baseapp, client: reject gRPC connections with out-of-range/nefarious x-cosmos-block-height values (#7663)

* baseapp, client: reject gRPC connections with out-of-range/nefarious x-cosmos-block-height values

Rejects gRPC connections that send out-of-range x-cosmos-block-height
values that previously weren't checked for. We now reject any negative
values and any value greater than max(int64) aka >9223372036854775807.

Also added an enforcement for returning an error if any negative heights
are passed into (*BaseApp).createQueryContext.

Fixes #7662

* baseapp, client: reject gRPC connections with out-of-range/nefarious x-cosmos-block-height values

Rejects gRPC connections that send out-of-range x-cosmos-block-height
values that previously weren't checked for. We now reject any negative
values and any value greater than max(int64) aka >9223372036854775807.

Also added an enforcement for returning an error if any negative heights
are passed into (*BaseApp).createQueryContext.

Fixes #7662

* Address Robert's feedback to extract negative height checker

* Fix tests

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

server/grpc/server_test.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/metadata"
@@ -48,6 +49,7 @@ func (s *IntegrationTestSuite) TestGRPCServer() {
 		grpc.WithInsecure(), // Or else we get "no transport security set"
 	)
 	s.Require().NoError(err)
+	defer conn.Close()
 
 	// gRPC query to test service should work
 	testClient := testdata.NewQueryClient(conn)
@@ -99,6 +101,42 @@ func (s *IntegrationTestSuite) TestGRPCServer() {
 	s.Require().True(servicesMap["cosmos.bank.v1beta1.Query"])
 }
 
+// Test and enforce that we upfront reject any connections to baseapp containing
+// invalid initial x-cosmos-block-height that aren't positive  and in the range [0, max(int64)]
+// See issue https://github.com/cosmos/cosmos-sdk/issues/7662.
+func (s *IntegrationTestSuite) TestGRPCServerInvalidHeaderHeights() {
+	t := s.T()
+	val0 := s.network.Validators[0]
+
+	// We should reject connections with invalid block heights off the bat.
+	invalidHeightStrs := []struct {
+		value   string
+		wantErr string
+	}{
+		{"-1", "height < 0"},
+		{"9223372036854775808", "value out of range"}, // > max(int64) by 1
+		{"-10", "height < 0"},
+		{"18446744073709551615", "value out of range"}, // max uint64, which is  > max(int64)
+		{"-9223372036854775809", "value out of range"}, // Out of the range of for negative int64
+	}
+	for _, tt := range invalidHeightStrs {
+		t.Run(tt.value, func(t *testing.T) {
+			conn, err := grpc.Dial(
+				val0.AppConfig.GRPC.Address,
+				grpc.WithInsecure(), // Or else we get "no transport security set"
+			)
+			defer conn.Close()
+
+			testClient := testdata.NewQueryClient(conn)
+			ctx := metadata.AppendToOutgoingContext(context.Background(), grpctypes.GRPCBlockHeightHeader, tt.value)
+			testRes, err := testClient.Echo(ctx, &testdata.EchoRequest{Message: "hello"})
+			require.Error(t, err)
+			require.Nil(t, testRes)
+			require.Contains(t, err.Error(), tt.wantErr)
+		})
+	}
+}
+
 func TestIntegrationTestSuite(t *testing.T) {
 	suite.Run(t, new(IntegrationTestSuite))
 }