BSC_Tests: Implement ecnryption related procedures

Let's verify the operation of the CIPHERING MODE COMMAND as issued
by MSC, performed by BSC and implemented by simulated BTS/MS.

Change-Id: Ibc06bd2177c63837a794a0ca1f54ebef17499e78

2 files changed, 35 insertions, 11 deletions

diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index d1f5c3d7..160d662b 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -1212,9 +1212,9 @@ private function f_tc_assignment_fr_a5_0(charstring id) runs on MSC_ConnHdlr {
 
 	ass_cmd.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
 	ass_cmd.pdu.bssmap.assignmentRequest.codecList := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
-	ass_cmd.pdu.bssmap.assignmentRequest.encryptionInformation :=
-							valueof(ts_BSSMAP_IE_EncrInfo(kc, '01'O));
+
 	f_establish_fully(pars, ass_cmd, exp_compl);
+	f_cipher_mode('01'O, kc);
 }
 
 testcase TC_assignment_fr_a5_0() runs on test_CT {
@@ -1239,10 +1239,9 @@ private function f_tc_assignment_fr_a5_1(charstring id) runs on MSC_ConnHdlr {
 
 	ass_cmd.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
 	ass_cmd.pdu.bssmap.assignmentRequest.codecList := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
-	ass_cmd.pdu.bssmap.assignmentRequest.encryptionInformation :=
-							valueof(ts_BSSMAP_IE_EncrInfo(kc, '02'O));
 
 	f_establish_fully(pars, ass_cmd, exp_compl);
+	f_cipher_mode('02'O, kc);
 }
 
 testcase TC_assignment_fr_a5_1() runs on test_CT {
@@ -1264,8 +1263,6 @@ private function f_tc_assignment_fr_a5_1_codec_missing(charstring id) runs on MS
 	const OCT8 kc := '0001020304050607'O;
 
 	ass_cmd.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
-	ass_cmd.pdu.bssmap.assignmentRequest.encryptionInformation :=
-							valueof(ts_BSSMAP_IE_EncrInfo(kc, '02'O));
 	f_establish_fully(pars, ass_cmd, exp_fail);
 }
 
@@ -1289,9 +1286,9 @@ private function f_tc_assignment_fr_a5_3(charstring id ) runs on MSC_ConnHdlr {
 
 	ass_cmd.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
 	ass_cmd.pdu.bssmap.assignmentRequest.codecList := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
-	ass_cmd.pdu.bssmap.assignmentRequest.encryptionInformation :=
-							valueof(ts_BSSMAP_IE_EncrInfo(kc, '08'O));
+
 	f_establish_fully(pars, ass_cmd, exp_compl);
+	f_cipher_mode('08'O, kc);
 }
 
 testcase TC_assignment_fr_a5_3() runs on test_CT {
@@ -1315,11 +1312,9 @@ private function f_tc_assignment_fr_a5_4(charstring id) runs on MSC_ConnHdlr {
 
 	ass_cmd.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
 	ass_cmd.pdu.bssmap.assignmentRequest.codecList := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
-	ass_cmd.pdu.bssmap.assignmentRequest.encryptionInformation :=
-							valueof(ts_BSSMAP_IE_EncrInfo(kc, '10'O));
-	ass_cmd.pdu.bssmap.assignmentRequest.kC128 := valueof(ts_BSSMAP_IE_Kc128(kc128));
 	/* TODO: expect GSM0808_CAUSE_CIPHERING_ALGORITHM_NOT_SUPPORTED cause value */
 	f_establish_fully(pars, ass_cmd, exp_fail);
+	f_cipher_mode('10'O, kc, kc128);
 }
 
 testcase TC_assignment_fr_a5_4() runs on test_CT {
diff --git a/bsc/MSC_ConnectionHandler.ttcn b/bsc/MSC_ConnectionHandler.ttcn
index d6154976..a76d1d68 100644
--- a/bsc/MSC_ConnectionHandler.ttcn
+++ b/bsc/MSC_ConnectionHandler.ttcn
@@ -99,6 +99,35 @@ function f_rsl_reply(template PDU_ML3_MS_NW l3, RSL_Message orig) runs on MSC_Co
 	RSL.send(ts_RSL_DATA_IND(chan_nr, link_id, enc_PDU_ML3_MS_NW(valueof(l3))));
 }
 
+function f_cipher_mode(OCT1 alg, OCT8 key, template OCT16 kc128 := omit) runs on MSC_ConnHdlr {
+	var PDU_BSSAP bssap;
+	var RSL_Message rsl;
+
+	if (isvalue(kc128)) {
+		BSSAP.send(ts_BSSMAP_CipherModeCmdKc128(alg, key, valueof(kc128)));
+	} else {
+		BSSAP.send(ts_BSSMAP_CipherModeCmd(alg, key));
+	}
+	alt {
+	/* RSL/UE Side */
+	[] RSL.receive(tr_RSL_ENCR_CMD(g_chan_nr, ?, alg, key)) -> value rsl {
+		var PDU_ML3_NW_MS l3 := dec_PDU_ML3_NW_MS(rsl.ies[3].body.l3_info.payload);
+		log("Rx L3 from net: ", l3);
+		if (ischosen(l3.msgs.rrm.cipheringModeCommand)) {
+			f_rsl_reply(ts_RRM_CiphModeCompl, rsl);
+		}
+		repeat;
+		}
+	[] BSSAP.receive(tr_BSSMAP_CipherModeCompl) -> value bssap {
+		// bssap.bssmap.cipherModeComplete.chosenEncryptionAlgorithm.algoritmhIdentifier
+		setverdict(pass);
+		}
+	[] BSSAP.receive(tr_BSSMAP_CipherModeRej) -> value bssap {
+		setverdict(fail, "Ciphering Mode Reject");
+		}
+	}
+}
+
 /* establish a channel fully, expecting an assignment matching 'exp' */
 function f_establish_fully(TestHdlrParams pars, PDU_BSSAP ass_cmd, template PDU_BSSAP exp_ass_cpl)
 runs on MSC_ConnHdlr return PDU_BSSAP {