contrib/wpa/src/eap_common/eap_sim_common.c

   1 /*
   2  * EAP peer/server: EAP-SIM/AKA/AKA' shared routines
   3  * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #include "common.h"
  12 #include "wpabuf.h"
  13 #include "crypto/aes_wrap.h"
  14 #include "crypto/crypto.h"
  15 #include "crypto/sha1.h"
  16 #include "crypto/sha256.h"
  17 #include "crypto/random.h"
  18 #include "eap_common/eap_defs.h"
  19 #include "eap_common/eap_sim_common.h"
  20
  21
  22 static int eap_sim_prf(const u8 *key, u8 *x, size_t xlen)
  23 {
  24         return fips186_2_prf(key, EAP_SIM_MK_LEN, x, xlen);
  25 }
  26
  27
  28 void eap_sim_derive_mk(const u8 *identity, size_t identity_len,
  29                        const u8 *nonce_mt, u16 selected_version,
  30                        const u8 *ver_list, size_t ver_list_len,
  31                        int num_chal, const u8 *kc, u8 *mk)
  32 {
  33         u8 sel_ver[2];
  34         const unsigned char *addr[5];
  35         size_t len[5];
  36
  37         addr[0] = identity;
  38         len[0] = identity_len;
  39         addr[1] = kc;
  40         len[1] = num_chal * EAP_SIM_KC_LEN;
  41         addr[2] = nonce_mt;
  42         len[2] = EAP_SIM_NONCE_MT_LEN;
  43         addr[3] = ver_list;
  44         len[3] = ver_list_len;
  45         addr[4] = sel_ver;
  46         len[4] = 2;
  47
  48         WPA_PUT_BE16(sel_ver, selected_version);
  49
  50         /* MK = SHA1(Identity|n*Kc|NONCE_MT|Version List|Selected Version) */
  51         sha1_vector(5, addr, len, mk);
  52         wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: MK", mk, EAP_SIM_MK_LEN);
  53 }
  54
  55
  56 void eap_aka_derive_mk(const u8 *identity, size_t identity_len,
  57                        const u8 *ik, const u8 *ck, u8 *mk)
  58 {
  59         const u8 *addr[3];
  60         size_t len[3];
  61
  62         addr[0] = identity;
  63         len[0] = identity_len;
  64         addr[1] = ik;
  65         len[1] = EAP_AKA_IK_LEN;
  66         addr[2] = ck;
  67         len[2] = EAP_AKA_CK_LEN;
  68
  69         /* MK = SHA1(Identity|IK|CK) */
  70         sha1_vector(3, addr, len, mk);
  71         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: IK", ik, EAP_AKA_IK_LEN);
  72         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: CK", ck, EAP_AKA_CK_LEN);
  73         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: MK", mk, EAP_SIM_MK_LEN);
  74 }
  75
  76
  77 int eap_sim_derive_keys(const u8 *mk, u8 *k_encr, u8 *k_aut, u8 *msk, u8 *emsk)
  78 {
  79         u8 buf[EAP_SIM_K_ENCR_LEN + EAP_SIM_K_AUT_LEN +
  80                EAP_SIM_KEYING_DATA_LEN + EAP_EMSK_LEN], *pos;
  81         if (eap_sim_prf(mk, buf, sizeof(buf)) < 0) {
  82                 wpa_printf(MSG_ERROR, "EAP-SIM: Failed to derive keys");
  83                 return -1;
  84         }
  85         pos = buf;
  86         os_memcpy(k_encr, pos, EAP_SIM_K_ENCR_LEN);
  87         pos += EAP_SIM_K_ENCR_LEN;
  88         os_memcpy(k_aut, pos, EAP_SIM_K_AUT_LEN);
  89         pos += EAP_SIM_K_AUT_LEN;
  90         os_memcpy(msk, pos, EAP_SIM_KEYING_DATA_LEN);
  91         pos += EAP_SIM_KEYING_DATA_LEN;
  92         os_memcpy(emsk, pos, EAP_EMSK_LEN);
  93
  94         wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: K_encr",
  95                         k_encr, EAP_SIM_K_ENCR_LEN);
  96         wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: K_aut",
  97                         k_aut, EAP_SIM_K_AUT_LEN);
  98         wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: keying material (MSK)",
  99                         msk, EAP_SIM_KEYING_DATA_LEN);
 100         wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: EMSK", emsk, EAP_EMSK_LEN);
 101         os_memset(buf, 0, sizeof(buf));
 102
 103         return 0;
 104 }
 105
 106
 107 int eap_sim_derive_keys_reauth(u16 _counter,
 108                                const u8 *identity, size_t identity_len,
 109                                const u8 *nonce_s, const u8 *mk, u8 *msk,
 110                                u8 *emsk)
 111 {
 112         u8 xkey[SHA1_MAC_LEN];
 113         u8 buf[EAP_SIM_KEYING_DATA_LEN + EAP_EMSK_LEN + 32];
 114         u8 counter[2];
 115         const u8 *addr[4];
 116         size_t len[4];
 117
 118         while (identity_len > 0 && identity[identity_len - 1] == 0) {
 119                 wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop null "
 120                            "character from the end of identity");
 121                 identity_len--;
 122         }
 123         addr[0] = identity;
 124         len[0] = identity_len;
 125         addr[1] = counter;
 126         len[1] = 2;
 127         addr[2] = nonce_s;
 128         len[2] = EAP_SIM_NONCE_S_LEN;
 129         addr[3] = mk;
 130         len[3] = EAP_SIM_MK_LEN;
 131
 132         WPA_PUT_BE16(counter, _counter);
 133
 134         wpa_printf(MSG_DEBUG, "EAP-SIM: Deriving keying data from reauth");
 135         wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
 136                           identity, identity_len);
 137         wpa_hexdump(MSG_DEBUG, "EAP-SIM: counter", counter, 2);
 138         wpa_hexdump(MSG_DEBUG, "EAP-SIM: NONCE_S", nonce_s,
 139                     EAP_SIM_NONCE_S_LEN);
 140         wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: MK", mk, EAP_SIM_MK_LEN);
 141
 142         /* XKEY' = SHA1(Identity|counter|NONCE_S|MK) */
 143         sha1_vector(4, addr, len, xkey);
 144         wpa_hexdump(MSG_DEBUG, "EAP-SIM: XKEY'", xkey, SHA1_MAC_LEN);
 145
 146         if (eap_sim_prf(xkey, buf, sizeof(buf)) < 0) {
 147                 wpa_printf(MSG_ERROR, "EAP-SIM: Failed to derive keys");
 148                 return -1;
 149         }
 150         if (msk) {
 151                 os_memcpy(msk, buf, EAP_SIM_KEYING_DATA_LEN);
 152                 wpa_hexdump(MSG_DEBUG, "EAP-SIM: keying material (MSK)",
 153                             msk, EAP_SIM_KEYING_DATA_LEN);
 154         }
 155         if (emsk) {
 156                 os_memcpy(emsk, buf + EAP_SIM_KEYING_DATA_LEN, EAP_EMSK_LEN);
 157                 wpa_hexdump(MSG_DEBUG, "EAP-SIM: EMSK", emsk, EAP_EMSK_LEN);
 158         }
 159         os_memset(buf, 0, sizeof(buf));
 160
 161         return 0;
 162 }
 163
 164
 165 int eap_sim_verify_mac(const u8 *k_aut, const struct wpabuf *req,
 166                        const u8 *mac, const u8 *extra, size_t extra_len)
 167 {
 168         unsigned char hmac[SHA1_MAC_LEN];
 169         const u8 *addr[2];
 170         size_t len[2];
 171         u8 *tmp;
 172
 173         if (mac == NULL || wpabuf_len(req) < EAP_SIM_MAC_LEN ||
 174             mac < wpabuf_head_u8(req) ||
 175             mac > wpabuf_head_u8(req) + wpabuf_len(req) - EAP_SIM_MAC_LEN)
 176                 return -1;
 177
 178         tmp = os_memdup(wpabuf_head(req), wpabuf_len(req));
 179         if (tmp == NULL)
 180                 return -1;
 181
 182         addr[0] = tmp;
 183         len[0] = wpabuf_len(req);
 184         addr[1] = extra;
 185         len[1] = extra_len;
 186
 187         /* HMAC-SHA1-128 */
 188         os_memset(tmp + (mac - wpabuf_head_u8(req)), 0, EAP_SIM_MAC_LEN);
 189         wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Verify MAC - msg",
 190                     tmp, wpabuf_len(req));
 191         wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Verify MAC - extra data",
 192                     extra, extra_len);
 193         wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: Verify MAC - K_aut",
 194                         k_aut, EAP_SIM_K_AUT_LEN);
 195         hmac_sha1_vector(k_aut, EAP_SIM_K_AUT_LEN, 2, addr, len, hmac);
 196         wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Verify MAC: MAC",
 197                     hmac, EAP_SIM_MAC_LEN);
 198         os_free(tmp);
 199
 200         return (os_memcmp_const(hmac, mac, EAP_SIM_MAC_LEN) == 0) ? 0 : 1;
 201 }
 202
 203
 204 void eap_sim_add_mac(const u8 *k_aut, const u8 *msg, size_t msg_len, u8 *mac,
 205                      const u8 *extra, size_t extra_len)
 206 {
 207         unsigned char hmac[SHA1_MAC_LEN];
 208         const u8 *addr[2];
 209         size_t len[2];
 210
 211         addr[0] = msg;
 212         len[0] = msg_len;
 213         addr[1] = extra;
 214         len[1] = extra_len;
 215
 216         /* HMAC-SHA1-128 */
 217         os_memset(mac, 0, EAP_SIM_MAC_LEN);
 218         wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Add MAC - msg", msg, msg_len);
 219         wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Add MAC - extra data",
 220                     extra, extra_len);
 221         wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: Add MAC - K_aut",
 222                         k_aut, EAP_SIM_K_AUT_LEN);
 223         hmac_sha1_vector(k_aut, EAP_SIM_K_AUT_LEN, 2, addr, len, hmac);
 224         os_memcpy(mac, hmac, EAP_SIM_MAC_LEN);
 225         wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Add MAC: MAC",
 226                     mac, EAP_SIM_MAC_LEN);
 227 }
 228
 229
 230 #if defined(EAP_AKA_PRIME) || defined(EAP_SERVER_AKA_PRIME)
 231 static void prf_prime(const u8 *k, const char *seed1,
 232                       const u8 *seed2, size_t seed2_len,
 233                       const u8 *seed3, size_t seed3_len,
 234                       u8 *res, size_t res_len)
 235 {
 236         const u8 *addr[5];
 237         size_t len[5];
 238         u8 hash[SHA256_MAC_LEN];
 239         u8 iter;
 240
 241         /*
 242          * PRF'(K,S) = T1 | T2 | T3 | T4 | ...
 243          * T1 = HMAC-SHA-256 (K, S | 0x01)
 244          * T2 = HMAC-SHA-256 (K, T1 | S | 0x02)
 245          * T3 = HMAC-SHA-256 (K, T2 | S | 0x03)
 246          * T4 = HMAC-SHA-256 (K, T3 | S | 0x04)
 247          * ...
 248          */
 249
 250         addr[0] = hash;
 251         len[0] = 0;
 252         addr[1] = (const u8 *) seed1;
 253         len[1] = os_strlen(seed1);
 254         addr[2] = seed2;
 255         len[2] = seed2_len;
 256         addr[3] = seed3;
 257         len[3] = seed3_len;
 258         addr[4] = &iter;
 259         len[4] = 1;
 260
 261         iter = 0;
 262         while (res_len) {
 263                 size_t hlen;
 264                 iter++;
 265                 hmac_sha256_vector(k, 32, 5, addr, len, hash);
 266                 len[0] = SHA256_MAC_LEN;
 267                 hlen = res_len > SHA256_MAC_LEN ? SHA256_MAC_LEN : res_len;
 268                 os_memcpy(res, hash, hlen);
 269                 res += hlen;
 270                 res_len -= hlen;
 271         }
 272 }
 273
 274
 275 void eap_aka_prime_derive_keys(const u8 *identity, size_t identity_len,
 276                                const u8 *ik, const u8 *ck, u8 *k_encr,
 277                                u8 *k_aut, u8 *k_re, u8 *msk, u8 *emsk)
 278 {
 279         u8 key[EAP_AKA_IK_LEN + EAP_AKA_CK_LEN];
 280         u8 keys[EAP_SIM_K_ENCR_LEN + EAP_AKA_PRIME_K_AUT_LEN +
 281                 EAP_AKA_PRIME_K_RE_LEN + EAP_MSK_LEN + EAP_EMSK_LEN];
 282         u8 *pos;
 283
 284         /*
 285          * MK = PRF'(IK'|CK',"EAP-AKA'"|Identity)
 286          * K_encr = MK[0..127]
 287          * K_aut  = MK[128..383]
 288          * K_re   = MK[384..639]
 289          * MSK    = MK[640..1151]
 290          * EMSK   = MK[1152..1663]
 291          */
 292
 293         os_memcpy(key, ik, EAP_AKA_IK_LEN);
 294         os_memcpy(key + EAP_AKA_IK_LEN, ck, EAP_AKA_CK_LEN);
 295
 296         prf_prime(key, "EAP-AKA'", identity, identity_len, NULL, 0,
 297                   keys, sizeof(keys));
 298
 299         pos = keys;
 300         os_memcpy(k_encr, pos, EAP_SIM_K_ENCR_LEN);
 301         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': K_encr",
 302                         k_encr, EAP_SIM_K_ENCR_LEN);
 303         pos += EAP_SIM_K_ENCR_LEN;
 304
 305         os_memcpy(k_aut, pos, EAP_AKA_PRIME_K_AUT_LEN);
 306         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': K_aut",
 307                         k_aut, EAP_AKA_PRIME_K_AUT_LEN);
 308         pos += EAP_AKA_PRIME_K_AUT_LEN;
 309
 310         os_memcpy(k_re, pos, EAP_AKA_PRIME_K_RE_LEN);
 311         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': K_re",
 312                         k_re, EAP_AKA_PRIME_K_RE_LEN);
 313         pos += EAP_AKA_PRIME_K_RE_LEN;
 314
 315         os_memcpy(msk, pos, EAP_MSK_LEN);
 316         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': MSK", msk, EAP_MSK_LEN);
 317         pos += EAP_MSK_LEN;
 318
 319         os_memcpy(emsk, pos, EAP_EMSK_LEN);
 320         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': EMSK", emsk, EAP_EMSK_LEN);
 321 }
 322
 323
 324 int eap_aka_prime_derive_keys_reauth(const u8 *k_re, u16 counter,
 325                                      const u8 *identity, size_t identity_len,
 326                                      const u8 *nonce_s, u8 *msk, u8 *emsk)
 327 {
 328         u8 seed3[2 + EAP_SIM_NONCE_S_LEN];
 329         u8 keys[EAP_MSK_LEN + EAP_EMSK_LEN];
 330         u8 *pos;
 331
 332         /*
 333          * MK = PRF'(K_re,"EAP-AKA' re-auth"|Identity|counter|NONCE_S)
 334          * MSK  = MK[0..511]
 335          * EMSK = MK[512..1023]
 336          */
 337
 338         WPA_PUT_BE16(seed3, counter);
 339         os_memcpy(seed3 + 2, nonce_s, EAP_SIM_NONCE_S_LEN);
 340
 341         prf_prime(k_re, "EAP-AKA' re-auth", identity, identity_len,
 342                   seed3, sizeof(seed3),
 343                   keys, sizeof(keys));
 344
 345         pos = keys;
 346         os_memcpy(msk, pos, EAP_MSK_LEN);
 347         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': MSK", msk, EAP_MSK_LEN);
 348         pos += EAP_MSK_LEN;
 349
 350         os_memcpy(emsk, pos, EAP_EMSK_LEN);
 351         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': EMSK", emsk, EAP_EMSK_LEN);
 352
 353         os_memset(keys, 0, sizeof(keys));
 354
 355         return 0;
 356 }
 357
 358
 359 int eap_sim_verify_mac_sha256(const u8 *k_aut, const struct wpabuf *req,
 360                               const u8 *mac, const u8 *extra, size_t extra_len)
 361 {
 362         unsigned char hmac[SHA256_MAC_LEN];
 363         const u8 *addr[2];
 364         size_t len[2];
 365         u8 *tmp;
 366
 367         if (mac == NULL || wpabuf_len(req) < EAP_SIM_MAC_LEN ||
 368             mac < wpabuf_head_u8(req) ||
 369             mac > wpabuf_head_u8(req) + wpabuf_len(req) - EAP_SIM_MAC_LEN)
 370                 return -1;
 371
 372         tmp = os_memdup(wpabuf_head(req), wpabuf_len(req));
 373         if (tmp == NULL)
 374                 return -1;
 375
 376         addr[0] = tmp;
 377         len[0] = wpabuf_len(req);
 378         addr[1] = extra;
 379         len[1] = extra_len;
 380
 381         /* HMAC-SHA-256-128 */
 382         os_memset(tmp + (mac - wpabuf_head_u8(req)), 0, EAP_SIM_MAC_LEN);
 383         wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Verify MAC - msg",
 384                     tmp, wpabuf_len(req));
 385         wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Verify MAC - extra data",
 386                     extra, extra_len);
 387         wpa_hexdump_key(MSG_MSGDUMP, "EAP-AKA': Verify MAC - K_aut",
 388                         k_aut, EAP_AKA_PRIME_K_AUT_LEN);
 389         hmac_sha256_vector(k_aut, EAP_AKA_PRIME_K_AUT_LEN, 2, addr, len, hmac);
 390         wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Verify MAC: MAC",
 391                     hmac, EAP_SIM_MAC_LEN);
 392         os_free(tmp);
 393
 394         return (os_memcmp_const(hmac, mac, EAP_SIM_MAC_LEN) == 0) ? 0 : 1;
 395 }
 396
 397
 398 void eap_sim_add_mac_sha256(const u8 *k_aut, const u8 *msg, size_t msg_len,
 399                             u8 *mac, const u8 *extra, size_t extra_len)
 400 {
 401         unsigned char hmac[SHA256_MAC_LEN];
 402         const u8 *addr[2];
 403         size_t len[2];
 404
 405         addr[0] = msg;
 406         len[0] = msg_len;
 407         addr[1] = extra;
 408         len[1] = extra_len;
 409
 410         /* HMAC-SHA-256-128 */
 411         os_memset(mac, 0, EAP_SIM_MAC_LEN);
 412         wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Add MAC - msg", msg, msg_len);
 413         wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Add MAC - extra data",
 414                     extra, extra_len);
 415         wpa_hexdump_key(MSG_MSGDUMP, "EAP-AKA': Add MAC - K_aut",
 416                         k_aut, EAP_AKA_PRIME_K_AUT_LEN);
 417         hmac_sha256_vector(k_aut, EAP_AKA_PRIME_K_AUT_LEN, 2, addr, len, hmac);
 418         os_memcpy(mac, hmac, EAP_SIM_MAC_LEN);
 419         wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Add MAC: MAC",
 420                     mac, EAP_SIM_MAC_LEN);
 421 }
 422
 423
 424 void eap_aka_prime_derive_ck_ik_prime(u8 *ck, u8 *ik, const u8 *sqn_ak,
 425                                       const u8 *network_name,
 426                                       size_t network_name_len)
 427 {
 428         u8 key[EAP_AKA_CK_LEN + EAP_AKA_IK_LEN];
 429         u8 hash[SHA256_MAC_LEN];
 430         const u8 *addr[5];
 431         size_t len[5];
 432         u8 fc;
 433         u8 l0[2], l1[2];
 434
 435         /* 3GPP TS 33.402 V8.0.0
