nas: add comment as to why attach request is only integrity protected

5 years ago · 4f8f6bf90c
parent 84d80f3e32
commit 4f8f6bf90c
1 changed files with 2 additions and 0 deletions
--- a/srsue/src/stack/upper/nas.cc
+++ b/srsue/src/stack/upper/nas.cc
@ -1762,6 +1762,8 @@ void nas::gen_attach_request(srslte::unique_byte_buffer_t& msg)
                  ctxt.guti.mnc,
                  ctxt.guti.mme_group_id,
                  ctxt.guti.mme_code);
+
+    // According to Sec 4.4.5, the attach request is always unciphered, even if a context exists
    liblte_mme_pack_attach_request_msg(
        &attach_req, LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT*)msg.get());