bsc: add TC_ciph_mode_a5_4

Establish a Signalling channel with A5/4 encryption.

Related: SYS#5324
Change-Id: I2428c21663dfa7d67e769da0127f74e8c01dfb97
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index a2a7804..4ae90bb 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -3326,7 +3326,18 @@
 	vc_conn.done;
 	f_shutdown_helper();
 }
+/* Establish a Signalling channel with A5/4 encryption. */
+testcase TC_ciph_mode_a5_4() runs on test_CT {
+	var MSC_ConnHdlr vc_conn;
+	var TestHdlrParams pars := f_gen_test_hdlr_pars();
+	pars.encr := valueof(t_EncrParams('10'O, f_rnd_octstring(8), f_rnd_octstring(16)));
 
+	f_init(1, true);
+	f_sleep(1.0);
+	vc_conn := f_start_handler(refers(f_tc_ciph_mode_a5), pars);
+	vc_conn.done;
+	f_shutdown_helper();
+}
 /* establish initial channel, enable ciphering followed by assignment to ciphered channel */
 private function f_tc_assignment_aoip_tla_v6(charstring id) runs on MSC_ConnHdlr {
 	var template PDU_BSSAP exp_compl := f_gen_exp_compl();
@@ -8923,6 +8934,7 @@
 	execute( TC_ciph_mode_a5_0() );
 	execute( TC_ciph_mode_a5_1() );
 	execute( TC_ciph_mode_a5_3() );
+	execute( TC_ciph_mode_a5_4() );
 
 	execute( TC_assignment_codec_fr() );
 	execute( TC_assignment_codec_fr_by_mode_modify() );