chore: Add gRPC validation for EscrowAddress (#6059)

* Add check that Channel exists for EscrowAddress

* Changed import of errors

* Fix compilation errors

* Fixed import

* Fix broken test

* Add test that checks for channelNotFound error

* Added HasChannel to ChannelKeeper interface and used it in gRPC validation

* Fix test and add back test for ChannelNotFound

* Change import alias.

* Added test case for invalid channelID

* Trim whitespace

* Update modules/apps/transfer/keeper/grpc_query.go

Condense check for existence of channel

Co-authored-by: Damian Nolan <damiannolan@gmail.com>

* Update modules/apps/transfer/keeper/grpc_query.go

Co-authored-by: Damian Nolan <damiannolan@gmail.com>

* Added tests for empty portID and empty channelID

---------

Co-authored-by: Damian Nolan <damiannolan@gmail.com>

modules/apps/transfer/keeper/grpc_query.go

@@ -15,6 +15,8 @@ import (
 	"github.com/cosmos/cosmos-sdk/types/query"
 
 	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
+	channeltypes "github.com/cosmos/ibc-go/v8/modules/core/04-channel/types"
+	host "github.com/cosmos/ibc-go/v8/modules/core/24-host"
 )
 
 var _ types.QueryServer = (*Keeper)(nil)
@@ -112,13 +114,25 @@ func (k Keeper) DenomHash(c context.Context, req *types.QueryDenomHashRequest) (
 }
 
 // EscrowAddress implements the EscrowAddress gRPC method
-func (Keeper) EscrowAddress(c context.Context, req *types.QueryEscrowAddressRequest) (*types.QueryEscrowAddressResponse, error) {
+func (k Keeper) EscrowAddress(c context.Context, req *types.QueryEscrowAddressRequest) (*types.QueryEscrowAddressResponse, error) {
 	if req == nil {
 		return nil, status.Error(codes.InvalidArgument, "empty request")
 	}
 
 	addr := types.GetEscrowAddress(req.PortId, req.ChannelId)
 
+	if err := validategRPCRequest(req.PortId, req.ChannelId); err != nil {
+		return nil, err
+	}
+
+	ctx := sdk.UnwrapSDKContext(c)
+	if !k.channelKeeper.HasChannel(ctx, req.PortId, req.ChannelId) {
+		return nil, status.Error(
+			codes.NotFound,
+			errorsmod.Wrapf(channeltypes.ErrChannelNotFound, "port ID (%s) channel ID (%s)", req.PortId, req.ChannelId).Error(),
+		)
+	}
+
 	return &types.QueryEscrowAddressResponse{
 		EscrowAddress: addr.String(),
 	}, nil
@@ -142,3 +156,15 @@ func (k Keeper) TotalEscrowForDenom(c context.Context, req *types.QueryTotalEscr
 		Amount: amount,
 	}, nil
 }
+
+func validategRPCRequest(portID, channelID string) error {
+	if err := host.PortIdentifierValidator(portID); err != nil {
+		return status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	if err := host.ChannelIdentifierValidator(channelID); err != nil {
+		return status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	return nil
+}

modules/apps/transfer/keeper/grpc_query_test.go

@@ -245,12 +245,44 @@ func (suite *KeeperTestSuite) TestEscrowAddress() {
 			},
 			true,
 		},
+		{
+			"failure - channel not found",
+			func() {
+				req = &types.QueryEscrowAddressRequest{
+					PortId:    ibctesting.InvalidID,
+					ChannelId: ibctesting.FirstChannelID,
+				}
+			},
+			false,
+		},
+		{
+			"failure - empty channelID",
+			func() {
+				req = &types.QueryEscrowAddressRequest{
+					PortId:    ibctesting.TransferPort,
+					ChannelId: "",
+				}
+			},
+			false,
+		},
+		{
+			"failure - empty portID",
+			func() {
+				req = &types.QueryEscrowAddressRequest{
+					PortId:    "",
+					ChannelId: ibctesting.FirstChannelID,
+				}
+			},
+			false,
+		},
 	}
 
 	for _, tc := range testCases {
 		tc := tc
 		suite.Run(fmt.Sprintf("Case %s", tc.msg), func() {
 			suite.SetupTest() // reset
+			path := ibctesting.NewTransferPath(suite.chainA, suite.chainB)
+			path.Setup()
 
 			tc.malleate()
 			ctx := suite.chainA.GetContext()

modules/apps/transfer/types/expected_keepers.go

@@ -39,6 +39,7 @@ type ChannelKeeper interface {
 	GetChannel(ctx sdk.Context, srcPort, srcChan string) (channel channeltypes.Channel, found bool)
 	GetNextSequenceSend(ctx sdk.Context, portID, channelID string) (uint64, bool)
 	GetAllChannelsWithPortPrefix(ctx sdk.Context, portPrefix string) []channeltypes.IdentifiedChannel
+	HasChannel(ctx sdk.Context, portID, channelID string) bool
 }
 
 // ClientKeeper defines the expected IBC client keeper