1252190Srpaulo/* 2252190Srpaulo * hostapd / EAP-pwd (RFC 5931) server 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" 13252190Srpaulo#include "eap_server/eap_i.h" 14252190Srpaulo#include "eap_common/eap_pwd_common.h" 15252190Srpaulo 16252190Srpaulo 17252190Srpaulostruct eap_pwd_data { 18252190Srpaulo enum { 19252190Srpaulo PWD_ID_Req, PWD_Commit_Req, PWD_Confirm_Req, SUCCESS, FAILURE 20252190Srpaulo } state; 21252190Srpaulo u8 *id_peer; 22252190Srpaulo size_t id_peer_len; 23252190Srpaulo u8 *id_server; 24252190Srpaulo size_t id_server_len; 25252190Srpaulo u8 *password; 26252190Srpaulo size_t password_len; 27252190Srpaulo u32 token; 28252190Srpaulo u16 group_num; 29252190Srpaulo EAP_PWD_group *grp; 30252190Srpaulo 31252190Srpaulo struct wpabuf *inbuf; 32252190Srpaulo size_t in_frag_pos; 33252190Srpaulo struct wpabuf *outbuf; 34252190Srpaulo size_t out_frag_pos; 35252190Srpaulo size_t mtu; 36252190Srpaulo 37252190Srpaulo BIGNUM *k; 38252190Srpaulo BIGNUM *private_value; 39252190Srpaulo BIGNUM *peer_scalar; 40252190Srpaulo BIGNUM *my_scalar; 41252190Srpaulo EC_POINT *my_element; 42252190Srpaulo EC_POINT *peer_element; 43252190Srpaulo 44252190Srpaulo u8 my_confirm[SHA256_MAC_LEN]; 45252190Srpaulo 46252190Srpaulo u8 msk[EAP_MSK_LEN]; 47252190Srpaulo u8 emsk[EAP_EMSK_LEN]; 48252190Srpaulo 49252190Srpaulo BN_CTX *bnctx; 50252190Srpaulo}; 51252190Srpaulo 52252190Srpaulo 53252190Srpaulostatic const char * eap_pwd_state_txt(int state) 54252190Srpaulo{ 55252190Srpaulo switch (state) { 56252190Srpaulo case PWD_ID_Req: 57252190Srpaulo return "PWD-ID-Req"; 58252190Srpaulo case PWD_Commit_Req: 59252190Srpaulo return "PWD-Commit-Req"; 60252190Srpaulo case PWD_Confirm_Req: 61252190Srpaulo return "PWD-Confirm-Req"; 62252190Srpaulo case SUCCESS: 63252190Srpaulo return "SUCCESS"; 64252190Srpaulo case FAILURE: 65252190Srpaulo return "FAILURE"; 66252190Srpaulo default: 67252190Srpaulo return "PWD-Unk"; 68252190Srpaulo } 69252190Srpaulo} 70252190Srpaulo 71252190Srpaulo 72252190Srpaulostatic void eap_pwd_state(struct eap_pwd_data *data, int state) 73252190Srpaulo{ 74252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: %s -> %s", 75252190Srpaulo eap_pwd_state_txt(data->state), eap_pwd_state_txt(state)); 76252190Srpaulo data->state = state; 77252190Srpaulo} 78252190Srpaulo 79252190Srpaulo 80252190Srpaulostatic void * eap_pwd_init(struct eap_sm *sm) 81252190Srpaulo{ 82252190Srpaulo struct eap_pwd_data *data; 83252190Srpaulo 84252190Srpaulo if (sm->user == NULL || sm->user->password == NULL || 85252190Srpaulo sm->user->password_len == 0) { 86252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): Password is not " 87252190Srpaulo "configured"); 88252190Srpaulo return NULL; 89252190Srpaulo } 90252190Srpaulo 91252190Srpaulo data = os_zalloc(sizeof(*data)); 92252190Srpaulo if (data == NULL) 93252190Srpaulo return NULL; 94252190Srpaulo 95252190Srpaulo data->group_num = sm->pwd_group; 96252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Selected group number %d", 97252190Srpaulo data->group_num); 98252190Srpaulo data->state = PWD_ID_Req; 99252190Srpaulo 100252190Srpaulo data->id_server = (u8 *) os_strdup("server"); 101252190Srpaulo if (data->id_server) 102252190Srpaulo data->id_server_len = os_strlen((char *) data->id_server); 103252190Srpaulo 104252190Srpaulo data->password = os_malloc(sm->user->password_len); 105252190Srpaulo if (data->password == NULL) { 106252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: Memory allocation password " 107252190Srpaulo "fail"); 108252190Srpaulo os_free(data->id_server); 109252190Srpaulo os_free(data); 110252190Srpaulo return NULL; 111252190Srpaulo } 112252190Srpaulo data->password_len = sm->user->password_len; 113252190Srpaulo os_memcpy(data->password, sm->user->password, data->password_len); 114252190Srpaulo 115252190Srpaulo data->bnctx = BN_CTX_new(); 116252190Srpaulo if (data->bnctx == NULL) { 117252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: bn context allocation fail"); 118252190Srpaulo os_free(data->password); 119252190Srpaulo os_free(data->id_server); 120252190Srpaulo os_free(data); 121252190Srpaulo return NULL; 122252190Srpaulo } 123252190Srpaulo 124252190Srpaulo data->in_frag_pos = data->out_frag_pos = 0; 125252190Srpaulo data->inbuf = data->outbuf = NULL; 126252190Srpaulo data->mtu = 1020; /* default from RFC 5931, make it configurable! */ 127252190Srpaulo 128252190Srpaulo return data; 129252190Srpaulo} 130252190Srpaulo 131252190Srpaulo 132252190Srpaulostatic void eap_pwd_reset(struct eap_sm *sm, void *priv) 133252190Srpaulo{ 134252190Srpaulo struct eap_pwd_data *data = priv; 135252190Srpaulo 136252190Srpaulo BN_free(data->private_value); 137252190Srpaulo BN_free(data->peer_scalar); 138252190Srpaulo BN_free(data->my_scalar); 139252190Srpaulo BN_free(data->k); 140252190Srpaulo BN_CTX_free(data->bnctx); 141252190Srpaulo EC_POINT_free(data->my_element); 142252190Srpaulo EC_POINT_free(data->peer_element); 143252190Srpaulo os_free(data->id_peer); 144252190Srpaulo os_free(data->id_server); 145252190Srpaulo os_free(data->password); 146252190Srpaulo if (data->grp) { 147252190Srpaulo EC_GROUP_free(data->grp->group); 148252190Srpaulo EC_POINT_free(data->grp->pwe); 149252190Srpaulo BN_free(data->grp->order); 150252190Srpaulo BN_free(data->grp->prime); 151252190Srpaulo os_free(data->grp); 152252190Srpaulo } 153252190Srpaulo os_free(data); 154252190Srpaulo} 155252190Srpaulo 156252190Srpaulo 157252190Srpaulostatic