bsc: add TC_ho_into_this_bsc_a5_1_3_no_chosen_enc_alg

Report: in inter-BSC incoming handover, when the MSC omits the Chosen
Encryption Algorithm IE in the Handover Request message, then osmo-bsc
starts an unencrypted lchan even if A5/0 is not permitted.

This test verifies that the Encryption Information is present in the
Channel Activation when the Chosen Enc Alg is omitted.

Related: SYS#5839
Change-Id: Ia94cc29bf66339ed782cb5101f3640f69cf73131
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 69e187c..44916c4 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -6131,6 +6131,22 @@
 	f_tc_ho_into_this_bsc_a5(f_encr_params('10'O));
 }
 
+/* Report: in inter-BSC incoming handover, when the MSC omits the Chosen Encryption Algorithm IE in the Handover Request
+ * message, then osmo-bsc starts an unencrypted lchan even if A5/0 is not permitted.
+ *
+ * This test verifies that the Encryption Information is present in the Channel Activation when the Chosen Enc Alg is
+ * omitted.
+ *
+ * Related: SYS#5839
+ */
+testcase TC_ho_into_this_bsc_a5_1_3_no_chosen_enc_alg() runs on test_CT {
+	f_tc_ho_into_this_bsc_a5(f_encr_params(alg_permitted := '0a'O, alg_expect := '08'O, alg_chosen := omit));
+}
+
+testcase TC_ho_into_this_bsc_a5_1_3() runs on test_CT {
+	f_tc_ho_into_this_bsc_a5(f_encr_params(alg_permitted := '0a'O, alg_expect := '08'O));
+}
+
 testcase TC_ho_into_this_bsc_tla_v6() runs on test_CT {
 	var TestHdlrParams pars := f_gen_test_hdlr_pars();
 	pars.host_aoip_tla := "::6";