 436          * (CK', IK') = F(CK, IK, <access network identity>)
 437          */
 438         /* TODO: CK', IK' generation should really be moved into the actual
 439          * AKA procedure with network name passed in there and option to use
 440          * AMF separation bit = 1 (3GPP TS 33.401). */
 441
 442         /* Change Request 33.402 CR 0033 to version 8.1.1 from
 443          * 3GPP TSG-SA WG3 Meeting #53 in September 2008:
 444          *
 445          * CK' || IK' = HMAC-SHA-256(Key, S)
 446          * S = FC || P0 || L0 || P1 || L1 || ... || Pn || Ln
 447          * Key = CK || IK
 448          * FC = 0x20
 449          * P0 = access network identity (3GPP TS 24.302)
 450          * L0 = length of acceess network identity (2 octets, big endian)
 451          * P1 = SQN xor AK (if AK is not used, AK is treaded as 000..0
 452          * L1 = 0x00 0x06
 453          */
 454
 455         fc = 0x20;
 456
 457         wpa_printf(MSG_DEBUG, "EAP-AKA': Derive (CK',IK') from (CK,IK)");
 458         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': CK", ck, EAP_AKA_CK_LEN);
 459         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': IK", ik, EAP_AKA_IK_LEN);
 460         wpa_printf(MSG_DEBUG, "EAP-AKA': FC = 0x%x", fc);
 461         wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA': P0 = Access network identity",
 462                           network_name, network_name_len);
 463         wpa_hexdump(MSG_DEBUG, "EAP-AKA': P1 = SQN xor AK", sqn_ak, 6);
 464
 465         os_memcpy(key, ck, EAP_AKA_CK_LEN);
 466         os_memcpy(key + EAP_AKA_CK_LEN, ik, EAP_AKA_IK_LEN);
 467         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': Key = CK || IK",
 468                         key, sizeof(key));
 469
 470         addr[0] = &fc;
 471         len[0] = 1;
 472         addr[1] = network_name;
 473         len[1] = network_name_len;
 474         WPA_PUT_BE16(l0, network_name_len);
 475         addr[2] = l0;
 476         len[2] = 2;
 477         addr[3] = sqn_ak;
 478         len[3] = 6;
 479         WPA_PUT_BE16(l1, 6);
 480         addr[4] = l1;
 481         len[4] = 2;
 482
 483         hmac_sha256_vector(key, sizeof(key), 5, addr, len, hash);
 484         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': KDF output (CK' || IK')",
 485                         hash, sizeof(hash));
 486
 487         os_memcpy(ck, hash, EAP_AKA_CK_LEN);
 488         os_memcpy(ik, hash + EAP_AKA_CK_LEN, EAP_AKA_IK_LEN);
 489         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': CK'", ck, EAP_AKA_CK_LEN);
 490         wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': IK'", ik, EAP_AKA_IK_LEN);
 491 }
 492 #endif /* EAP_AKA_PRIME || EAP_SERVER_AKA_PRIME */
 493
 494
 495 int eap_sim_parse_attr(const u8 *start, const u8 *end,
 496                        struct eap_sim_attrs *attr, int aka, int encr)
 497 {
 498         const u8 *pos = start, *apos;
 499         size_t alen, plen, i, list_len;
 500
 501         os_memset(attr, 0, sizeof(*attr));
 502         attr->id_req = NO_ID_REQ;
 503         attr->notification = -1;
 504         attr->counter = -1;
 505         attr->selected_version = -1;
 506         attr->client_error_code = -1;
 507
 508         while (pos < end) {
 509                 if (pos + 2 > end) {
 510                         wpa_printf(MSG_INFO, "EAP-SIM: Attribute overflow(1)");
 511                         return -1;
 512                 }
 513                 wpa_printf(MSG_MSGDUMP, "EAP-SIM: Attribute: Type=%d Len=%d",
 514                            pos[0], pos[1] * 4);
 515                 if (pos + pos[1] * 4 > end) {
 516                         wpa_printf(MSG_INFO, "EAP-SIM: Attribute overflow "
 517                                    "(pos=%p len=%d end=%p)",
 518                                    pos, pos[1] * 4, end);
 519                         return -1;
 520                 }
 521                 if (pos[1] == 0) {
 522                         wpa_printf(MSG_INFO, "EAP-SIM: Attribute underflow");
 523                         return -1;
 524                 }
 525                 apos = pos + 2;
 526                 alen = pos[1] * 4 - 2;
 527                 wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Attribute data",
 528                             apos, alen);
 529
 530                 switch (pos[0]) {
 531                 case EAP_SIM_AT_RAND:
 532                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_RAND");
 533                         apos += 2;
 534                         alen -= 2;
 535                         if ((!aka && (alen % GSM_RAND_LEN)) ||
 536                             (aka && alen != EAP_AKA_RAND_LEN)) {
 537                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_RAND"
 538                                            " (len %lu)",
 539                                            (unsigned long) alen);
 540                                 return -1;
 541                         }
 542                         attr->rand = apos;
 543                         attr->num_chal = alen / GSM_RAND_LEN;
 544                         break;
 545                 case EAP_SIM_AT_AUTN:
 546                         wpa_printf(MSG_DEBUG, "EAP-AKA: AT_AUTN");
 547                         if (!aka) {
 548                                 wpa_printf(MSG_DEBUG, "EAP-SIM: "
 549                                            "Unexpected AT_AUTN");
 550                                 return -1;
 551                         }
 552                         apos += 2;
 553                         alen -= 2;
 554                         if (alen != EAP_AKA_AUTN_LEN) {
 555                                 wpa_printf(MSG_INFO, "EAP-AKA: Invalid AT_AUTN"
 556                                            " (len %lu)",
 557                                            (unsigned long) alen);
 558                                 return -1;
 559                         }
 560                         attr->autn = apos;
 561                         break;
 562                 case EAP_SIM_AT_PADDING:
 563                         if (!encr) {
 564                                 wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
 565                                            "AT_PADDING");
 566                                 return -1;
 567                         }
 568                         wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) AT_PADDING");
 569                         for (i = 2; i < alen; i++) {
 570                                 if (apos[i] != 0) {
 571                                         wpa_printf(MSG_INFO, "EAP-SIM: (encr) "
 572                                                    "AT_PADDING used a non-zero"
 573                                                    " padding byte");
 574                                         wpa_hexdump(MSG_DEBUG, "EAP-SIM: "
 575                                                     "(encr) padding bytes",
 576                                                     apos + 2, alen - 2);
 577                                         return -1;
 578                                 }
 579                         }
 580                         break;
 581                 case EAP_SIM_AT_NONCE_MT:
 582                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_NONCE_MT");
 583                         if (alen != 2 + EAP_SIM_NONCE_MT_LEN) {
 584                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
