| /* |
| * hostapd / EAP-pwd (RFC 5931) server |
| * Copyright (c) 2010, Dan Harkins <dharkins@lounge.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the BSD license. |
| * |
| * Alternatively, this software may be distributed under the terms of the |
| * GNU General Public License version 2 as published by the Free Software |
| * Foundation. |
| * |
| * See README and COPYING for more details. |
| */ |
| |
| #include "includes.h" |
| |
| #include "common.h" |
| #include "eap_server/eap_i.h" |
| #include "eap_common/eap_pwd_common.h" |
| |
| |
| struct eap_pwd_data { |
| enum { |
| PWD_ID_Req, PWD_Commit_Req, PWD_Confirm_Req, SUCCESS, FAILURE |
| } state; |
| u8 *id_peer; |
| size_t id_peer_len; |
| u8 *id_server; |
| size_t id_server_len; |
| u8 *password; |
| size_t password_len; |
| u32 token; |
| u16 group_num; |
| EAP_PWD_group *grp; |
| |
| BIGNUM *k; |
| BIGNUM *private_value; |
| BIGNUM *peer_scalar; |
| BIGNUM *my_scalar; |
| EC_POINT *my_element; |
| EC_POINT *peer_element; |
| |
| u8 my_confirm[SHA256_DIGEST_LENGTH]; |
| |
| u8 msk[EAP_MSK_LEN]; |
| u8 emsk[EAP_EMSK_LEN]; |
| |
| BN_CTX *bnctx; |
| }; |
| |
| |
| static const char * eap_pwd_state_txt(int state) |
| { |
| switch (state) { |
| case PWD_ID_Req: |
| return "PWD-ID-Req"; |
| case PWD_Commit_Req: |
| return "PWD-Commit-Req"; |
| case PWD_Confirm_Req: |
| return "PWD-Confirm-Req"; |
| case SUCCESS: |
| return "SUCCESS"; |
| case FAILURE: |
| return "FAILURE"; |
| default: |
| return "PWD-Unk"; |
| } |
| } |
| |
| |
| static void eap_pwd_state(struct eap_pwd_data *data, int state) |
| { |
| wpa_printf(MSG_DEBUG, "EAP-pwd: %s -> %s", |
| eap_pwd_state_txt(data->state), eap_pwd_state_txt(state)); |
| data->state = state; |
| } |
| |
| |
| static void * eap_pwd_init(struct eap_sm *sm) |
| { |
| struct eap_pwd_data *data; |
| |
| if (sm->user == NULL || sm->user->password == NULL || |
| sm->user->password_len == 0) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): Password is not " |
| "configured"); |
| return NULL; |
| } |
| |
| data = os_zalloc(sizeof(*data)); |
| if (data == NULL) |
| return NULL; |
| |
| data->group_num = sm->pwd_group; |
| wpa_printf(MSG_DEBUG, "EAP-pwd: Selected group number %d", |
| data->group_num); |
| data->state = PWD_ID_Req; |
| |
| data->id_server = (u8 *) os_strdup("server"); |
| if (data->id_server) |
| data->id_server_len = os_strlen((char *) data->id_server); |
| |
| data->password = os_malloc(sm->user->password_len); |
| if (data->password == NULL) { |
| wpa_printf(MSG_INFO, "EAP-PWD: Memory allocation password " |
| "fail"); |
| os_free(data->id_server); |
| os_free(data); |
| return NULL; |
| } |
| data->password_len = sm->user->password_len; |
| os_memcpy(data->password, sm->user->password, data->password_len); |
| |
| data->bnctx = BN_CTX_new(); |
| if (data->bnctx == NULL) { |
| wpa_printf(MSG_INFO, "EAP-PWD: bn context allocation fail"); |
| os_free(data->password); |
| os_free(data->id_server); |
| os_free(data); |
| return NULL; |
| } |
| |
| return data; |
| } |
| |
| |
| static void eap_pwd_reset(struct eap_sm *sm, void *priv) |
| { |
| struct eap_pwd_data *data = priv; |
| |
| BN_free(data->private_value); |
| BN_free(data->peer_scalar); |
| BN_free(data->my_scalar); |
| BN_free(data->k); |
| BN_CTX_free(data->bnctx); |
| EC_POINT_free(data->my_element); |
| EC_POINT_free(data->peer_element); |
| os_free(data->id_peer); |
