Make C4 function globally available
This function perform 64 -> 128 bit key expansion which useful for
converting between UMTS CK and GSM Kc, A5/3 and A5/4, GEA3 and GEA4
keys.
Change-Id: I5a6c6deef6027cd6af144c9062d4c9166be26904
Related: OS#1582
diff --git a/src/gsm/auth_core.c b/src/gsm/auth_core.c
index f1ec2ed..3aac069 100644
--- a/src/gsm/auth_core.c
+++ b/src/gsm/auth_core.c
@@ -106,7 +106,7 @@
}
/* C4 function to derive UMTS CK from GSM Kc */
-static inline void c4_function(uint8_t *ck, const uint8_t *kc)
+void osmo_c4(uint8_t *ck, const uint8_t *kc)
{
memcpy(ck, kc, 8);
memcpy(ck+8, kc, 8);
@@ -125,7 +125,7 @@
if ((vec->auth_types & OSMO_AUTH_TYPE_GSM) &&
!(vec->auth_types & OSMO_AUTH_TYPE_UMTS)) {
c5_function(vec->ik, vec->kc);
- c4_function(vec->ck, vec->kc);
+ osmo_c4(vec->ck, vec->kc);
/* We cannot actually set OSMO_AUTH_TYPE_UMTS as we have no
* AUTN and no RES, and thus can only perform GSM
* authentication with this tuple.