Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 1 | /* Osmocom Visitor Location Register (VLR) Autentication FSM */ |
| 2 | |
| 3 | /* (C) 2016 by Harald Welte <laforge@gnumonks.org> |
| 4 | * |
| 5 | * All Rights Reserved |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU Affero General Public License as published by |
| 9 | * the Free Software Foundation; either version 3 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU Affero General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Affero General Public License |
| 18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | |
| 23 | #include <osmocom/core/fsm.h> |
| 24 | #include <osmocom/core/utils.h> |
| 25 | #include <osmocom/gsm/gsup.h> |
Neels Hofmeyr | 9084396 | 2017-09-04 15:04:35 +0200 | [diff] [blame] | 26 | #include <osmocom/msc/vlr.h> |
| 27 | #include <osmocom/msc/debug.h> |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 28 | |
| 29 | #include "vlr_core.h" |
| 30 | #include "vlr_auth_fsm.h" |
| 31 | |
| 32 | #define S(x) (1 << (x)) |
| 33 | |
| 34 | static const struct value_string fsm_auth_event_names[] = { |
| 35 | OSMO_VALUE_STRING(VLR_AUTH_E_START), |
| 36 | OSMO_VALUE_STRING(VLR_AUTH_E_HLR_SAI_ACK), |
| 37 | OSMO_VALUE_STRING(VLR_AUTH_E_HLR_SAI_NACK), |
| 38 | OSMO_VALUE_STRING(VLR_AUTH_E_HLR_SAI_ABORT), |
| 39 | OSMO_VALUE_STRING(VLR_AUTH_E_MS_AUTH_RESP), |
| 40 | OSMO_VALUE_STRING(VLR_AUTH_E_MS_AUTH_FAIL), |
| 41 | OSMO_VALUE_STRING(VLR_AUTH_E_MS_ID_IMSI), |
| 42 | { 0, NULL } |
| 43 | }; |
| 44 | |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 45 | /* private state of the auth_fsm_instance */ |
| 46 | struct auth_fsm_priv { |
| 47 | struct vlr_subscr *vsub; |
| 48 | bool by_imsi; |
| 49 | bool is_r99; |
| 50 | bool is_utran; |
| 51 | bool auth_requested; |
| 52 | |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 53 | int auth_tuple_max_reuse_count; /* see vlr->cfg instead */ |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 54 | }; |
| 55 | |
| 56 | /*********************************************************************** |
| 57 | * Utility functions |
| 58 | ***********************************************************************/ |
| 59 | |
| 60 | /* Always use either vlr_subscr_get_auth_tuple() or vlr_subscr_has_auth_tuple() |
| 61 | * instead, to ensure proper use count. |
| 62 | * Return an auth tuple with the lowest use_count among the auth tuples. If |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 63 | * max_reuse_count >= 0, return NULL if all available auth tuples have a use |
| 64 | * count > max_reuse_count. If max_reuse_count is negative, return a currently |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 65 | * least used auth tuple without enforcing a maximum use count. If there are |
| 66 | * no auth tuples, return NULL. |
| 67 | */ |
Neels Hofmeyr | 8b6e536 | 2018-11-30 02:57:33 +0100 | [diff] [blame] | 68 | static struct vlr_auth_tuple * |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 69 | _vlr_subscr_next_auth_tuple(struct vlr_subscr *vsub, int max_reuse_count) |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 70 | { |
| 71 | unsigned int count; |
| 72 | unsigned int idx; |
Neels Hofmeyr | 8b6e536 | 2018-11-30 02:57:33 +0100 | [diff] [blame] | 73 | struct vlr_auth_tuple *at = NULL; |
| 74 | unsigned int key_seq = VLR_KEY_SEQ_INVAL; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 75 | |
| 76 | if (!vsub) |
| 77 | return NULL; |
| 78 | |
| 79 | if (vsub->last_tuple) |
| 80 | key_seq = vsub->last_tuple->key_seq; |
| 81 | |
Neels Hofmeyr | 8b6e536 | 2018-11-30 02:57:33 +0100 | [diff] [blame] | 82 | if (key_seq == VLR_KEY_SEQ_INVAL) |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 83 | /* Start with 0 after increment modulo array size */ |
| 84 | idx = ARRAY_SIZE(vsub->auth_tuples) - 1; |
| 85 | else |
| 86 | idx = key_seq; |
| 87 | |
| 88 | for (count = ARRAY_SIZE(vsub->auth_tuples); count > 0; count--) { |
| 89 | idx = (idx + 1) % ARRAY_SIZE(vsub->auth_tuples); |
| 90 | |
Neels Hofmeyr | 8b6e536 | 2018-11-30 02:57:33 +0100 | [diff] [blame] | 91 | if (vsub->auth_tuples[idx].key_seq == VLR_KEY_SEQ_INVAL) |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 92 | continue; |
| 93 | |
| 94 | if (!at || vsub->auth_tuples[idx].use_count < at->use_count) |
| 95 | at = &vsub->auth_tuples[idx]; |
| 96 | } |
| 97 | |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 98 | if (!at || (max_reuse_count >= 0 && at->use_count > max_reuse_count)) |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 99 | return NULL; |
| 100 | |
| 101 | return at; |
| 102 | } |
| 103 | |
| 104 | /* Return an auth tuple and increment its use count. */ |
Neels Hofmeyr | 8b6e536 | 2018-11-30 02:57:33 +0100 | [diff] [blame] | 105 | static struct vlr_auth_tuple * |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 106 | vlr_subscr_get_auth_tuple(struct vlr_subscr *vsub, int max_reuse_count) |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 107 | { |
Neels Hofmeyr | 8b6e536 | 2018-11-30 02:57:33 +0100 | [diff] [blame] | 108 | struct vlr_auth_tuple *at = _vlr_subscr_next_auth_tuple(vsub, |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 109 | max_reuse_count); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 110 | if (!at) |
| 111 | return NULL; |
| 112 | at->use_count++; |
| 113 | return at; |
| 114 | } |
| 115 | |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 116 | /* Return whether an auth tuple with a matching use_count is available. */ |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 117 | static bool vlr_subscr_has_auth_tuple(struct vlr_subscr *vsub, |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 118 | int max_reuse_count) |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 119 | { |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 120 | return _vlr_subscr_next_auth_tuple(vsub, max_reuse_count) != NULL; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 121 | } |
| 122 | |
| 123 | static bool check_auth_resp(struct vlr_subscr *vsub, bool is_r99, |
| 124 | bool is_utran, const uint8_t *res, |
| 125 | uint8_t res_len) |
| 126 | { |
Neels Hofmeyr | 8b6e536 | 2018-11-30 02:57:33 +0100 | [diff] [blame] | 127 | struct vlr_auth_tuple *at = vsub->last_tuple; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 128 | struct osmo_auth_vector *vec = &at->vec; |
| 129 | bool check_umts; |
Neels Hofmeyr | 11d2ce3 | 2018-03-10 00:25:20 +0100 | [diff] [blame] | 130 | bool res_is_umts_aka; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 131 | OSMO_ASSERT(at); |
| 132 | |
Neels Hofmeyr | a9099bc | 2018-03-10 04:22:50 +0100 | [diff] [blame] | 133 | LOGVSUBP(LOGL_DEBUG, vsub, "AUTH on %s received %s: %s (%u bytes)\n", |
| 134 | is_utran ? "UTRAN" : "GERAN", |
| 135 | is_utran ? "RES" : "SRES/RES", |
| 136 | osmo_hexdump_nospc(res, res_len), res_len); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 137 | |
| 138 | /* RES must be present and at least 32bit */ |
Neels Hofmeyr | 11d2ce3 | 2018-03-10 00:25:20 +0100 | [diff] [blame] | 139 | if (!res || !res_len) { |
| 140 | LOGVSUBP(LOGL_NOTICE, vsub, "AUTH SRES/RES missing\n"); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 141 | goto out_false; |
| 142 | } |
| 143 | |
Neels Hofmeyr | 11d2ce3 | 2018-03-10 00:25:20 +0100 | [diff] [blame] | 144 | /* We're deciding the UMTS AKA-ness of the response by the RES size. So let's make sure we can't |
| 145 | * mix them up by size. On UTRAN, we expect full length RES always, no way to mix up there. */ |
| 146 | if (!is_utran && vec->res_len == sizeof(vec->sres)) |
| 147 | LOGVSUBP(LOGL_ERROR, vsub, "Unforeseen situation: UMTS AKA's RES length" |
| 148 | " equals the size of SRES: %u -- this code wants to differentiate" |
| 149 | " the two by their size, which won't work properly now.\n", vec->res_len); |
| 150 | |
| 151 | /* RES must be either vec->res_len (UMTS AKA) or sizeof(sres) (GSM AKA) */ |
| 152 | if (res_len == vec->res_len) |
| 153 | res_is_umts_aka = true; |
| 154 | else if (res_len == sizeof(vec->sres)) |
| 155 | res_is_umts_aka = false; |
| 156 | else { |
| 157 | if (is_utran) |
| 158 | LOGVSUBP(LOGL_NOTICE, vsub, "AUTH RES has invalid length: %u." |
| 159 | " Expected %u (UMTS AKA)\n", |
| 160 | res_len, vec->res_len); |
| 161 | else |
| 162 | LOGVSUBP(LOGL_NOTICE, vsub, "AUTH SRES/RES has invalid length: %u." |
| 163 | " Expected either %zu (GSM AKA) or %u (UMTS AKA)\n", |
| 164 | res_len, sizeof(vec->sres), vec->res_len); |
| 165 | goto out_false; |
| 166 | } |
| 167 | |
| 168 | check_umts = (is_r99 |
| 169 | && (vec->auth_types & OSMO_AUTH_TYPE_UMTS) |
| 170 | && res_is_umts_aka); |
| 171 | |
| 172 | /* Even on an R99 capable MS with a UMTS AKA capable USIM, |
| 173 | * the MS may still choose to only perform GSM AKA, as |
| 174 | * long as the bearer is GERAN -- never on UTRAN: */ |
| 175 | if (is_utran && !check_umts) { |
| 176 | LOGVSUBP(LOGL_ERROR, vsub, |
| 177 | "AUTH via UTRAN, cannot allow GSM AKA" |
| 178 | " (MS is %sR99 capable, vec has %sUMTS AKA tokens, res_len=%u is %s)\n", |
| 179 | is_r99 ? "" : "NOT ", |
| 180 | (vec->auth_types & OSMO_AUTH_TYPE_UMTS) ? "" : "NO ", |
| 181 | res_len, (res_len == vec->res_len)? "valid" : "INVALID on UTRAN"); |
| 182 | goto out_false; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 183 | } |
| 184 | |
| 185 | if (check_umts) { |
| 186 | if (res_len != vec->res_len |
| 187 | || memcmp(res, vec->res, res_len)) { |
| 188 | LOGVSUBP(LOGL_INFO, vsub, "UMTS AUTH failure:" |
| 189 | " mismatching res (expected res=%s)\n", |
| 190 | osmo_hexdump(vec->res, vec->res_len)); |
| 191 | goto out_false; |
| 192 | } |
| 193 | |
| 194 | LOGVSUBP(LOGL_INFO, vsub, "AUTH established UMTS security" |
| 195 | " context\n"); |
| 196 | vsub->sec_ctx = VLR_SEC_CTX_UMTS; |
| 197 | return true; |
| 198 | } else { |
| 199 | if (res_len != sizeof(vec->sres) |
| 200 | || memcmp(res, vec->sres, sizeof(vec->sres))) { |
| 201 | LOGVSUBP(LOGL_INFO, vsub, "GSM AUTH failure:" |
| 202 | " mismatching sres (expected sres=%s)\n", |
| 203 | osmo_hexdump(vec->sres, sizeof(vec->sres))); |
| 204 | goto out_false; |
| 205 | } |
| 206 | |
| 207 | LOGVSUBP(LOGL_INFO, vsub, "AUTH established GSM security" |
| 208 | " context\n"); |
| 209 | vsub->sec_ctx = VLR_SEC_CTX_GSM; |
| 210 | return true; |
| 211 | } |
| 212 | |
| 213 | out_false: |
| 214 | vsub->sec_ctx = VLR_SEC_CTX_NONE; |
| 215 | return false; |
| 216 | } |
| 217 | |
| 218 | static void auth_fsm_onenter_failed(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| 219 | { |
| 220 | struct auth_fsm_priv *afp = fi->priv; |
| 221 | struct vlr_subscr *vsub = afp->vsub; |
| 222 | |
| 223 | /* If authentication hasn't even started, e.g. the HLR sent no auth |
| 224 | * info, then we also don't need to tell the HLR about an auth failure. |
| 225 | */ |
Max | 770fbd2 | 2018-01-24 12:48:33 +0100 | [diff] [blame] | 226 | if (afp->auth_requested) { |
| 227 | int rc = vlr_subscr_tx_auth_fail_rep(vsub); |
| 228 | if (rc < 0) |
| 229 | LOGVSUBP(LOGL_ERROR, vsub, "Failed to communicate AUTH failure to HLR\n"); |
| 230 | } |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 231 | } |
| 232 | |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 233 | static const char *vlr_auth_fsm_result_name(enum gsm48_reject_value result) |
| 234 | { |
| 235 | if (!result) |
| 236 | return "PASSED"; |
| 237 | return get_value_string(gsm48_gmm_cause_names, result); |
| 238 | } |
| 239 | |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 240 | /* Terminate the Auth FSM Instance and notify parent */ |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 241 | static void auth_fsm_term(struct osmo_fsm_inst *fi, enum gsm48_reject_value result) |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 242 | { |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 243 | LOGPFSM(fi, "Authentication terminating with result %s\n", |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 244 | vlr_auth_fsm_result_name(result)); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 245 | |
| 246 | /* Do one final state transition (mostly for logging purpose) */ |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 247 | if (!result) |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 248 | osmo_fsm_inst_state_chg(fi, VLR_SUB_AS_AUTHENTICATED, 0, 0); |
| 249 | else |
| 250 | osmo_fsm_inst_state_chg(fi, VLR_SUB_AS_AUTH_FAILED, 0, 0); |
| 251 | |
| 252 | /* return the result to the parent FSM */ |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 253 | osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, &result); |
Neels Hofmeyr | 868f505 | 2018-12-28 00:20:20 +0100 | [diff] [blame] | 254 | } |
| 255 | |
| 256 | static void auth_fsm_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause) |
| 257 | { |
| 258 | struct auth_fsm_priv *afp = fi->priv; |
| 259 | struct vlr_subscr *vsub = afp->vsub; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 260 | vsub->auth_fsm = NULL; |
| 261 | } |
| 262 | |
| 263 | /* back-end function transmitting authentication. Caller ensures we have valid |
| 264 | * tuple */ |
| 265 | static int _vlr_subscr_authenticate(struct osmo_fsm_inst *fi) |
| 266 | { |
| 267 | struct auth_fsm_priv *afp = fi->priv; |
| 268 | struct vlr_subscr *vsub = afp->vsub; |
Neels Hofmeyr | 8b6e536 | 2018-11-30 02:57:33 +0100 | [diff] [blame] | 269 | struct vlr_auth_tuple *at; |
Neels Hofmeyr | fe718bc | 2018-03-11 01:24:33 +0100 | [diff] [blame] | 270 | bool use_umts_aka; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 271 | |
| 272 | /* Caller ensures we have vectors available */ |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 273 | at = vlr_subscr_get_auth_tuple(vsub, afp->auth_tuple_max_reuse_count); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 274 | if (!at) { |
| 275 | LOGPFSML(fi, LOGL_ERROR, "A previous check ensured that an" |
| 276 | " auth tuple was available, but now there is in fact" |
| 277 | " none.\n"); |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 278 | auth_fsm_term(fi, GSM48_REJECT_NETWORK_FAILURE); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 279 | return -1; |
| 280 | } |
| 281 | |
Neels Hofmeyr | fe718bc | 2018-03-11 01:24:33 +0100 | [diff] [blame] | 282 | use_umts_aka = vlr_use_umts_aka(&at->vec, afp->is_r99); |
| 283 | LOGPFSM(fi, "got auth tuple: use_count=%d key_seq=%d" |
| 284 | " -- will use %s AKA (is_r99=%s, at->vec.auth_types=0x%x)\n", |
| 285 | at->use_count, at->key_seq, |
| 286 | use_umts_aka ? "UMTS" : "GSM", afp->is_r99 ? "yes" : "no", at->vec.auth_types); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 287 | |
| 288 | /* Transmit auth req to subscriber */ |
| 289 | afp->auth_requested = true; |
| 290 | vsub->last_tuple = at; |
Neels Hofmeyr | fe718bc | 2018-03-11 01:24:33 +0100 | [diff] [blame] | 291 | vsub->vlr->ops.tx_auth_req(vsub->msc_conn_ref, at, use_umts_aka); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 292 | return 0; |
| 293 | } |
| 294 | |
| 295 | /*********************************************************************** |
| 296 | * FSM State Action functions |
| 297 | ***********************************************************************/ |
| 298 | |
| 299 | /* Initial State of TS 23.018 AUT_VLR */ |
| 300 | static void auth_fsm_needs_auth(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| 301 | { |
| 302 | struct auth_fsm_priv *afp = fi->priv; |
| 303 | struct vlr_subscr *vsub = afp->vsub; |
| 304 | |
| 305 | OSMO_ASSERT(event == VLR_AUTH_E_START); |
| 306 | |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 307 | /* Start off with the default max_reuse_count, possibly change that if we |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 308 | * need to re-use an old tuple. */ |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 309 | afp->auth_tuple_max_reuse_count = vsub->vlr->cfg.auth_tuple_max_reuse_count; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 310 | |
| 311 | /* Check if we have vectors available */ |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 312 | if (!vlr_subscr_has_auth_tuple(vsub, afp->auth_tuple_max_reuse_count)) { |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 313 | /* Obtain_Authentication_Sets_VLR */ |
Max | 770fbd2 | 2018-01-24 12:48:33 +0100 | [diff] [blame] | 314 | int rc = vlr_subscr_req_sai(vsub, NULL, NULL); |
| 315 | if (rc < 0) |
| 316 | LOGPFSM(fi, "Failed to request Authentication Sets from VLR\n"); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 317 | osmo_fsm_inst_state_chg(fi, VLR_SUB_AS_NEEDS_AUTH_WAIT_AI, |
| 318 | GSM_29002_TIMER_M, 0); |
| 319 | } else { |
| 320 | /* go straight ahead with sending auth request */ |
| 321 | osmo_fsm_inst_state_chg(fi, VLR_SUB_AS_WAIT_RESP, |
| 322 | vlr_timer(vsub->vlr, 3260), 3260); |
| 323 | _vlr_subscr_authenticate(fi); |
| 324 | } |
| 325 | } |
| 326 | |
| 327 | /* Waiting for Authentication Info from HLR */ |
| 328 | static void auth_fsm_wait_ai(struct osmo_fsm_inst *fi, uint32_t event, |
| 329 | void *data) |
| 330 | { |
| 331 | struct auth_fsm_priv *afp = fi->priv; |
| 332 | struct vlr_subscr *vsub = afp->vsub; |
| 333 | struct osmo_gsup_message *gsup = data; |
Alexander Couzens | a09f498 | 2019-08-19 15:41:33 +0200 | [diff] [blame] | 334 | enum gsm48_reject_value gsm48_rej; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 335 | |
| 336 | if (event == VLR_AUTH_E_HLR_SAI_NACK) |
| 337 | LOGPFSM(fi, "GSUP: rx Auth Info Error cause: %d: %s\n", |
| 338 | gsup->cause, |
| 339 | get_value_string(gsm48_gmm_cause_names, gsup->cause)); |
| 340 | |
| 341 | /* We are in what corresponds to the |
| 342 | * Wait_For_Authentication_Sets state of TS 23.018 OAS_VLR */ |
| 343 | if ((event == VLR_AUTH_E_HLR_SAI_ACK && !gsup->num_auth_vectors) |
| 344 | || (event == VLR_AUTH_E_HLR_SAI_NACK && |
| 345 | gsup->cause != GMM_CAUSE_IMSI_UNKNOWN) |
| 346 | || (event == VLR_AUTH_E_HLR_SAI_ABORT)) { |
| 347 | if (vsub->vlr->cfg.auth_reuse_old_sets_on_error |
| 348 | && vlr_subscr_has_auth_tuple(vsub, -1)) { |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 349 | /* To re-use an old tuple, disable the max_reuse_count |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 350 | * constraint. */ |
Neels Hofmeyr | 33f5341 | 2017-10-29 02:11:18 +0100 | [diff] [blame] | 351 | afp->auth_tuple_max_reuse_count = -1; |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 352 | goto pass; |
| 353 | } |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 354 | } |
| 355 | |
| 356 | switch (event) { |
| 357 | case VLR_AUTH_E_HLR_SAI_ACK: |
Alexander Couzens | a09f498 | 2019-08-19 15:41:33 +0200 | [diff] [blame] | 358 | if (!gsup->num_auth_vectors) { |
| 359 | auth_fsm_term(fi, GSM48_REJECT_NETWORK_FAILURE); |
| 360 | return; |
| 361 | } |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 362 | vlr_subscr_update_tuples(vsub, gsup); |
| 363 | goto pass; |
| 364 | break; |
| 365 | case VLR_AUTH_E_HLR_SAI_NACK: |
Alexander Couzens | a09f498 | 2019-08-19 15:41:33 +0200 | [diff] [blame] | 366 | case VLR_AUTH_E_HLR_SAI_ABORT: |
| 367 | vlr_gmm_cause_to_mm_cause(gsup->cause, &gsm48_rej); |