| os_free(data->id_server); |
| os_free(data->password); |
| if (data->grp) { |
| EC_GROUP_free(data->grp->group); |
| EC_POINT_free(data->grp->pwe); |
| BN_free(data->grp->order); |
| BN_free(data->grp->prime); |
| os_free(data->grp); |
| } |
| os_free(data); |
| } |
| |
| |
| static struct wpabuf * |
| eap_pwd_build_id_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id) |
| { |
| struct wpabuf *req; |
| |
| wpa_printf(MSG_DEBUG, "EAP-pwd: ID/Request"); |
| req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, |
| sizeof(struct eap_pwd_hdr) + |
| sizeof(struct eap_pwd_id) + data->id_server_len, |
| EAP_CODE_REQUEST, id); |
| if (req == NULL) { |
| eap_pwd_state(data, FAILURE); |
| return NULL; |
| } |
| |
| /* an lfsr is good enough to generate unpredictable tokens */ |
| data->token = os_random(); |
| wpabuf_put_u8(req, EAP_PWD_OPCODE_ID_EXCH); |
| wpabuf_put_be16(req, data->group_num); |
| wpabuf_put_u8(req, EAP_PWD_DEFAULT_RAND_FUNC); |
| wpabuf_put_u8(req, EAP_PWD_DEFAULT_PRF); |
| wpabuf_put_data(req, &data->token, sizeof(data->token)); |
| wpabuf_put_u8(req, EAP_PWD_PREP_NONE); |
| wpabuf_put_data(req, data->id_server, data->id_server_len); |
| |
| return req; |
| } |
| |
| |
| static struct wpabuf * |
| eap_pwd_build_commit_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id) |
| { |
| struct wpabuf *req = NULL; |
| BIGNUM *mask = NULL, *x = NULL, *y = NULL; |
| u8 *scalar = NULL, *element = NULL; |
| u16 offset; |
| |
| wpa_printf(MSG_DEBUG, "EAP-pwd: Commit/Request"); |
| |
| if (((data->private_value = BN_new()) == NULL) || |
| ((data->my_element = EC_POINT_new(data->grp->group)) == NULL) || |
| ((data->my_scalar = BN_new()) == NULL) || |
| ((mask = BN_new()) == NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): scalar allocation " |
| "fail"); |
| goto fin; |
| } |
| |
| BN_rand_range(data->private_value, data->grp->order); |
| BN_rand_range(mask, data->grp->order); |
| BN_add(data->my_scalar, data->private_value, mask); |
| BN_mod(data->my_scalar, data->my_scalar, data->grp->order, |
| data->bnctx); |
| |
| if (!EC_POINT_mul(data->grp->group, data->my_element, NULL, |
| data->grp->pwe, mask, data->bnctx)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): element allocation " |
| "fail"); |
| eap_pwd_state(data, FAILURE); |
| goto fin; |
| } |
| |
| if (!EC_POINT_invert(data->grp->group, data->my_element, data->bnctx)) |
| { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): element inversion " |
| "fail"); |
| goto fin; |
| } |
| BN_free(mask); |
| |
| if (((x = BN_new()) == NULL) || |
| ((y = BN_new()) == NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): point allocation " |
| "fail"); |
| goto fin; |
| } |
| if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, |
| data->my_element, x, y, |
| data->bnctx)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): point assignment " |
| "fail"); |
| goto fin; |
| } |
| |
| if (((scalar = os_malloc(BN_num_bytes(data->grp->order))) == NULL) || |
| ((element = os_malloc(BN_num_bytes(data->grp->prime) * 2)) == |
| NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): data allocation fail"); |
| goto fin; |
| } |
| |
| /* |
| * bignums occupy as little memory as possible so one that is |
| * sufficiently smaller than the prime or order might need pre-pending |
| * with zeros. |
| */ |
| os_memset(scalar, 0, BN_num_bytes(data->grp->order)); |
