eap_pwd.c revision 337817
1252190Srpaulo/* 2252190Srpaulo * EAP peer method: EAP-pwd (RFC 5931) 3252190Srpaulo * Copyright (c) 2010, Dan Harkins <dharkins@lounge.org> 4252190Srpaulo * 5252190Srpaulo * This software may be distributed under the terms of the BSD license. 6252190Srpaulo * See README for more details. 7252190Srpaulo */ 8252190Srpaulo 9252190Srpaulo#include "includes.h" 10252190Srpaulo 11252190Srpaulo#include "common.h" 12252190Srpaulo#include "crypto/sha256.h" 13289549Srpaulo#include "crypto/ms_funcs.h" 14252190Srpaulo#include "eap_peer/eap_i.h" 15252190Srpaulo#include "eap_common/eap_pwd_common.h" 16252190Srpaulo 17252190Srpaulo 18252190Srpaulostruct eap_pwd_data { 19252190Srpaulo enum { 20281806Srpaulo PWD_ID_Req, PWD_Commit_Req, PWD_Confirm_Req, 21281806Srpaulo SUCCESS_ON_FRAG_COMPLETION, SUCCESS, FAILURE 22252190Srpaulo } state; 23252190Srpaulo u8 *id_peer; 24252190Srpaulo size_t id_peer_len; 25252190Srpaulo u8 *id_server; 26252190Srpaulo size_t id_server_len; 27252190Srpaulo u8 *password; 28252190Srpaulo size_t password_len; 29289549Srpaulo int password_hash; 30252190Srpaulo u16 group_num; 31252190Srpaulo EAP_PWD_group *grp; 32252190Srpaulo 33252190Srpaulo struct wpabuf *inbuf; 34252190Srpaulo size_t in_frag_pos; 35252190Srpaulo struct wpabuf *outbuf; 36252190Srpaulo size_t out_frag_pos; 37252190Srpaulo size_t mtu; 38252190Srpaulo 39252190Srpaulo BIGNUM *k; 40252190Srpaulo BIGNUM *private_value; 41252190Srpaulo BIGNUM *server_scalar; 42252190Srpaulo BIGNUM *my_scalar; 43252190Srpaulo EC_POINT *my_element; 44252190Srpaulo EC_POINT *server_element; 45252190Srpaulo 46252190Srpaulo u8 msk[EAP_MSK_LEN]; 47252190Srpaulo u8 emsk[EAP_EMSK_LEN]; 48281806Srpaulo u8 session_id[1 + SHA256_MAC_LEN]; 49252190Srpaulo 50252190Srpaulo BN_CTX *bnctx; 51252190Srpaulo}; 52252190Srpaulo 53252190Srpaulo 54252190Srpaulo#ifndef CONFIG_NO_STDOUT_DEBUG 55252190Srpaulostatic const char * eap_pwd_state_txt(int state) 56252190Srpaulo{ 57252190Srpaulo switch (state) { 58252190Srpaulo case PWD_ID_Req: 59252190Srpaulo return "PWD-ID-Req"; 60252190Srpaulo case PWD_Commit_Req: 61252190Srpaulo return "PWD-Commit-Req"; 62252190Srpaulo case PWD_Confirm_Req: 63252190Srpaulo return "PWD-Confirm-Req"; 64281806Srpaulo case SUCCESS_ON_FRAG_COMPLETION: 65281806Srpaulo return "SUCCESS_ON_FRAG_COMPLETION"; 66252190Srpaulo case SUCCESS: 67252190Srpaulo return "SUCCESS"; 68252190Srpaulo case FAILURE: 69252190Srpaulo return "FAILURE"; 70252190Srpaulo default: 71252190Srpaulo return "PWD-UNK"; 72252190Srpaulo } 73252190Srpaulo} 74252190Srpaulo#endif /* CONFIG_NO_STDOUT_DEBUG */ 75252190Srpaulo 76252190Srpaulo 77252190Srpaulostatic void eap_pwd_state(struct eap_pwd_data *data, int state) 78252190Srpaulo{ 79252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-PWD: %s -> %s", 80252190Srpaulo eap_pwd_state_txt(data->state), eap_pwd_state_txt(state)); 81252190Srpaulo data->state = state; 82252190Srpaulo} 83252190Srpaulo 84252190Srpaulo 85252190Srpaulostatic void * eap_pwd_init(struct eap_sm *sm) 86252190Srpaulo{ 87252190Srpaulo struct eap_pwd_data *data; 88252190Srpaulo const u8 *identity, *password; 89252190Srpaulo size_t identity_len, password_len; 90281806Srpaulo int fragment_size; 91289549Srpaulo int pwhash; 92252190Srpaulo 93289549Srpaulo password = eap_get_config_password2(sm, &password_len, &pwhash); 94252190Srpaulo if (password == NULL) { 95252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: No password configured!"); 96252190Srpaulo return NULL; 97252190Srpaulo } 98252190Srpaulo 99252190Srpaulo identity = eap_get_config_identity(sm, &identity_len); 100252190Srpaulo if (identity == NULL) { 101252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: No identity configured!"); 102252190Srpaulo return NULL; 103252190Srpaulo } 104252190Srpaulo 105252190Srpaulo if ((data = os_zalloc(sizeof(*data))) == NULL) { 106252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: memory allocation data fail"); 107252190Srpaulo return NULL; 108252190Srpaulo } 109252190Srpaulo 110252190Srpaulo if ((data->bnctx = BN_CTX_new()) == NULL) { 111252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: bn context allocation fail"); 112252190Srpaulo os_free(data); 113252190Srpaulo return NULL; 114252190Srpaulo } 115252190Srpaulo 116252190Srpaulo if ((data->id_peer = os_malloc(identity_len)) == NULL) { 117252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: memory allocation id fail"); 118252190Srpaulo BN_CTX_free(data->bnctx); 119252190Srpaulo os_free(data); 120252190Srpaulo return NULL; 121252190Srpaulo } 122252190Srpaulo 123252190Srpaulo os_memcpy(data->id_peer, identity, identity_len); 124252190Srpaulo data->id_peer_len = identity_len; 125252190Srpaulo 126252190Srpaulo if ((data->password = os_malloc(password_len)) == NULL) { 127252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: memory allocation psk fail"); 128252190Srpaulo BN_CTX_free(data->bnctx); 129281806Srpaulo bin_clear_free(data->id_peer, data->id_peer_len); 130252190Srpaulo os_free(data); 131252190Srpaulo return NULL; 132252190Srpaulo } 133252190Srpaulo os_memcpy(data->password, password, password_len); 134252190Srpaulo data->password_len = password_len; 135289549Srpaulo data->password_hash = pwhash; 136252190Srpaulo 137252190Srpaulo data->out_frag_pos = data->in_frag_pos = 0; 138252190Srpaulo data->inbuf = data->outbuf = NULL; 139281806Srpaulo fragment_size = eap_get_config_fragment_size(sm); 140281806Srpaulo if (fragment_size <= 0) 141281806Srpaulo data->mtu = 1020; /* default from RFC 5931 */ 142281806Srpaulo else 143281806Srpaulo data->mtu = fragment_size; 144252190Srpaulo 145252190Srpaulo data->state = PWD_ID_Req; 146252190Srpaulo 147252190Srpaulo return data; 148252190Srpaulo} 149252190Srpaulo 150252190Srpaulo 151252190Srpaulostatic void eap_pwd_deinit(struct eap_sm *sm, void *priv) 152252190Srpaulo{ 153252190Srpaulo struct eap_pwd_data *data = priv; 154252190Srpaulo 155281806Srpaulo BN_clear_free(data->private_value); 156281806Srpaulo BN_clear_free(data->server_scalar); 157281806Srpaulo BN_clear_free(data->my_scalar); 158281806Srpaulo BN_clear_free(data->k); 159252190Srpaulo BN_CTX_free(data->bnctx); 160281806Srpaulo EC_POINT_clear_free(data->my_element); 161281806Srpaulo EC_POINT_clear_free(data->server_element); 162281806Srpaulo bin_clear_free(data->id_peer, data->id_peer_len); 163281806Srpaulo bin_clear_free(data->id_server, data->id_server_len); 164281806Srpaulo bin_clear_free(data->password, data->password_len); 165252190Srpaulo if (data->grp) { 166252190Srpaulo EC_GROUP_free(data->grp->group); 167281806Srpaulo EC_POINT_clear_free(data->grp->pwe); 168281806Srpaulo BN_clear_free(data->grp->order); 169281806Srpaulo BN_clear_free(data->grp->prime); 170252190Srpaulo os_free(data->grp); 171252190Srpaulo } 172281806Srpaulo wpabuf_free(data->inbuf); 173281806Srpaulo wpabuf_free(data->outbuf); 174281806Srpaulo bin_clear_free(data, sizeof(*data)); 175252190Srpaulo} 176252190Srpaulo 177252190Srpaulo 178252190Srpaulostatic u8 * eap_pwd_getkey(struct eap_sm *sm, void *priv, size_t *len) 179252190Srpaulo{ 180252190Srpaulo struct eap_pwd_data *data = priv; 181252190Srpaulo u8 *key; 182252190Srpaulo 183252190Srpaulo if (data->state != SUCCESS) 184252190Srpaulo return NULL; 185252190Srpaulo 186252190Srpaulo key = os_malloc(EAP_MSK_LEN); 187252190Srpaulo if (key == NULL) 188252190Srpaulo return NULL; 189252190Srpaulo 190252190Srpaulo os_memcpy(key, data->msk, EAP_MSK_LEN); 191252190Srpaulo *len = EAP_MSK_LEN; 192252190Srpaulo 193252190Srpaulo return key; 194252190Srpaulo} 195252190Srpaulo 196252190Srpaulo 197281806Srpaulostatic u8 * eap_pwd_get_session_id(struct eap_sm *sm, void *priv, size_t *len) 198281806Srpaulo{ 199281806Srpaulo struct eap_pwd_data *data = priv; 200281806Srpaulo u8 *id; 201281806Srpaulo 202281806Srpaulo if (data->state != SUCCESS) 203281806Srpaulo return NULL; 204281806Srpaulo 205281806Srpaulo id = os_malloc(1 + SHA256_MAC_LEN); 206281806Srpaulo if (id == NULL) 207281806Srpaulo return NULL; 208281806Srpaulo 209281806Srpaulo os_memcpy(id, data->session_id, 1 + SHA256_MAC_LEN); 210281806Srpaulo *len = 1 + SHA256_MAC_LEN; 211281806Srpaulo 212281806Srpaulo return id; 213281806Srpaulo} 214281806Srpaulo 215281806Srpaulo 216252190Srpaulostatic void 217252190Srpauloeap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data, 218252190Srpaulo struct eap_method_ret *ret, 219252190Srpaulo const struct wpabuf *reqData, 220252190Srpaulo const u8 *payload, size_t payload_len) 221252190Srpaulo{ 222252190Srpaulo struct eap_pwd_id *id; 223289549Srpaulo const u8 *password; 224289549Srpaulo size_t password_len; 225289549Srpaulo u8 pwhashhash[16]; 226289549Srpaulo int res; 227252190Srpaulo 228252190Srpaulo if (data->state != PWD_ID_Req) { 229252190Srpaulo ret->ignore = TRUE; 230252190Srpaulo eap_pwd_state(data, FAILURE); 231252190Srpaulo return; 232252190Srpaulo } 233252190Srpaulo 234252190Srpaulo if (payload_len < sizeof(struct eap_pwd_id)) { 235252190Srpaulo ret->ignore = TRUE; 236252190Srpaulo eap_pwd_state(data, FAILURE); 237252190Srpaulo return; 238252190Srpaulo } 239252190Srpaulo 240252190Srpaulo id = (struct eap_pwd_id *) payload; 241252190Srpaulo data->group_num = be_to_host16(id->group_num); 242289549Srpaulo wpa_printf(MSG_DEBUG, 243289549Srpaulo "EAP-PWD: Server EAP-pwd-ID proposal: group=%u random=%u prf=%u prep=%u", 244289549Srpaulo data->group_num, id->random_function, id->prf, id->prep); 245252190Srpaulo if ((id->random_function != EAP_PWD_DEFAULT_RAND_FUNC) || 246252190Srpaulo (id->prf != EAP_PWD_DEFAULT_PRF)) { 247252190Srpaulo ret->ignore = TRUE; 248252190Srpaulo eap_pwd_state(data, FAILURE); 249252190Srpaulo return; 250252190Srpaulo } 251252190Srpaulo 252289549Srpaulo if (id->prep != EAP_PWD_PREP_NONE && 253289549Srpaulo id->prep != EAP_PWD_PREP_MS) { 254289549Srpaulo wpa_printf(MSG_DEBUG, 255289549Srpaulo "EAP-PWD: Unsupported password pre-processing technique (Prep=%u)", 256289549Srpaulo id->prep); 257289549Srpaulo eap_pwd_state(data, FAILURE); 258289549Srpaulo return; 259289549Srpaulo } 260289549Srpaulo 261289549Srpaulo if (id->prep == EAP_PWD_PREP_NONE && data->password_hash) { 262289549Srpaulo wpa_printf(MSG_DEBUG, 263289549Srpaulo "EAP-PWD: Unhashed password not available"); 264289549Srpaulo eap_pwd_state(data, FAILURE); 265289549Srpaulo return; 266289549Srpaulo } 267289549Srpaulo 268252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-PWD (peer): using group %d", 269252190Srpaulo data->group_num); 270252190Srpaulo 271252190Srpaulo data->id_server = os_malloc(payload_len - sizeof(struct eap_pwd_id)); 272252190Srpaulo if (data->id_server == NULL) { 273252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: memory allocation id fail"); 274252190Srpaulo eap_pwd_state(data, FAILURE); 275252190Srpaulo return; 276252190Srpaulo } 277252190Srpaulo data->id_server_len = payload_len - sizeof(struct eap_pwd_id); 278252190Srpaulo os_memcpy(data->id_server, id->identity, data->id_server_len); 279252190Srpaulo wpa_hexdump_ascii(MSG_INFO, "EAP-PWD (peer): server sent id of", 280252190Srpaulo data->id_server, data->id_server_len); 281252190Srpaulo 282281806Srpaulo data->grp = os_zalloc(sizeof(EAP_PWD_group)); 283281806Srpaulo if (data->grp == NULL) { 284252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: failed to allocate memory for " 285252190Srpaulo "group"); 286252190Srpaulo eap_pwd_state(data, FAILURE); 287252190Srpaulo return; 288252190Srpaulo } 289252190Srpaulo 290289549Srpaulo if (id->prep == EAP_PWD_PREP_MS) { 291289549Srpaulo#ifdef CONFIG_FIPS 292289549Srpaulo wpa_printf(MSG_ERROR, 293289549Srpaulo "EAP-PWD (peer): MS password hash not supported in FIPS mode"); 294289549Srpaulo eap_pwd_state(data, FAILURE); 295289549Srpaulo return; 296289549Srpaulo#else /* CONFIG_FIPS */ 297289549Srpaulo if (data->password_hash) { 298289549Srpaulo res = hash_nt_password_hash(data->password, pwhashhash); 299289549Srpaulo } else { 300289549Srpaulo u8 pwhash[16]; 301289549Srpaulo 302289549Srpaulo res = nt_password_hash(data->password, 303289549Srpaulo data->password_len, pwhash); 304289549Srpaulo if (res == 0) 305289549Srpaulo res = hash_nt_password_hash(pwhash, pwhashhash); 306289549Srpaulo os_memset(pwhash, 0, sizeof(pwhash)); 307289549Srpaulo } 308289549Srpaulo 309289549Srpaulo if (res) { 310289549Srpaulo eap_pwd_state(data, FAILURE); 311289549Srpaulo return; 312289549Srpaulo } 313289549Srpaulo 314289549Srpaulo password = pwhashhash; 315289549Srpaulo password_len = sizeof(pwhashhash); 316289549Srpaulo#endif /* CONFIG_FIPS */ 317289549Srpaulo } else { 318289549Srpaulo password = data->password; 319289549Srpaulo password_len = data->password_len; 320289549Srpaulo } 321289549Srpaulo 322252190Srpaulo /* compute PWE */ 323289549Srpaulo res = compute_password_element(data->grp, data->group_num, 324289549Srpaulo password, password_len, 325289549Srpaulo data->id_server, data->id_server_len, 326289549Srpaulo data->id_peer, data->id_peer_len, 327289549Srpaulo id->token); 328289549Srpaulo os_memset(pwhashhash, 0, sizeof(pwhashhash)); 329289549Srpaulo if (res) { 330252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): unable to compute PWE"); 331252190Srpaulo eap_pwd_state(data, FAILURE); 332252190Srpaulo return; 333252190Srpaulo } 334252190Srpaulo 335252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-PWD (peer): computed %d bit PWE...", 336252190Srpaulo BN_num_bits(data->grp->prime)); 337252190Srpaulo 338252190Srpaulo data->outbuf = wpabuf_alloc(sizeof(struct eap_pwd_id) + 339252190Srpaulo data->id_peer_len); 340252190Srpaulo if (data->outbuf == NULL) { 341252190Srpaulo eap_pwd_state(data, FAILURE); 342252190Srpaulo return; 343252190Srpaulo } 344252190Srpaulo wpabuf_put_be16(data->outbuf, data->group_num); 345252190Srpaulo wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_RAND_FUNC); 346252190Srpaulo wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_PRF); 347252190Srpaulo wpabuf_put_data(data->outbuf, id->token, sizeof(id->token)); 348252190Srpaulo wpabuf_put_u8(data->outbuf, EAP_PWD_PREP_NONE); 349252190Srpaulo wpabuf_put_data(data->outbuf, data->id_peer, data->id_peer_len); 350252190Srpaulo 351252190Srpaulo eap_pwd_state(data, PWD_Commit_Req); 352252190Srpaulo} 353252190Srpaulo 354252190Srpaulo 355252190Srpaulostatic void 356252190Srpauloeap_pwd_perform_commit_exchange(struct eap_sm *sm, struct eap_pwd_data *data, 357252190Srpaulo struct eap_method_ret *ret, 358252190Srpaulo const struct wpabuf *reqData, 359252190Srpaulo const u8 *payload, size_t payload_len) 360252190Srpaulo{ 361252190Srpaulo EC_POINT *K = NULL, *point = NULL; 362252190Srpaulo BIGNUM *mask = NULL, *x = NULL, *y = NULL, *cofactor = NULL; 363252190Srpaulo u16 offset; 364252190Srpaulo u8 *ptr, *scalar = NULL, *element = NULL; 365289549Srpaulo size_t prime_len, order_len; 366252190Srpaulo 367289549Srpaulo if (data->state != PWD_Commit_Req) { 368289549Srpaulo ret->ignore = TRUE; 369289549Srpaulo goto fin; 370289549Srpaulo } 371289549Srpaulo 372289549Srpaulo prime_len = BN_num_bytes(data->grp->prime); 373289549Srpaulo order_len = BN_num_bytes(data->grp->order); 374289549Srpaulo 375289549Srpaulo if (payload_len != 2 * prime_len + order_len) { 376289549Srpaulo wpa_printf(MSG_INFO, 377289549Srpaulo "EAP-pwd: Unexpected Commit payload length %u (expected %u)", 378289549Srpaulo (unsigned int) payload_len, 379289549Srpaulo (unsigned int) (2 * prime_len + order_len)); 380289549Srpaulo goto fin; 381289549Srpaulo } 382289549Srpaulo 383252190Srpaulo if (((data->private_value = BN_new()) == NULL) || 384252190Srpaulo ((data->my_element = EC_POINT_new(data->grp->group)) == NULL) || 385252190Srpaulo ((cofactor = BN_new()) == NULL) || 386252190Srpaulo ((data->my_scalar = BN_new()) == NULL) || 387252190Srpaulo ((mask = BN_new()) == NULL)) { 388252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): scalar allocation fail"); 389252190Srpaulo goto fin; 390252190Srpaulo } 391252190Srpaulo 392252190Srpaulo if (!EC_GROUP_get_cofactor(data->grp->group, cofactor, NULL)) { 393252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd (peer): unable to get cofactor " 394252190Srpaulo "for curve"); 395252190Srpaulo goto fin; 396252190Srpaulo } 397252190Srpaulo 398281806Srpaulo if (BN_rand_range(data->private_value, data->grp->order) != 1 || 399281806Srpaulo BN_rand_range(mask, data->grp->order) != 1 || 400281806Srpaulo BN_add(data->my_scalar, data->private_value, mask) != 1 || 401281806Srpaulo BN_mod(data->my_scalar, data->my_scalar, data->grp->order, 402281806Srpaulo data->bnctx) != 1) { 403281806Srpaulo wpa_printf(MSG_INFO, 404281806Srpaulo "EAP-pwd (peer): unable to get randomness"); 405281806Srpaulo goto fin; 406281806Srpaulo } 407252190Srpaulo 408252190Srpaulo if (!EC_POINT_mul(data->grp->group, data->my_element, NULL, 409252190Srpaulo data->grp->pwe, mask, data->bnctx)) { 410252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): element allocation " 411252190Srpaulo "fail"); 412252190Srpaulo eap_pwd_state(data, FAILURE); 413252190Srpaulo goto fin; 414252190Srpaulo } 415252190Srpaulo 416252190Srpaulo if (!EC_POINT_invert(data->grp->group, data->my_element, data->bnctx)) 417252190Srpaulo { 