 585                                            "AT_NONCE_MT length");
 586                                 return -1;
 587                         }
 588                         attr->nonce_mt = apos + 2;
 589                         break;
 590                 case EAP_SIM_AT_PERMANENT_ID_REQ:
 591                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_PERMANENT_ID_REQ");
 592                         attr->id_req = PERMANENT_ID;
 593                         break;
 594                 case EAP_SIM_AT_MAC:
 595                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_MAC");
 596                         if (alen != 2 + EAP_SIM_MAC_LEN) {
 597                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_MAC "
 598                                            "length");
 599                                 return -1;
 600                         }
 601                         attr->mac = apos + 2;
 602                         break;
 603                 case EAP_SIM_AT_NOTIFICATION:
 604                         if (alen != 2) {
 605                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
 606                                            "AT_NOTIFICATION length %lu",
 607                                            (unsigned long) alen);
 608                                 return -1;
 609                         }
 610                         attr->notification = apos[0] * 256 + apos[1];
 611                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_NOTIFICATION %d",
 612                                    attr->notification);
 613                         break;
 614                 case EAP_SIM_AT_ANY_ID_REQ:
 615                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_ANY_ID_REQ");
 616                         attr->id_req = ANY_ID;
 617                         break;
 618                 case EAP_SIM_AT_IDENTITY:
 619                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_IDENTITY");
 620                         plen = WPA_GET_BE16(apos);
 621                         apos += 2;
 622                         alen -= 2;
 623                         if (plen > alen) {
 624                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
 625                                            "AT_IDENTITY (Actual Length %lu, "
 626                                            "remaining length %lu)",
 627                                            (unsigned long) plen,
 628                                            (unsigned long) alen);
 629                                 return -1;
 630                         }
 631
 632                         attr->identity = apos;
 633                         attr->identity_len = plen;
 634                         break;
 635                 case EAP_SIM_AT_VERSION_LIST:
 636                         if (aka) {
 637                                 wpa_printf(MSG_DEBUG, "EAP-AKA: "
 638                                            "Unexpected AT_VERSION_LIST");
 639                                 return -1;
 640                         }
 641                         list_len = apos[0] * 256 + apos[1];
 642                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_VERSION_LIST");
 643                         if (list_len < 2 || list_len > alen - 2) {
 644                                 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
 645                                            "AT_VERSION_LIST (list_len=%lu "
 646                                            "attr_len=%lu)",
 647                                            (unsigned long) list_len,
 648                                            (unsigned long) alen);
 649                                 return -1;
 650                         }
 651                         attr->version_list = apos + 2;
 652                         attr->version_list_len = list_len;
 653                         break;
 654                 case EAP_SIM_AT_SELECTED_VERSION:
 655                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_SELECTED_VERSION");
 656                         if (alen != 2) {
 657                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
 658                                            "AT_SELECTED_VERSION length %lu",
 659                                            (unsigned long) alen);
 660                                 return -1;
 661                         }
 662                         attr->selected_version = apos[0] * 256 + apos[1];
 663                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_SELECTED_VERSION "
 664                                    "%d", attr->selected_version);
 665                         break;
 666                 case EAP_SIM_AT_FULLAUTH_ID_REQ:
 667                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_FULLAUTH_ID_REQ");
 668                         attr->id_req = FULLAUTH_ID;
 669                         break;
 670                 case EAP_SIM_AT_COUNTER:
 671                         if (!encr) {
 672                                 wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
 673                                            "AT_COUNTER");
 674                                 return -1;
 675                         }
 676                         if (alen != 2) {
 677                                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid "
 678                                            "AT_COUNTER (alen=%lu)",
 679                                            (unsigned long) alen);
 680                                 return -1;
 681                         }
 682                         attr->counter = apos[0] * 256 + apos[1];
 683                         wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) AT_COUNTER %d",
 684                                    attr->counter);
 685                         break;
 686                 case EAP_SIM_AT_COUNTER_TOO_SMALL:
 687                         if (!encr) {
 688                                 wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
 689                                            "AT_COUNTER_TOO_SMALL");
 690                                 return -1;
 691                         }
 692                         if (alen != 2) {
 693                                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid "
 694                                            "AT_COUNTER_TOO_SMALL (alen=%lu)",
 695                                            (unsigned long) alen);
 696                                 return -1;
 697                         }
 698                         wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
 699                                    "AT_COUNTER_TOO_SMALL");
 700                         attr->counter_too_small = 1;
 701                         break;
 702                 case EAP_SIM_AT_NONCE_S:
 703                         if (!encr) {
 704                                 wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
 705                                            "AT_NONCE_S");
 706                                 return -1;
 707                         }
 708                         wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
 709                                    "AT_NONCE_S");
 710                         if (alen != 2 + EAP_SIM_NONCE_S_LEN) {
 711                                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid "
 712                                            "AT_NONCE_S (alen=%lu)",
 713                                            (unsigned long) alen);
 714                                 return -1;
 715                         }
 716                         attr->nonce_s = apos + 2;
 717                         break;
 718                 case EAP_SIM_AT_CLIENT_ERROR_CODE:
 719                         if (alen != 2) {
 720                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
 721                                            "AT_CLIENT_ERROR_CODE length %lu",
 722                                            (unsigned long) alen);
 723                                 return -1;
 724                         }
 725                         attr->client_error_code = apos[0] * 256 + apos[1];
 726                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_CLIENT_ERROR_CODE "
 727                                    "%d", attr->client_error_code);
 728                         break;
 729                 case EAP_SIM_AT_IV:
 730                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_IV");
 731                         if (alen != 2 + EAP_SIM_MAC_LEN) {
 732                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_IV "
 733                                            "length %lu", (unsigned long) alen);
 734                                 return -1;
 735                         }
 736                         attr->iv = apos + 2;
 737                         break;
 738                 case EAP_SIM_AT_ENCR_DATA:
 739                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_ENCR_DATA");
 740                         attr->encr_data = apos + 2;
 741                         attr->encr_data_len = alen - 2;
 742                         if (attr->encr_data_len % 16) {
 743                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
 744                                            "AT_ENCR_DATA length %lu",
 745                                            (unsigned long)
 746                                            attr->encr_data_len);
 747                                 return -1;
 748                         }
 749                         break;
 750                 case EAP_SIM_AT_NEXT_PSEUDONYM:
 751                         if (!encr) {
 752                                 wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
 753                                            "AT_NEXT_PSEUDONYM");
 754                                 return -1;
 755                         }
 756                         wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
 757                                    "AT_NEXT_PSEUDONYM");
 758                         plen = apos[0] * 256 + apos[1];
 759                         if (plen > alen - 2) {
 760                                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid"
 761                                            " AT_NEXT_PSEUDONYM (actual"
 762                                            " len %lu, attr len %lu)",
 763                                            (unsigned long) plen,
 764                                            (unsigned long) alen);
 765                                 return -1;
 766                         }
 767                         attr->next_pseudonym = pos + 4;
 768                         attr->next_pseudonym_len = plen;
 769                         break;
 770                 case EAP_SIM_AT_NEXT_REAUTH_ID:
 771                         if (!encr) {
 772                                 wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
 773                                            "AT_NEXT_REAUTH_ID");
 774                                 return -1;
 775                         }
 776                         wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
 777                                    "AT_NEXT_REAUTH_ID");
 778                         plen = apos[0] * 256 + apos[1];
 779                         if (plen > alen - 2) {
 780                                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid"
 781                                            " AT_NEXT_REAUTH_ID (actual"
 782                                            " len %lu, attr len %lu)",
 783                                            (unsigned long) plen,
 784                                            (unsigned long) alen);
 785                                 return -1;
 786                         }
 787                         attr->next_reauth_id = pos + 4;
 788                         attr->next_reauth_id_len = plen;
 789                         break;
 790                 case EAP_SIM_AT_RES:
 791                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_RES");
 792                         attr->res_len_bits = WPA_GET_BE16(apos);
 793                         apos += 2;
 794                         alen -= 2;
 795                         if (!aka || alen < EAP_AKA_MIN_RES_LEN ||
 796                             alen > EAP_AKA_MAX_RES_LEN) {
 797                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_RES "
 798                                            "(len %lu)",
 799                                            (unsigned long) alen);
 800                                 return -1;
 801                         }
 802                         attr->res = apos;
 803                         attr->res_len = alen;
 804                         break;
 805                 case EAP_SIM_AT_AUTS:
 806                         wpa_printf(MSG_DEBUG, "EAP-AKA: AT_AUTS");
 807                         if (!aka) {
 808                                 wpa_printf(MSG_DEBUG, "EAP-SIM: "
 809                                            "Unexpected AT_AUTS");
 810                                 return -1;
 811                         }
 812                         if (alen != EAP_AKA_AUTS_LEN) {
 813                                 wpa_printf(MSG_INFO, "EAP-AKA: Invalid AT_AUTS"
 814                                            " (len %lu)",
 815                                            (unsigned long) alen);
 816                                 return -1;
 817                         }
 818                         attr->auts = apos;
 819                         break;
 820                 case EAP_SIM_AT_CHECKCODE:
 821                         wpa_printf(MSG_DEBUG, "EAP-AKA: AT_CHECKCODE");
 822                         if (!aka) {
 823                                 wpa_printf(MSG_DEBUG, "EAP-SIM: "
 824                                            "Unexpected AT_CHECKCODE");
 825                                 return -1;
 826                         }
 827                         apos += 2;
 828                         alen -= 2;
 829                         if (alen != 0 && alen != EAP_AKA_CHECKCODE_LEN &&
 830                             alen != EAP_AKA_PRIME_CHECKCODE_LEN) {
 831                                 wpa_printf(MSG_INFO, "EAP-AKA: Invalid "
 832                                            "AT_CHECKCODE (len %lu)",
 833                                            (unsigned long) alen);
 834                                 return -1;
 835                         }
 836                         attr->checkcode = apos;
 837                         attr->checkcode_len = alen;
 838                         break;
 839                 case EAP_SIM_AT_RESULT_IND:
 840                         if (encr) {
