feat(x/tx): support bytes field as signer (port: #21850) (#24503)

Co-authored-by: yihuang <huang@crypto.com>
Co-authored-by: Alex | Interchain Labs <alex@interchainlabs.io>

x/tx/CHANGELOG.md

@@ -33,6 +33,10 @@ Since v0.13.0, x/tx follows Cosmos SDK semver: https://github.com/cosmos/cosmos-
 
 ## [Unreleased]
 
+### Improvements
+
+* [#21850](https://github.com/cosmos/cosmos-sdk/pull/21850) Support bytes field as signer.
+
 ## [v0.14.0](https://github.com/cosmos/cosmos-sdk/releases/tag/x/tx/v0.14.0) - 2025-04-24
 
 * SDK v0.53.x support.

x/tx/internal/testpb/signers.proto

@@ -92,7 +92,7 @@ message DeeplyNestedRepeatedSigner {
 
 message BadSigner {
   option (cosmos.msg.v1.signer) = "signer";
-  bytes signer                  = 1;
+  int32 signer                  = 1;
 }
 
 message NoSignerOption {
@@ -104,7 +104,22 @@ message ValidatorSigner {
   string signer                 = 1 [(cosmos_proto.scalar) = "cosmos.ValidatorAddressString"];
 }
 
+message ValidatorSigners {
+  option (cosmos.msg.v1.signer) = "signers";
+  repeated string signers       = 1 [(cosmos_proto.scalar) = "cosmos.ValidatorAddressString"];
+}
+
+message ValidatorByteSigner {
+  option (cosmos.msg.v1.signer) = "signer";
+  bytes signer                  = 1;
+}
+
+message ValidatorByteSigners {
+  option (cosmos.msg.v1.signer) = "signers";
+  repeated bytes signers        = 1 [(cosmos_proto.scalar) = "cosmos.ValidatorAddressString"];
+}
+
 service TestSimpleSigner {
   option (cosmos.msg.v1.service) = true;
   rpc TestSimpleSigner(SimpleSigner) returns (SimpleSigner) {}
-}
+}

x/tx/signing/context.go

@@ -301,6 +301,23 @@ func (c *Context) makeGetSignersFunc(descriptor protoreflect.MessageDescriptor)
 				}
 				return arr, nil
 			}
+		case protoreflect.BytesKind:
+			if field.IsList() {
+				fieldGetters[i] = func(msg proto.Message, arr [][]byte) ([][]byte, error) {
+					list := msg.ProtoReflect().Get(field).List()
+					n := list.Len()
+					for i := 0; i < n; i++ {
+						addrBz := list.Get(i).Bytes()
+						arr = append(arr, addrBz)
+					}
+					return arr, nil
+				}
+			} else {
+				fieldGetters[i] = func(msg proto.Message, arr [][]byte) ([][]byte, error) {
+					addrBz := msg.ProtoReflect().Get(field).Bytes()
+					return append(arr, addrBz), nil
+				}
+			}
 		default:
 			return nil, fmt.Errorf("unexpected field type %s for field %s in message %s", field.Kind(), fieldName, descriptor.FullName())
 		}

x/tx/signing/context_test.go

@@ -199,6 +199,27 @@ func TestGetSigners(t *testing.T) {
 			},
 			want: [][]byte{[]byte("foo")},
 		},
+		{
+			name: "validator signers",
+			msg: &testpb.ValidatorSigners{
+				Signers: []string{"val" + hex.EncodeToString([]byte("foo"))},
+			},
+			want: [][]byte{[]byte("foo")},
+		},
+		{
+			name: "validator bytes signer",
+			msg: &testpb.ValidatorByteSigner{
+				Signer: []byte("foo"),
+			},
+			want: [][]byte{[]byte("foo")},
+		},
+		{
+			name: "validator bytes signers",
+			msg: &testpb.ValidatorByteSigners{
+				Signers: [][]byte{[]byte("foo")},
+			},
+			want: [][]byte{[]byte("foo")},
+		},
 	}
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {