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/*
* 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;
}