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00018 #include "includes.h"
00019
00020 #include "common.h"
00021 #include "crypto/aes_wrap.h"
00022 #include "eap_common/eap_psk_common.h"
00023 #include "eap_server/eap_i.h"
00024
00025
00026 struct eap_psk_data {
00027 enum { PSK_1, PSK_3, SUCCESS, FAILURE } state;
00028 u8 rand_s[EAP_PSK_RAND_LEN];
00029 u8 rand_p[EAP_PSK_RAND_LEN];
00030 u8 *id_p, *id_s;
00031 size_t id_p_len, id_s_len;
00032 u8 ak[EAP_PSK_AK_LEN], kdk[EAP_PSK_KDK_LEN], tek[EAP_PSK_TEK_LEN];
00033 u8 msk[EAP_MSK_LEN];
00034 u8 emsk[EAP_EMSK_LEN];
00035 };
00036
00037
00038 static void * eap_psk_init(struct eap_sm *sm)
00039 {
00040 struct eap_psk_data *data;
00041
00042 data = os_zalloc(sizeof(*data));
00043 if (data == NULL)
00044 return NULL;
00045 data->state = PSK_1;
00046 data->id_s = (u8 *) "hostapd";
00047 data->id_s_len = 7;
00048
00049 return data;
00050 }
00051
00052
00053 static void eap_psk_reset(struct eap_sm *sm, void *priv)
00054 {
00055 struct eap_psk_data *data = priv;
00056 os_free(data->id_p);
00057 os_free(data);
00058 }
00059
00060
00061 static struct wpabuf * eap_psk_build_1(struct eap_sm *sm,
00062 struct eap_psk_data *data, u8 id)
00063 {
00064 struct wpabuf *req;
00065 struct eap_psk_hdr_1 *psk;
00066
00067 wpa_printf(MSG_DEBUG, "EAP-PSK: PSK-1 (sending)");
00068
00069 if (os_get_random(data->rand_s, EAP_PSK_RAND_LEN)) {
00070 wpa_printf(MSG_ERROR, "EAP-PSK: Failed to get random data");
00071 data->state = FAILURE;
00072 return NULL;
00073 }
00074 wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: RAND_S (server rand)",
00075 data->rand_s, EAP_PSK_RAND_LEN);
00076
00077 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
00078 sizeof(*psk) + data->id_s_len,
00079 EAP_CODE_REQUEST, id);
00080 if (req == NULL) {
00081 wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory "
00082 "request");
00083 data->state = FAILURE;
00084 return NULL;
00085 }
00086
00087 psk = wpabuf_put(req, sizeof(*psk));
00088 psk->flags = EAP_PSK_FLAGS_SET_T(0);
00089 os_memcpy(psk->rand_s, data->rand_s, EAP_PSK_RAND_LEN);
00090 wpabuf_put_data(req, data->id_s, data->id_s_len);
00091
00092 return req;
00093 }
00094
00095
00096 static struct wpabuf * eap_psk_build_3(struct eap_sm *sm,
00097 struct eap_psk_data *data, u8 id)
00098 {
00099 struct wpabuf *req;
00100 struct eap_psk_hdr_3 *psk;
00101 u8 *buf, *pchannel, nonce[16];
00102 size_t buflen;
00103
00104 wpa_printf(MSG_DEBUG, "EAP-PSK: PSK-3 (sending)");
00105
00106 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PSK,
00107 sizeof(*psk) + 4 + 16 + 1, EAP_CODE_REQUEST, id);
00108 if (req == NULL) {
00109 wpa_printf(MSG_ERROR, "EAP-PSK: Failed to allocate memory "
00110 "request");
00111 data->state = FAILURE;
00112 return NULL;
00113 }
00114
00115 psk = wpabuf_put(req, sizeof(*psk));
00116 psk->flags = EAP_PSK_FLAGS_SET_T(2);
00117 os_memcpy(psk->rand_s, data->rand_s, EAP_PSK_RAND_LEN);
00118