418252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): element inversion fail"); 419252190Srpaulo goto fin; 420252190Srpaulo } 421252190Srpaulo 422252190Srpaulo if (((x = BN_new()) == NULL) || 423252190Srpaulo ((y = BN_new()) == NULL)) { 424252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): point allocation fail"); 425252190Srpaulo goto fin; 426252190Srpaulo } 427252190Srpaulo 428252190Srpaulo /* process the request */ 429252190Srpaulo if (((data->server_scalar = BN_new()) == NULL) || 430252190Srpaulo ((data->k = BN_new()) == NULL) || 431252190Srpaulo ((K = EC_POINT_new(data->grp->group)) == NULL) || 432252190Srpaulo ((point = EC_POINT_new(data->grp->group)) == NULL) || 433252190Srpaulo ((data->server_element = EC_POINT_new(data->grp->group)) == NULL)) 434252190Srpaulo { 435252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): peer data allocation " 436252190Srpaulo "fail"); 437252190Srpaulo goto fin; 438252190Srpaulo } 439252190Srpaulo 440252190Srpaulo /* element, x then y, followed by scalar */ 441252190Srpaulo ptr = (u8 *) payload; 442252190Srpaulo BN_bin2bn(ptr, BN_num_bytes(data->grp->prime), x); 443252190Srpaulo ptr += BN_num_bytes(data->grp->prime); 444252190Srpaulo BN_bin2bn(ptr, BN_num_bytes(data->grp->prime), y); 445252190Srpaulo ptr += BN_num_bytes(data->grp->prime); 446252190Srpaulo BN_bin2bn(ptr, BN_num_bytes(data->grp->order), data->server_scalar); 447252190Srpaulo if (!EC_POINT_set_affine_coordinates_GFp(data->grp->group, 448252190Srpaulo data->server_element, x, y, 449252190Srpaulo data->bnctx)) { 450252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): setting peer element " 451252190Srpaulo "fail"); 452252190Srpaulo goto fin; 453252190Srpaulo } 454252190Srpaulo 455252190Srpaulo /* check to ensure server's element is not in a small sub-group */ 456252190Srpaulo if (BN_cmp(cofactor, BN_value_one())) { 457252190Srpaulo if (!EC_POINT_mul(data->grp->group, point, NULL, 458252190Srpaulo data->server_element, cofactor, NULL)) { 459252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): cannot multiply " 460252190Srpaulo "server element by order!\n"); 461252190Srpaulo goto fin; 462252190Srpaulo } 463252190Srpaulo if (EC_POINT_is_at_infinity(data->grp->group, point)) { 464252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): server element " 465252190Srpaulo "is at infinity!\n"); 466252190Srpaulo goto fin; 467252190Srpaulo } 468252190Srpaulo } 469252190Srpaulo 470252190Srpaulo /* compute the shared key, k */ 471252190Srpaulo if ((!EC_POINT_mul(data->grp->group, K, NULL, data->grp->pwe, 472252190Srpaulo data->server_scalar, data->bnctx)) || 473252190Srpaulo (!EC_POINT_add(data->grp->group, K, K, data->server_element, 474252190Srpaulo data->bnctx)) || 475252190Srpaulo (!EC_POINT_mul(data->grp->group, K, NULL, K, data->private_value, 476252190Srpaulo data->bnctx))) { 477252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): computing shared key " 478252190Srpaulo "fail"); 479252190Srpaulo goto fin; 480252190Srpaulo } 481252190Srpaulo 482252190Srpaulo /* ensure that the shared key isn't in a small sub-group */ 483252190Srpaulo if (BN_cmp(cofactor, BN_value_one())) { 484252190Srpaulo if (!EC_POINT_mul(data->grp->group, K, NULL, K, cofactor, 485252190Srpaulo NULL)) { 486252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): cannot multiply " 487252190Srpaulo "shared key point by order"); 488252190Srpaulo goto fin; 489252190Srpaulo } 490252190Srpaulo } 491252190Srpaulo 492252190Srpaulo /* 493252190Srpaulo * This check is strictly speaking just for the case above where 494252190Srpaulo * co-factor > 1 but it was suggested that even though this is probably 495252190Srpaulo * never going to happen it is a simple and safe check "just to be 496252190Srpaulo * sure" so let's be safe. 497252190Srpaulo */ 498252190Srpaulo if (EC_POINT_is_at_infinity(data->grp->group, K)) { 499252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): shared key point is at " 500252190Srpaulo "infinity!\n"); 501252190Srpaulo goto fin; 502252190Srpaulo } 503252190Srpaulo 504252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, K, data->k, 505252190Srpaulo NULL, data->bnctx)) { 506252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): unable to extract " 507252190Srpaulo "shared secret from point"); 508252190Srpaulo goto fin; 509252190Srpaulo } 510252190Srpaulo 511252190Srpaulo /* now do the response */ 512252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 513252190Srpaulo data->my_element, x, y, 514252190Srpaulo data->bnctx)) { 515252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): point assignment fail"); 516252190Srpaulo goto fin; 517252190Srpaulo } 518252190Srpaulo 519252190Srpaulo if (((scalar = os_malloc(BN_num_bytes(data->grp->order))) == NULL) || 520252190Srpaulo ((element = os_malloc(BN_num_bytes(data->grp->prime) * 2)) == 521252190Srpaulo NULL)) { 522252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): data allocation fail"); 523252190Srpaulo goto fin; 524252190Srpaulo } 525252190Srpaulo 526252190Srpaulo /* 527252190Srpaulo * bignums occupy as little memory as possible so one that is 528252190Srpaulo * sufficiently smaller than the prime or order might need pre-pending 529252190Srpaulo * with zeros. 