/* * EAP peer method: EAP-GPSK (draft-ietf-emu-eap-gpsk-08.txt) * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Alternatively, this software may be distributed under the terms of BSD * license. * * See README and COPYING for more details. */ #include "includes.h" #include "common.h" #include "eap_i.h" #include "config_ssid.h" #include "eap_gpsk_common.h" struct eap_gpsk_data { enum { GPSK_1, GPSK_3, SUCCESS, FAILURE } state; u8 rand_server[EAP_GPSK_RAND_LEN]; u8 rand_peer[EAP_GPSK_RAND_LEN]; u8 msk[EAP_MSK_LEN]; u8 emsk[EAP_EMSK_LEN]; u8 sk[EAP_GPSK_MAX_SK_LEN]; size_t sk_len; u8 pk[EAP_GPSK_MAX_PK_LEN]; size_t pk_len; u8 session_id; int session_id_set; u8 *id_peer; size_t id_peer_len; u8 *id_server; size_t id_server_len; int vendor; /* CSuite/Specifier */ int specifier; /* CSuite/Specifier */ u8 *psk; size_t psk_len; }; static u8 * eap_gpsk_send_gpsk_2(struct eap_gpsk_data *data, u8 identifier, const u8 *csuite_list, size_t csuite_list_len, size_t *respDataLen); static u8 * eap_gpsk_send_gpsk_4(struct eap_gpsk_data *data, u8 identifier, size_t *respDataLen); #ifndef CONFIG_NO_STDOUT_DEBUG static const char * eap_gpsk_state_txt(int state) { switch (state) { case GPSK_1: return "GPSK-1"; case GPSK_3: return "GPSK-3"; case SUCCESS: return "SUCCESS"; case FAILURE: return "FAILURE"; default: return "?"; } } #endif /* CONFIG_NO_STDOUT_DEBUG */ static void eap_gpsk_state(struct eap_gpsk_data *data, int state) { wpa_printf(MSG_DEBUG, "EAP-GPSK: %s -> %s", eap_gpsk_state_txt(data->state), eap_gpsk_state_txt(state)); data->state = state; } static void eap_gpsk_deinit(struct eap_sm *sm, void *priv); static void * eap_gpsk_init(struct eap_sm *sm) { struct wpa_ssid *config = eap_get_config(sm); struct eap_gpsk_data *data; if (config == NULL) { wpa_printf(MSG_INFO, "EAP-GPSK: No configuration found"); return NULL; } if (config->eappsk == NULL) { wpa_printf(MSG_INFO, "EAP-GPSK: No key (eappsk) configured"); return NULL; } data = os_zalloc(sizeof(*data)); if (data == NULL) return NULL; data->state = GPSK_1; if (config->nai) { data->id_peer = os_malloc(config->nai_len); if (data->id_peer == NULL) { eap_gpsk_deinit(sm, data); return NULL; } os_memcpy(data->id_peer, config->nai, config->nai_len); data->id_peer_len = config->nai_len; } data->psk = os_malloc(config->eappsk_len); if (data->psk == NULL) { eap_gpsk_deinit(sm, data); return NULL; } os_memcpy(data->psk, config->eappsk, config->eappsk_len); data->psk_len = config->eappsk_len; return data; } static void eap_gpsk_deinit(struct eap_sm *sm, void *priv) { struct eap_gpsk_data *data = priv; os_free(data->id_server); os_free(data->id_peer); os_free(data->psk); os_free(data); } const u8 * eap_gpsk_process_id_server(struct eap_gpsk_data *data, const u8 *pos, const u8 *end) { u16 alen; if (end - pos < 2) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short GPSK-1 packet"); return NULL; } alen = WPA_GET_BE16(pos); pos += 2; if (end - pos < alen) { wpa_printf(MSG_DEBUG, "EAP-GPSK: ID_Server overflow"); return NULL; } os_free(data->id_server); data->id_server = os_malloc(alen); if (data->id_server == NULL) { wpa_printf(MSG_DEBUG, "EAP-GPSK: No memory for ID_Server"); return NULL; } os_memcpy(data->id_server, pos, alen); data->id_server_len = alen; wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server", data->id_server, data->id_server_len); pos += alen; return pos; } const u8 * eap_gpsk_process_rand_server(struct