Cloud platform authentication method, client, middleware and system

The embodiment of the invention provides a cloud platform authentication method, a client, middleware and a system. The cloud platform authentication method comprises the following steps: acquiring configuration information of a token, wherein the configuration information comprises token generation information and expiration time of the token; and sending a token authentication request to authentication middleware, wherein the authentication request carries the configuration information and the authentication-free identifier, so that the authentication middleware judges whether the token is legal or not according to the token generation information and the expiration time after judging and knowing that the authentication request is not authenticated for the first time according to the authentication-free identifier. According to the embodiment of the invention, the authentication middleware can directly authenticate the token which is not authenticated for the first time according tothe authentication-free i