.Msg = (*MsgUpdateParams)(nil)
 	_ sdk.Msg = (*MsgIBCSoftwareUpgrade)(nil)
 	_ sdk.Msg = (*MsgRecoverClient)(nil)
+	_ sdk.Msg = (*MsgProvideCounterparty)(nil)
 
 	_ sdk.HasValidateBasic = (*MsgCreateClient)(nil)
 	_ sdk.HasValidateBasic = (*MsgUpdateClient)(nil)
@@ -28,6 +31,7 @@ var (
 	_ sdk.HasValidateBasic = (*MsgUpdateParams)(nil)
 	_ sdk.HasValidateBasic = (*MsgIBCSoftwareUpgrade)(nil)
 	_ sdk.HasValidateBasic = (*MsgRecoverClient)(nil)
+	_ sdk.HasValidateBasic = (*MsgProvideCounterparty)(nil)
 
 	_ codectypes.UnpackInterfacesMessage = (*MsgCreateClient)(nil)
 	_ codectypes.UnpackInterfacesMessage = (*MsgUpdateClient)(nil)
@@ -265,6 +269,32 @@ func (msg *MsgRecoverClient) ValidateBasic() error {
 	return nil
 }
 
+// NewMsgProvideCounterparty creates a new MsgProvideCounterparty instance
+func NewMsgProvideCounterparty(signer, clientID, counterpartyID string) *MsgProvideCounterparty {
+	return &MsgProvideCounterparty{
+		Signer:         signer,
+		ClientId:       clientID,
+		CounterpartyId: counterpartyID,
+	}
+}
+
+// ValidateBasic performs basic checks on a MsgProvideCounterparty.
+func (msg *MsgProvideCounterparty) ValidateBasic() error {
+	if _, err := sdk.AccAddressFromBech32(msg.Signer); err != nil {
+		return errorsmod.Wrapf(ibcerrors.ErrInvalidAddress, "string could not be parsed as address: %v", err)
+	}
+
+	if err := host.ClientIdentifierValidator(msg.ClientId); err != nil {
+		return err
+	}
+
+	if strings.TrimSpace(msg.CounterpartyId) == "" {
+		return errorsmod.Wrapf(ErrInvalidCounterparty, "counterparty client id cannot be empty")
+	}
+
+	return nil
+}
+
 // NewMsgIBCSoftwareUpgrade creates a new MsgIBCSoftwareUpgrade instance
 func NewMsgIBCSoftwareUpgrade(signer string, plan upgradetypes.Plan, upgradedClientState exported.ClientState) (*MsgIBCSoftwareUpgrade, error) {
 	anyClient, err := PackClientState(upgradedClientState)

modules/core/24-host/client_keys.go

@@ -40,3 +40,7 @@ func FullConsensusStateKey(clientID string, height exported.Height) []byte {
 func ConsensusStateKey(height exported.Height) []byte {
 	return []byte(ConsensusStatePath(height))
 }
+
+func CounterpartyKey() []byte {
+	return []byte(KeyCounterparty)
+}

modules/core/24-host/client_paths.go

@@ -12,6 +12,7 @@ var KeyClientStorePrefix = []byte("clients")
 const (
 	KeyClientState          = "clientState"
 	KeyConsensusStatePrefix = "consensusStates"
+	KeyCounterparty         = "counterparty"
 )
 
 // FullClientPath returns the full path of a specific client path in the format:
@@ -42,6 +43,12 @@ func FullConsensusStatePath(clientID string, height exported.Height) string {
 	return FullClientPath(clientID, ConsensusStatePath(height))
 }
 
+// FullCounterpartyPath takes a client identifier and returns a Path under which to
+// store the counterparty of a client.
+func FullCounterpartyPath(clientID string) string {
+	return FullClientPath(clientID, KeyCounterparty)
+}
+
 // ConsensusStatePath returns the suffix store key for the consensus state at a
 // particular height stored in a client prefixed store.
 func ConsensusStatePath(height exported.Height) string {

modules/core/keeper/msg_server.go

@@ -3,6 +3,7 @@ package keeper
 import (
 	"context"
 	"errors"
+	"strings"
 
 	errorsmod "cosmossdk.io/errors"
 
@@ -43,7 +44,13 @@ func (k *Keeper) CreateClient(goCtx context.Context, msg *clienttypes.MsgCreateC
 		return nil, err
 	}
 