 841                                 wpa_printf(MSG_ERROR, "EAP-SIM: Encrypted "
 842                                            "AT_RESULT_IND");
 843                                 return -1;
 844                         }
 845                         if (alen != 2) {
 846                                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
 847                                            "AT_RESULT_IND (alen=%lu)",
 848                                            (unsigned long) alen);
 849                                 return -1;
 850                         }
 851                         wpa_printf(MSG_DEBUG, "EAP-SIM: AT_RESULT_IND");
 852                         attr->result_ind = 1;
 853                         break;
 854 #if defined(EAP_AKA_PRIME) || defined(EAP_SERVER_AKA_PRIME)
 855                 case EAP_SIM_AT_KDF_INPUT:
 856                         if (aka != 2) {
 857                                 wpa_printf(MSG_INFO, "EAP-AKA: Unexpected "
 858                                            "AT_KDF_INPUT");
 859                                 return -1;
 860                         }
 861
 862                         wpa_printf(MSG_DEBUG, "EAP-AKA: AT_KDF_INPUT");
 863                         plen = WPA_GET_BE16(apos);
 864                         apos += 2;
 865                         alen -= 2;
 866                         if (plen > alen) {
 867                                 wpa_printf(MSG_INFO, "EAP-AKA': Invalid "
 868                                            "AT_KDF_INPUT (Actual Length %lu, "
 869                                            "remaining length %lu)",
 870                                            (unsigned long) plen,
 871                                            (unsigned long) alen);
 872                                 return -1;
 873                         }
 874                         attr->kdf_input = apos;
 875                         attr->kdf_input_len = plen;
 876                         break;
 877                 case EAP_SIM_AT_KDF:
 878                         if (aka != 2) {
 879                                 wpa_printf(MSG_INFO, "EAP-AKA: Unexpected "
 880                                            "AT_KDF");
 881                                 return -1;
 882                         }
 883
 884                         wpa_printf(MSG_DEBUG, "EAP-AKA: AT_KDF");
 885                         if (alen != 2) {
 886                                 wpa_printf(MSG_INFO, "EAP-AKA': Invalid "
 887                                            "AT_KDF (len %lu)",
 888                                            (unsigned long) alen);
 889                                 return -1;
 890                         }
 891                         if (attr->kdf_count == EAP_AKA_PRIME_KDF_MAX) {
 892                                 wpa_printf(MSG_DEBUG, "EAP-AKA': Too many "
 893                                            "AT_KDF attributes - ignore this");
 894                                 break;
 895                         }
 896                         attr->kdf[attr->kdf_count] = WPA_GET_BE16(apos);
 897                         attr->kdf_count++;
 898                         break;
 899                 case EAP_SIM_AT_BIDDING:
 900                         wpa_printf(MSG_DEBUG, "EAP-AKA: AT_BIDDING");
 901                         if (alen != 2) {
 902                                 wpa_printf(MSG_INFO, "EAP-AKA: Invalid "
 903                                            "AT_BIDDING (len %lu)",
 904                                            (unsigned long) alen);
 905                                 return -1;
 906                         }
 907                         attr->bidding = apos;
 908                         break;
 909 #endif /* EAP_AKA_PRIME || EAP_SERVER_AKA_PRIME */
 910                 default:
 911                         if (pos[0] < 128) {
 912                                 wpa_printf(MSG_INFO, "EAP-SIM: Unrecognized "
 913                                            "non-skippable attribute %d",
 914                                            pos[0]);
 915                                 return -1;
 916                         }
 917
 918                         wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized skippable"
 919                                    " attribute %d ignored", pos[0]);
 920                         break;
 921                 }
 922
 923                 pos += pos[1] * 4;
 924         }
 925
 926         wpa_printf(MSG_DEBUG, "EAP-SIM: Attributes parsed successfully "
 927                    "(aka=%d encr=%d)", aka, encr);
 928
 929         return 0;
 930 }
 931
 932
 933 u8 * eap_sim_parse_encr(const u8 *k_encr, const u8 *encr_data,
 934                         size_t encr_data_len, const u8 *iv,
 935                         struct eap_sim_attrs *attr, int aka)
 936 {
 937         u8 *decrypted;
 938
 939         if (!iv) {
 940                 wpa_printf(MSG_INFO, "EAP-SIM: Encrypted data, but no IV");
 941                 return NULL;
 942         }
 943
 944         decrypted = os_memdup(encr_data, encr_data_len);
 945         if (decrypted == NULL)
 946                 return NULL;
 947
 948         if (aes_128_cbc_decrypt(k_encr, iv, decrypted, encr_data_len)) {
 949                 os_free(decrypted);
 950                 return NULL;
 951         }
 952         wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Decrypted AT_ENCR_DATA",
 953                     decrypted, encr_data_len);
 954
 955         if (eap_sim_parse_attr(decrypted, decrypted + encr_data_len, attr,
 956                                aka, 1)) {
 957                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Failed to parse "
 958                            "decrypted AT_ENCR_DATA");
 959                 os_free(decrypted);
 960                 return NULL;
 961         }
 962
 963         return decrypted;
 964 }
 965
 966
 967 #define EAP_SIM_INIT_LEN 128
 968
 969 struct eap_sim_msg {
 970         struct wpabuf *buf;
 971         size_t mac, iv, encr; /* index from buf */
 972 };
 973
 974
 975 struct eap_sim_msg * eap_sim_msg_init(int code, int id, int type, int subtype)
 976 {
 977         struct eap_sim_msg *msg;
 978         struct eap_hdr *eap;
 979         u8 *pos;
 980
 981         msg = os_zalloc(sizeof(*msg));
 982         if (msg == NULL)
 983                 return NULL;
 984
 985         msg->buf = wpabuf_alloc(EAP_SIM_INIT_LEN);
 986         if (msg->buf == NULL) {
 987                 os_free(msg);
 988                 return NULL;
 989         }
 990         eap = wpabuf_put(msg->buf, sizeof(*eap));
 991         eap->code = code;
 992         eap->identifier = id;
 993
 994         pos = wpabuf_put(msg->buf, 4);
 995         *pos++ = type;
 996         *pos++ = subtype;
 997         *pos++ = 0; /* Reserved */
 998         *pos++ = 0; /* Reserved */
 999
1000         return msg;
1001 }
1002
1003
1004 struct wpabuf * eap_sim_msg_finish(struct eap_sim_msg *msg, int type,
1005                                    const u8 *k_aut,
1006                                    const u8 *extra, size_t extra_len)
1007 {
1008         struct eap_hdr *eap;
1009         struct wpabuf *buf;
1010
1011         if (msg == NULL)
1012                 return NULL;
1013
1014         eap = wpabuf_mhead(msg->buf);
1015         eap->length = host_to_be16(wpabuf_len(msg->buf));
1016
1017 #if defined(EAP_AKA_PRIME) || defined(EAP_SERVER_AKA_PRIME)
