Section: 13.1 Protection at the network or transport layer 13.1.0 General
Content: All network functions shall support mutually authenticated TLS and HTTPS as specified in RFC 7540 [47] and RFC 2818 [90]. The identities in the end entity certificates shall be used for authentication and policy checks. Network functions shall support both server-side and client-side certificates. TLS client and server certificates shall be compliant with the SBA certificate profile specified in clause 6.1.3c of TS 33.310[ Network Domain Security (NDS); Authentication Framework (AF) ]  [5]. The TLS profile shall follow the profile given in clause 6.2 of TS 33.210[ Network Domain Security (NDS); IP network layer security ]  [3] with the restriction that it shall be compliant with the profile given by HTTP/2 as defined in RFC 7540 [47]. TLS clients shall include the SNI extension as specified in RFC 7540 [47]. TLS shall be used for transport protection within a PLMN unless network security is provided by other means. NOTE 1: Regardless of whether TLS is used or not, NDS/IP as specified in TS 33.210[ Network Domain Security (NDS); IP network layer security ]  [3] and TS 33.310[ Network Domain Security (NDS); Authentication Framework (AF) ]  [5] can be used for network layer protection. NOTE 2: If interfaces are trusted (e.g. physically protected), it is for the PLMN-operator to decide whether to use cryptographic protection. NOTE 3: It is a vendor implementation decision how the SNI extension is being used in TLS servers.