00119
00120 buflen = data->id_s_len + EAP_PSK_RAND_LEN;
00121 buf = os_malloc(buflen);
00122 if (buf == NULL)
00123 goto fail;
00124
00125 os_memcpy(buf, data->id_s, data->id_s_len);
00126 os_memcpy(buf + data->id_s_len, data->rand_p, EAP_PSK_RAND_LEN);
00127 if (omac1_aes_128(data->ak, buf, buflen, psk->mac_s))
00128 goto fail;
00129 os_free(buf);
00130
00131 if (eap_psk_derive_keys(data->kdk, data->rand_p, data->tek, data->msk,
00132 data->emsk))
00133 goto fail;
00134 wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: TEK", data->tek, EAP_PSK_TEK_LEN);
00135 wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: MSK", data->msk, EAP_MSK_LEN);
00136 wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: EMSK", data->emsk, EAP_EMSK_LEN);
00137
00138 os_memset(nonce, 0, sizeof(nonce));
00139 pchannel = wpabuf_put(req, 4 + 16 + 1);
00140 os_memcpy(pchannel, nonce + 12, 4);
00141 os_memset(pchannel + 4, 0, 16);
00142 pchannel[4 + 16] = EAP_PSK_R_FLAG_DONE_SUCCESS << 6;
00143 wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL (plaintext)",
00144 pchannel, 4 + 16 + 1);
00145 if (aes_128_eax_encrypt(data->tek, nonce, sizeof(nonce),
00146 wpabuf_head(req), 22,
00147 pchannel + 4 + 16, 1, pchannel + 4))
00148 goto fail;
00149 wpa_hexdump(MSG_DEBUG, "EAP-PSK: PCHANNEL (encrypted)",
00150 pchannel, 4 + 16 + 1);
00151
00152 return req;
00153
00154 fail:
00155 wpabuf_free(req);
00156 data->state = FAILURE;
00157 return NULL;
00158 }
00159
00160
00161 static struct wpabuf * eap_psk_buildReq(struct eap_sm *sm, void *priv, u8 id)
00162 {
00163 struct eap_psk_data *data = priv;
00164
00165 switch (data->state) {
00166 case PSK_1:
00167 return eap_psk_build_1(sm, data, id);
00168 case PSK_3:
00169 return eap_psk_build_3(sm, data, id);
00170 default:
00171 wpa_printf(MSG_DEBUG, "EAP-PSK: Unknown state %d in buildReq",
00172 data->state);
00173 break;
00174 }
00175 return NULL;
00176 }
00177
00178
00179 static Boolean eap_psk_check(struct eap_sm *sm, void *priv,
00180 struct wpabuf *respData)
00181 {
00182 struct eap_psk_data *data = priv;
00183 size_t len;
00184 u8 t;
00185 const u8 *pos;
00186
00187 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &len);
00188 if (pos == NULL || len < 1) {
00189 wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
00190 return TRUE;
00191 }
00192 t = EAP_PSK_FLAGS_GET_T(*pos);
00193
00194 wpa_printf(MSG_DEBUG, "EAP-PSK: received frame: T=%d", t);
00195
00196 if (data->state == PSK_1 && t != 1) {
00197 wpa_printf(MSG_DEBUG, "EAP-PSK: Expected PSK-2 - "
00198 "ignore T=%d", t);
00199 return TRUE;
00200 }
00201
00202 if (data->state == PSK_3 && t != 3) {
00203 wpa_printf(MSG_DEBUG, "EAP-PSK: Expected PSK-4 - "
00204 "ignore T=%d", t);
00205 return TRUE;
00206 }
00207
00208 if ((t == 1 && len < sizeof(struct eap_psk_hdr_2)) ||
00209 (t == 3 && len < sizeof(struct eap_psk_hdr_4))) {
00210 wpa_printf(MSG_DEBUG, "EAP-PSK: Too short frame");