eap_gpsk_data *data, const u8 *pos, const u8 *end) { if (pos == NULL) return NULL; if (end - pos < EAP_GPSK_RAND_LEN) { wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Server overflow"); return NULL; } os_memcpy(data->rand_server, pos, EAP_GPSK_RAND_LEN); wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server", data->rand_server, EAP_GPSK_RAND_LEN); pos += EAP_GPSK_RAND_LEN; return pos; } static int eap_gpsk_select_csuite(struct eap_sm *sm, struct eap_gpsk_data *data, const u8 *csuite_list, size_t csuite_list_len) { struct eap_gpsk_csuite *csuite; int i, count; count = csuite_list_len / sizeof(struct eap_gpsk_csuite); data->vendor = EAP_GPSK_VENDOR_IETF; data->specifier = EAP_GPSK_CIPHER_RESERVED; csuite = (struct eap_gpsk_csuite *) csuite_list; for (i = 0; i < count; i++) { int vendor, specifier; vendor = WPA_GET_BE32(csuite->vendor); specifier = WPA_GET_BE16(csuite->specifier); wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite[%d]: %d:%d", i, vendor, specifier); if (data->vendor == EAP_GPSK_VENDOR_IETF && data->specifier == EAP_GPSK_CIPHER_RESERVED && eap_gpsk_supported_ciphersuite(vendor, specifier)) { data->vendor = vendor; data->specifier = specifier; } csuite++; } if (data->vendor == EAP_GPSK_VENDOR_IETF && data->specifier == EAP_GPSK_CIPHER_RESERVED) { wpa_msg(sm->msg_ctx, MSG_INFO, "EAP-GPSK: No supported " "ciphersuite found"); return -1; } wpa_printf(MSG_DEBUG, "EAP-GPSK: Selected ciphersuite %d:%d", data->vendor, data->specifier); return 0; } const u8 * eap_gpsk_process_csuite_list(struct eap_sm *sm, struct eap_gpsk_data *data, const u8 **list, size_t *list_len, const u8 *pos, const u8 *end) { if (pos == NULL) return NULL; if (end - pos < 2) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short GPSK-1 packet"); return NULL; } *list_len = WPA_GET_BE16(pos); pos += 2; if (end - pos < (int) *list_len) { wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_List overflow"); return NULL; } if (*list_len == 0 || (*list_len % sizeof(struct eap_gpsk_csuite))) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Invalid CSuite_List len %lu", (unsigned long) *list_len); return NULL; } *list = pos; pos += *list_len; if (eap_gpsk_select_csuite(sm, data, *list, *list_len) < 0) return NULL; return pos; } static u8 * eap_gpsk_process_gpsk_1(struct eap_sm *sm, struct eap_gpsk_data *data, struct eap_method_ret *ret, const u8 *reqData, size_t reqDataLen, const u8 *payload, size_t payload_len, size_t *respDataLen) { size_t csuite_list_len; const u8 *csuite_list, *pos, *end; const struct eap_hdr *req; u8 *resp; if (data->state != GPSK_1) { ret->ignore = TRUE; return NULL; } wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Request/GPSK-1"); end = payload + payload_len; pos = eap_gpsk_process_id_server(data, payload, end); pos = eap_gpsk_process_rand_server(data, pos, end); pos = eap_gpsk_process_csuite_list(sm, data, &csuite_list, &csuite_list_len, pos, end); if (pos == NULL) { eap_gpsk_state(data, FAILURE); return NULL; } req = (const struct eap_hdr *) reqData; resp = eap_gpsk_send_gpsk_2(data, req->identifier, csuite_list, csuite_list_len, respDataLen); if (resp == NULL) return NULL; eap_gpsk_state(data, GPSK_3); return (u8 *) resp; } static u8 * eap_gpsk_send_gpsk_2(struct eap_gpsk_data *data, u8 identifier, const u8 *csuite_list, size_t csuite_list_len, size_t *respDataLen) { struct eap_hdr *resp; size_t len, miclen; u8 *rpos, *start; struct eap_gpsk_csuite *csuite; wpa_printf(MSG_DEBUG, "EAP-GPSK: Sending Response/GPSK-2"); miclen = eap_gpsk_mic_len(data->vendor, data->specifier); len = 1 + 2 + data->id_peer_len + 2 + data->id_server_len + 2 * EAP_GPSK_RAND_LEN + 2 + csuite_list_len + sizeof(struct eap_gpsk_csuite) + 2 + miclen; resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, respDataLen, len, EAP_CODE_RESPONSE, identifier, &rpos); if (resp == NULL) return NULL; *rpos++ = EAP_GPSK_OPCODE_GPSK_2; start = rpos; wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Peer", data->id_peer, data->id_peer_len); WPA_PUT_BE16(rpos, data->id_peer_len); rpos += 2; if (data->id_peer) os_memcpy(rpos, data->id_peer, data->id_peer_len); rpos += data->id_peer_len; WPA_PUT_BE16(rpos, data->id_server_len); rpos += 2; if (data->id_server) os_memcpy(rpos, data->id_server, data->id_server_len); rpos += data->id_server_len; if (os_get_random(data->rand_peer, EAP_GPSK_RAND_LEN)) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to get random data " "for RAND_Peer"); eap_gpsk_state(data, FAILURE); os_free(resp); return NULL; } wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer", data->rand_peer, EAP_GPSK_RAND_LEN); os_memcpy(rpos, data->rand_peer, EAP_GPSK_RAND_LEN); rpos += EAP_GPSK_RAND_LEN; os_memcpy(rpos, data->rand_server, EAP_GPSK_RAND_LEN); rpos += EAP_GPSK_RAND_LEN; WPA_PUT_BE16(rpos, csuite_list_len); rpos += 2; os_memcpy(rpos, csuite_list, csuite_list_len); rpos += csuite_list_len; csuite = (struct eap_gpsk_csuite *) rpos; WPA_PUT_BE32(csuite->vendor, data->vendor); WPA_PUT_BE16(csuite->specifier, data->specifier); rpos = (u8 *) (csuite + 1); if (eap_gpsk_derive_keys(data->psk, data->psk_len, data->vendor, data->specifier, data->rand_peer, data->rand_server, data->id_peer, data->id_peer_len, data->id_server, data->id_server_len, data->msk, data->emsk, data->sk, &data->sk_len, data->pk, &data->pk_len) < 0) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to derive keys"); eap_gpsk_state(data, FAILURE); os_free(resp); return NULL; } /* No PD_Payload_1 */ WPA_PUT_BE16(rpos, 0); rpos += 2; if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor, data->specifier, start, rpos - start, rpos) < 0) { eap_gpsk_state(data, FAILURE); os_free(resp); return NULL; } return (u8 *) resp; } const u8 * eap_gpsk_validate_rand(struct eap_gpsk_data *data, const u8 *pos, const u8 *end) { if (end - pos < EAP_GPSK_RAND_LEN) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for " "RAND_Peer"); return NULL; } if (os_memcmp(pos, data->rand_peer, EAP_GPSK_RAND_LEN) != 0) { wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-2 and " "GPSK-3 did not match"); wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-2", data->rand_peer, EAP_GPSK_RAND_LEN); wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-3", pos, EAP_GPSK_RAND_LEN); return NULL; } pos += EAP_GPSK_RAND_LEN; if (end - pos < EAP_GPSK_RAND_LEN) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for " "RAND_Server"); return NULL; } if (os_memcmp(pos, data->rand_server, EAP_GPSK_RAND_LEN) != 0) { wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1 and " "GPSK-3 did not match"); wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1", data->rand_server, EAP_GPSK_RAND_LEN); wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-3", pos, EAP_GPSK_RAND_LEN); return NULL; } pos += EAP_GPSK_RAND_LEN; return