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ran_msg_a.c: use gsm0808_create_cipher2() 

Use new API in Cipher Mode Command to prepare for A5/4 support.

Depends: Ib3906085e0c6e5a496a9f755f0f786238a86ca34 (libosmocore)
Related: SYS#5324
Change-Id: Ib238d367b8d5d07b6ab4cb2e48fbf4ce22ca4476
This commit is contained in:
Neels Hofmeyr 2021-06-09 22:26:11 +02:00
parent 07c8b7cb2e
commit cdcfc80176
2 changed files with 17 additions and 13 deletions
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1
TODO-RELEASE
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@ -7,3 +7,4 @@
# If any interfaces have been added since the last public release: c:r:a + 1. # If any interfaces have been added since the last public release: c:r:a + 1.
# If any interfaces have been removed or changed since the last public release: c:r:0. # If any interfaces have been removed or changed since the last public release: c:r:0.
#library what description / commit summary line #library what description / commit summary line
libosmocore >1.5.1 A5/4 support requires new API gsm0808_create_cipher2()

29
src/libmsc/ran_msg_a.c
View File

@ -1058,14 +1058,17 @@ osmo_static_assert(sizeof(((struct gsm0808_encrypt_info*)0)->key) >= sizeof(((st
gsm0808_encrypt_info_key_fits_osmo_auth_vec_kc); gsm0808_encrypt_info_key_fits_osmo_auth_vec_kc);
static struct msgb *ran_a_make_cipher_mode_command(struct osmo_fsm_inst *fi, const struct ran_cipher_mode_command *cm) static struct msgb *ran_a_make_cipher_mode_command(struct osmo_fsm_inst *fi, const struct ran_cipher_mode_command *cm)
{ {
struct gsm0808_encrypt_info ei = {}; struct gsm0808_cipher_mode_command cmc = {
.cipher_response_mode_present = true,
.cipher_response_mode = 1, /* 1: include IMEISV (3GPP TS 48.008 3.2.2.34) */
};
struct gsm0808_encrypt_info *ei = &cmc.ei;
char buf[16 * 2 + 1]; char buf[16 * 2 + 1];
const uint8_t cipher_response_mode = 1;
if (make_encrypt_info_perm_algo(fi, &ei, cm->geran.a5_encryption_mask, cm->classmark)) if (make_encrypt_info_perm_algo(fi, ei, cm->geran.a5_encryption_mask, cm->classmark))
return NULL; return NULL;
if (ei.perm_algo_len == 0) { if (ei->perm_algo_len == 0) {
LOG_RAN_A_ENC(fi, LOGL_ERROR, "cannot start ciphering, no intersection between MSC-configured" LOG_RAN_A_ENC(fi, LOGL_ERROR, "cannot start ciphering, no intersection between MSC-configured"
" and MS-supported A5 algorithms. MSC: 0x%02x MS: %s\n", " and MS-supported A5 algorithms. MSC: 0x%02x MS: %s\n",
cm->geran.a5_encryption_mask, osmo_gsm48_classmark_a5_name(cm->classmark)); cm->geran.a5_encryption_mask, osmo_gsm48_classmark_a5_name(cm->classmark));
@ -1076,26 +1079,26 @@ static struct msgb *ran_a_make_cipher_mode_command(struct osmo_fsm_inst *fi, con
* tokens. vec->kc was calculated from the GSM algorithm and is not * tokens. vec->kc was calculated from the GSM algorithm and is not
* necessarily a match for the UMTS AKA tokens. */ * necessarily a match for the UMTS AKA tokens. */
if (cm->geran.umts_aka) if (cm->geran.umts_aka)
osmo_auth_c3(ei.key, cm->vec->ck, cm->vec->ik); osmo_auth_c3(ei->key, cm->vec->ck, cm->vec->ik);
else else
memcpy(ei.key, cm->vec->kc, sizeof(cm->vec->kc)); memcpy(ei->key, cm->vec->kc, sizeof(cm->vec->kc));
ei.key_len = sizeof(cm->vec->kc); ei->key_len = sizeof(cm->vec->kc);
/* Store chosen GERAN key where the caller asked it to be stored. /* Store chosen GERAN key where the caller asked it to be stored.
* alg_id remains unknown until we receive a Cipher Mode Complete from the BSC */ * alg_id remains unknown until we receive a Cipher Mode Complete from the BSC */
if (cm->geran.chosen_key) { if (cm->geran.chosen_key) {
if (ei.key_len > sizeof(cm->geran.chosen_key->key)) { if (ei->key_len > sizeof(cm->geran.chosen_key->key)) {
LOG_RAN_A_ENC(fi, LOGL_ERROR, "Chosen key is larger than I can store\n"); LOG_RAN_A_ENC(fi, LOGL_ERROR, "Chosen key is larger than I can store\n");
return NULL; return NULL;
} }
memcpy(cm->geran.chosen_key->key, ei.key, ei.key_len); memcpy(cm->geran.chosen_key->key, ei->key, ei->key_len);
cm->geran.chosen_key->key_len = ei.key_len; cm->geran.chosen_key->key_len = ei->key_len;
} }
LOG_RAN_A_ENC(fi, LOGL_DEBUG, "Tx BSSMAP CIPHER MODE COMMAND to BSC, %u ciphers (%s) key %s\n", LOG_RAN_A_ENC(fi, LOGL_DEBUG, "Tx BSSMAP CIPHER MODE COMMAND to BSC, %u ciphers (%s) key %s\n",
ei.perm_algo_len, osmo_hexdump_nospc(ei.perm_algo, ei.perm_algo_len), ei->perm_algo_len, osmo_hexdump_nospc(ei->perm_algo, ei->perm_algo_len),
osmo_hexdump_buf(buf, sizeof(buf), ei.key, ei.key_len, NULL, false)); osmo_hexdump_buf(buf, sizeof(buf), ei->key, ei->key_len, NULL, false));
return gsm0808_create_cipher(&ei, cm->geran.retrieve_imeisv ? &cipher_response_mode : NULL); return gsm0808_create_cipher2(&cmc);
} }
struct msgb *ran_a_make_handover_request(struct osmo_fsm_inst *log_fi, const struct ran_handover_request *n) struct msgb *ran_a_make_handover_request(struct osmo_fsm_inst *log_fi, const struct ran_handover_request *n)