)

const (
	// unixProtocol is the only supported protocol for remote KMS provider.
	unixProtocol = "unix"
	// Current version for the protocol interface definition.
	kmsapiVersion = "v1beta1"

	versionErrorf = "KMS provider api version %s is not supported, only %s is supported now"
)

// The gRPC implementation for envelope.Service.
type gRPCService struct {
	kmsClient      kmsapi.KeyManagementServiceClient

// which are used to report a version error if allowVersion returns false.
func (check *Checker) verifyVersionf(at poser, v goVersion, format string, args ...interface{}) bool {
	if !check.allowVersion(at, v) {
		check.versionErrorf(at, v, format, args...)
		return false
	}
	return true

// current package.
func (check *Checker) verifyVersionf(at positioner, v goVersion, format string, args ...interface{}) bool {
	if !check.allowVersion(at, v) {
		check.versionErrorf(at, v, format, args...)
		return false
	}
	return true
}

// TODO(gri) Consider a more direct (position-independent) mechanism
//           to identify which file we're in so that version checks

		var reverse bool
		if T != nil && sig.tparams != nil {
			if !versionErr && !check.allowVersion(instErrPos, go1_21) {
				if inst != nil {
					check.versionErrorf(instErrPos, go1_21, "partially instantiated function in assignment")
				} else {
					check.versionErrorf(instErrPos, go1_21, "implicitly instantiated function in assignment")
				}
			}
			gsig := NewSignatureType(nil, nil, nil, sig.params, sig.results, sig.variadic)

func (check *Checker) softErrorf(at poser, code Code, format string, args ...any) {
	err := check.newError(code)
	err.addf(at, format, args...)
	err.soft = true
	err.report()
}

func (check *Checker) versionErrorf(at poser, v goVersion, format string, args ...any) {
	msg := check.sprintf(format, args...)
	err := check.newError(UnsupportedFeature)
	err.addf(at, "%s requires %s or later", msg, v)
	err.report()
}

		var reverse bool
		if T != nil && sig.tparams != nil {
			if !versionErr && !check.allowVersion(instErrPos, go1_21) {
				if ix != nil {
					check.versionErrorf(instErrPos, go1_21, "partially instantiated function in assignment")
				} else {
					check.versionErrorf(instErrPos, go1_21, "implicitly instantiated function in assignment")
				}
			}
			gsig := NewSignatureType(nil, nil, nil, sig.params, sig.results, sig.variadic)

	if encryptErr != nil {
		t.Error(encryptErr)
	}
}

func TestUnsupportedVersion(t *testing.T) {
	t.Parallel()
	ver := "invalid"
	data := []byte("test data")
	wantErr := fmt.Errorf(versionErrorf, ver, kmsapiVersion)
	endpoint := newEndpoint()

	f := mock.NewBase64Plugin(t, endpoint.path)
	f.SetVersion(ver)

	ctx := testContext(t)

	s, err := NewGRPCService(ctx, endpoint.endpoint, 1*time.Second)

func (check *Checker) softErrorf(at positioner, code Code, format string, args ...any) {
	err := check.newError(code)
	err.addf(at, format, args...)
	err.soft = true
	err.report()
}

func (check *Checker) versionErrorf(at positioner, v goVersion, format string, args ...any) {
	msg := check.sprintf(format, args...)
	err := check.newError(UnsupportedFeature)
	err.addf(at, "%s requires %s or later", msg, v)
	err.report()
}

			if Identical(s.Elem(), a.Elem()) {
				if check == nil || check.allowVersion(x, go1_20) {
					return true
				}
				// check != nil
				if cause != nil {
					// TODO(gri) consider restructuring versionErrorf so we can use it here and below
					*cause = "conversion of slice to array requires go1.20 or later"
				}
				return false
			}
		case *Pointer:
			if a, _ := under(a.Elem()).(*Array); a != nil {

			if Identical(s.Elem(), a.Elem()) {
				if check == nil || check.allowVersion(x, go1_20) {
					return true
				}
				// check != nil
				if cause != nil {
					// TODO(gri) consider restructuring versionErrorf so we can use it here and below
					*cause = "conversion of slice to array requires go1.20 or later"
				}
				return false
			}
		case *Pointer:
			if a, _ := under(a.Elem()).(*Array); a != nil {