| os_memset(element, 0, BN_num_bytes(data->grp->prime) * 2); |
| offset = BN_num_bytes(data->grp->order) - |
| BN_num_bytes(data->my_scalar); |
| BN_bn2bin(data->my_scalar, scalar + offset); |
| |
| offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x); |
| BN_bn2bin(x, element + offset); |
| offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y); |
| BN_bn2bin(y, element + BN_num_bytes(data->grp->prime) + offset); |
| |
| req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, |
| sizeof(struct eap_pwd_hdr) + |
| (2 * BN_num_bytes(data->grp->prime)) + |
| BN_num_bytes(data->grp->order), |
| EAP_CODE_REQUEST, id); |
| if (req == NULL) |
| goto fin; |
| wpabuf_put_u8(req, EAP_PWD_OPCODE_COMMIT_EXCH); |
| |
| /* We send the element as (x,y) followed by the scalar */ |
| wpabuf_put_data(req, element, (2 * BN_num_bytes(data->grp->prime))); |
| wpabuf_put_data(req, scalar, BN_num_bytes(data->grp->order)); |
| |
| fin: |
| os_free(scalar); |
| os_free(element); |
| BN_free(x); |
| BN_free(y); |
| if (req == NULL) |
| eap_pwd_state(data, FAILURE); |
| |
| return req; |
| } |
| |
| |
| static struct wpabuf * |
| eap_pwd_build_confirm_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id) |
| { |
| struct wpabuf *req = NULL; |
| BIGNUM *x = NULL, *y = NULL; |
| HMAC_CTX ctx; |
| u8 conf[SHA256_DIGEST_LENGTH], *cruft = NULL, *ptr; |
| u16 grp; |
| |
| wpa_printf(MSG_DEBUG, "EAP-pwd: Confirm/Request"); |
| |
| /* Each component of the cruft will be at most as big as the prime */ |
| if (((cruft = os_malloc(BN_num_bytes(data->grp->prime))) == NULL) || |
| ((x = BN_new()) == NULL) || ((y = BN_new()) == NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): debug allocation " |
| "fail"); |
| goto fin; |
| } |
| |
| /* |
| * commit is H(k | server_element | server_scalar | peer_element | |
| * peer_scalar | ciphersuite) |
| */ |
| H_Init(&ctx); |
| |
| /* |
| * Zero the memory each time because this is mod prime math and some |
| * value may start with a few zeros and the previous one did not. |
| * |
| * First is k |
| */ |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(data->k, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| |
| /* server element: x, y */ |
| if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, |
| data->my_element, x, y, |
| data->bnctx)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " |
| "assignment fail"); |
| goto fin; |
| } |
| |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(x, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(y, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| |
| /* server scalar */ |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(data->my_scalar, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->order)); |
| |
| /* peer element: x, y */ |
| if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, |
| data->peer_element, x, y, |
| data->bnctx)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " |
| "assignment fail"); |
| goto fin; |
| } |
| |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(x, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(y, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| |
| /* peer scalar */ |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(data->peer_scalar, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->order)); |
| |
| /* ciphersuite */ |