| 368 | auth_fsm_term(fi, gsm48_rej); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 369 | break; |
| 370 | } |
| 371 | |
| 372 | return; |
| 373 | pass: |
| 374 | osmo_fsm_inst_state_chg(fi, VLR_SUB_AS_WAIT_RESP, |
| 375 | vlr_timer(vsub->vlr, 3260), 3260); |
| 376 | _vlr_subscr_authenticate(fi); |
| 377 | } |
| 378 | |
| 379 | /* Waiting for Authentication Response from MS */ |
| 380 | static void auth_fsm_wait_auth_resp(struct osmo_fsm_inst *fi, uint32_t event, |
| 381 | void *data) |
| 382 | { |
| 383 | struct auth_fsm_priv *afp = fi->priv; |
| 384 | struct vlr_subscr *vsub = afp->vsub; |
| 385 | struct vlr_instance *vlr = vsub->vlr; |
| 386 | struct vlr_auth_resp_par *par = data; |
| 387 | int rc; |
| 388 | |
| 389 | switch (event) { |
| 390 | case VLR_AUTH_E_MS_AUTH_RESP: |
| 391 | rc = check_auth_resp(vsub, par->is_r99, par->is_utran, |
| 392 | par->res, par->res_len); |
| 393 | if (rc == false) { |
| 394 | if (!afp->by_imsi) { |
| 395 | vlr->ops.tx_id_req(vsub->msc_conn_ref, |
| 396 | GSM_MI_TYPE_IMSI); |
| 397 | osmo_fsm_inst_state_chg(fi, |
| 398 | VLR_SUB_AS_WAIT_ID_IMSI, |
| 399 | vlr_timer(vlr, 3270), 3270); |
| 400 | } else { |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 401 | auth_fsm_term(fi, GSM48_REJECT_ILLEGAL_MS); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 402 | } |
| 403 | } else { |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 404 | auth_fsm_term(fi, 0); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 405 | } |
| 406 | break; |
| 407 | case VLR_AUTH_E_MS_AUTH_FAIL: |
| 408 | if (par->auts) { |
| 409 | /* First failure, start re-sync attempt */ |
Max | 770fbd2 | 2018-01-24 12:48:33 +0100 | [diff] [blame] | 410 | rc = vlr_subscr_req_sai(vsub, par->auts, |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 411 | vsub->last_tuple->vec.rand); |
| 412 | osmo_fsm_inst_state_chg(fi, |
| 413 | VLR_SUB_AS_NEEDS_AUTH_WAIT_SAI_RESYNC, |
| 414 | GSM_29002_TIMER_M, 0); |
| 415 | } else |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 416 | auth_fsm_term(fi, GSM48_REJECT_ILLEGAL_MS); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 417 | break; |
| 418 | } |
| 419 | } |
| 420 | |
| 421 | /* Waiting for Authentication Info from HLR (resync case) */ |
| 422 | static void auth_fsm_wait_ai_resync(struct osmo_fsm_inst *fi, |
| 423 | uint32_t event, void *data) |
| 424 | { |
| 425 | struct auth_fsm_priv *afp = fi->priv; |
| 426 | struct vlr_subscr *vsub = afp->vsub; |
| 427 | struct osmo_gsup_message *gsup = data; |
| 428 | |
| 429 | /* We are in what corresponds to the |
| 430 | * Wait_For_Authentication_Sets state of TS 23.018 OAS_VLR */ |
| 431 | if ((event == VLR_AUTH_E_HLR_SAI_ACK && !gsup->num_auth_vectors) || |
| 432 | (event == VLR_AUTH_E_HLR_SAI_NACK && |
| 433 | gsup->cause != GMM_CAUSE_IMSI_UNKNOWN) || |
| 434 | (event == VLR_AUTH_E_HLR_SAI_ABORT)) { |
| 435 | /* result = procedure error */ |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 436 | auth_fsm_term(fi, GSM48_REJECT_NETWORK_FAILURE); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 437 | } |
| 438 | switch (event) { |
| 439 | case VLR_AUTH_E_HLR_SAI_ACK: |
| 440 | vlr_subscr_update_tuples(vsub, gsup); |
| 441 | goto pass; |
| 442 | break; |
| 443 | case VLR_AUTH_E_HLR_SAI_NACK: |
| 444 | auth_fsm_term(fi, |
| 445 | gsup->cause == GMM_CAUSE_IMSI_UNKNOWN? |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 446 | GSM48_REJECT_IMSI_UNKNOWN_IN_HLR |
| 447 | : GSM48_REJECT_NETWORK_FAILURE); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 448 | break; |
| 449 | } |
| 450 | |
| 451 | return; |
| 452 | pass: |
| 453 | osmo_fsm_inst_state_chg(fi, VLR_SUB_AS_WAIT_RESP_RESYNC, |
| 454 | vlr_timer(vsub->vlr, 3260), 3260); |
| 455 | _vlr_subscr_authenticate(fi); |
| 456 | } |
| 457 | |
| 458 | /* Waiting for AUTH RESP from MS (re-sync case) */ |
