type UserConversion interface {
	User(chain []*x509.Certificate) (*authenticator.Response, bool, error)
}

// UserConversionFunc is a function that implements the UserConversion interface.
type UserConversionFunc func(chain []*x509.Certificate) (*authenticator.Response, bool, error)

// User implements x509.UserConversion
func (f UserConversionFunc) User(chain []*x509.Certificate) (*authenticator.Response, bool, error) {
	return f(chain)
}

			Certs: getCerts(t, clientCNCert),
			User: UserConversionFunc(func(chain []*x509.Certificate) (*authenticator.Response, bool, error) {
				return nil, false, errors.New("custom error")
			}),

			ExpectOK:  false,
			ExpectErr: true,
		},
		"custom conversion success": {
			Opts:  getDefaultVerifyOptions(t),
			Certs: getCerts(t, clientCNCert),