| grp = htons(data->group_num); |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| ptr = cruft; |
| os_memcpy(ptr, &grp, sizeof(u16)); |
| ptr += sizeof(u16); |
| *ptr = EAP_PWD_DEFAULT_RAND_FUNC; |
| ptr += sizeof(u8); |
| *ptr = EAP_PWD_DEFAULT_PRF; |
| ptr += sizeof(u8); |
| H_Update(&ctx, cruft, ptr-cruft); |
| |
| /* all done with the random function */ |
| H_Final(&ctx, conf); |
| os_memcpy(data->my_confirm, conf, SHA256_DIGEST_LENGTH); |
| |
| req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, |
| sizeof(struct eap_pwd_hdr) + SHA256_DIGEST_LENGTH, |
| EAP_CODE_REQUEST, id); |
| if (req == NULL) |
| goto fin; |
| |
| wpabuf_put_u8(req, EAP_PWD_OPCODE_CONFIRM_EXCH); |
| wpabuf_put_data(req, conf, SHA256_DIGEST_LENGTH); |
| |
| fin: |
| os_free(cruft); |
| BN_free(x); |
| BN_free(y); |
| if (req == NULL) |
| eap_pwd_state(data, FAILURE); |
| |
| return req; |
| } |
| |
| |
| static struct wpabuf * |
| eap_pwd_build_req(struct eap_sm *sm, void *priv, u8 id) |
| { |
| struct eap_pwd_data *data = priv; |
| |
| switch (data->state) { |
| case PWD_ID_Req: |
| return eap_pwd_build_id_req(sm, data, id); |
| case PWD_Commit_Req: |
| return eap_pwd_build_commit_req(sm, data, id); |
| case PWD_Confirm_Req: |
| return eap_pwd_build_confirm_req(sm, data, id); |
| default: |
| wpa_printf(MSG_INFO, "EAP-pwd: Unknown state %d in build_req", |
| data->state); |
| break; |
| } |
| |
| return NULL; |
| } |
| |
| |
| static Boolean eap_pwd_check(struct eap_sm *sm, void *priv, |
| struct wpabuf *respData) |
| { |
| struct eap_pwd_data *data = priv; |
| const u8 *pos; |
| size_t len; |
| |
| pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PWD, respData, &len); |
| if (pos == NULL || len < 1) { |
| wpa_printf(MSG_INFO, "EAP-pwd: Invalid frame"); |
| return TRUE; |
| } |
| |
| wpa_printf(MSG_DEBUG, "EAP-pwd: Received frame: opcode=%d", *pos); |
| |
| if (data->state == PWD_ID_Req && *pos == EAP_PWD_OPCODE_ID_EXCH) |
| return FALSE; |
| |
| if (data->state == PWD_Commit_Req && |
| *pos == EAP_PWD_OPCODE_COMMIT_EXCH) |
| return FALSE; |
| |
| if (data->state == PWD_Confirm_Req && |
| *pos == EAP_PWD_OPCODE_CONFIRM_EXCH) |
| return FALSE; |
| |
| wpa_printf(MSG_INFO, "EAP-pwd: Unexpected opcode=%d in state=%d", |
| *pos, data->state); |
| |
| return TRUE; |
| } |
| |
| |
| static void eap_pwd_process_id_resp(struct eap_sm *sm, |
| struct eap_pwd_data *data, |
| const u8 *payload, size_t payload_len) |
| { |
| struct eap_pwd_id *id; |
| |
| if (payload_len < sizeof(struct eap_pwd_id)) { |
| wpa_printf(MSG_INFO, "EAP-pwd: Invalid ID response"); |
| return; |
| } |
| |
| id = (struct eap_pwd_id *) payload; |
| if ((data->group_num != be_to_host16(id->group_num)) || |
| (id->random_function != EAP_PWD_DEFAULT_RAND_FUNC) || |
| (os_memcmp(id->token, (u8 *)&data->token, sizeof(data->token))) || |
| (id->prf != EAP_PWD_DEFAULT_PRF)) { |
| wpa_printf(MSG_INFO, "EAP-pwd: peer changed parameters"); |
| eap_pwd_state(data, FAILURE); |
| return; |
| } |
| data->id_peer = os_malloc(payload_len - sizeof(struct eap_pwd_id)); |
| if (data->id_peer == NULL) { |
| wpa_printf(MSG_INFO, "EAP-PWD: memory allocation id fail"); |
| return; |
| } |
| data->id_peer_len = payload_len - sizeof(struct eap_pwd_id); |
| os_memcpy(data->id_peer, id->identity, data->id_peer_len); |
| wpa_hexdump_ascii(MSG_DEBUG, "EAP-PWD (server): peer sent id of", |
| data->id_peer, data->id_peer_len); |
| |
