milenage: Add function to compute OPC from OP and K
diff --git a/src/gsm/milenage/milenage.c b/src/gsm/milenage/milenage.c
index cc4e95c..b43f986 100644
--- a/src/gsm/milenage/milenage.c
+++ b/src/gsm/milenage/milenage.c
@@ -327,3 +327,18 @@
return 0;
}
+
+int milenage_opc_gen(u8 *opc, const u8 *k, const u8 *op)
+{
+ int i;
+
+ /* Encrypt OP using K */
+ if (aes_128_encrypt_block(k, op, opc))
+ return -1;
+
+ /* XOR the resulting Ek(OP) with OP */
+ for (i = 0; i < 16; i++)
+ opc[i] = opc[i] ^ op[i];
+
+ return 0;
+}
diff --git a/src/gsm/milenage/milenage.h b/src/gsm/milenage/milenage.h
index d5054d6..a91e946 100644
--- a/src/gsm/milenage/milenage.h
+++ b/src/gsm/milenage/milenage.h
@@ -30,4 +30,6 @@
int milenage_f2345(const u8 *opc, const u8 *k, const u8 *_rand,
u8 *res, u8 *ck, u8 *ik, u8 *ak, u8 *akstar);
+int milenage_opc_gen(u8 *opc, const u8 *k, const u8 *op);
+
#endif /* MILENAGE_H */
diff --git a/tests/auth/milenage_test.c b/tests/auth/milenage_test.c
index da7c800..7c996f0 100644
--- a/tests/auth/milenage_test.c
+++ b/tests/auth/milenage_test.c
@@ -37,6 +37,24 @@
},
};
+static int opc_test(const struct osmo_sub_auth_data *aud)
+{
+ int rc;
+ uint8_t opc[16];
+#if 0
+ const uint8_t op[16] = { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+ 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f };
+#else
+ const uint8_t op[16] = { 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0 };
+#endif
+
+ rc = milenage_opc_gen(opc, aud->u.umts.k, op);
+
+ printf("OP:\t%s\n", osmo_hexdump(op, sizeof(op)));
+ printf("OPC:\t%s\n", osmo_hexdump(opc, sizeof(opc)));
+ return rc;
+}
+
int main(int argc, char **argv)
{
struct osmo_auth_vector _vec;
@@ -73,6 +91,8 @@
printf("AUTS success: SEQ.MS = %lu\n", test_aud.u.umts.sqn);
}
+ opc_test(&test_aud);
+
exit(0);
}