umts aka: add sqn_ms out-param, print SQN.MS in osmo-auc-gen

When doing UMTS AKA with AUTS, it can be interesting to know the SQN.MS that
was encoded in the AUTS. The only way to know this is to provide it as a
separate out-parameter from milenage_gen_vec_auts(), because the SQN.MS from
AUTS stored in umts.sqn is immediately modified non-trivially by
milenage_gen_vec(). Add sqn_ms to struct osmo_sub_auth_data to retain SQN.MS
even after a vector was generated.

Use this to print out SQN.MS for 'osmo-auc-gen -3 -A'.

Adjust test suite expectations.

Related: OS#2464
Change-Id: I9fc05bbf169d06716f40b995154fd42a3f91bef3

4 files changed, 14 insertions, 1 deletions

diff --git a/include/osmocom/crypt/auth.h b/include/osmocom/crypt/auth.h
index 059e734c..6d2c783d 100644
--- a/include/osmocom/crypt/auth.h
+++ b/include/osmocom/crypt/auth.h
@@ -39,6 +39,7 @@ struct osmo_sub_auth_data {
 			int opc_is_op;	/*!< is the OPC field OPC (0) or OP (1) ? */
 			unsigned int ind_bitlen; /*!< nr of bits not in SEQ, only SQN */
 			unsigned int ind; /*!< which IND slot to use an SQN from */
+			uint64_t sqn_ms; /*!< sqn from AUTS (output value only) */
 		} umts;
 		struct {
 			uint8_t ki[16];	/*!< secret key */
diff --git a/src/gsm/auth_milenage.c b/src/gsm/auth_milenage.c
index 6dd4f45a..e1a1dfba 100644
--- a/src/gsm/auth_milenage.c
+++ b/src/gsm/auth_milenage.c
@@ -158,9 +158,10 @@ static int milenage_gen_vec_auts(struct osmo_auth_vector *vec,
 	if (rc < 0)
 		return rc;
 
+	aud->u.umts.sqn_ms = osmo_load64be_ext(sqn_out, 6) >> 16;
 	/* Update our "largest used SQN" from the USIM -- milenage_gen_vec()
 	 * below will increment SQN. */
-	aud->u.umts.sqn = osmo_load64be_ext(sqn_out, 6) >> 16;
+	aud->u.umts.sqn = aud->u.umts.sqn_ms;
 
 	return milenage_gen_vec(vec, aud, _rand);
 }
diff --git a/tests/osmo-auc-gen/osmo-auc-gen_test.ok b/tests/osmo-auc-gen/osmo-auc-gen_test.ok
index 82923f10..2840783a 100644
--- a/tests/osmo-auc-gen/osmo-auc-gen_test.ok
+++ b/tests/osmo-auc-gen/osmo-auc-gen_test.ok
@@ -103,6 +103,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	32
 IND:	0
+SQN.MS:	23
 
 
 > osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind 5
@@ -118,6 +119,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	37
 IND:	5
+SQN.MS:	23
 
 
 > osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind 23
@@ -133,6 +135,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	55
 IND:	23
+SQN.MS:	23
 
 
 > osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind 31
@@ -148,6 +151,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	63
 IND:	31
+SQN.MS:	23
 
 
 > osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 0
@@ -163,6 +167,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	24
 IND:	0
+SQN.MS:	23
 
 
 > osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 1
@@ -178,6 +183,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	24
 IND:	0
+SQN.MS:	23
 
 
 > osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 1 --ind 1
@@ -193,6 +199,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	25
 IND:	1
+SQN.MS:	23
 
 
 > osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 8
@@ -208,6 +215,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	256
 IND:	0
+SQN.MS:	23
 
 
 > osmo-auc-gen -3 -a milenage -r 39fa2f4e3d523d8619a73b4f65c3e14d -k EB215756028D60E3275E613320AEC880 -o FB2A3D1B360F599ABAB99DB8669F8308 -A 979498b1f72d3e28c59fa2e72f9c --ind-len 8 --ind 1
@@ -223,6 +231,7 @@ SRES:	9b36efdf
 Kc:	059a4f668f6fbe39
 SQN:	257
 IND:	1
+SQN.MS:	23
 
 
 expecting error:
diff --git a/utils/osmo-auc-gen.c b/utils/osmo-auc-gen.c
index d4ae1b9e..fee97678 100644
--- a/utils/osmo-auc-gen.c
+++ b/utils/osmo-auc-gen.c
@@ -317,6 +317,8 @@ int main(int argc, char **argv)
 		if (test_aud.type == OSMO_AUTH_TYPE_UMTS) {
 			printf("SQN:\t%" PRIu64 "\n", test_aud.u.umts.sqn);
 			printf("IND:\t%u\n", (unsigned int)(test_aud.u.umts.sqn & ind_mask));
+			if (auts_is_set)
+				printf("SQN.MS:\t%" PRIu64 "\n", test_aud.u.umts.sqn_ms);
 		}
 	}