1018         if (k_aut && msg->mac && type == EAP_TYPE_AKA_PRIME) {
1019                 eap_sim_add_mac_sha256(k_aut, (u8 *) wpabuf_head(msg->buf),
1020                                        wpabuf_len(msg->buf),
1021                                        (u8 *) wpabuf_mhead(msg->buf) +
1022                                        msg->mac, extra, extra_len);
1023         } else
1024 #endif /* EAP_AKA_PRIME || EAP_SERVER_AKA_PRIME */
1025         if (k_aut && msg->mac) {
1026                 eap_sim_add_mac(k_aut, (u8 *) wpabuf_head(msg->buf),
1027                                 wpabuf_len(msg->buf),
1028                                 (u8 *) wpabuf_mhead(msg->buf) + msg->mac,
1029                                 extra, extra_len);
1030         }
1031
1032         buf = msg->buf;
1033         os_free(msg);
1034         return buf;
1035 }
1036
1037
1038 void eap_sim_msg_free(struct eap_sim_msg *msg)
1039 {
1040         if (msg) {
1041                 wpabuf_free(msg->buf);
1042                 os_free(msg);
1043         }
1044 }
1045
1046
1047 u8 * eap_sim_msg_add_full(struct eap_sim_msg *msg, u8 attr,
1048                           const u8 *data, size_t len)
1049 {
1050         int attr_len = 2 + len;
1051         int pad_len;
1052         u8 *start;
1053
1054         if (msg == NULL)
1055                 return NULL;
1056
1057         pad_len = (4 - attr_len % 4) % 4;
1058         attr_len += pad_len;
1059         if (wpabuf_resize(&msg->buf, attr_len))
1060                 return NULL;
1061         start = wpabuf_put(msg->buf, 0);
1062         wpabuf_put_u8(msg->buf, attr);
1063         wpabuf_put_u8(msg->buf, attr_len / 4);
1064         wpabuf_put_data(msg->buf, data, len);
1065         if (pad_len)
1066                 os_memset(wpabuf_put(msg->buf, pad_len), 0, pad_len);
1067         return start;
1068 }
1069
1070
1071 u8 * eap_sim_msg_add(struct eap_sim_msg *msg, u8 attr, u16 value,
1072                      const u8 *data, size_t len)
1073 {
1074         int attr_len = 4 + len;
1075         int pad_len;
1076         u8 *start;
1077
1078         if (msg == NULL)
1079                 return NULL;
1080
1081         pad_len = (4 - attr_len % 4) % 4;
1082         attr_len += pad_len;
1083         if (wpabuf_resize(&msg->buf, attr_len))
1084                 return NULL;
1085         start = wpabuf_put(msg->buf, 0);
1086         wpabuf_put_u8(msg->buf, attr);
1087         wpabuf_put_u8(msg->buf, attr_len / 4);
1088         wpabuf_put_be16(msg->buf, value);
1089         if (data)
1090                 wpabuf_put_data(msg->buf, data, len);
1091         else
1092                 wpabuf_put(msg->buf, len);
1093         if (pad_len)
1094                 os_memset(wpabuf_put(msg->buf, pad_len), 0, pad_len);
1095         return start;
1096 }
1097
1098
1099 u8 * eap_sim_msg_add_mac(struct eap_sim_msg *msg, u8 attr)
1100 {
1101         u8 *pos = eap_sim_msg_add(msg, attr, 0, NULL, EAP_SIM_MAC_LEN);
1102         if (pos)
1103                 msg->mac = (pos - wpabuf_head_u8(msg->buf)) + 4;
1104         return pos;
1105 }
1106
1107
1108 int eap_sim_msg_add_encr_start(struct eap_sim_msg *msg, u8 attr_iv,
1109                                u8 attr_encr)
1110 {
1111         u8 *pos = eap_sim_msg_add(msg, attr_iv, 0, NULL, EAP_SIM_IV_LEN);
1112         if (pos == NULL)
1113                 return -1;
1114         msg->iv = (pos - wpabuf_head_u8(msg->buf)) + 4;
1115         if (random_get_bytes(wpabuf_mhead_u8(msg->buf) + msg->iv,
1116                              EAP_SIM_IV_LEN)) {
1117                 msg->iv = 0;
1118                 return -1;
1119         }
1120
1121         pos = eap_sim_msg_add(msg, attr_encr, 0, NULL, 0);
1122         if (pos == NULL) {
1123                 msg->iv = 0;
1124                 return -1;
1125         }
1126         msg->encr = pos - wpabuf_head_u8(msg->buf);
1127
1128         return 0;
1129 }
1130
1131
1132 int eap_sim_msg_add_encr_end(struct eap_sim_msg *msg, u8 *k_encr, int attr_pad)
1133 {
1134         size_t encr_len;
1135
1136         if (msg == NULL || k_encr == NULL || msg->iv == 0 || msg->encr == 0)
1137                 return -1;
1138
1139         encr_len = wpabuf_len(msg->buf) - msg->encr - 4;
1140         if (encr_len % 16) {
1141                 u8 *pos;
1142                 int pad_len = 16 - (encr_len % 16);
1143                 if (pad_len < 4) {
1144                         wpa_printf(MSG_WARNING, "EAP-SIM: "
1145                                    "eap_sim_msg_add_encr_end - invalid pad_len"
1146                                    " %d", pad_len);
1147                         return -1;
1148                 }
1149                 wpa_printf(MSG_DEBUG, "   *AT_PADDING");
1150                 pos = eap_sim_msg_add(msg, attr_pad, 0, NULL, pad_len - 4);
1151                 if (pos == NULL)
1152                         return -1;
1153                 os_memset(pos + 4, 0, pad_len - 4);
1154                 encr_len += pad_len;
1155         }
1156         wpa_printf(MSG_DEBUG, "   (AT_ENCR_DATA data len %lu)",
1157                    (unsigned long) encr_len);
1158         wpabuf_mhead_u8(msg->buf)[msg->encr + 1] = encr_len / 4 + 1;
1159         return aes_128_cbc_encrypt(k_encr, wpabuf_head_u8(msg->buf) + msg->iv,
1160                                    wpabuf_mhead_u8(msg->buf) + msg->encr + 4,
1161                                    encr_len);
1162 }
1163
1164
1165 void eap_sim_report_notification(void *msg_ctx, int notification, int aka)
1166 {
1167 #ifndef CONFIG_NO_STDOUT_DEBUG
1168         const char *type = aka ? "AKA" : "SIM";
1169 #endif /* CONFIG_NO_STDOUT_DEBUG */
1170
1171         switch (notification) {
1172         case EAP_SIM_GENERAL_FAILURE_AFTER_AUTH:
1173                 wpa_printf(MSG_WARNING, "EAP-%s: General failure "
1174                            "notification (after authentication)", type);
1175                 break;
1176         case EAP_SIM_TEMPORARILY_DENIED:
1177                 wpa_printf(MSG_WARNING, "EAP-%s: Failure notification: "
1178                            "User has been temporarily denied access to the "
1179                            "requested service", type);
1180                 break;
1181         case EAP_SIM_NOT_SUBSCRIBED:
1182                 wpa_printf(MSG_WARNING, "EAP-%s: Failure notification: "
1183                            "User has not subscribed to the requested service",
1184                            type);
1185                 break;
1186         case EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH:
1187                 wpa_printf(MSG_WARNING, "EAP-%s: General failure "
1188                            "notification (before authentication)", type);
1189                 break;
1190         case EAP_SIM_SUCCESS:
1191                 wpa_printf(MSG_INFO, "EAP-%s: Successful authentication "
1192                            "notification", type);
1193                 break;
1194         default:
1195                 if (notification >= 32768) {
1196                         wpa_printf(MSG_INFO, "EAP-%s: Unrecognized "
1197                                    "non-failure notification %d",
1198                                    type, notification);
1199                 } else {
1200                         wpa_printf(MSG_WARNING, "EAP-%s: Unrecognized "
1201                                    "failure notification %d",
1202                                    type, notification);
1203                 }
1204         }
1205 }