gravitational/teleport · error

proto: wrong wireType =

Error message

proto: wrong wireType = %d for field DeviceUsage

What it means

Thrown by the gogoproto-generated Unmarshal for a message with a DeviceUsage field (field number 3), declared as a varint enum. The decoder expects wire type 0 for this field; any other wire type on the wire is rejected with this error. It indicates the serialized bytes do not match the compiled schema.

Solutions

  1. Use matching Teleport versions on both ends of the RPC (upgrade the older side).
  2. Regenerate api/client/proto bindings from the current .proto.
  3. Discard/re-serialize corrupted data produced under the old schema.
  4. Verify the sender marshals DeviceUsage as an enum varint, not a string.

Example fix

// before: mismatched api module (old plugin)
require github.com/gravitational/teleport/api v0.0.0-old
// after: pin api to the version matching the auth server
require github.com/gravitational/teleport/api vX.Y.Z // same major/minor as server
Defensive patterns

Strategy: try-catch

Validate before calling

// Verify sender/receiver schema agreement before decode:
// marshal an empty message and compare field tags if unsure
probe, _ := proto.Marshal(&proto.DeviceUsageProbe{})
if len(probe) == 0 { /* schema absent in this build */ }

Type guard

func isProtoWireErr(err error) bool {
  var uwn gogoproto.Error // or check message text
  return err != nil && strings.Contains(err.Error(), "wrong wireType")
}

Try / catch

if err := proto.Unmarshal(data, &m); err != nil {
  if strings.Contains(err.Error(), "field DeviceUsage") {
    log.Warn("DeviceUsage wire mismatch; upgrading client recommended")
  }
  return err
}

Prevention

When it happens

Trigger: Decoding a device-related Auth Service message whose field 3 was encoded with wire type != 0 — e.g. a peer built from a .proto where DeviceUsage is a string or embedded message.

Common situations: Teleport version skew during rolling upgrades, forgetting to `make proto` after schema changes, plugins/terraform provider pinned to an older api release, or corrupt cached payloads.

Related errors

AI-assisted analysis of gravitational/teleport@1283425b60 (2026-09-02). Data as JSON: /api/errors/64e8ad2ad271fc18. Report an issue: GitHub.

Appendix: source

Thrown at api/client/proto/authservice.pb.go:60564

			}
			m.DeviceType = 0
			for shift := uint(0); ; shift += 7 {
				if shift >= 64 {
					return ErrIntOverflowAuthservice
				}
				if iNdEx >= l {
					return io.ErrUnexpectedEOF
				}
				b := dAtA[iNdEx]
				iNdEx++
				m.DeviceType |= DeviceType(b&0x7F) << shift
				if b < 0x80 {
					break
				}
			}
		case 3:
			if wireType != 0 {
				return fmt.Errorf("proto: wrong wireType = %d for field DeviceUsage", wireType)
			}
			m.DeviceUsage = 0
			for shift := uint(0); ; shift += 7 {
				if shift >= 64 {
					return ErrIntOverflowAuthservice
				}
				if iNdEx >= l {
					return io.ErrUnexpectedEOF
				}
				b := dAtA[iNdEx]
				iNdEx++
				m.DeviceUsage |= DeviceUsage(b&0x7F) << shift
				if b < 0x80 {
					break
				}
			}
		case 4:
			if wireType != 2 {

View on GitHub (pinned to 1283425b60)