| if ((data->grp = os_malloc(sizeof(EAP_PWD_group))) == NULL) { |
| wpa_printf(MSG_INFO, "EAP-PWD: failed to allocate memory for " |
| "group"); |
| return; |
| } |
| if (compute_password_element(data->grp, data->group_num, |
| data->password, data->password_len, |
| data->id_server, data->id_server_len, |
| data->id_peer, data->id_peer_len, |
| (u8 *) &data->token)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): unable to compute " |
| "PWE"); |
| return; |
| } |
| wpa_printf(MSG_DEBUG, "EAP-PWD (server): computed %d bit PWE...", |
| BN_num_bits(data->grp->prime)); |
| |
| eap_pwd_state(data, PWD_Commit_Req); |
| } |
| |
| |
| static void |
| eap_pwd_process_commit_resp(struct eap_sm *sm, struct eap_pwd_data *data, |
| const u8 *payload, size_t payload_len) |
| { |
| u8 *ptr; |
| BIGNUM *x = NULL, *y = NULL, *cofactor = NULL; |
| EC_POINT *K = NULL, *point = NULL; |
| int res = 0; |
| |
| wpa_printf(MSG_DEBUG, "EAP-pwd: Received commit response"); |
| |
| if (((data->peer_scalar = BN_new()) == NULL) || |
| ((data->k = BN_new()) == NULL) || |
| ((cofactor = BN_new()) == NULL) || |
| ((x = BN_new()) == NULL) || |
| ((y = BN_new()) == NULL) || |
| ((point = EC_POINT_new(data->grp->group)) == NULL) || |
| ((K = EC_POINT_new(data->grp->group)) == NULL) || |
| ((data->peer_element = EC_POINT_new(data->grp->group)) == NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): peer data allocation " |
| "fail"); |
| goto fin; |
| } |
| |
| if (!EC_GROUP_get_cofactor(data->grp->group, cofactor, NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): unable to get " |
| "cofactor for curve"); |
| goto fin; |
| } |
| |
| /* element, x then y, followed by scalar */ |
| ptr = (u8 *) payload; |
| BN_bin2bn(ptr, BN_num_bytes(data->grp->prime), x); |
| ptr += BN_num_bytes(data->grp->prime); |
| BN_bin2bn(ptr, BN_num_bytes(data->grp->prime), y); |
| ptr += BN_num_bytes(data->grp->prime); |
| BN_bin2bn(ptr, BN_num_bytes(data->grp->order), data->peer_scalar); |
| if (!EC_POINT_set_affine_coordinates_GFp(data->grp->group, |
| data->peer_element, x, y, |
| data->bnctx)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): setting peer element " |
| "fail"); |
| goto fin; |
| } |
| |
| /* check to ensure peer's element is not in a small sub-group */ |
| if (BN_cmp(cofactor, BN_value_one())) { |
| if (!EC_POINT_mul(data->grp->group, point, NULL, |
| data->peer_element, cofactor, NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): cannot " |
| "multiply peer element by order"); |
| goto fin; |
| } |
| if (EC_POINT_is_at_infinity(data->grp->group, point)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): peer element " |
| "is at infinity!\n"); |
| goto fin; |
| } |
| } |
| |
| /* compute the shared key, k */ |
| if ((!EC_POINT_mul(data->grp->group, K, NULL, data->grp->pwe, |
| data->peer_scalar, data->bnctx)) || |
| (!EC_POINT_add(data->grp->group, K, K, data->peer_element, |
| data->bnctx)) || |
| (!EC_POINT_mul(data->grp->group, K, NULL, K, data->private_value, |
| data->bnctx))) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): computing shared key " |
| "fail"); |
| goto fin; |
| } |
| |
| /* ensure that the shared key isn't in a small sub-group */ |
| if (BN_cmp(cofactor, BN_value_one())) { |
| if (!EC_POINT_mul(data->grp->group, K, NULL, K, cofactor, |
| NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): cannot " |
| "multiply shared key point by order!\n"); |
