fragattacks/src/eap_server/eap_gpsk.c
2008-10-29 19:30:23 +02:00

634 lines
16 KiB
C

/*
* hostapd / EAP-GPSK (draft-ietf-emu-eap-gpsk-08.txt) server
* 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_server/eap_i.h"
#include "eap_common/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 *id_peer;
size_t id_peer_len;
u8 *id_server;
size_t id_server_len;
#define MAX_NUM_CSUITES 2
struct eap_gpsk_csuite csuite_list[MAX_NUM_CSUITES];
size_t csuite_count;
int vendor; /* CSuite/Vendor */
int specifier; /* CSuite/Specifier */
};
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 "?";
}
}
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_init(struct eap_sm *sm)
{
struct eap_gpsk_data *data;
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->state = GPSK_1;
/* TODO: add support for configuring ID_Server */
data->id_server = (u8 *) os_strdup("hostapd");
if (data->id_server)
data->id_server_len = os_strlen((char *) data->id_server);
data->csuite_count = 0;
if (eap_gpsk_supported_ciphersuite(EAP_GPSK_VENDOR_IETF,
EAP_GPSK_CIPHER_AES)) {
WPA_PUT_BE32(data->csuite_list[data->csuite_count].vendor,
EAP_GPSK_VENDOR_IETF);
WPA_PUT_BE16(data->csuite_list[data->csuite_count].specifier,
EAP_GPSK_CIPHER_AES);
data->csuite_count++;
}
if (eap_gpsk_supported_ciphersuite(EAP_GPSK_VENDOR_IETF,
EAP_GPSK_CIPHER_SHA256)) {
WPA_PUT_BE32(data->csuite_list[data->csuite_count].vendor,
EAP_GPSK_VENDOR_IETF);
WPA_PUT_BE16(data->csuite_list[data->csuite_count].specifier,
EAP_GPSK_CIPHER_SHA256);
data->csuite_count++;
}
return data;
}
static void eap_gpsk_reset(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);
}
static struct wpabuf * eap_gpsk_build_gpsk_1(struct eap_sm *sm,
struct eap_gpsk_data *data, u8 id)
{
size_t len;
struct wpabuf *req;
wpa_printf(MSG_DEBUG, "EAP-GPSK: Request/GPSK-1");
if (os_get_random(data->rand_server, EAP_GPSK_RAND_LEN)) {
wpa_printf(MSG_ERROR, "EAP-GPSK: Failed to get random data");
eap_gpsk_state(data, FAILURE);
return NULL;
}
wpa_hexdump(MSG_MSGDUMP, "EAP-GPSK: RAND_Server",
data->rand_server, EAP_GPSK_RAND_LEN);
len = 1 + 2 + data->id_server_len + EAP_GPSK_RAND_LEN + 2 +
data->csuite_count * sizeof(struct eap_gpsk_csuite);
req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, len,
EAP_CODE_REQUEST, id);
if (req == NULL) {
wpa_printf(MSG_ERROR, "EAP-GPSK: Failed to allocate memory "
"for request/GPSK-1");
eap_gpsk_state(data, FAILURE);
return NULL;
}
wpabuf_put_u8(req, EAP_GPSK_OPCODE_GPSK_1);
wpabuf_put_be16(req, data->id_server_len);
wpabuf_put_data(req, data->id_server, data->id_server_len);
wpabuf_put_data(req, data->rand_server, EAP_GPSK_RAND_LEN);
wpabuf_put_be16(req,
data->csuite_count * sizeof(struct eap_gpsk_csuite));
wpabuf_put_data(req, data->csuite_list,
data->csuite_count * sizeof(struct eap_gpsk_csuite));
return req;
}
static struct wpabuf * eap_gpsk_build_gpsk_3(struct eap_sm *sm,
struct eap_gpsk_data *data, u8 id)
{
u8 *pos, *start;
size_t len, miclen;
struct eap_gpsk_csuite *csuite;
struct wpabuf *req;
wpa_printf(MSG_DEBUG, "EAP-GPSK: Request/GPSK-3");
miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
len = 1 + 2 * EAP_GPSK_RAND_LEN + 2 + data->id_server_len +
sizeof(struct eap_gpsk_csuite) + 2 + miclen;
req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, len,
EAP_CODE_REQUEST, id);
if (req == NULL) {
wpa_printf(MSG_ERROR, "EAP-GPSK: Failed to allocate memory "
"for request/GPSK-3");
eap_gpsk_state(data, FAILURE);
return NULL;
}
wpabuf_put_u8(req, EAP_GPSK_OPCODE_GPSK_3);
start = wpabuf_put(req, 0);
wpabuf_put_data(req, data->rand_peer, EAP_GPSK_RAND_LEN);
wpabuf_put_data(req, data->rand_server, EAP_GPSK_RAND_LEN);
wpabuf_put_be16(req, data->id_server_len);
wpabuf_put_data(req, data->id_server, data->id_server_len);
csuite = wpabuf_put(req, sizeof(*csuite));
WPA_PUT_BE32(csuite->vendor, data->vendor);
WPA_PUT_BE16(csuite->specifier, data->specifier);
/* no PD_Payload_2 */
wpabuf_put_be16(req, 0);
pos = wpabuf_put(req, miclen);
if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
data->specifier, start, pos - start, pos) < 0)
{
os_free(req);
eap_gpsk_state(data, FAILURE);
return NULL;
}
return req;
}
static struct wpabuf * eap_gpsk_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
struct eap_gpsk_data *data = priv;
switch (data->state) {
case GPSK_1:
return eap_gpsk_build_gpsk_1(sm, data, id);
case GPSK_3:
return eap_gpsk_build_gpsk_3(sm, data, id);
default:
wpa_printf(MSG_DEBUG, "EAP-GPSK: Unknown state %d in buildReq",
data->state);
break;
}
return NULL;
}
static Boolean eap_gpsk_check(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
struct eap_gpsk_data *data = priv;
const u8 *pos;
size_t len;
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GPSK, respData, &len);
if (pos == NULL || len < 1) {
wpa_printf(MSG_INFO, "EAP-GPSK: Invalid frame");
return TRUE;
}
wpa_printf(MSG_DEBUG, "EAP-GPSK: Received frame: opcode=%d", *pos);
if (data->state == GPSK_1 && *pos == EAP_GPSK_OPCODE_GPSK_2)
return FALSE;
if (data->state == GPSK_3 && *pos == EAP_GPSK_OPCODE_GPSK_4)
return FALSE;
wpa_printf(MSG_INFO, "EAP-GPSK: Unexpected opcode=%d in state=%d",
*pos, data->state);
return TRUE;
}
static void eap_gpsk_process_gpsk_2(struct eap_sm *sm,
struct eap_gpsk_data *data,
const u8 *payload, size_t payloadlen)
{
const u8 *pos, *end;
u16 alen;
const struct eap_gpsk_csuite *csuite;
size_t i, miclen;
u8 mic[EAP_GPSK_MAX_MIC_LEN];
if (data->state != GPSK_1)
return;
wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Response/GPSK-2");
pos = payload;
end = payload + payloadlen;
if (end - pos < 2) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"ID_Peer length");
eap_gpsk_state(data, FAILURE);
return;
}
alen = WPA_GET_BE16(pos);
pos += 2;
if (end - pos < alen) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"ID_Peer");
eap_gpsk_state(data, FAILURE);
return;
}
os_free(data->id_peer);
data->id_peer = os_malloc(alen);
if (data->id_peer == NULL) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Not enough memory to store "
"%d-octet ID_Peer", alen);
return;
}
os_memcpy(data->id_peer, pos, alen);
data->id_peer_len = alen;
wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Peer",
data->id_peer, data->id_peer_len);
pos += alen;
if (end - pos < 2) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"ID_Server length");
eap_gpsk_state(data, FAILURE);
return;
}
alen = WPA_GET_BE16(pos);
pos += 2;
if (end - pos < alen) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"ID_Server");
eap_gpsk_state(data, FAILURE);
return;
}
if (alen != data->id_server_len ||
os_memcmp(pos, data->id_server, alen) != 0) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: ID_Server in GPSK-1 and "
"GPSK-2 did not match");
eap_gpsk_state(data, FAILURE);
return;
}
pos += alen;
if (end - pos < EAP_GPSK_RAND_LEN) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"RAND_Peer");
eap_gpsk_state(data, FAILURE);
return;
}
os_memcpy(data->rand_peer, pos, EAP_GPSK_RAND_LEN);
wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer",
data->rand_peer, EAP_GPSK_RAND_LEN);
pos += EAP_GPSK_RAND_LEN;
if (end - pos < EAP_GPSK_RAND_LEN) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"RAND_Server");
eap_gpsk_state(data, FAILURE);
return;
}
if (os_memcmp(data->rand_server, pos, EAP_GPSK_RAND_LEN) != 0) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1 and "
"GPSK-2 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-2",
pos, EAP_GPSK_RAND_LEN);
eap_gpsk_state(data, FAILURE);
return;
}
pos += EAP_GPSK_RAND_LEN;
if (end - pos < 2) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"CSuite_List length");
eap_gpsk_state(data, FAILURE);
return;
}
alen = WPA_GET_BE16(pos);
pos += 2;
if (end - pos < alen) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"CSuite_List");
eap_gpsk_state(data, FAILURE);
return;
}
if (alen != data->csuite_count * sizeof(struct eap_gpsk_csuite) ||
os_memcmp(pos, data->csuite_list, alen) != 0) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_List in GPSK-1 and "
"GPSK-2 did not match");
eap_gpsk_state(data, FAILURE);
return;
}
pos += alen;
if (end - pos < (int) sizeof(*csuite)) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"CSuite_Sel");
eap_gpsk_state(data, FAILURE);
return;
}
csuite = (const struct eap_gpsk_csuite *) pos;
for (i = 0; i < data->csuite_count; i++) {
if (os_memcmp(csuite, &data->csuite_list[i], sizeof(*csuite))
== 0)
break;
}
if (i == data->csuite_count) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Peer selected unsupported "
"ciphersuite %d:%d",
WPA_GET_BE32(csuite->vendor),
WPA_GET_BE16(csuite->specifier));
eap_gpsk_state(data, FAILURE);