void eap_pwd_build_id_req(struct eap_sm *sm, struct eap_pwd_data *data, 158252190Srpaulo u8 id) 159252190Srpaulo{ 160252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: ID/Request"); 161252190Srpaulo /* 162252190Srpaulo * if we're fragmenting then we already have an id request, just return 163252190Srpaulo */ 164252190Srpaulo if (data->out_frag_pos) 165252190Srpaulo return; 166252190Srpaulo 167252190Srpaulo data->outbuf = wpabuf_alloc(sizeof(struct eap_pwd_id) + 168252190Srpaulo data->id_server_len); 169252190Srpaulo if (data->outbuf == NULL) { 170252190Srpaulo eap_pwd_state(data, FAILURE); 171252190Srpaulo return; 172252190Srpaulo } 173252190Srpaulo 174252190Srpaulo /* an lfsr is good enough to generate unpredictable tokens */ 175252190Srpaulo data->token = os_random(); 176252190Srpaulo wpabuf_put_be16(data->outbuf, data->group_num); 177252190Srpaulo wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_RAND_FUNC); 178252190Srpaulo wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_PRF); 179252190Srpaulo wpabuf_put_data(data->outbuf, &data->token, sizeof(data->token)); 180252190Srpaulo wpabuf_put_u8(data->outbuf, EAP_PWD_PREP_NONE); 181252190Srpaulo wpabuf_put_data(data->outbuf, data->id_server, data->id_server_len); 182252190Srpaulo} 183252190Srpaulo 184252190Srpaulo 185252190Srpaulostatic void eap_pwd_build_commit_req(struct eap_sm *sm, 186252190Srpaulo struct eap_pwd_data *data, u8 id) 187252190Srpaulo{ 188252190Srpaulo BIGNUM *mask = NULL, *x = NULL, *y = NULL; 189252190Srpaulo u8 *scalar = NULL, *element = NULL; 190252190Srpaulo u16 offset; 191252190Srpaulo 192252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Commit/Request"); 193252190Srpaulo /* 194252190Srpaulo * if we're fragmenting then we already have an commit request, just 195252190Srpaulo * return 196252190Srpaulo */ 197252190Srpaulo if (data->out_frag_pos) 198252190Srpaulo return; 199252190Srpaulo 200252190Srpaulo if (((data->private_value = BN_new()) == NULL) || 201252190Srpaulo ((data->my_element = EC_POINT_new(data->grp->group)) == NULL) || 202252190Srpaulo ((data->my_scalar = BN_new()) == NULL) || 203252190Srpaulo ((mask = BN_new()) == NULL)) { 204252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): scalar allocation " 205252190Srpaulo "fail"); 206252190Srpaulo goto fin; 207252190Srpaulo } 208252190Srpaulo 209252190Srpaulo BN_rand_range(data->private_value, data->grp->order); 210252190Srpaulo BN_rand_range(mask, data->grp->order); 211252190Srpaulo BN_add(data->my_scalar, data->private_value, mask); 212252190Srpaulo BN_mod(data->my_scalar, data->my_scalar, data->grp->order, 213252190Srpaulo data->bnctx); 214252190Srpaulo 215252190Srpaulo if (!EC_POINT_mul(data->grp->group, data->my_element, NULL, 216252190Srpaulo data->grp->pwe, mask, data->bnctx)) { 217252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): element allocation " 218252190Srpaulo "fail"); 219252190Srpaulo eap_pwd_state(data, FAILURE); 220252190Srpaulo goto fin; 221252190Srpaulo } 222252190Srpaulo 223252190Srpaulo if (!EC_POINT_invert(data->grp->group, data->my_element, data->bnctx)) 224252190Srpaulo { 225252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): element inversion " 226252190Srpaulo "fail"); 227252190Srpaulo goto fin; 228252190Srpaulo } 229252190Srpaulo BN_free(mask); 230252190Srpaulo 231252190Srpaulo if (((x = BN_new()) == NULL) || 232252190Srpaulo ((y = BN_new()) == NULL)) { 233252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): point allocation " 234252190Srpaulo "fail"); 235252190Srpaulo goto fin; 236252190Srpaulo } 237252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 238252190Srpaulo data->my_element, x, y, 239252190Srpaulo data->bnctx)) { 240252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): point assignment " 241252190Srpaulo "fail"); 242252190Srpaulo goto fin; 243252190Srpaulo } 244252190Srpaulo 245252190Srpaulo if (((scalar = os_malloc(BN_num_bytes(data->grp->order))) == NULL) || 246252190Srpaulo ((element = os_malloc(BN_num_bytes(data->grp->prime) * 2)) == 247252190Srpaulo NULL)) { 248252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): data allocation fail"); 249252190Srpaulo goto fin; 250252190Srpaulo } 251252190Srpaulo 252252190Srpaulo /* 253252190Srpaulo * bignums occupy as little memory as possible so one that is 254252190Srpaulo * sufficiently smaller than the prime or order might need pre-pending 255252190Srpaulo * with zeros. 256252190Srpaulo */ 257252190Srpaulo os_memset(scalar, 0, BN_num_bytes(data->grp->order)); 258252190Srpaulo os_memset(element, 0, BN_num_bytes(data->grp->prime) * 2); 259252190Srpaulo offset = BN_num_bytes(data->grp->order) - 260252190Srpaulo BN_num_bytes(data->my_scalar); 261252190Srpaulo BN_bn2bin(data->my_scalar, scalar + offset); 262252190Srpaulo 263252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 264252190Srpaulo BN_bn2bin(x, element + offset); 265252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 266252190Srpaulo BN_bn2bin(y, element + BN_num_bytes(data->grp->prime) + offset); 267252190Srpaulo 268252190Srpaulo data->outbuf = wpabuf_alloc(2 * BN_num_bytes(data->grp->prime) + 269252190Srpaulo BN_num_bytes(data->grp->order)); 270252190Srpaulo if (data->outbuf == NULL) 271252190Srpaulo goto fin; 272252190Srpaulo 273252190Srpaulo /* We send the element as (x,y) followed by the scalar */ 274252190Srpaulo wpabuf_put_data(data->outbuf, element, 275252190Srpaulo 2 * BN_num_bytes(data->grp->prime)); 276252190Srpaulo wpabuf_put_data(data->outbuf, scalar, BN_num_bytes(data->grp->order)); 277252190Srpaulo 278252190Srpaulofin: 279252190Srpaulo os_free(scalar); 280252190Srpaulo os_free(element); 281252190Srpaulo BN_free(x); 282252190Srpaulo BN_free(y); 283252190Srpaulo if (data->outbuf == NULL) 284252190Srpaulo eap_pwd_state(data, FAILURE); 285252190Srpaulo} 286252190Srpaulo 287252190Srpaulo 288252190Srpaulostatic void eap_pwd_build_confirm_req(struct eap_sm *sm, 289252190Srpaulo struct eap_pwd_data *data, u8 id) 290252190Srpaulo{ 291252190Srpaulo BIGNUM *x = NULL, *y = NULL; 292252190Srpaulo struct crypto_hash *hash; 293252190Srpaulo u8 conf[SHA256_MAC_LEN], *cruft = NULL, *ptr; 294252190Srpaulo u16 grp; 295252190Srpaulo int offset; 296252190Srpaulo 297252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Confirm/Request"); 298252190Srpaulo /* 299252190Srpaulo * if we're fragmenting then we already have an confirm request, just 300252190Srpaulo * return 301252190Srpaulo */ 302252190Srpaulo if (data->out_frag_pos) 303252190Srpaulo return; 304252190Srpaulo 305252190Srpaulo /* Each component of the cruft will be at most as big as the prime */ 306252190Srpaulo if (((cruft = os_malloc(BN_num_bytes(data->grp->prime))) == NULL) || 307252190Srpaulo ((x = BN_new()) == NULL) || ((y = BN_new()) == NULL)) { 308252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): debug allocation " 309252190Srpaulo "fail"); 310252190Srpaulo goto fin; 311252190Srpaulo } 312252190Srpaulo 313252190Srpaulo /* 314252190Srpaulo * commit is H(k | server_element | server_scalar | peer_element | 315252190Srpaulo * peer_scalar | ciphersuite) 316252190Srpaulo */ 317252190Srpaulo hash = eap_pwd_h_init(); 318252190Srpaulo if (hash == NULL) 319252190Srpaulo goto fin; 320252190Srpaulo 321252190Srpaulo /* 322252190Srpaulo * Zero the memory each time because this is mod prime math and some 323252190Srpaulo * value may start with a few zeros and the previous one did not. 324252190Srpaulo * 325252190Srpaulo * First is k 326252190Srpaulo */ 327252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 328252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(data->k); 329252190Srpaulo BN_bn2bin(data->k, cruft + offset); 330252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 331252190Srpaulo 332252190Srpaulo /* server element: x, y */ 333252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 334252190Srpaulo data->my_element, x, y, 335252190Srpaulo data->bnctx)) { 336252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " 337252190Srpaulo "assignment fail"); 338252190Srpaulo goto fin; 339252190Srpaulo } 340252190Srpaulo 341252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 342252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 343252190Srpaulo BN_bn2bin(x, cruft + offset); 344252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 345252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 346252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 347252190Srpaulo BN_bn2bin(y, cruft + offset); 348252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 349252190Srpaulo 350252190Srpaulo /* server scalar */ 351252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 352252190Srpaulo offset = BN_num_bytes(data->grp->order) - 353252190Srpaulo BN_num_bytes(data->my_scalar); 354252190Srpaulo BN_bn2bin(data->my_scalar, cruft + offset); 355252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order)); 356252190Srpaulo 357252190Srpaulo /* peer element: x, y */ 358252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 359252190Srpaulo data->peer_element, x, y, 360252190Srpaulo data->bnctx)) { 361252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " 362252190Srpaulo "assignment fail"); 363252190Srpaulo goto fin; 364252190Srpaulo } 365252190Srpaulo 366252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 367252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 368252190Srpaulo BN_bn2bin(x, cruft + offset); 369252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 370252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 371252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 372252190Srpaulo BN_bn2bin(y, cruft + offset); 373252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 374252190Srpaulo 375252190Srpaulo /* peer scalar */ 376252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 377252190Srpaulo offset = BN_num_bytes(data->grp->order) - 378252190Srpaulo BN_num_bytes(data->peer_scalar); 379252190Srpaulo BN_bn2bin(data->peer_scalar, cruft + offset); 380252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order)); 381252190Srpaulo 382252190Srpaulo /* ciphersuite */ 383252190Srpaulo grp = htons(data->group_num); 384252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 385252190Srpaulo ptr = cruft; 386252190Srpaulo os_memcpy(ptr, &grp, sizeof(u16)); 387252190Srpaulo ptr += sizeof(u16); 388252190Srpaulo *ptr = EAP_PWD_DEFAULT_RAND_FUNC; 389252190Srpaulo ptr += sizeof(u8); 390252190Srpaulo *ptr = EAP_PWD_DEFAULT_PRF; 391252190Srpaulo ptr += sizeof(u8); 392252190Srpaulo eap_pwd_h_update(hash, cruft, ptr - cruft); 393252190Srpaulo 394252190Srpaulo /* all done with the random function */ 395252190Srpaulo eap_pwd_h_final(hash, conf); 396252190Srpaulo os_memcpy(data->my_confirm, conf, SHA256_MAC_LEN); 397252190Srpaulo 398252190Srpaulo data->outbuf = wpabuf_alloc(SHA256_MAC_LEN); 399252190Srpaulo if (data->outbuf == NULL) 400252190Srpaulo goto fin; 401252190Srpaulo 402252190Srpaulo wpabuf_put_data(data->outbuf, conf, SHA256_MAC_LEN); 403252190Srpaulo 404252190Srpaulofin: 405252190Srpaulo os_free(cruft); 406252190Srpaulo BN_free(x); 407252190Srpaulo BN_free(y); 408252190Srpaulo if (data->outbuf == NULL) 409252190Srpaulo eap_pwd_state(data, FAILURE); 410252190Srpaulo} 411252190Srpaulo 412252190Srpaulo 413252190Srpaulostatic struct wpabuf * 414252190Srpauloeap_pwd_build_req(struct eap_sm *sm, void *priv, u8 id) 415252190Srpaulo{ 416252190Srpaulo struct eap_pwd_data *data = priv; 417252190Srpaulo struct wpabuf *req; 418252190Srpaulo u8 lm_exch; 419252190Srpaulo const u8 *buf; 420252190Srpaulo u16 totlen = 0; 421252190Srpaulo size_t len; 422252190Srpaulo 423252190Srpaulo /* 424252190Srpaulo * if we're buffering response fragments then just ACK 425252190Srpaulo */ 426252190Srpaulo if (data->in_frag_pos) { 427252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: ACKing a fragment!!"); 428252190Srpaulo req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, 429252190Srpaulo EAP_PWD_HDR_SIZE, EAP_CODE_REQUEST, id); 430252190Srpaulo if (req == NULL) { 431252190Srpaulo eap_pwd_state(data, FAILURE); 432252190Srpaulo return NULL; 433252190Srpaulo } 434252190Srpaulo switch (data->state) { 435252190Srpaulo case PWD_ID_Req: 436252190Srpaulo wpabuf_put_u8(req, EAP_PWD_OPCODE_ID_EXCH); 437252190Srpaulo break; 438252190Srpaulo case PWD_Commit_Req: 439252190Srpaulo wpabuf_put_u8(req, EAP_PWD_OPCODE_COMMIT_EXCH); 440252190Srpaulo break; 441252190Srpaulo case PWD_Confirm_Req: 442252190Srpaulo wpabuf_put_u8(req, EAP_PWD_OPCODE_CONFIRM_EXCH); 443252190Srpaulo break; 444252190Srpaulo default: 445252190Srpaulo eap_pwd_state(data, FAILURE); /* just to be sure */ 446252190Srpaulo wpabuf_free(req); 447252190Srpaulo return NULL; 448252190Srpaulo } 449252190Srpaulo return req; 450252190Srpaulo } 451252190Srpaulo 452252190Srpaulo /* 453252190Srpaulo * build the data portion of a request 454252190Srpaulo */ 455252190Srpaulo switch (data->state) { 456252190Srpaulo case PWD_ID_Req: 457252190Srpaulo eap_pwd_build_id_req(sm, data, id); 458252190Srpaulo lm_exch = EAP_PWD_OPCODE_ID_EXCH; 459252190Srpaulo break; 460252190Srpaulo case PWD_Commit_Req: 461252190Srpaulo eap_pwd_build_commit_req(sm, data, id); 462252190Srpaulo lm_exch = EAP_PWD_OPCODE_COMMIT_EXCH; 463252190Srpaulo break; 464252190Srpaulo case PWD_Confirm_Req: 465252190Srpaulo eap_pwd_build_confirm_req(sm, data, id); 466252190Srpaulo lm_exch = EAP_PWD_OPCODE_CONFIRM_EXCH; 467252190Srpaulo break; 468252190Srpaulo default: 469252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: Unknown state %d in build_req", 470252190Srpaulo data->state); 471252190Srpaulo eap_pwd_state(data, FAILURE); 472252190Srpaulo lm_exch = 0; /* hush now, sweet compiler */ 473252190Srpaulo break; 474252190Srpaulo } 475252190Srpaulo 476252190Srpaulo if (data->state == FAILURE) 477252190Srpaulo return NULL; 478252190Srpaulo 479252190Srpaulo /* 480252190Srpaulo * determine whether that data needs to be fragmented 481252190Srpaulo */ 482252190Srpaulo len = wpabuf_len(data->outbuf) - data->out_frag_pos; 483252190Srpaulo if ((len + EAP_PWD_HDR_SIZE) > data->mtu) { 484252190Srpaulo len = data->mtu - EAP_PWD_HDR_SIZE; 485252190Srpaulo EAP_PWD_SET_MORE_BIT(lm_exch); 486252190Srpaulo /* 487252190Srpaulo * if this is the first fragment, need to set the M bit 488252190Srpaulo * and add the total length to the eap_pwd_hdr 489252190Srpaulo */ 490252190Srpaulo if (data->out_frag_pos == 0) { 491252190Srpaulo EAP_PWD_SET_LENGTH_BIT(lm_exch); 492252190Srpaulo totlen = wpabuf_len(data->outbuf) + 493252190Srpaulo EAP_PWD_HDR_SIZE + sizeof(u16); 494252190Srpaulo len -= sizeof(u16); 495252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Fragmenting output, " 496252190Srpaulo "total length = %d", totlen); 497252190Srpaulo } 498252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Send a %d byte fragment", 499252190Srpaulo (int) len); 500252190Srpaulo } 501252190Srpaulo 502252190Srpaulo /* 503252190Srpaulo * alloc an eap request and populate it with the data 504252190Srpaulo */ 505252190Srpaulo req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, 506252190Srpaulo EAP_PWD_HDR_SIZE + len + 507252190Srpaulo (totlen ? sizeof(u16) : 0), 508252190Srpaulo EAP_CODE_REQUEST, id); 509252190Srpaulo if (req == NULL) { 510252190Srpaulo eap_pwd_state(data, FAILURE); 511252190Srpaulo return NULL; 512252190Srpaulo } 513252190Srpaulo 514252190Srpaulo wpabuf_put_u8(req, lm_exch); 515252190Srpaulo if (EAP_PWD_GET_LENGTH_BIT(lm_exch)) 516252190Srpaulo wpabuf_put_be16(req, totlen); 517252190Srpaulo 518252190Srpaulo buf = wpabuf_head_u8(data->outbuf); 519252190Srpaulo wpabuf_put_data(req, buf + data->out_frag_pos, len); 520252190Srpaulo data->out_frag_pos += len; 521252190Srpaulo /* 522252190Srpaulo * either not fragged or last fragment, either way free up the data 523252190Srpaulo */ 524252190Srpaulo if (data->out_frag_pos >= wpabuf_len(data->outbuf)) { 525252190Srpaulo wpabuf_free(data->outbuf); 526252190Srpaulo data->out_frag_pos = 0; 527252190Srpaulo } 528252190Srpaulo 529252190Srpaulo return req; 530252190Srpaulo} 531252190Srpaulo 532252190Srpaulo 533252190Srpaulostatic Boolean eap_pwd_check(struct eap_sm *sm, void *priv, 534252190Srpaulo struct wpabuf *respData) 535252190Srpaulo{ 536252190Srpaulo struct eap_pwd_data *data = priv; 537252190Srpaulo const u8 *pos; 538252190Srpaulo size_t len; 