| goto fin; |
| } |
| } |
| |
| /* |
| * This check is strictly speaking just for the case above where |
| * co-factor > 1 but it was suggested that even though this is probably |
| * never going to happen it is a simple and safe check "just to be |
| * sure" so let's be safe. |
| */ |
| if (EC_POINT_is_at_infinity(data->grp->group, K)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): shared key point is " |
| "at infinity"); |
| goto fin; |
| } |
| if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, K, data->k, |
| NULL, data->bnctx)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): unable to extract " |
| "shared secret from secret point"); |
| goto fin; |
| } |
| res = 1; |
| |
| fin: |
| EC_POINT_free(K); |
| EC_POINT_free(point); |
| BN_free(cofactor); |
| BN_free(x); |
| BN_free(y); |
| |
| if (res) |
| eap_pwd_state(data, PWD_Confirm_Req); |
| else |
| eap_pwd_state(data, FAILURE); |
| } |
| |
| |
| static void |
| eap_pwd_process_confirm_resp(struct eap_sm *sm, struct eap_pwd_data *data, |
| const u8 *payload, size_t payload_len) |
| { |
| BIGNUM *x = NULL, *y = NULL; |
| HMAC_CTX ctx; |
| u32 cs; |
| u16 grp; |
| u8 conf[SHA256_DIGEST_LENGTH], *cruft = NULL, *ptr; |
| |
| /* build up the ciphersuite: group | random_function | prf */ |
| grp = htons(data->group_num); |
| ptr = (u8 *) &cs; |
| os_memcpy(ptr, &grp, sizeof(u16)); |
| ptr += sizeof(u16); |
| *ptr = EAP_PWD_DEFAULT_RAND_FUNC; |
| ptr += sizeof(u8); |
| *ptr = EAP_PWD_DEFAULT_PRF; |
| |
| /* each component of the cruft will be at most as big as the prime */ |
| if (((cruft = os_malloc(BN_num_bytes(data->grp->prime))) == NULL) || |
| ((x = BN_new()) == NULL) || ((y = BN_new()) == NULL)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (peer): allocation fail"); |
| goto fin; |
| } |
| |
| /* |
| * commit is H(k | peer_element | peer_scalar | server_element | |
| * server_scalar | ciphersuite) |
| */ |
| H_Init(&ctx); |
| |
| /* k */ |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(data->k, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| |
| /* peer element: x, y */ |
| if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, |
| data->peer_element, x, y, |
| data->bnctx)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " |
| "assignment fail"); |
| goto fin; |
| } |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(x, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(y, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| |
| /* peer scalar */ |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(data->peer_scalar, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->order)); |
| |
| /* server element: x, y */ |
| if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, |
| data->my_element, x, y, |
| data->bnctx)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point " |
| "assignment fail"); |
| goto fin; |
| } |
| |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(x, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(y, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime)); |
| |
| /* server scalar */ |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| BN_bn2bin(data->my_scalar, cruft); |
| H_Update(&ctx, cruft, BN_num_bytes(data->grp->order)); |
| |
| /* ciphersuite */ |
| os_memset(cruft, 0, BN_num_bytes(data->grp->prime)); |
| H_Update(&ctx, (u8 *)&cs, sizeof(u32)); |
| |
| /* all done */ |