return;
}
data->vendor = WPA_GET_BE32(csuite->vendor);
data->specifier = WPA_GET_BE16(csuite->specifier);
wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_Sel %d:%d",
data->vendor, data->specifier);
pos += sizeof(*csuite);
if (end - pos < 2) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"PD_Payload_1 length");
eap_gpsk_state(data, FAILURE);
return;
}
alen = WPA_GET_BE16(pos);
pos += 2;
if (end - pos < alen) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"PD_Payload_1");
eap_gpsk_state(data, FAILURE);
return;
}
wpa_hexdump(MSG_DEBUG, "EAP-GPSK: PD_Payload_1", pos, alen);
pos += alen;
if (sm->user == NULL || sm->user->password == NULL) {
wpa_printf(MSG_INFO, "EAP-GPSK: No PSK/password configured "
"for the user");
eap_gpsk_state(data, FAILURE);
return;
}
if (eap_gpsk_derive_keys(sm->user->password, sm->user->password_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);
return;
}
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);
eap_gpsk_state(data, FAILURE);
return;
}
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");
eap_gpsk_state(data, FAILURE);
return;
}
if (os_memcmp(mic, pos, miclen) != 0) {
wpa_printf(MSG_INFO, "EAP-GPSK: Incorrect MIC in GPSK-2");
wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Received MIC", pos, miclen);
wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Computed MIC", mic, miclen);
eap_gpsk_state(data, FAILURE);
return;
}
pos += miclen;
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));
}
eap_gpsk_state(data, GPSK_3);
}
static void eap_gpsk_process_gpsk_4(struct eap_sm *sm,
struct eap_gpsk_data *data,
const u8 *payload, size_t payloadlen)
{
const u8 *pos, *end;
u16 alen;
size_t miclen;
u8 mic[EAP_GPSK_MAX_MIC_LEN];
if (data->state != GPSK_3)
return;
wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Response/GPSK-4");
pos = payload;
end = payload + payloadlen;
if (end - pos < 2) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"PD_Payload_1 length");
eap_gpsk_state(data, FAILURE);
return;
}
alen = WPA_GET_BE16(pos);
pos += 2;
if (end - pos < alen) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short message for "
"PD_Payload_1");
eap_gpsk_state(data, FAILURE);
return;
}
wpa_hexdump(MSG_DEBUG, "EAP-GPSK: PD_Payload_1", pos, alen);
pos += alen;
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);
eap_gpsk_state(data, FAILURE);
return;
}
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");
eap_gpsk_state(data, FAILURE);
return;
}
if (os_memcmp(mic, pos, miclen) != 0) {
wpa_printf(MSG_INFO, "EAP-GPSK: Incorrect MIC in GPSK-4");
wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Received MIC", pos, miclen);
wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Computed MIC", mic, miclen);
eap_gpsk_state(data, FAILURE);
return;
}
pos += miclen;
if (pos != end) {
wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignored %lu bytes of extra "
"data in the end of GPSK-4",
(unsigned long) (end - pos));
}
eap_gpsk_state(data, SUCCESS);
}
static void eap_gpsk_process(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
struct eap_gpsk_data *data = priv;
const u8 *pos;
size_t len;
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GPSK, respData, &len);
if (pos == NULL || len < 1)
return;
switch (*pos) {
case EAP_GPSK_OPCODE_GPSK_2:
eap_gpsk_process_gpsk_2(sm, data, pos + 1, len - 1);
break;
case EAP_GPSK_OPCODE_GPSK_4:
eap_gpsk_process_gpsk_4(sm, data, pos + 1, len - 1);
break;
}
}
static Boolean eap_gpsk_isDone(struct eap_sm *sm, void *priv)
{
struct eap_gpsk_data *data = priv;
return data->state == SUCCESS || data->state == FAILURE;
}
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;
}
static Boolean eap_gpsk_isSuccess(struct eap_sm *sm, void *priv)
{
struct eap_gpsk_data *data = priv;
return data->state == SUCCESS;
}
int eap_server_gpsk_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_GPSK, "GPSK");
if (eap == NULL)
return -1;
eap->init = eap_gpsk_init;
eap->reset = eap_gpsk_reset;
eap->buildReq = eap_gpsk_buildReq;
eap->check = eap_gpsk_check;
eap->process = eap_gpsk_process;
eap->isDone = eap_gpsk_isDone;
eap->getKey = eap_gpsk_getKey;
eap->isSuccess = eap_gpsk_isSuccess;
eap->get_emsk = eap_gpsk_get_emsk;
ret = eap_server_method_register(eap);
if (ret)
eap_server_method_free(eap);
return ret;
}