| 459 | static void auth_fsm_wait_auth_resp_resync(struct osmo_fsm_inst *fi, |
| 460 | uint32_t event, void *data) |
| 461 | { |
| 462 | struct auth_fsm_priv *afp = fi->priv; |
| 463 | struct vlr_subscr *vsub = afp->vsub; |
| 464 | struct vlr_auth_resp_par *par = data; |
| 465 | struct vlr_instance *vlr = vsub->vlr; |
| 466 | int rc; |
| 467 | |
| 468 | switch (event) { |
| 469 | case VLR_AUTH_E_MS_AUTH_RESP: |
| 470 | rc = check_auth_resp(vsub, par->is_r99, par->is_utran, |
| 471 | par->res, par->res_len); |
| 472 | if (rc == false) { |
| 473 | if (!afp->by_imsi) { |
| 474 | vlr->ops.tx_id_req(vsub->msc_conn_ref, |
| 475 | GSM_MI_TYPE_IMSI); |
| 476 | osmo_fsm_inst_state_chg(fi, |
| 477 | VLR_SUB_AS_WAIT_ID_IMSI, |
| 478 | vlr_timer(vlr, 3270), 3270); |
| 479 | } else { |
| 480 | /* Result = Aborted */ |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 481 | auth_fsm_term(fi, GSM48_REJECT_SYNCH_FAILURE); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 482 | } |
| 483 | } else { |
| 484 | /* Result = Pass */ |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 485 | auth_fsm_term(fi, 0); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 486 | } |
| 487 | break; |
| 488 | case VLR_AUTH_E_MS_AUTH_FAIL: |
| 489 | /* Second failure: Result = Fail */ |
Neels Hofmeyr | 1580959 | 2018-04-06 02:57:51 +0200 | [diff] [blame] | 490 | auth_fsm_term(fi, GSM48_REJECT_SYNCH_FAILURE); |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 491 | break; |
| 492 | } |
| 493 | } |
| 494 | |
| 495 | /* AUT_VLR waiting for Obtain_IMSI_VLR result */ |
| 496 | static void auth_fsm_wait_imsi(struct osmo_fsm_inst *fi, uint32_t event, |
| 497 | void *data) |
| 498 | { |
| 499 | struct auth_fsm_priv *afp = fi->priv; |
| 500 | struct vlr_subscr *vsub = afp->vsub; |
| 501 | const char *mi_string = data; |
| 502 | |
| 503 | switch (event) { |
| 504 | case VLR_AUTH_E_MS_ID_IMSI: |
| 505 | if (vsub->imsi[0] |
| 506 | && !vlr_subscr_matches_imsi(vsub, mi_string)) { |
| 507 | LOGVSUBP(LOGL_ERROR, vsub, "IMSI in ID RESP differs:" |
| 508 | " %s\n", mi_string); |
| 509 | } else { |
| 510 | strncpy(vsub->imsi, mi_string, sizeof(vsub->imsi)); |
| 511 | vsub->imsi[sizeof(vsub->imsi)-1] = '\0'; |
| 512 | } |
| 513 | /* retry with identity=IMSI */ |
| 514 | afp->by_imsi = true; |
| 515 | osmo_fsm_inst_state_chg(fi, VLR_SUB_AS_NEEDS_AUTH, 0, 0); |
| 516 | osmo_fsm_inst_dispatch(fi, VLR_AUTH_E_START, NULL); |
| 517 | break; |
| 518 | } |
| 519 | } |
| 520 | |
| 521 | static const struct osmo_fsm_state auth_fsm_states[] = { |
| 522 | [VLR_SUB_AS_NEEDS_AUTH] = { |
| 523 | .name = OSMO_STRINGIFY(VLR_SUB_AS_NEEDS_AUTH), |
| 524 | .in_event_mask = S(VLR_AUTH_E_START), |
| 525 | .out_state_mask = S(VLR_SUB_AS_NEEDS_AUTH_WAIT_AI) | |
| 526 | S(VLR_SUB_AS_WAIT_RESP), |
| 527 | .action = auth_fsm_needs_auth, |
| 528 | }, |
| 529 | [VLR_SUB_AS_NEEDS_AUTH_WAIT_AI] = { |
| 530 | .name = OSMO_STRINGIFY(VLR_SUB_AS_NEEDS_AUTH_WAIT_AI), |
| 531 | .in_event_mask = S(VLR_AUTH_E_HLR_SAI_ACK) | |
| 532 | S(VLR_AUTH_E_HLR_SAI_NACK), |
| 533 | .out_state_mask = S(VLR_SUB_AS_AUTH_FAILED) | |
| 534 | S(VLR_SUB_AS_WAIT_RESP), |
| 535 | .action = auth_fsm_wait_ai, |
| 536 | }, |
| 537 | [VLR_SUB_AS_WAIT_RESP] = { |
| 538 | .name = OSMO_STRINGIFY(VLR_SUB_AS_WAIT_RESP), |
| 539 | .in_event_mask = S(VLR_AUTH_E_MS_AUTH_RESP) | |
| 540 | S(VLR_AUTH_E_MS_AUTH_FAIL), |
| 541 | .out_state_mask = S(VLR_SUB_AS_WAIT_ID_IMSI) | |
| 542 | S(VLR_SUB_AS_AUTH_FAILED) | |
| 543 | S(VLR_SUB_AS_AUTHENTICATED) | |
| 544 | S(VLR_SUB_AS_NEEDS_AUTH_WAIT_SAI_RESYNC), |
| 545 | .action = auth_fsm_wait_auth_resp, |
| 546 | }, |
| 547 | [VLR_SUB_AS_NEEDS_AUTH_WAIT_SAI_RESYNC] = { |
| 548 | .name = OSMO_STRINGIFY(VLR_SUB_AS_NEEDS_AUTH_WAIT_SAI_RESYNC), |
| 549 | .in_event_mask = S(VLR_AUTH_E_HLR_SAI_ACK) | |
