TTCN-3 native function wrapper for SNOW-3G
Change-Id: I7fca69ea8b4aed48d5a64885b762ab85be71ef03
diff --git a/mme/key_derivation.c b/mme/key_derivation.c
new file mode 100644
index 0000000..36e4c91
--- /dev/null
+++ b/mme/key_derivation.c
@@ -0,0 +1,82 @@
+#include <stdint.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <gnutls/crypto.h>
+
+/* From nextepc/src/mme/mme-kdf.c under AGPLv3+ */
+
+void mme_kdf_nas(uint8_t algorithm_type_distinguishers,
+ uint8_t algorithm_identity, const uint8_t *kasme, uint8_t *knas)
+{
+ uint8_t s[7];
+ uint8_t out[32];
+
+ s[0] = 0x15; /* FC Value */
+
+ s[1] = algorithm_type_distinguishers;
+ s[2] = 0x00;
+ s[3] = 0x01;
+
+ s[4] = algorithm_identity;
+ s[5] = 0x00;
+ s[6] = 0x01;
+
+ gnutls_hmac_fast(GNUTLS_MAC_SHA256, kasme, 32, s, 7, out);
+ memcpy(knas, out+16, 16);
+}
+
+void mme_kdf_enb(const uint8_t *kasme, uint32_t ul_count, uint8_t *kenb)
+{
+ uint8_t s[7];
+
+ s[0] = 0x11; /* FC Value */
+
+ ul_count = htonl(ul_count);
+ memcpy(s+1, &ul_count, 4);
+
+ s[5] = 0x00;
+ s[6] = 0x04;
+
+ gnutls_hmac_fast(GNUTLS_MAC_SHA256, kasme, 32, s, 7, kenb);
+}
+
+void mme_kdf_nh(const uint8_t *kasme, const uint8_t *sync_input, uint8_t *kenb)
+{
+ uint8_t s[35];
+
+ s[0] = 0x12; /* FC Value */
+
+ memcpy(s+1, sync_input, 32);
+
+ s[33] = 0x00;
+ s[34] = 0x20;
+
+ gnutls_hmac_fast(GNUTLS_MAC_SHA256, kasme, 32, s, 35, kenb);
+}
+
+/* From nextepc/src/hss/hss-auc.c under AGPLv3+ */
+
+#define FC_VALUE 0x10
+
+void hss_auc_kasme(const uint8_t *ck, const uint8_t *ik, const uint8_t plmn_id[3],
+ const uint8_t *sqn, const uint8_t *ak, uint8_t *kasme)
+{
+ uint8_t s[14];
+ uint8_t k[32];
+ int i;
+
+ memcpy(&k[0], ck, 16);
+ memcpy(&k[16], ik, 16);
+
+ s[0] = FC_VALUE;
+ memcpy(&s[1], plmn_id, 3);
+ s[4] = 0x00;
+ s[5] = 0x03;
+
+ for (i = 0; i < 6; i++)
+ s[6+i] = sqn[i] ^ ak[i];
+ s[12] = 0x00;
+ s[13] = 0x06;
+
+ gnutls_hmac_fast(GNUTLS_MAC_SHA256, k, 32, s, 14, kasme);
+}