00211 return TRUE;
00212 }
00213
00214 return FALSE;
00215 }
00216
00217
00218 static void eap_psk_process_2(struct eap_sm *sm,
00219 struct eap_psk_data *data,
00220 struct wpabuf *respData)
00221 {
00222 const struct eap_psk_hdr_2 *resp;
00223 u8 *pos, mac[EAP_PSK_MAC_LEN], *buf;
00224 size_t left, buflen;
00225 int i;
00226 const u8 *cpos;
00227
00228 if (data->state != PSK_1)
00229 return;
00230
00231 wpa_printf(MSG_DEBUG, "EAP-PSK: Received PSK-2");
00232
00233 cpos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData,
00234 &left);
00235 if (cpos == NULL || left < sizeof(*resp)) {
00236 wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
00237 return;
00238 }
00239 resp = (const struct eap_psk_hdr_2 *) cpos;
00240 cpos = (const u8 *) (resp + 1);
00241 left -= sizeof(*resp);
00242
00243 os_free(data->id_p);
00244 data->id_p = os_malloc(left);
00245 if (data->id_p == NULL) {
00246 wpa_printf(MSG_INFO, "EAP-PSK: Failed to allocate memory for "
00247 "ID_P");
00248 return;
00249 }
00250 os_memcpy(data->id_p, cpos, left);
00251 data->id_p_len = left;
00252 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PSK: ID_P",
00253 data->id_p, data->id_p_len);
00254
00255 if (eap_user_get(sm, data->id_p, data->id_p_len, 0) < 0) {
00256 wpa_hexdump_ascii(MSG_DEBUG, "EAP-PSK: unknown ID_P",
00257 data->id_p, data->id_p_len);
00258 data->state = FAILURE;
00259 return;
00260 }
00261
00262 for (i = 0;
00263 i < EAP_MAX_METHODS &&
00264 (sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
00265 sm->user->methods[i].method != EAP_TYPE_NONE);
00266 i++) {
00267 if (sm->user->methods[i].vendor == EAP_VENDOR_IETF &&
00268 sm->user->methods[i].method == EAP_TYPE_PSK)
00269 break;
00270 }
00271
00272 if (i >= EAP_MAX_METHODS ||
00273 sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
00274 sm->user->methods[i].method != EAP_TYPE_PSK) {
00275 wpa_hexdump_ascii(MSG_DEBUG,
00276 "EAP-PSK: EAP-PSK not enabled for ID_P",
00277 data->id_p, data->id_p_len);
00278 data->state = FAILURE;
00279 return;
00280 }
00281
00282 if (sm->user->password == NULL ||
00283 sm->user->password_len != EAP_PSK_PSK_LEN) {
00284 wpa_hexdump_ascii(MSG_DEBUG, "EAP-PSK: invalid password in "
00285 "user database for ID_P",
00286 data->id_p, data->id_p_len);
00287 data->state = FAILURE;
00288 return;
00289 }
00290 if (eap_psk_key_setup(sm->user->password, data->ak, data->kdk)) {
00291 data->state = FAILURE;
00292 return;
00293 }
00294 wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: AK", data->ak, EAP_PSK_AK_LEN);
00295 wpa_hexdump_key(MSG_DEBUG, "EAP-PSK: KDK", data->kdk, EAP_PSK_KDK_LEN);
00296
00297 wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: RAND_P (client rand)",
00298 resp->rand_p, EAP_PSK_RAND_LEN);
00299 os_memcpy(data->rand_p, resp->rand_p, EAP_PSK_RAND_LEN);
00300
00301
00302 buflen = data->id_p_len + data->id_s_len + 2 * EAP_PSK_RAND_LEN;
00303 buf = os_malloc(buflen);
00304 if (buf == NULL) {
