Auth: Import milenage implementation from hostap (Jouni Malinen)

... and add integration into the osmo_auth core.

1 files changed, 110 insertions, 0 deletions

diff --git a/src/gsm/auth_milenage.c b/src/gsm/auth_milenage.c
new file mode 100644
index 00000000..2630350c
--- /dev/null
+++ b/src/gsm/auth_milenage.c
@@ -0,0 +1,110 @@
+/* GSM/GPRS/3G authentication core infrastructure */
+
+/* (C) 2011 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <osmocom/crypt/auth.h>
+#include "milenage/common.h"
+#include "milenage/milenage.h"
+
+static void sqn_u64_to_48bit(uint8_t *sqn, const uint64_t sqn64)
+{
+	sqn[5] = (sqn64 >>  0) & 0xff;
+	sqn[4] = (sqn64 >>  8) & 0xff;
+	sqn[3] = (sqn64 >> 16) & 0xff;
+	sqn[2] = (sqn64 >> 24) & 0xff;
+	sqn[1] = (sqn64 >> 32) & 0xff;
+	sqn[0] = (sqn64 >> 40) & 0xff;
+}
+
+static uint64_t sqn_48bit_to_u64(const uint8_t *sqn)
+{
+	uint64_t sqn64;
+
+	sqn64 = sqn[0];
+	sqn64 <<= 8;
+	sqn64 |= sqn[1];
+	sqn64 <<= 8;
+	sqn64 |= sqn[2];
+	sqn64 <<= 8;
+	sqn64 |= sqn[3];
+	sqn64 <<= 8;
+	sqn64 |= sqn[4];
+	sqn64 <<= 8;
+	sqn64 |= sqn[5];
+
+	return sqn64;
+}
+
+
+static int milenage_gen_vec(struct osmo_auth_vector *vec,
+			    struct osmo_sub_auth_data *aud,
+			    const uint8_t *_rand)
+{
+	size_t res_len = sizeof(vec->res);
+	uint8_t sqn[6];
+	int rc;
+
+	sqn_u64_to_48bit(sqn, aud->umts.sqn);
+	milenage_generate(aud->umts.opc, aud->umts.amf, aud->umts.k,
+			  sqn, _rand,
+			  vec->autn, vec->ik, vec->ck, vec->res, &res_len);
+	vec->res_len = res_len;
+	rc = gsm_milenage(aud->umts.opc, aud->umts.k, _rand, vec->sres, vec->kc);
+	if (rc < 0)
+		return rc;
+
+	vec->auth_types = OSMO_AUTH_TYPE_UMTS | OSMO_AUTH_TYPE_GSM;
+	memcpy(vec->rand, _rand, sizeof(vec->rand));
+	aud->umts.sqn++;
+
+	return 0;
+}
+
+static int milenage_gen_vec_auts(struct osmo_auth_vector *vec,
+				 struct osmo_sub_auth_data *aud,
+				 const uint8_t *auts, const uint8_t *rand_auts,
+				 const uint8_t *_rand)
+{
+	uint8_t sqn_out[6];
+	int rc;
+
+	rc = milenage_auts(aud->umts.opc, aud->umts.k,
+			   rand_auts, auts, sqn_out);
+	if (rc < 0)
+		return rc;
+
+	aud->umts.sqn = sqn_48bit_to_u64(sqn_out) + 1;
+
+	return milenage_gen_vec(vec, aud, _rand);
+}
+
+static struct osmo_auth_impl milenage_alg = {
+	.algo = OSMO_AUTH_ALG_MILENAGE,
+	.name = "MILENAGE (libosmogsm built-in)",
+	.priority = 1000,
+	.gen_vec = &milenage_gen_vec,
+	.gen_vec_auts = &milenage_gen_vec_auts,
+};
+
+static __attribute__((constructor)) void on_dso_load_milenage(void)
+{
+	osmo_auth_register(&milenage_alg);
+}