539252190Srpaulo 540252190Srpaulo pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PWD, respData, &len); 541252190Srpaulo if (pos == NULL || len < 1) { 542252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: Invalid frame"); 543252190Srpaulo return TRUE; 544252190Srpaulo } 545252190Srpaulo 546252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Received frame: exch = %d, len = %d", 547252190Srpaulo EAP_PWD_GET_EXCHANGE(*pos), (int) len); 548252190Srpaulo 549252190Srpaulo if (data->state == PWD_ID_Req && 550252190Srpaulo ((EAP_PWD_GET_EXCHANGE(*pos)) == EAP_PWD_OPCODE_ID_EXCH)) 551252190Srpaulo return FALSE; 552252190Srpaulo 553252190Srpaulo if (data->state == PWD_Commit_Req && 554252190Srpaulo ((EAP_PWD_GET_EXCHANGE(*pos)) == EAP_PWD_OPCODE_COMMIT_EXCH)) 555252190Srpaulo return FALSE; 556252190Srpaulo 557252190Srpaulo if (data->state == PWD_Confirm_Req && 558252190Srpaulo ((EAP_PWD_GET_EXCHANGE(*pos)) == EAP_PWD_OPCODE_CONFIRM_EXCH)) 559252190Srpaulo return FALSE; 560252190Srpaulo 561252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: Unexpected opcode=%d in state=%d", 562252190Srpaulo *pos, data->state); 563252190Srpaulo 564252190Srpaulo return TRUE; 565252190Srpaulo} 566252190Srpaulo 567252190Srpaulo 568252190Srpaulostatic void eap_pwd_process_id_resp(struct eap_sm *sm, 569252190Srpaulo struct eap_pwd_data *data, 570252190Srpaulo const u8 *payload, size_t payload_len) 571252190Srpaulo{ 572252190Srpaulo struct eap_pwd_id *id; 573252190Srpaulo 574252190Srpaulo if (payload_len < sizeof(struct eap_pwd_id)) { 575252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: Invalid ID response"); 576252190Srpaulo return; 577252190Srpaulo } 578252190Srpaulo 579252190Srpaulo id = (struct eap_pwd_id *) payload; 580252190Srpaulo if ((data->group_num != be_to_host16(id->group_num)) || 581252190Srpaulo (id->random_function != EAP_PWD_DEFAULT_RAND_FUNC) || 582252190Srpaulo (os_memcmp(id->token, (u8 *)&data->token, sizeof(data->token))) || 583252190Srpaulo (id->prf != EAP_PWD_DEFAULT_PRF)) { 584252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: peer changed parameters"); 585252190Srpaulo eap_pwd_state(data, FAILURE); 586252190Srpaulo return; 587252190Srpaulo } 588252190Srpaulo data->id_peer = os_malloc(payload_len - sizeof(struct eap_pwd_id)); 589252190Srpaulo if (data->id_peer == NULL) { 590252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: memory allocation id fail"); 591252190Srpaulo return; 592252190Srpaulo } 593252190Srpaulo data->id_peer_len = payload_len - sizeof(struct eap_pwd_id); 594252190Srpaulo os_memcpy(data->id_peer, id->identity, data->id_peer_len); 595252190Srpaulo wpa_hexdump_ascii(MSG_DEBUG, "EAP-PWD (server): peer sent id of", 596252190Srpaulo data->id_peer, data->id_peer_len); 597252190Srpaulo 598252190Srpaulo if ((data->grp = os_malloc(sizeof(EAP_PWD_group))) == NULL) { 599252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD: failed to allocate memory for " 600252190Srpaulo "group"); 601252190Srpaulo return; 602252190Srpaulo } 603252190Srpaulo if (compute_password_element(data->grp, data->group_num, 604252190Srpaulo data->password, data->password_len, 605252190Srpaulo data->id_server, data->id_server_len, 606252190Srpaulo data->id_peer, data->id_peer_len, 607252190Srpaulo (u8 *) &data->token)) { 608252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): unable to compute " 609252190Srpaulo "PWE"); 610252190Srpaulo return; 611252190Srpaulo } 612252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-PWD (server): computed %d bit PWE...", 613252190Srpaulo BN_num_bits(data->grp->prime)); 614252190Srpaulo 615252190Srpaulo eap_pwd_state(data, PWD_Commit_Req); 616252190Srpaulo} 617252190Srpaulo 618252190Srpaulo 619252190Srpaulostatic void 620252190Srpauloeap_pwd_process_commit_resp(struct eap_sm *sm, struct eap_pwd_data *data, 621252190Srpaulo const u8 *payload, size_t payload_len) 622252190Srpaulo{ 623252190Srpaulo u8 *ptr; 624252190Srpaulo BIGNUM *x = NULL, *y = NULL, *cofactor = NULL; 625252190Srpaulo EC_POINT *K = NULL, *point = NULL; 626252190Srpaulo int res = 0; 627252190Srpaulo 628252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Received commit response"); 629252190Srpaulo 630252190Srpaulo if (((data->peer_scalar = BN_new()) == NULL) || 631252190Srpaulo ((data->k = BN_new()) == NULL) || 632252190Srpaulo ((cofactor = BN_new()) == NULL) || 633252190Srpaulo ((x = BN_new()) == NULL) || 634252190Srpaulo ((y = BN_new()) == NULL) || 635252190Srpaulo ((point = EC_POINT_new(data->grp->group)) == NULL) || 636252190Srpaulo ((K = EC_POINT_new(data->grp->group)) == NULL) || 637252190Srpaulo ((data->peer_element = EC_POINT_new(data->grp->group)) == NULL)) { 638252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): peer data allocation " 639252190Srpaulo "fail"); 640252190Srpaulo goto fin; 641252190Srpaulo } 642252190Srpaulo 643252190Srpaulo if (!EC_GROUP_get_cofactor(data->grp->group, cofactor, NULL)) { 644252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): unable to get " 645252190Srpaulo "cofactor for curve"); 646252190Srpaulo goto fin; 647252190Srpaulo } 648252190Srpaulo 649252190Srpaulo /* element, x then y, followed by scalar */ 650252190Srpaulo ptr = (u8 *) payload; 651252190Srpaulo BN_bin2bn(ptr, BN_num_bytes(data->grp->prime), x); 652252190Srpaulo ptr += BN_num_bytes(data->grp->prime); 653252190Srpaulo BN_bin2bn(ptr, BN_num_bytes(data->grp->prime), y); 654252190Srpaulo ptr += BN_num_bytes(data->grp->prime); 655252190Srpaulo BN_bin2bn(ptr, BN_num_bytes(data->grp->order), data->peer_scalar); 656252190Srpaulo if (!EC_POINT_set_affine_coordinates_GFp(data->grp->group, 657252190Srpaulo data->peer_element, x, y, 658252190Srpaulo data->bnctx)) { 659252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): setting peer element " 660252190Srpaulo "fail"); 661252190Srpaulo goto fin; 662252190Srpaulo } 663252190Srpaulo 664252190Srpaulo /* check to ensure peer's element is not in a small sub-group */ 665252190Srpaulo if (BN_cmp(cofactor, BN_value_one())) { 666252190Srpaulo if (!EC_POINT_mul(data->grp->group, point, NULL, 667252190Srpaulo data->peer_element, cofactor, NULL)) { 668252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): cannot " 669252190Srpaulo "multiply peer element by order"); 670252190Srpaulo goto fin; 671252190Srpaulo } 672252190Srpaulo if (EC_POINT_is_at_infinity(data->grp->group, point)) { 673252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): peer element " 674252190Srpaulo "is at infinity!\n"); 675252190Srpaulo goto fin; 676252190Srpaulo } 677252190Srpaulo } 678252190Srpaulo 679252190Srpaulo /* compute the shared key, k */ 680252190Srpaulo if ((!EC_POINT_mul(data->grp->group, K, NULL, data->grp->pwe, 681252190Srpaulo data->peer_scalar, data->bnctx)) || 682252190Srpaulo (!EC_POINT_add(data->grp->group, K, K, data->peer_element, 683252190Srpaulo data->bnctx)) || 684252190Srpaulo (!EC_POINT_mul(data->grp->group, K, NULL, K, data->private_value, 685252190Srpaulo data->bnctx))) { 686252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): computing shared key " 687252190Srpaulo "fail"); 688252190Srpaulo goto fin; 689252190Srpaulo } 690252190Srpaulo 691252190Srpaulo /* ensure that the shared key isn't in a small sub-group */ 692252190Srpaulo if (BN_cmp(cofactor, BN_value_one())) { 693252190Srpaulo if (!EC_POINT_mul(data->grp->group, K, NULL, K, cofactor, 694252190Srpaulo NULL)) { 695252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): cannot " 696252190Srpaulo "multiply shared key point by order!\n"); 697252190Srpaulo goto fin; 698252190Srpaulo } 699252190Srpaulo } 700252190Srpaulo 701252190Srpaulo /* 702252190Srpaulo * This check is strictly speaking just for the case above where 703252190Srpaulo * co-factor > 1 but it was suggested that even though this is probably 704252190Srpaulo * never going to happen it is a simple and safe check "just to be 705252190Srpaulo * sure" so let's be safe. 706252190Srpaulo */ 707252190Srpaulo if (EC_POINT_is_at_infinity(data->grp->group, K)) { 708252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): shared key point is " 709252190Srpaulo "at infinity"); 710252190Srpaulo goto fin; 711252190Srpaulo } 712252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, K, data->k, 713252190Srpaulo NULL, data->bnctx)) { 714252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): unable to extract " 715252190Srpaulo "shared secret from secret point"); 716252190Srpaulo goto fin; 717252190Srpaulo } 718252190Srpaulo res = 1; 719252190Srpaulo 720252190Srpaulofin: 721252190Srpaulo EC_POINT_free(K); 722252190Srpaulo EC_POINT_free(point); 723252190Srpaulo BN_free(cofactor); 724252190Srpaulo BN_free(x); 725252190Srpaulo BN_free(y); 726252190Srpaulo 727252190Srpaulo if (res) 728252190Srpaulo eap_pwd_state(data, PWD_Confirm_Req); 729252190Srpaulo else 730252190Srpaulo eap_pwd_state(data, FAILURE); 731252190Srpaulo} 732252190Srpaulo 733252190Srpaulo 734252190Srpaulostatic void 735252190Srpauloeap_pwd_process_confirm_resp(struct eap_sm *sm, struct eap_pwd_data *data, 736252190Srpaulo const u8 *payload, size_t payload_len) 737252190Srpaulo{ 738252190Srpaulo BIGNUM *x = NULL, *y = NULL; 739252190Srpaulo struct crypto_hash *hash; 740252190Srpaulo u32 cs; 741252190Srpaulo u16 grp; 742252190Srpaulo u8 conf[SHA256_MAC_LEN], *cruft = NULL, *ptr; 743252190Srpaulo int offset; 744252190Srpaulo 745252190Srpaulo /* build up the ciphersuite: group | random_function | prf */ 746252190Srpaulo grp = htons(data->group_num); 747252190Srpaulo ptr = (u8 *) &cs; 748252190Srpaulo os_memcpy(ptr, &grp, sizeof(u16)); 749252190Srpaulo ptr += sizeof(u16); 750252190Srpaulo *ptr = EAP_PWD_DEFAULT_RAND_FUNC; 751252190Srpaulo ptr += sizeof(u8); 752252190Srpaulo *ptr = EAP_PWD_DEFAULT_PRF; 753252190Srpaulo 754252190Srpaulo /* each component of the cruft will be at most as big as the prime */ 755252190Srpaulo if (((cruft = os_malloc(BN_num_bytes(data->grp->prime))) == NULL) || 756252190Srpaulo ((x = BN_new()) == NULL) || ((y = BN_new()) == NULL)) { 757252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (peer): allocation fail"); 758252190Srpaulo goto fin; 759252190Srpaulo } 760252190Srpaulo 761252190Srpaulo /* 762252190Srpaulo * commit is H(k | peer_element | peer_scalar | server_element | 763252190Srpaulo * server_scalar | ciphersuite) 764252190Srpaulo */ 765252190Srpaulo hash = eap_pwd_h_init(); 766252190Srpaulo if (hash == NULL) 767252190Srpaulo goto fin; 768252190Srpaulo 769252190Srpaulo /* k */ 770252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 771252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(data->k); 772252190Srpaulo BN_bn2bin(data->k, cruft + offset); 773252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 774252190Srpaulo 775252190Srpaulo /* peer element: x, y */ 776252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 777252190Srpaulo data->peer_element, x, y, 778252190Srpaulo data->bnctx)) { 779252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " 780252190Srpaulo "assignment fail"); 781252190Srpaulo goto fin; 782252190Srpaulo } 783252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 784252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 785252190Srpaulo BN_bn2bin(x, cruft + offset); 786252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 787252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 788252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 789252190Srpaulo BN_bn2bin(y, cruft + offset); 790252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 791252190Srpaulo 792252190Srpaulo /* peer scalar */ 793252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 794252190Srpaulo offset = BN_num_bytes(data->grp->order) - 795252190Srpaulo BN_num_bytes(data->peer_scalar); 796252190Srpaulo BN_bn2bin(data->peer_scalar, cruft + offset); 797252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order)); 798252190Srpaulo 799252190Srpaulo /* server element: x, y */ 800252190Srpaulo if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, 801252190Srpaulo data->my_element, x, y, 802252190Srpaulo data->bnctx)) { 803252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " 804252190Srpaulo "assignment fail"); 805252190Srpaulo goto fin; 806252190Srpaulo } 807252190Srpaulo 808252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 809252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); 810252190Srpaulo BN_bn2bin(x, cruft + offset); 811252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 812252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 813252190Srpaulo offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); 814252190Srpaulo BN_bn2bin(y, cruft + offset); 815252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime)); 816252190Srpaulo 817252190Srpaulo /* server scalar */ 818252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 819252190Srpaulo offset = BN_num_bytes(data->grp->order) - 820252190Srpaulo BN_num_bytes(data->my_scalar); 821252190Srpaulo BN_bn2bin(data->my_scalar, cruft + offset); 822252190Srpaulo eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order)); 823252190Srpaulo 824252190Srpaulo /* ciphersuite */ 825252190Srpaulo os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); 826252190Srpaulo eap_pwd_h_update(hash, (u8 *) &cs, sizeof(u32)); 827252190Srpaulo 828252190Srpaulo /* all done */ 829252190Srpaulo eap_pwd_h_final(hash, conf); 830252190Srpaulo 831252190Srpaulo ptr = (u8 *) payload; 832252190Srpaulo if (os_memcmp(conf, ptr, SHA256_MAC_LEN)) { 833252190Srpaulo wpa_printf(MSG_INFO, "EAP-PWD (server): confirm did not " 834252190Srpaulo "verify"); 835252190Srpaulo goto fin; 836252190Srpaulo } 837252190Srpaulo 838252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd (server): confirm verified"); 839252190Srpaulo if (compute_keys(data->grp, data->bnctx, data->k, 840252190Srpaulo data->peer_scalar, data->my_scalar, conf, 841252190Srpaulo data->my_confirm, &cs, data->msk, data->emsk) < 0) 842252190Srpaulo eap_pwd_state(data, FAILURE); 843252190Srpaulo else 844252190Srpaulo eap_pwd_state(data, SUCCESS); 845252190Srpaulo 846252190Srpaulofin: 847252190Srpaulo os_free(cruft); 848252190Srpaulo BN_free(x); 849252190Srpaulo BN_free(y); 850252190Srpaulo} 851252190Srpaulo 852252190Srpaulo 853252190Srpaulostatic void eap_pwd_process(struct eap_sm *sm, void *priv, 854252190Srpaulo struct wpabuf *respData) 855252190Srpaulo{ 856252190Srpaulo struct eap_pwd_data *data = priv; 857252190Srpaulo const u8 *pos; 858252190Srpaulo size_t len; 859252190Srpaulo u8 lm_exch; 860252190Srpaulo u16 tot_len; 861252190Srpaulo 862252190Srpaulo pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PWD, respData, &len); 863252190Srpaulo if ((pos == NULL) || (len < 1)) { 864252190Srpaulo wpa_printf(MSG_INFO, "Bad EAP header! pos %s and len = %d", 865252190Srpaulo (pos == NULL) ? "is NULL" : "is not NULL", 866252190Srpaulo (int) len); 867252190Srpaulo return; 868252190Srpaulo } 869252190Srpaulo 870252190Srpaulo lm_exch = *pos; 871252190Srpaulo pos++; /* skip over the bits and the exch */ 872252190Srpaulo len--; 873252190Srpaulo 874252190Srpaulo /* 875252190Srpaulo * if we're fragmenting then this should be an ACK with no data, 876252190Srpaulo * just return and continue fragmenting in the "build" section above 877252190Srpaulo */ 878252190Srpaulo if (data->out_frag_pos) { 879252190Srpaulo if (len > 1) 880252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: Bad response! " 881252190Srpaulo "Fragmenting but not an ACK"); 882252190Srpaulo else 883252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: received ACK from " 884252190Srpaulo "peer"); 885252190Srpaulo return; 886252190Srpaulo } 887252190Srpaulo /* 888252190Srpaulo * if we're receiving fragmented packets then we need to buffer... 