Method for setting up a secure connection between LWM2M devices

A client device for setting up a connection with a server device, the client device and the server device supporting a Light Weight Machine to Machine, LWM2M protocol, the client device is configured to:

• set up a Datagram Transport Layer Security, DTLS, or Transport Layer Security, TLS, connection with a bootstrap server,
• perform a bootstrapping procedure with the bootstrap server, comprising generating a temporary identity of the client device, and indicating, during the bootstrapping procedure, that the bootstrap server is to set up the DTLS or TLS connection to the server device on behalf of the client device, wherein the indicating comprises delegating the generated temporary identity of the client device to the bootstrap server,
• receive, from the bootstrap server, a session ticket and a session key, and
• set up the connection to the server device as a DTLS or TLS session resumption procedure using the received session ticket and session key.

A method performed in a bootstrap server for enabling setting up of a connection between a client device and a server device, the client device and the server device supporting a Light Weight Machine to Machine, LWM2M protocol, the method comprising:

• setting up a Datagram Transport Layer Security, DTLS, connection or Transport Layer Security, TLS with the client device,
• performing a bootstrapping procedure with the client device, comprising receiving, during the bootstrapping procedure, an indication that the bootstrap server is to set up the DTLS or TLS connection to the server device on behalf of the client device,
• setting up a DTLS or TLS connection to the server device using an identity of the client device, wherein the identity of the client device comprises a temporary identity usable only for delegation and acquiring a DTLS or TLS session resumption ticket,
• indicating, to the server device desire to use a DTLS or TLS session resumption, and receiving a session ticket in response, and
• sending, to the client device the session ticket and a session key, enabling the client device to set up the connection to the server device as a DTLS or TLS session resumption.

A bootstrap server for enabling setting up of a connection between a client device and a server device, the client device and the server device supporting a Light Weight Machine to Machine, LWM2M protocol, the bootstrap server being configured to:

• set up a Datagram Transport Layer Security, DTLS, connection or Transport Layer Security, TLS with the client device,
• perform a bootstrapping procedure with the client device, comprising receiving, during the bootstrapping procedure, an indication that the bootstrap server is to set up the DTLS or TLS connection to the server device on behalf of the client device,
• set up a DTLS or TLS connection to the server using an identity of the client device, wherein the identity of the client device comprises a temporary identity usable only for delegation and acquiring a DTLS or TLS session resumption ticket,
• indicate, to the server device desire to use a DTLS or TLS session resumption, and receiving a session ticket in response, and
• send, to the client device the session ticket and a session key, enabling the client device to set up the connection to the server device as a DTLS or TLS session resumption.