-	return &clienttypes.MsgCreateClientResponse{ClientId: clientID}, nil
+	k.ClientKeeper.SetCreator(ctx, clientID, msg.Signer)
+
+	if strings.TrimSpace(msg.CounterpartyId) != "" {
+		k.ClientKeeper.SetCounterparty(ctx, clientID, msg.CounterpartyId)
+	}
+
+	return &clienttypes.MsgCreateClientResponse{}, nil
 }
 
 // UpdateClient defines a rpc handler method for MsgUpdateClient.
@@ -135,6 +142,22 @@ func (k *Keeper) IBCSoftwareUpgrade(goCtx context.Context, msg *clienttypes.MsgI
 	return &clienttypes.MsgIBCSoftwareUpgradeResponse{}, nil
 }
 
+// ProvideCounterparty defines a rpc handler method for MsgProvideCounterparty.
+func (k *Keeper) ProvideCounterparty(goCtx context.Context, msg *clienttypes.MsgProvideCounterparty) (*clienttypes.MsgProvideCounterpartyResponse, error) {
+	ctx := sdk.UnwrapSDKContext(goCtx)
+
+	if creator := k.ClientKeeper.GetCreator(ctx, msg.ClientId); creator != msg.Signer {
+		return nil, errorsmod.Wrapf(ibcerrors.ErrUnauthorized, "expected %s, got %s", creator, msg.Signer)
+	}
+
+	if counterparty := k.ClientKeeper.GetCounterparty(ctx, msg.ClientId); counterparty != "" {
+		return nil, errorsmod.Wrapf(clienttypes.ErrInvalidCounterparty, "counterparty already exists for client %s", msg.ClientId)
+	}
+	k.ClientKeeper.SetCounterparty(ctx, msg.ClientId, msg.CounterpartyId)
+
+	return &clienttypes.MsgProvideCounterpartyResponse{}, nil
+}
+
 // ConnectionOpenInit defines a rpc handler method for MsgConnectionOpenInit.
 func (k *Keeper) ConnectionOpenInit(goCtx context.Context, msg *connectiontypes.MsgConnectionOpenInit) (*connectiontypes.MsgConnectionOpenInitResponse, error) {
 	ctx := sdk.UnwrapSDKContext(goCtx)

proto/ibc/core/client/v1/tx.proto

@@ -29,6 +29,9 @@ service Msg {
   // RecoverClient defines a rpc handler method for MsgRecoverClient.
   rpc RecoverClient(MsgRecoverClient) returns (MsgRecoverClientResponse);
 
+  // ProvideCounterparty defines a rpc handler method for MsgProvideCounterparty.
+  rpc ProvideCounterparty(MsgProvideCounterparty) returns (MsgProvideCounterpartyResponse);
+
   // IBCSoftwareUpgrade defines a rpc handler method for MsgIBCSoftwareUpgrade.
   rpc IBCSoftwareUpgrade(MsgIBCSoftwareUpgrade) returns (MsgIBCSoftwareUpgradeResponse);
 
@@ -49,6 +52,8 @@ message MsgCreateClient {
   google.protobuf.Any consensus_state = 2;
   // signer address
   string signer = 3;
+  // optional counterparty client identifier
+  string counterparty_id = 4;
 }
 
 // MsgCreateClientResponse defines the Msg/CreateClient response type.
@@ -140,6 +145,25 @@ message MsgRecoverClient {
 // MsgRecoverClientResponse defines the Msg/RecoverClient response type.
 message MsgRecoverClientResponse {}
 
+// MsgProvideCounterparty defines the message used to provide the counterparty client
+// identifier. Can only be invoked one time by the signer of MsgCreateClient if the counterparty
+// client identifier was not provided in the initial MsgCreateClient message.
+message MsgProvideCounterparty {
+  option (cosmos.msg.v1.signer) = "signer";
+
+  option (gogoproto.goproto_getters) = false;
+
+  // client unique identifier
+  string client_id = 1;
+  // counterparty client identifier
+  string counterparty_id = 2;
+  // signer address
+  string signer = 3;
+}
+
+// MsgProvideCounterpartyResponse defines the Msg/ProvideCounterparty response type.
+message MsgProvideCounterpartyResponse {}
+
 // MsgIBCSoftwareUpgrade defines the message used to schedule an upgrade of an IBC client using a v1 governance proposal
 message MsgIBCSoftwareUpgrade {
   option (cosmos.msg.v1.signer)    = "signer";