| H_Final(&ctx, conf); |
| |
| ptr = (u8 *) payload; |
| if (os_memcmp(conf, ptr, SHA256_DIGEST_LENGTH)) { |
| wpa_printf(MSG_INFO, "EAP-PWD (server): confirm did not " |
| "verify"); |
| goto fin; |
| } |
| |
| wpa_printf(MSG_DEBUG, "EAP-pwd (server): confirm verified"); |
| if (compute_keys(data->grp, data->bnctx, data->k, |
| data->peer_scalar, data->my_scalar, conf, |
| data->my_confirm, &cs, data->msk, data->emsk) < 0) |
| eap_pwd_state(data, FAILURE); |
| else |
| eap_pwd_state(data, SUCCESS); |
| |
| fin: |
| os_free(cruft); |
| BN_free(x); |
| BN_free(y); |
| } |
| |
| |
| static void eap_pwd_process(struct eap_sm *sm, void *priv, |
| struct wpabuf *respData) |
| { |
| struct eap_pwd_data *data = priv; |
| const u8 *pos; |
| size_t len; |
| u8 exch; |
| |
| pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PWD, respData, &len); |
| if ((pos == NULL) || (len < 1)) { |
| wpa_printf(MSG_INFO, "Bad EAP header! pos %s and len = %d", |
| (pos == NULL) ? "is NULL" : "is not NULL", |
| (int) len); |
| return; |
| } |
| |
| exch = *pos & 0x3f; |
| switch (exch) { |
| case EAP_PWD_OPCODE_ID_EXCH: |
| eap_pwd_process_id_resp(sm, data, pos + 1, len - 1); |
| break; |
| case EAP_PWD_OPCODE_COMMIT_EXCH: |
| eap_pwd_process_commit_resp(sm, data, pos + 1, len - 1); |
| break; |
| case EAP_PWD_OPCODE_CONFIRM_EXCH: |
| eap_pwd_process_confirm_resp(sm, data, pos + 1, len - 1); |
| break; |
| } |
| } |
| |
| |
| static u8 * eap_pwd_getkey(struct eap_sm *sm, void *priv, size_t *len) |
| { |
| struct eap_pwd_data *data = priv; |
| u8 *key; |
| |
| if (data->state != SUCCESS) |
| return NULL; |
| |
| key = os_malloc(EAP_MSK_LEN); |
| if (key == NULL) |
| return NULL; |
| |
| os_memcpy(key, data->msk, EAP_MSK_LEN); |
| *len = EAP_MSK_LEN; |
| |
| return key; |
| } |
| |
| |
| static u8 * eap_pwd_get_emsk(struct eap_sm *sm, void *priv, size_t *len) |
| { |
| struct eap_pwd_data *data = priv; |
| u8 *key; |
| |
| if (data->state != SUCCESS) |
| return NULL; |
| |
| key = os_malloc(EAP_EMSK_LEN); |
| if (key == NULL) |
| return NULL; |
| |
| os_memcpy(key, data->emsk, EAP_EMSK_LEN); |
| *len = EAP_EMSK_LEN; |
| |
| return key; |
| } |
| |
| |
| static Boolean eap_pwd_is_success(struct eap_sm *sm, void *priv) |
| { |
| struct eap_pwd_data *data = priv; |
| return data->state == SUCCESS; |
| } |
| |
| |
| static Boolean eap_pwd_is_done(struct eap_sm *sm, void *priv) |
| { |
| struct eap_pwd_data *data = priv; |
| return (data->state == SUCCESS) || (data->state == FAILURE); |
| } |
| |
| |
| int eap_server_pwd_register(void) |
| { |
| struct eap_method *eap; |
| int ret; |
| struct timeval tp; |
| struct timezone tz; |
| u32 sr; |
| |
| EVP_add_digest(EVP_sha256()); |
| |
| sr = 0xdeaddada; |
| (void) gettimeofday(&tp, &tz); |
| sr ^= (tp.tv_sec ^ tp.tv_usec); |
| srandom(sr); |
| |
| eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION, |
| EAP_VENDOR_IETF, EAP_TYPE_PWD, |
| "PWD"); |
| if (eap == NULL) |
| return -1; |
| |
| eap->init = eap_pwd_init; |
| eap->reset = eap_pwd_reset; |
| eap->buildReq = eap_pwd_build_req; |
| eap->check = eap_pwd_check; |
| eap->process = eap_pwd_process; |
| eap->isDone = eap_pwd_is_done; |
| eap->getKey = eap_pwd_getkey; |
| eap->get_emsk = eap_pwd_get_emsk; |
| eap->isSuccess = eap_pwd_is_success; |
| |
| ret = eap_server_method_register(eap); |
| if (ret) |
| eap_server_method_free(eap); |
| return ret; |
| } |
| |