530252190Srpaulo */ 531252190Srpaulo os_memset(scalar, 0, BN_num_bytes(data->grp->order)); 532252190Srpaulo os_memset(element, 0, BN_num_bytes(data->grp->prime) * 2); 533252190Srpaulo offset = BN_num_bytes(data->grp->order) - 534252190Srpaulo BN_num_bytes(data->my_scalar); 535252190Srpaulo BN_bn2bin(data->my_scalar, scalar + offset); 536252190Srpaulo 537252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 538252190Srpaulo BN_bn2bin(x, element + offset); 539252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 540252190Srpaulo BN_bn2bin(y, element + BN_num_bytes(data->grp->prime) + offset); 541252190Srpaulo 542252190Srpaulo data->outbuf = wpabuf_alloc(BN_num_bytes(data->grp->order) + 543252190Srpaulo 2 * BN_num_bytes(data->grp->prime)); 544252190Srpaulo if (data->outbuf == NULL) 545252190Srpaulo goto fin; 546252190Srpaulo 547252190Srpaulo /* we send the element as (x,y) follwed by the scalar */ 548252190Srpaulo wpabuf_put_data(data->outbuf, element, 549252190Srpaulo 2 * BN_num_bytes(data->grp->prime)); 550252190Srpaulo wpabuf_put_data(data->outbuf, scalar, BN_num_bytes(data->grp->order)); 551252190Srpaulo 552252190Srpaulofin: 553252190Srpaulo os_free(scalar); 554252190Srpaulo os_free(element); 555281806Srpaulo BN_clear_free(x); 556281806Srpaulo BN_clear_free(y); 557337817Scy BN_clear_free(mask); 558281806Srpaulo BN_clear_free(cofactor); 559281806Srpaulo EC_POINT_clear_free(K); 560281806Srpaulo EC_POINT_clear_free(point); 561252190Srpaulo if (data->outbuf == NULL) 562252190Srpaulo eap_pwd_state(data, FAILURE); 563252190Srpaulo else 564252190Srpaulo eap_pwd_state(data, PWD_Confirm_Req); 565252190Srpaulo} 566252190Srpaulo 567252190Srpaulo 568252190Srpaulostatic void 569252190Srpauloeap_pwd_perform_confirm_exchange(struct eap_sm *sm, struct eap_pwd_data *data, 570252190Srpaulo struct eap_method_ret *ret, 571252190Srpaulo const struct wpabuf *reqData, 572252190Srpaulo const u8 *payload, size_t payload_len) 573252190Srpaulo{ 574252190Srpaulo BIGNUM *x = NULL, *y = NULL; 575252190Srpaulo struct crypto_hash *hash; 576252190Srpaulo u32 cs; 577252190Srpaulo u16 grp; 578252190Srpaulo u8 conf[SHA256_MAC_LEN], *cruft = NULL, *ptr; 579252190Srpaulo int offset; 580252190Srpaulo 581289549Srpaulo if (data->state != PWD_Confirm_Req) { 582289549Srpaulo ret->ignore = TRUE; 583289549Srpaulo goto fin; 584289549Srpaulo } 585289549Srpaulo 586289549Srpaulo if (payload_len != SHA256_MAC_LEN) { 587289549Srpaulo wpa_printf(MSG_INFO, 588289549Srpaulo "EAP-pwd: Unexpected Confirm payload length %u (expected %u)", 589289549Srpaulo (unsigned int) payload_len, SHA256_MAC_LEN); 590289549Srpaulo goto fin; 591289549Srpaulo } 592289549Srpaulo 593252190Srpaulo /* 594252190Srpaulo * first build up the ciphersuite which is group | random_function | 595252190Srpaulo * prf 596252190Srpaulo */ 597252190Srpaulo grp = htons(data->group_num); 598252190Srpaulo ptr = (u8 *) &cs; 599252190Srpaulo os_memcpy(ptr, &grp, sizeof(u16)); 600252190Srpaulo ptr += sizeof(u16); 601252190Srpaulo *ptr = EAP_PWD_DEFAULT_RAND_FUNC; 602252190Srpaulo ptr += sizeof(u8); 603252190Srpaulo *ptr = EAP_PWD_DEFAULT_PRF; 604252190Srpaulo 605252190Srpaulo /* each component of the cruft will be at most as big as the prime */ 606252190Srpaulo if (((cruft = os_malloc(BN_num_bytes(data->grp->prime))) == NULL) || 607252190Srpaulo ((x = BN_new()) == NULL) || ((y = BN_new()) == NULL)) { 608252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): confirm allocation " 609252190Srpaulo "fail"); 610252190Srpaulo goto fin; 611252190Srpaulo } 612252190Srpaulo 613252190Srpaulo /* 614252190Srpaulo * server's commit is H(k | server_element | server_scalar | 615252190Srpaulo * peer_element | peer_scalar | ciphersuite) 616252190Srpaulo */ 617252190Srpaulo hash = eap_pwd_h_init(); 618252190Srpaulo if (hash == NULL) 619252190Srpaulo goto fin; 620252190Srpaulo 621252190Srpaulo /* 622252190Srpaulo * zero the memory each time because this is mod prime math and some 623252190Srpaulo * value may start with a few zeros and the previous one did not. 624252190Srpaulo */ 625252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 626252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(data->k); 627252190Srpaulo BN_bn2bin(data->k, cruft + offset); 628252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 629252190Srpaulo 630252190Srpaulo /* server element: x, y */ 631252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 632252190Srpaulo data->server_element, x, y, 633252190Srpaulo data->bnctx)) { 634252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " 635252190Srpaulo "assignment fail"); 636252190Srpaulo goto fin; 637252190Srpaulo } 638252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 639252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 640252190Srpaulo BN_bn2bin(x, cruft + offset); 641252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 642252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 643252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 644252190Srpaulo BN_bn2bin(y, cruft + offset); 645252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 646252190Srpaulo 647252190Srpaulo /* server scalar */ 648252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 649252190Srpaulo offset = BN_num_bytes(data->grp->order) - 650252190Srpaulo BN_num_bytes(data->server_scalar); 651252190Srpaulo BN_bn2bin(data->server_scalar, cruft + offset); 652252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order)); 653252190Srpaulo 654252190Srpaulo /* my element: x, y */ 655252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 656252190Srpaulo data->my_element, x, y, 657252190Srpaulo data->bnctx)) { 658252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " 659252190Srpaulo "assignment fail"); 660252190Srpaulo goto fin; 661252190Srpaulo } 662252190Srpaulo 663252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 664252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 665252190Srpaulo BN_bn2bin(x, cruft + offset); 666252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 667252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 668252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 669252190Srpaulo BN_bn2bin(y, cruft + offset); 670252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 671252190Srpaulo 672252190Srpaulo /* my scalar */ 673252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 674252190Srpaulo offset = BN_num_bytes(data->grp->order) - 675252190Srpaulo BN_num_bytes(data->my_scalar); 676252190Srpaulo BN_bn2bin(data->my_scalar, cruft + offset); 677252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order)); 678252190Srpaulo 679252190Srpaulo /* the ciphersuite */ 680252190Srpaulo eap_pwd_h_update(hash, (u8 *) &cs, sizeof(u32)); 681252190Srpaulo 682252190Srpaulo /* random function fin */ 683252190Srpaulo eap_pwd_h_final(hash, conf); 684252190Srpaulo 685252190Srpaulo ptr = (u8 *) payload; 686281806Srpaulo if (os_memcmp_const(conf, ptr, SHA256_MAC_LEN)) { 687252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): confirm did not verify"); 688252190Srpaulo goto fin; 689252190Srpaulo } 690252190Srpaulo 691252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd (peer): confirm verified"); 692252190Srpaulo 693252190Srpaulo /* 694252190Srpaulo * compute confirm: 695252190Srpaulo * H(k | peer_element | peer_scalar | server_element | server_scalar | 696252190Srpaulo * ciphersuite) 697252190Srpaulo */ 698252190Srpaulo hash = eap_pwd_h_init(); 699252190Srpaulo if (hash == NULL) 700252190Srpaulo goto fin; 701252190Srpaulo 702252190Srpaulo /* k */ 703252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 704252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(data->k); 705252190Srpaulo BN_bn2bin(data->k, cruft + offset); 706252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 707252190Srpaulo 708252190Srpaulo /* my element */ 709252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 710252190Srpaulo data->my_element, x, y, 711252190Srpaulo data->bnctx)) { 712252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): confirm point " 713252190Srpaulo "assignment fail"); 714252190Srpaulo goto fin; 715252190Srpaulo } 716252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 717252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 718252190Srpaulo BN_bn2bin(x, cruft + offset); 719252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 720252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 721252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 722252190Srpaulo BN_bn2bin(y, cruft + offset); 723252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 724252190Srpaulo 725252190Srpaulo /* my scalar */ 726252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 727252190Srpaulo offset = BN_num_bytes(data->grp->order) - 728252190Srpaulo BN_num_bytes(data->my_scalar); 729252190Srpaulo BN_bn2bin(data->my_scalar, cruft + offset); 730252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order)); 731252190Srpaulo 732252190Srpaulo /* server element: x, y */ 733252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 734252190Srpaulo data->server_element, x, y, 735252190Srpaulo data->bnctx)) { 736252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): confirm point " 737252190Srpaulo "assignment fail"); 738252190Srpaulo goto fin; 739252190Srpaulo } 740252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 741252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 742252190Srpaulo BN_bn2bin(x, cruft + offset); 743252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 744252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 745252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 746252190Srpaulo BN_bn2bin(y, cruft + offset); 747252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 748252190Srpaulo 749252190Srpaulo /* server scalar */ 750252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 751252190Srpaulo offset = BN_num_bytes(data->grp->order) - 752252190Srpaulo BN_num_bytes(data->server_scalar); 753252190Srpaulo BN_bn2bin(data->server_scalar, cruft + offset); 754252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order)); 755252190Srpaulo 756252190Srpaulo /* the ciphersuite */ 757252190Srpaulo eap_pwd_h_update(hash, (u8 *) &cs, sizeof(u32)); 758252190Srpaulo 759252190Srpaulo /* all done */ 760252190Srpaulo eap_pwd_h_final(hash, conf); 761252190Srpaulo 762252190Srpaulo if (compute_keys(data->grp, data->bnctx, data->k, 763252190Srpaulo data->my_scalar, data->server_scalar, conf, ptr, 764281806Srpaulo &cs, data->msk, data->emsk, data->session_id) < 0) { 765252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): unable to compute MSK | " 766252190Srpaulo "EMSK"); 767252190Srpaulo goto fin; 768252190Srpaulo } 769252190Srpaulo 770252190Srpaulo data->outbuf = wpabuf_alloc(SHA256_MAC_LEN); 771252190Srpaulo if (data->outbuf == NULL) 772252190Srpaulo goto fin; 773252190Srpaulo 774252190Srpaulo wpabuf_put_data(data->outbuf, conf, SHA256_MAC_LEN); 775252190Srpaulo 776252190Srpaulofin: 777337817Scy if (data->grp) 778337817Scy bin_clear_free(cruft, BN_num_bytes(data->grp->prime)); 779281806Srpaulo BN_clear_free(x); 780281806Srpaulo BN_clear_free(y); 781252190Srpaulo if (data->outbuf == NULL) { 782281806Srpaulo ret->methodState = METHOD_DONE; 783252190Srpaulo ret->decision = DECISION_FAIL; 784252190Srpaulo eap_pwd_state(data, FAILURE); 785252190Srpaulo } else { 786281806Srpaulo eap_pwd_state(data, SUCCESS_ON_FRAG_COMPLETION); 787252190Srpaulo } 788252190Srpaulo} 789252190Srpaulo 790252190Srpaulo 791252190Srpaulostatic struct wpabuf * 792252190Srpauloeap_pwd_process(struct eap_sm *sm, void *priv, struct eap_method_ret *ret, 793252190Srpaulo const struct wpabuf *reqData) 794252190Srpaulo{ 795252190Srpaulo struct eap_pwd_data *data = priv; 796252190Srpaulo struct wpabuf *resp = NULL; 797252190Srpaulo const u8 *pos, *buf; 798252190Srpaulo size_t len; 799252190Srpaulo u16 tot_len = 0; 800252190Srpaulo u8 lm_exch; 801252190Srpaulo 802252190Srpaulo pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PWD, reqData, &len); 803252190Srpaulo if ((pos == NULL) || (len < 1)) { 804252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Got a frame but pos is %s and " 805252190Srpaulo "len is %d", 806252190Srpaulo pos == NULL ? "NULL" : "not NULL", (int) len); 807252190Srpaulo ret->ignore = TRUE; 808252190Srpaulo return NULL; 809252190Srpaulo } 810252190Srpaulo 811252190Srpaulo ret->ignore = FALSE; 812252190Srpaulo ret->methodState = METHOD_MAY_CONT; 813252190Srpaulo ret->decision = DECISION_FAIL; 814252190Srpaulo ret->allowNotifications = FALSE; 815252190Srpaulo 816252190Srpaulo lm_exch = *pos; 817252190Srpaulo pos++; /* skip over the bits and the exch */ 818252190Srpaulo len--; 819252190Srpaulo 820252190Srpaulo /* 821252190Srpaulo * we're fragmenting so send out the next fragment 822252190Srpaulo */ 823252190Srpaulo if (data->out_frag_pos) { 824252190Srpaulo /* 825252190Srpaulo * this should be an ACK 826252190Srpaulo */ 827252190Srpaulo if (len) 828252190Srpaulo wpa_printf(MSG_INFO, "Bad Response! Fragmenting but " 829252190Srpaulo "not an ACK"); 830252190Srpaulo 831252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Got an ACK for a fragment"); 832252190Srpaulo /* 833252190Srpaulo * check if there are going to be more fragments 834252190Srpaulo */ 835252190Srpaulo len = wpabuf_len(data->outbuf) - data->out_frag_pos; 836252190Srpaulo if ((len + EAP_PWD_HDR_SIZE) > data->mtu) { 837252190Srpaulo len = data->mtu - EAP_PWD_HDR_SIZE; 838252190Srpaulo EAP_PWD_SET_MORE_BIT(lm_exch); 839252190Srpaulo } 840252190Srpaulo resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, 841252190Srpaulo EAP_PWD_HDR_SIZE + len, 842252190Srpaulo EAP_CODE_RESPONSE, eap_get_id(reqData)); 843252190Srpaulo if (resp == NULL) { 844252190Srpaulo wpa_printf(MSG_INFO, "Unable to allocate memory for " 845252190Srpaulo "next fragment!"); 846252190Srpaulo return NULL; 847252190Srpaulo } 848252190Srpaulo wpabuf_put_u8(resp, lm_exch); 849252190Srpaulo buf = wpabuf_head_u8(data->outbuf); 850252190Srpaulo wpabuf_put_data(resp, buf + data->out_frag_pos, len); 851252190Srpaulo data->out_frag_pos += len; 852252190Srpaulo /* 853252190Srpaulo * this is the last fragment so get rid of the out buffer 854252190Srpaulo */ 855252190Srpaulo if (data->out_frag_pos >= wpabuf_len(data->outbuf)) { 856252190Srpaulo wpabuf_free(data->outbuf); 857252190Srpaulo data->outbuf = NULL; 858252190Srpaulo data->out_frag_pos = 0; 859252190Srpaulo } 860252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Send %s fragment of %d bytes", 861252190Srpaulo data->out_frag_pos == 0 ? "last" : "next", 862252190Srpaulo (int) len); 863281806Srpaulo if (data->state == SUCCESS_ON_FRAG_COMPLETION) { 864281806Srpaulo ret->methodState = METHOD_DONE; 865281806Srpaulo ret->decision = DECISION_UNCOND_SUCC; 866281806Srpaulo eap_pwd_state(data, SUCCESS); 867281806Srpaulo } 868252190Srpaulo return resp; 869252190Srpaulo } 870252190Srpaulo 871252190Srpaulo /* 872252190Srpaulo * see if this is a fragment that needs buffering 873252190Srpaulo * 874252190Srpaulo * if it's the first fragment there'll be a length field 875252190Srpaulo */ 876252190Srpaulo if (EAP_PWD_GET_LENGTH_BIT(lm_exch)) { 877289549Srpaulo if (len < 2) { 878289549Srpaulo wpa_printf(MSG_DEBUG, 879289549Srpaulo "EAP-pwd: Frame too short to contain Total-Length field"); 880289549Srpaulo ret->ignore = TRUE; 881289549Srpaulo return NULL; 882289549Srpaulo } 883252190Srpaulo tot_len = WPA_GET_BE16(pos); 884252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Incoming fragments whose " 885252190Srpaulo "total length = %d", tot_len); 886281806Srpaulo if (tot_len > 15000) 887281806Srpaulo return NULL; 888289549Srpaulo if (data->inbuf) { 889289549Srpaulo wpa_printf(MSG_DEBUG, 890289549Srpaulo "EAP-pwd: Unexpected new fragment start when previous fragment is still in use"); 891289549Srpaulo ret->ignore = TRUE; 892289549Srpaulo return NULL; 893289549Srpaulo } 894252190Srpaulo data->inbuf = wpabuf_alloc(tot_len); 895252190Srpaulo if (data->inbuf == NULL) { 896252190Srpaulo wpa_printf(MSG_INFO, "Out of memory to buffer " 897252190Srpaulo "fragments!"); 898252190Srpaulo return NULL; 899252190Srpaulo } 900289549Srpaulo data->in_frag_pos = 0; 901252190Srpaulo pos += sizeof(u16); 902252190Srpaulo len -= sizeof(u16); 903252190Srpaulo } 904252190Srpaulo /* 905252190Srpaulo * buffer and ACK the fragment 906252190Srpaulo */ 907337817Scy if (EAP_PWD_GET_MORE_BIT(lm_exch) || data->in_frag_pos) { 908252190Srpaulo data->in_frag_pos += len; 909252190Srpaulo if (data->in_frag_pos > wpabuf_size(data->inbuf)) { 910252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: Buffer overflow attack " 911252190Srpaulo "detected (%d vs. %d)!", 912252190Srpaulo (int) data->in_frag_pos, 913252190Srpaulo (int) wpabuf_len(data->inbuf)); 914252190Srpaulo wpabuf_free(data->inbuf); 915281806Srpaulo data->inbuf = NULL; 916252190Srpaulo data->in_frag_pos = 0; 917252190Srpaulo return NULL; 918252190Srpaulo } 919252190Srpaulo wpabuf_put_data(data->inbuf, pos, len); 920337817Scy } 921337817Scy if (EAP_PWD_GET_MORE_BIT(lm_exch)) { 922252190Srpaulo resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, 923252190Srpaulo EAP_PWD_HDR_SIZE, 924252190Srpaulo EAP_CODE_RESPONSE, eap_get_id(reqData)); 925252190Srpaulo if (resp != NULL) 926252190Srpaulo wpabuf_put_u8(resp, (EAP_PWD_GET_EXCHANGE(lm_exch))); 927252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: ACKing a %d byte fragment", 928252190Srpaulo (int) len); 929252190Srpaulo return resp; 930252190Srpaulo } 931252190Srpaulo /* 932252190Srpaulo * we're buffering and this is the last