B.2 Introduction

24.1093GPPBootstrapping interface (Ub) and network application function interface (Ua)Protocol detailsRelease 17TS

B.2.1 General

A bootstrapping session established using a bootstrapping procedure (cf. clause 4 and annex A) is used between a UE and a NAF. The BSF provides to the NAF a NAF specific key material (Ks_NAF or Ks_ext_NAF and optionally Ks_int_NAF) which is derived from the key material (Ks). The NAF uses this key to authenticate and optionally secure (i.e. integrity protect and encrypt) the communications between it and the UE. The BSF will also provide the NAF the expiration time of the bootstrapping session. When the bootstrapping session becomes invalid the NAF will stop using the session, and indicate to the UE that bootstrapping session has expired and that new session needs to be established.

An example of the signalling flows of the authentication procedure using HTTP Digest authentication as specified in RFC 7616 [36] is given in clause B.3.

B.2.2 Key required to interpret signalling flows

The key to interpret signalling flows is specified in clause A.2.2.