00305 data->state = FAILURE;
00306 return;
00307 }
00308 os_memcpy(buf, data->id_p, data->id_p_len);
00309 pos = buf + data->id_p_len;
00310 os_memcpy(pos, data->id_s, data->id_s_len);
00311 pos += data->id_s_len;
00312 os_memcpy(pos, data->rand_s, EAP_PSK_RAND_LEN);
00313 pos += EAP_PSK_RAND_LEN;
00314 os_memcpy(pos, data->rand_p, EAP_PSK_RAND_LEN);
00315 if (omac1_aes_128(data->ak, buf, buflen, mac)) {
00316 os_free(buf);
00317 data->state = FAILURE;
00318 return;
00319 }
00320 os_free(buf);
00321 wpa_hexdump(MSG_DEBUG, "EAP-PSK: MAC_P", resp->mac_p, EAP_PSK_MAC_LEN);
00322 if (os_memcmp(mac, resp->mac_p, EAP_PSK_MAC_LEN) != 0) {
00323 wpa_printf(MSG_INFO, "EAP-PSK: Invalid MAC_P");
00324 wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: Expected MAC_P",
00325 mac, EAP_PSK_MAC_LEN);
00326 data->state = FAILURE;
00327 return;
00328 }
00329
00330 data->state = PSK_3;
00331 }
00332
00333
00334 static void eap_psk_process_4(struct eap_sm *sm,
00335 struct eap_psk_data *data,
00336 struct wpabuf *respData)
00337 {
00338 const struct eap_psk_hdr_4 *resp;
00339 u8 *decrypted, nonce[16];
00340 size_t left;
00341 const u8 *pos, *tag;
00342
00343 if (data->state != PSK_3)
00344 return;
00345
00346 wpa_printf(MSG_DEBUG, "EAP-PSK: Received PSK-4");
00347
00348 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &left);
00349 if (pos == NULL || left < sizeof(*resp)) {
00350 wpa_printf(MSG_INFO, "EAP-PSK: Invalid frame");
00351 return;
00352 }
00353 resp = (const struct eap_psk_hdr_4 *) pos;
00354 pos = (const u8 *) (resp + 1);
00355 left -= sizeof(*resp);
00356
00357 wpa_hexdump(MSG_MSGDUMP, "EAP-PSK: Encrypted PCHANNEL", pos, left);
00358
00359 if (left < 4 + 16 + 1) {
00360 wpa_printf(MSG_INFO, "EAP-PSK: Too short PCHANNEL data in "
00361 "PSK-4 (len=%lu, expected 21)",
00362 (unsigned long) left);
00363 return;
00364 }
00365
00366 if (pos[0] == 0 && pos[1] == 0 && pos[2] == 0 && pos[3] == 0) {
00367 wpa_printf(MSG_DEBUG, "EAP-PSK: Nonce did not increase");
00368 return;
00369 }
00370
00371 os_memset(nonce, 0, 12);
00372 os_memcpy(nonce + 12, pos, 4);
00373 pos += 4;
00374 left -= 4;
00375 tag = pos;
00376 pos += 16;
00377 left -= 16;
00378
00379 decrypted = os_malloc(left);
00380 if (decrypted == NULL)
00381 return;
00382 os_memcpy(decrypted, pos, left);
00383
00384 if (aes_128_eax_decrypt(data->tek, nonce, sizeof(nonce),
00385 wpabuf_head(respData), 22, decrypted, left,
00386 tag)) {
00387 wpa_printf(MSG_WARNING, "EAP-PSK: PCHANNEL decryption failed");
00388 os_free(decrypted);
00389 data->state = FAILURE;
00390 return;
00391 }
00392 wpa_hexdump(MSG_DEBUG, "EAP-PSK: Decrypted PCHANNEL message",
00393 decrypted, left);
00394
00395
00396 switch (decrypted[0] >> 6) {
00397 case EAP_PSK_R_FLAG_CONT:
00398 wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - CONT - unsupported");
00399 data->state = FAILURE;
00400 break;
00401 case EAP_PSK_R_FLAG_DONE_SUCCESS:
00402 wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - DONE_SUCCESS");
00403 data->state = SUCCESS;
00404 break;
00405 case EAP_PSK_R_FLAG_DONE_FAILURE:
00406 wpa_printf(MSG_DEBUG, "EAP-PSK: R flag - DONE_FAILURE");
00407 data->state = FAILURE;
00408 break;
00409 }
00410 os_free(decrypted);
00411 }
00412
00413
00414 static void eap_psk_process(struct eap_sm *sm, void *priv,
00415 struct wpabuf *respData)
00416 {
00417 struct eap_psk_data *data = priv;
00418 const u8 *pos;
00419 size_t len;
00420
00421 if (sm->user == NULL || sm->user->password == NULL) {
00422 wpa_printf(MSG_INFO, "EAP-PSK: Plaintext password not "
00423 "configured");
00424 data->state = FAILURE;
00425 return;
00426 }
00427
00428 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PSK, respData, &len);
00429 if (pos == NULL || len < 1)
00430 return;
00431
00432 switch (EAP_PSK_FLAGS_GET_T(*pos)) {
00433 case 1:
00434 eap_psk_process_2(sm, data, respData);
00435 break;
00436 case 3:
00437 eap_psk_process_4(sm, data, respData);
00438 break;
00439 }
00440 }
00441
00442
00443 static Boolean eap_psk_isDone(struct eap_sm *sm, void *priv)
00444 {
00445 struct eap_psk_data *data = priv;
00446 return data->state == SUCCESS || data->state == FAILURE;
00447 }
00448
00449
00450 static u8 * eap_psk_getKey(struct eap_sm *sm, void *priv, size_t *len)
00451 {
00452 struct eap_psk_data *data = priv;
00453 u8 *key;
00454
00455 if (data->state != SUCCESS)
00456 return NULL;
00457
00458 key = os_malloc(EAP_MSK_LEN);
00459 if (key == NULL)
00460 return NULL;
00461 os_memcpy(key, data->msk, EAP_MSK_LEN);
00462 *len = EAP_MSK_LEN;
00463
00464 return key;
00465 }
00466
00467
00468 static u8 * eap_psk_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
00469 {
00470 struct eap_psk_data *data = priv;
00471 u8 *key;
00472
00473 if (data->state != SUCCESS)
00474 return NULL;
00475
00476 key = os_malloc(EAP_EMSK_LEN);
00477 if (key == NULL)
00478 return NULL;
00479 os_memcpy(key, data->emsk, EAP_EMSK_LEN);
00480 *len = EAP_EMSK_LEN;
00481
00482 return key;
00483 }
00484
00485
00486 static Boolean eap_psk_isSuccess(struct eap_sm *sm, void *priv)
00487 {
00488 struct eap_psk_data *data = priv;
00489 return data->state == SUCCESS;
00490 }
00491
00492
00493 int eap_server_psk_register(void)
00494 {
00495 struct eap_method *eap;
00496 int ret;
00497
00498 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
00499 EAP_VENDOR_IETF, EAP_TYPE_PSK, "PSK");
00500 if (eap == NULL)
00501 return -1;
00502
00503 eap->init = eap_psk_init;
00504 eap->reset = eap_psk_reset;
00505 eap->buildReq = eap_psk_buildReq;
00506 eap->check = eap_psk_check;
00507 eap->process = eap_psk_process;
00508 eap->isDone = eap_psk_isDone;
00509 eap->getKey = eap_psk_getKey;
00510 eap->isSuccess = eap_psk_isSuccess;
00511 eap->get_emsk = eap_psk_get_emsk;
00512
00513 ret = eap_server_method_register(eap);
00514 if (ret)
00515 eap_server_method_free(eap);
00516 return ret;
00517 }