fragment 933252190Srpaulo */ 934252190Srpaulo if (data->in_frag_pos) { 935252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Last fragment, %d bytes", 936252190Srpaulo (int) len); 937252190Srpaulo pos = wpabuf_head_u8(data->inbuf); 938252190Srpaulo len = data->in_frag_pos; 939252190Srpaulo } 940252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: processing frame: exch %d, len %d", 941252190Srpaulo EAP_PWD_GET_EXCHANGE(lm_exch), (int) len); 942252190Srpaulo 943252190Srpaulo switch (EAP_PWD_GET_EXCHANGE(lm_exch)) { 944252190Srpaulo case EAP_PWD_OPCODE_ID_EXCH: 945252190Srpaulo eap_pwd_perform_id_exchange(sm, data, ret, reqData, 946252190Srpaulo pos, len); 947252190Srpaulo break; 948252190Srpaulo case EAP_PWD_OPCODE_COMMIT_EXCH: 949252190Srpaulo eap_pwd_perform_commit_exchange(sm, data, ret, reqData, 950252190Srpaulo pos, len); 951252190Srpaulo break; 952252190Srpaulo case EAP_PWD_OPCODE_CONFIRM_EXCH: 953252190Srpaulo eap_pwd_perform_confirm_exchange(sm, data, ret, reqData, 954252190Srpaulo pos, len); 955252190Srpaulo break; 956252190Srpaulo default: 957252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: Ignoring message with unknown " 958252190Srpaulo "opcode %d", lm_exch); 959252190Srpaulo break; 960252190Srpaulo } 961252190Srpaulo /* 962252190Srpaulo * if we buffered the just processed input now's the time to free it 963252190Srpaulo */ 964252190Srpaulo if (data->in_frag_pos) { 965252190Srpaulo wpabuf_free(data->inbuf); 966281806Srpaulo data->inbuf = NULL; 967252190Srpaulo data->in_frag_pos = 0; 968252190Srpaulo } 969252190Srpaulo 970281806Srpaulo if (data->outbuf == NULL) { 971281806Srpaulo ret->methodState = METHOD_DONE; 972281806Srpaulo ret->decision = DECISION_FAIL; 973252190Srpaulo return NULL; /* generic failure */ 974281806Srpaulo } 975252190Srpaulo 976252190Srpaulo /* 977252190Srpaulo * we have output! Do we need to fragment it? 978252190Srpaulo */ 979289549Srpaulo lm_exch = EAP_PWD_GET_EXCHANGE(lm_exch); 980252190Srpaulo len = wpabuf_len(data->outbuf); 981252190Srpaulo if ((len + EAP_PWD_HDR_SIZE) > data->mtu) { 982252190Srpaulo resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, data->mtu, 983252190Srpaulo EAP_CODE_RESPONSE, eap_get_id(reqData)); 984252190Srpaulo /* 985252190Srpaulo * if so it's the first so include a length field 986252190Srpaulo */ 987252190Srpaulo EAP_PWD_SET_LENGTH_BIT(lm_exch); 988252190Srpaulo EAP_PWD_SET_MORE_BIT(lm_exch); 989252190Srpaulo tot_len = len; 990252190Srpaulo /* 991252190Srpaulo * keep the packet at the MTU 992252190Srpaulo */ 993252190Srpaulo len = data->mtu - EAP_PWD_HDR_SIZE - sizeof(u16); 994252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Fragmenting output, total " 995252190Srpaulo "length = %d", tot_len); 996252190Srpaulo } else { 997252190Srpaulo resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, 998252190Srpaulo EAP_PWD_HDR_SIZE + len, 999252190Srpaulo EAP_CODE_RESPONSE, eap_get_id(reqData)); 1000252190Srpaulo } 1001252190Srpaulo if (resp == NULL) 1002252190Srpaulo return NULL; 1003252190Srpaulo 1004252190Srpaulo wpabuf_put_u8(resp, lm_exch); 1005252190Srpaulo if (EAP_PWD_GET_LENGTH_BIT(lm_exch)) { 1006252190Srpaulo wpabuf_put_be16(resp, tot_len); 1007252190Srpaulo data->out_frag_pos += len; 1008252190Srpaulo } 1009252190Srpaulo buf = wpabuf_head_u8(data->outbuf); 1010252190Srpaulo wpabuf_put_data(resp, buf, len); 1011252190Srpaulo /* 1012252190Srpaulo * if we're not fragmenting then there's no need to carry this around 1013252190Srpaulo */ 1014252190Srpaulo if (data->out_frag_pos == 0) { 1015252190Srpaulo wpabuf_free(data->outbuf); 1016252190Srpaulo data->outbuf = NULL; 1017252190Srpaulo data->out_frag_pos = 0; 1018281806Srpaulo if (data->state == SUCCESS_ON_FRAG_COMPLETION) { 1019281806Srpaulo ret->methodState = METHOD_DONE; 1020281806Srpaulo ret->decision = DECISION_UNCOND_SUCC; 1021281806Srpaulo eap_pwd_state(data, SUCCESS); 1022281806Srpaulo } 1023252190Srpaulo } 1024252190Srpaulo 1025252190Srpaulo return resp; 1026252190Srpaulo} 1027252190Srpaulo 1028252190Srpaulo 1029252190Srpaulostatic Boolean eap_pwd_key_available(struct eap_sm *sm, void *priv) 1030252190Srpaulo{ 1031252190Srpaulo struct eap_pwd_data *data = priv; 1032252190Srpaulo return data->state == SUCCESS; 1033252190Srpaulo} 1034252190Srpaulo 1035252190Srpaulo 1036252190Srpaulostatic u8 * eap_pwd_get_emsk(struct eap_sm *sm, void *priv, size_t *len) 1037252190Srpaulo{ 1038252190Srpaulo struct eap_pwd_data *data = priv; 1039252190Srpaulo u8 *key; 1040252190Srpaulo 1041252190Srpaulo if (data->state != SUCCESS) 1042252190Srpaulo return NULL; 1043252190Srpaulo 1044252190Srpaulo if ((key = os_malloc(EAP_EMSK_LEN)) == NULL) 1045252190Srpaulo return NULL; 1046252190Srpaulo 1047252190Srpaulo os_memcpy(key, data->emsk, EAP_EMSK_LEN); 1048252190Srpaulo *len = EAP_EMSK_LEN; 1049252190Srpaulo 1050252190Srpaulo return key; 1051252190Srpaulo} 1052252190Srpaulo 1053252190Srpaulo 1054252190Srpauloint eap_peer_pwd_register(void) 1055252190Srpaulo{ 1056252190Srpaulo struct eap_method *eap; 1057252190Srpaulo 1058252190Srpaulo eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION, 1059252190Srpaulo EAP_VENDOR_IETF, EAP_TYPE_PWD, "PWD"); 1060252190Srpaulo if (eap == NULL) 1061252190Srpaulo return -1; 1062252190Srpaulo 1063252190Srpaulo eap->init = eap_pwd_init; 1064252190Srpaulo eap->deinit = eap_pwd_deinit; 1065252190Srpaulo eap->process = eap_pwd_process; 1066252190Srpaulo eap->isKeyAvailable = eap_pwd_key_available; 1067252190Srpaulo eap->getKey = eap_pwd_getkey; 1068281806Srpaulo eap->getSessionId = eap_pwd_get_session_id; 1069252190Srpaulo eap->get_emsk = eap_pwd_get_emsk; 1070252190Srpaulo 1071337817Scy return eap_peer_method_register(eap); 1072252190Srpaulo} 1073