pos; } const u8 * eap_gpsk_validate_id_server(struct eap_gpsk_data *data, const u8 *pos, const u8 *end) { size_t len; if (pos == NULL) return NULL; if (end - pos < (int) 2) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for " "length(ID_Server)"); return NULL; } len = WPA_GET_BE16(pos); pos += 2; if (end - pos < (int) len) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for " "ID_Server"); return NULL; } if (len != data->id_server_len || os_memcmp(pos, data->id_server, len) != 0) { wpa_printf(MSG_INFO, "EAP-GPSK: ID_Server did not match with " "the one used in GPSK-1"); wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server in GPSK-1", data->id_server, data->id_server_len); wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server in GPSK-3", pos, len); return NULL; } pos += len; return pos; } const u8 * eap_gpsk_validate_csuite(struct eap_gpsk_data *data, const u8 *pos, const u8 *end) { int vendor, specifier; const struct eap_gpsk_csuite *csuite; if (pos == NULL) return NULL; if (end - pos < (int) sizeof(*csuite)) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for " "CSuite_Sel"); return NULL; } csuite = (const struct eap_gpsk_csuite *) pos; vendor = WPA_GET_BE32(csuite->vendor); specifier = WPA_GET_BE16(csuite->specifier); pos += sizeof(*csuite); if (vendor != data->vendor || specifier != data->specifier) { wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_Sel (%d:%d) does not " "match with the one sent in GPSK-2 (%d:%d)", vendor, specifier, data->vendor, data->specifier); return NULL; } return pos; } const u8 * eap_gpsk_validate_pd_payload_2(struct eap_gpsk_data *data, const u8 *pos, const u8 *end) { u16 alen; if (pos == NULL) return NULL; if (end - pos < 2) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for " "PD_Payload_2 length"); return NULL; } alen = WPA_GET_BE16(pos); pos += 2; if (end - pos < alen) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for " "%d-octet PD_Payload_2", alen); return NULL; } wpa_hexdump(MSG_DEBUG, "EAP-GPSK: PD_Payload_2", pos, alen); pos += alen; return pos; } const u8 * eap_gpsk_validate_gpsk_3_mic(struct eap_gpsk_data *data, const u8 *payload, const u8 *pos, const u8 *end) { size_t miclen; u8 mic[EAP_GPSK_MAX_MIC_LEN]; if (pos == NULL) return NULL; miclen = eap_gpsk_mic_len(data->vendor, data->specifier); if (end - pos < (int) miclen) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for MIC " "(left=%lu miclen=%lu)", (unsigned long) (end - pos), (unsigned long) miclen); return NULL; } if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor, data->specifier, payload, pos - payload, mic) < 0) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to compute MIC"); return NULL; } if (os_memcmp(mic, pos, miclen) != 0) { wpa_printf(MSG_INFO, "EAP-GPSK: Incorrect MIC in GPSK-3"); wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Received MIC", pos, miclen); wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Computed MIC", mic, miclen); return NULL; } pos += miclen; return pos; } static u8 * eap_gpsk_process_gpsk_3(struct eap_sm *sm, struct eap_gpsk_data *data, struct eap_method_ret *ret, const u8 *reqData, size_t reqDataLen, const u8 *payload, size_t payload_len, size_t *respDataLen) { u8 *resp; const struct eap_hdr *req; const u8 *pos, *end; if (data->state != GPSK_3) { ret->ignore = TRUE; return NULL; } wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Request/GPSK-3"); end = payload + payload_len; pos = eap_gpsk_validate_rand(data, payload, end); pos = eap_gpsk_validate_id_server(data, pos, end); pos = eap_gpsk_validate_csuite(data, pos, end); pos = eap_gpsk_validate_pd_payload_2(data, pos, end); pos = eap_gpsk_validate_gpsk_3_mic(data, payload, pos, end); if (pos == NULL) { eap_gpsk_state(data, FAILURE); return NULL; } if (pos != end) { wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignored %lu bytes of extra " "data in the end of GPSK-2", (unsigned long) (end - pos)); } req = (const struct eap_hdr *) reqData; resp = eap_gpsk_send_gpsk_4(data, req->identifier, respDataLen); if (resp == NULL) return NULL; eap_gpsk_state(data, SUCCESS); ret->methodState = METHOD_DONE; ret->decision = DECISION_UNCOND_SUCC; return (u8 *) resp; } static u8 * eap_gpsk_send_gpsk_4(struct eap_gpsk_data *data, u8 identifier, size_t *respDataLen) { struct eap_hdr *resp; u8 *rpos, *start; size_t len; wpa_printf(MSG_DEBUG, "EAP-GPSK: Sending Response/GPSK-4"); len = 1 + 2 + eap_gpsk_mic_len(data->vendor, data->specifier); resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, respDataLen, len, EAP_CODE_RESPONSE, identifier, &rpos); if (resp == NULL) return NULL; *rpos++ = EAP_GPSK_OPCODE_GPSK_4; start = rpos; /* No PD_Payload_3 */ WPA_PUT_BE16(rpos, 0); rpos += 2; if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor, data->specifier, start, rpos - start, rpos) < 0) { eap_gpsk_state(data, FAILURE); os_free(resp); return NULL; } return (u8 *) resp; } static u8 * eap_gpsk_process(struct eap_sm *sm, void *priv, struct eap_method_ret *ret, const u8 *reqData, size_t reqDataLen, size_t *respDataLen) { struct eap_gpsk_data *data = priv; u8 *resp; const u8 *pos; size_t len; pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GPSK, reqData, reqDataLen, &len); if (pos == NULL || len < 1) { ret->ignore = TRUE; return NULL; } wpa_printf(MSG_DEBUG, "EAP-GPSK: Received frame: opcode %d", *pos); ret->ignore = FALSE; ret->methodState = METHOD_MAY_CONT; ret->decision = DECISION_FAIL; ret->allowNotifications = FALSE; switch (*pos) { case EAP_GPSK_OPCODE_GPSK_1: resp = eap_gpsk_process_gpsk_1(sm, data, ret, reqData, reqDataLen, pos + 1, len - 1, respDataLen); break; case EAP_GPSK_OPCODE_GPSK_3: resp = eap_gpsk_process_gpsk_3(sm, data, ret, reqData, reqDataLen, pos + 1, len - 1, respDataLen); break; default: wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignoring message with " "unknown opcode %d", *pos); ret->ignore = TRUE; return NULL; } return resp; } static Boolean eap_gpsk_isKeyAvailable(struct eap_sm *sm, void *priv) { struct eap_gpsk_data *data = priv; return data->state == SUCCESS; } static u8 * eap_gpsk_getKey(struct eap_sm *sm, void *priv, size_t *len) { struct eap_gpsk_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_gpsk_get_emsk(struct eap_sm *sm, void *priv, size_t *len) { struct eap_gpsk_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; } int eap_peer_gpsk_register(void) { struct eap_method *eap; int ret; eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION, EAP_VENDOR_IETF, EAP_TYPE_GPSK, "GPSK"); if (eap == NULL) return -1; eap->init = eap_gpsk_init; eap->deinit = eap_gpsk_deinit; eap->process = eap_gpsk_process; eap->isKeyAvailable = eap_gpsk_isKeyAvailable; eap->getKey = eap_gpsk_getKey; eap->get_emsk = eap_gpsk_get_emsk; ret = eap_peer_method_register(eap); if (ret) eap_peer_method_free(eap); return ret; }