libosmogsm: Factor out the C2 derivation function
3GPP specifies the C2 derivation function (generating GSM SRES from UMTS XRES)
independent of the MILENAGE algorithm. So instead of open-coding it in
milenage.c:gsm_milenage(), let's create a separate public function
osmo_auth_c2() similar to the already-existing osmo_auth_c3() function.
gsm_milenage() can then simply use that function.
Change-Id: I0e7cd55f5578f891cb6cc1b0442920ba5beddae4
diff --git a/TODO-RELEASE b/TODO-RELEASE
index d082ee3..b239efa 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -15,3 +15,4 @@
gsm0503_tch_hr_decode() marked as deprecated
libosmogsm ADD new osmo_sub_auth_data2 / osmo_auth_gen_vec2 / osmo_auth_gen_vec_auts2
libosmogsm MODIFY osmo_auth_impl callback function signature change. No known external users
+libosmogsm ADD osmo_auth_c2