fix BSSMAP Cipher Mode Cmd: properly set permitted algorithms
The bit shifting is performed in gsm0808_enc_encrypt_info(), and must not be
done when populating the gsm0808_encrypt_info struct.
Provide vlr_ciph_to_gsm0808_alg_id() to translate the enum vlr_ciph to the
GSM0808_* constants we need to put in the gsm0808_encrypt_info struct instead.
Related: OS#2745
Change-Id: If75f95e8a5cc8b9979610ce6d746c1f0073ee39a
diff --git a/include/osmocom/msc/vlr.h b/include/osmocom/msc/vlr.h
index 9e6b12c..640d35b 100644
--- a/include/osmocom/msc/vlr.h
+++ b/include/osmocom/msc/vlr.h
@@ -7,6 +7,7 @@
#include <osmocom/gsm/protocol/gsm_23_003.h>
#include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
#include <osmocom/gsm/gsm23003.h>
+#include <osmocom/gsm/gsm0808.h>
#include <osmocom/msc/gsm_data.h>
// for GSM_NAME_LENGTH
#include <osmocom/msc/gsm_subscriber.h>
@@ -172,6 +173,21 @@
VLR_CIPH_A5_3, /*< A5/3, 'new secure' encryption */
};
+static inline uint8_t vlr_ciph_to_gsm0808_alg_id(enum vlr_ciph ciph)
+{
+ switch (ciph) {
+ default:
+ case VLR_CIPH_NONE:
+ return GSM0808_ALG_ID_A5_0;
+ case VLR_CIPH_A5_1:
+ return GSM0808_ALG_ID_A5_1;
+ case VLR_CIPH_A5_2:
+ return GSM0808_ALG_ID_A5_2;
+ case VLR_CIPH_A5_3:
+ return GSM0808_ALG_ID_A5_3;
+ }
+}
+
struct vlr_ops {
/* encode + transmit an AUTH REQ towards the MS.
* \param[in] at auth tuple providing rand, key_seq and autn.
diff --git a/src/libmsc/a_iface.c b/src/libmsc/a_iface.c
index f863517..69b4c09 100644
--- a/src/libmsc/a_iface.c
+++ b/src/libmsc/a_iface.c
@@ -198,7 +198,7 @@
if (include_imeisv)
crm_ptr = &crm;
- ei.perm_algo[0] = (uint8_t) (1 << cipher);
+ ei.perm_algo[0] = vlr_ciph_to_gsm0808_alg_id(cipher);
ei.perm_algo_len = 1;
msg_resp = gsm0808_create_cipher(&ei, crm_ptr);