| 550 | S(VLR_AUTH_E_HLR_SAI_NACK), |
| 551 | .out_state_mask = S(VLR_SUB_AS_AUTH_FAILED) | |
| 552 | S(VLR_SUB_AS_WAIT_RESP_RESYNC), |
| 553 | .action = auth_fsm_wait_ai_resync, |
| 554 | }, |
| 555 | [VLR_SUB_AS_WAIT_RESP_RESYNC] = { |
| 556 | .name = OSMO_STRINGIFY(VLR_SUB_AS_WAIT_RESP_RESYNC), |
| 557 | .in_event_mask = S(VLR_AUTH_E_MS_AUTH_RESP) | |
| 558 | S(VLR_AUTH_E_MS_AUTH_FAIL), |
| 559 | .out_state_mask = S(VLR_SUB_AS_AUTH_FAILED) | |
| 560 | S(VLR_SUB_AS_AUTHENTICATED), |
| 561 | .action = auth_fsm_wait_auth_resp_resync, |
| 562 | }, |
| 563 | [VLR_SUB_AS_WAIT_ID_IMSI] = { |
| 564 | .name = OSMO_STRINGIFY(VLR_SUB_AS_WAIT_ID_IMSI), |
| 565 | .in_event_mask = S(VLR_AUTH_E_MS_ID_IMSI), |
| 566 | .out_state_mask = S(VLR_SUB_AS_NEEDS_AUTH), |
| 567 | .action = auth_fsm_wait_imsi, |
| 568 | }, |
| 569 | [VLR_SUB_AS_AUTHENTICATED] = { |
| 570 | .name = OSMO_STRINGIFY(VLR_SUB_AS_AUTHENTICATED), |
| 571 | .in_event_mask = 0, |
| 572 | .out_state_mask = 0, |
| 573 | }, |
| 574 | [VLR_SUB_AS_AUTH_FAILED] = { |
| 575 | .name = OSMO_STRINGIFY(VLR_SUB_AS_AUTH_FAILED), |
| 576 | .in_event_mask = 0, |
| 577 | .out_state_mask = 0, |
| 578 | .onenter = auth_fsm_onenter_failed, |
| 579 | }, |
| 580 | }; |
| 581 | |
| 582 | struct osmo_fsm vlr_auth_fsm = { |
| 583 | .name = "VLR_Authenticate", |
| 584 | .states = auth_fsm_states, |
| 585 | .num_states = ARRAY_SIZE(auth_fsm_states), |
| 586 | .allstate_event_mask = 0, |
| 587 | .allstate_action = NULL, |
| 588 | .log_subsys = DVLR, |
| 589 | .event_names = fsm_auth_event_names, |
Neels Hofmeyr | 868f505 | 2018-12-28 00:20:20 +0100 | [diff] [blame] | 590 | .cleanup = auth_fsm_cleanup, |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 591 | }; |
| 592 | |
| 593 | /*********************************************************************** |
| 594 | * User API (for SGSN/MSC code) |
| 595 | ***********************************************************************/ |
| 596 | |
| 597 | /* MSC->VLR: Start Procedure Authenticate_VLR (TS 23.012 Ch. 4.1.2.2) */ |
| 598 | struct osmo_fsm_inst *auth_fsm_start(struct vlr_subscr *vsub, |
| 599 | uint32_t log_level, |
| 600 | struct osmo_fsm_inst *parent, |
| 601 | uint32_t parent_term_event, |
| 602 | bool is_r99, |
| 603 | bool is_utran) |
| 604 | { |
| 605 | struct osmo_fsm_inst *fi; |
| 606 | struct auth_fsm_priv *afp; |
| 607 | |
| 608 | fi = osmo_fsm_inst_alloc_child(&vlr_auth_fsm, parent, |
| 609 | parent_term_event); |
Neels Hofmeyr | c698ab9 | 2017-11-07 13:23:13 +0100 | [diff] [blame] | 610 | if (!fi) { |
| 611 | osmo_fsm_inst_dispatch(parent, parent_term_event, 0); |
| 612 | return NULL; |
| 613 | } |
Harald Welte | b8b85a1 | 2016-06-17 00:06:42 +0200 | [diff] [blame] | 614 | |
| 615 | afp = talloc_zero(fi, struct auth_fsm_priv); |
| 616 | if (!afp) { |
| 617 | osmo_fsm_inst_dispatch(parent, parent_term_event, 0); |
| 618 | return NULL; |
| 619 | } |
| 620 | |
| 621 | afp->vsub = vsub; |
| 622 | if (vsub->imsi[0]) |
| 623 | afp->by_imsi = true; |
| 624 | afp->is_r99 = is_r99; |
| 625 | afp->is_utran = is_utran; |
| 626 | fi->priv = afp; |
| 627 | vsub->auth_fsm = fi; |
| 628 | |
| 629 | osmo_fsm_inst_dispatch(fi, VLR_AUTH_E_START, NULL); |
| 630 | |
| 631 | return fi; |
| 632 | } |
Sylvain Munaut | da9f37e | 2019-03-14 11:02:36 +0100 | [diff] [blame] | 633 | |
| 634 | bool auth_try_reuse_tuple(struct vlr_subscr *vsub, uint8_t key_seq) |
| 635 | { |
| 636 | int max_reuse_count = vsub->vlr->cfg.auth_tuple_max_reuse_count; |
| 637 | struct vlr_auth_tuple *at = vsub->last_tuple; |
| 638 | |
| 639 | if (!at) |
| 640 | return false; |
| 641 | if ((max_reuse_count >= 0) && (at->use_count > max_reuse_count)) |
| 642 | return false; |
| 643 | if (at->key_seq != key_seq) |
| 644 | return false; |
| 645 | at->use_count++; |
| 646 | return true; |
| 647 | } |