889252190Srpaulo * 890252190Srpaulo * the first fragment has a total length 891252190Srpaulo */ 892252190Srpaulo if (EAP_PWD_GET_LENGTH_BIT(lm_exch)) { 893252190Srpaulo tot_len = WPA_GET_BE16(pos); 894252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Incoming fragments, total " 895252190Srpaulo "length = %d", tot_len); 896252190Srpaulo data->inbuf = wpabuf_alloc(tot_len); 897252190Srpaulo if (data->inbuf == NULL) { 898252190Srpaulo wpa_printf(MSG_INFO, "EAP-pwd: Out of memory to " 899252190Srpaulo "buffer fragments!"); 900252190Srpaulo return; 901252190Srpaulo } 902252190Srpaulo pos += sizeof(u16); 903252190Srpaulo len -= sizeof(u16); 904252190Srpaulo } 905252190Srpaulo /* 906252190Srpaulo * the first and all intermediate fragments have the M bit set 907252190Srpaulo */ 908252190Srpaulo if (EAP_PWD_GET_MORE_BIT(lm_exch)) { 909252190Srpaulo if ((data->in_frag_pos + len) > wpabuf_size(data->inbuf)) { 910252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Buffer overflow " 911252190Srpaulo "attack detected! (%d+%d > %d)", 912252190Srpaulo (int) data->in_frag_pos, (int) len, 913252190Srpaulo (int) wpabuf_size(data->inbuf)); 914252190Srpaulo eap_pwd_state(data, FAILURE); 915252190Srpaulo return; 916252190Srpaulo } 917252190Srpaulo wpabuf_put_data(data->inbuf, pos, len); 918252190Srpaulo data->in_frag_pos += len; 919252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Got a %d byte fragment", 920252190Srpaulo (int) len); 921252190Srpaulo return; 922252190Srpaulo } 923252190Srpaulo /* 924252190Srpaulo * last fragment won't have the M bit set (but we're obviously 925252190Srpaulo * buffering fragments so that's how we know it's the last) 926252190Srpaulo */ 927252190Srpaulo if (data->in_frag_pos) { 928252190Srpaulo wpabuf_put_data(data->inbuf, pos, len); 929252190Srpaulo data->in_frag_pos += len; 930252190Srpaulo pos = wpabuf_head_u8(data->inbuf); 931252190Srpaulo len = data->in_frag_pos; 932252190Srpaulo wpa_printf(MSG_DEBUG, "EAP-pwd: Last fragment, %d bytes", 933252190Srpaulo (int) len); 934252190Srpaulo } 935252190Srpaulo switch (EAP_PWD_GET_EXCHANGE(lm_exch)) { 936252190Srpaulo case EAP_PWD_OPCODE_ID_EXCH: 937252190Srpaulo eap_pwd_process_id_resp(sm, data, pos, len); 938252190Srpaulo break; 939252190Srpaulo case EAP_PWD_OPCODE_COMMIT_EXCH: 940252190Srpaulo eap_pwd_process_commit_resp(sm, data, pos, len); 941252190Srpaulo break; 942252190Srpaulo case EAP_PWD_OPCODE_CONFIRM_EXCH: 943252190Srpaulo eap_pwd_process_confirm_resp(sm, data, pos, len); 944252190Srpaulo break; 945252190Srpaulo } 946252190Srpaulo /* 947252190Srpaulo * if we had been buffering fragments, here's a great place 948252190Srpaulo * to clean up 949252190Srpaulo */ 950252190Srpaulo if (data->in_frag_pos) { 951252190Srpaulo wpabuf_free(data->inbuf); 952252190Srpaulo data->in_frag_pos = 0; 953252190Srpaulo } 954252190Srpaulo} 955252190Srpaulo 956252190Srpaulo 957252190Srpaulostatic u8 * eap_pwd_getkey(struct eap_sm *sm, void *priv, size_t *len) 958252190Srpaulo{ 959252190Srpaulo struct eap_pwd_data *data = priv; 960252190Srpaulo u8 *key; 961252190Srpaulo 962252190Srpaulo if (data->state != SUCCESS) 963252190Srpaulo return NULL; 964252190Srpaulo 965252190Srpaulo key = os_malloc(EAP_MSK_LEN); 966252190Srpaulo if (key == NULL) 967252190Srpaulo return NULL; 968252190Srpaulo 969252190Srpaulo os_memcpy(key, data->msk, EAP_MSK_LEN); 970252190Srpaulo *len = EAP_MSK_LEN; 971252190Srpaulo 972252190Srpaulo return key; 973252190Srpaulo} 974252190Srpaulo 975252190Srpaulo 976252190Srpaulostatic u8 * eap_pwd_get_emsk(struct eap_sm *sm, void *priv, size_t *len) 977252190Srpaulo{ 978252190Srpaulo struct eap_pwd_data *data = priv; 979252190Srpaulo u8 *key; 980252190Srpaulo 981252190Srpaulo if (data->state != SUCCESS) 982252190Srpaulo return NULL; 983252190Srpaulo 984252190Srpaulo key = os_malloc(EAP_EMSK_LEN); 985252190Srpaulo if (key == NULL) 986252190Srpaulo return NULL; 987252190Srpaulo 988252190Srpaulo os_memcpy(key, data->emsk, EAP_EMSK_LEN); 989252190Srpaulo *len = EAP_EMSK_LEN; 990252190Srpaulo 991252190Srpaulo return key; 992252190Srpaulo} 993252190Srpaulo 994252190Srpaulo 995252190Srpaulostatic Boolean eap_pwd_is_success(struct eap_sm *sm, void *priv) 996252190Srpaulo{ 997252190Srpaulo struct eap_pwd_data *data = priv; 998252190Srpaulo return data->state == SUCCESS; 999252190Srpaulo} 1000252190Srpaulo 1001252190Srpaulo 1002252190Srpaulostatic Boolean eap_pwd_is_done(struct eap_sm *sm, void *priv) 1003252190Srpaulo{ 1004252190Srpaulo struct eap_pwd_data *data = priv; 1005252190Srpaulo return (data->state == SUCCESS) || (data->state == FAILURE); 1006252190Srpaulo} 1007252190Srpaulo 1008252190Srpaulo 1009252190Srpauloint eap_server_pwd_register(void) 1010252190Srpaulo{ 1011252190Srpaulo struct eap_method *eap; 1012252190Srpaulo int ret; 1013252190Srpaulo struct timeval tp; 1014252190Srpaulo struct timezone tz; 1015252190Srpaulo u32 sr; 1016252190Srpaulo 1017252190Srpaulo EVP_add_digest(EVP_sha256()); 1018252190Srpaulo 1019252190Srpaulo sr = 0xdeaddada; 1020252190Srpaulo (void) gettimeofday(&tp, &tz); 1021252190Srpaulo sr ^= (tp.tv_sec ^ tp.tv_usec); 1022252190Srpaulo srandom(sr); 1023252190Srpaulo 1024252190Srpaulo eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION, 1025252190Srpaulo EAP_VENDOR_IETF, EAP_TYPE_PWD, 1026252190Srpaulo "PWD"); 1027252190Srpaulo if (eap == NULL) 1028252190Srpaulo return -1; 1029252190Srpaulo 1030252190Srpaulo eap->init = eap_pwd_init; 1031252190Srpaulo eap->reset = eap_pwd_reset; 1032252190Srpaulo eap->buildReq = eap_pwd_build_req; 1033252190Srpaulo eap->check = eap_pwd_check; 1034252190Srpaulo eap->process = eap_pwd_process; 1035252190Srpaulo eap->isDone = eap_pwd_is_done; 1036252190Srpaulo eap->getKey = eap_pwd_getkey; 1037252190Srpaulo eap->get_emsk = eap_pwd_get_emsk; 1038252190Srpaulo eap->isSuccess = eap_pwd_is_success; 1039252190Srpaulo 1040252190Srpaulo ret = eap_server_method_register(eap); 1041252190Srpaulo if (ret) 1042252190Srpaulo eap_server_method_free(eap); 1043252190Srpaulo return ret; 1044252190Srpaulo} 1045252190Srpaulo 1046