/*
* EAP peer method: EAP-TNC (Trusted Network Connect)
* Copyright (c) 2007, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "eap_i.h"
#include "tncc.h"
struct eap_tnc_data {
enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state;
struct tncc_data *tncc;
struct wpabuf *in_buf;
struct wpabuf *out_buf;
size_t out_used;
size_t fragment_size;
};
/* EAP-TNC Flags */
#define EAP_TNC_FLAGS_LENGTH_INCLUDED 0x80
#define EAP_TNC_FLAGS_MORE_FRAGMENTS 0x40
#define EAP_TNC_FLAGS_START 0x20
#define EAP_TNC_VERSION_MASK 0x07
#define EAP_TNC_VERSION 1
static void * eap_tnc_init(struct eap_sm *sm)
{
struct eap_tnc_data *data;
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->state = WAIT_START;
data->fragment_size = 1300;
data->tncc = tncc_init();
if (data->tncc == NULL) {
os_free(data);
return NULL;
}
return data;
}
static void eap_tnc_deinit(struct eap_sm *sm, void *priv)
{
struct eap_tnc_data *data = priv;
wpabuf_free(data->in_buf);
wpabuf_free(data->out_buf);
tncc_deinit(data->tncc);
os_free(data);
}
static struct wpabuf * eap_tnc_build_frag_ack(u8 id, u8 code)
{
struct wpabuf *msg;
msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1, code, id);
if (msg == NULL) {
wpa_printf(MSG_ERROR, "EAP-TNC: Failed to allocate memory "
"for fragment ack");
return NULL;
}
wpabuf_put_u8(msg, EAP_TNC_VERSION); /* Flags */
wpa_printf(MSG_DEBUG, "EAP-TNC: Send fragment ack");
return msg;
}
static struct wpabuf * eap_tnc_build_msg(struct eap_tnc_data *data,
struct eap_method_ret *ret, u8 id)
{
struct wpabuf *resp;
u8 flags;
size_t send_len, plen;
ret->ignore = FALSE;
wpa_printf(MSG_DEBUG, "EAP-TNC: Generating Response");
ret->allowNotifications = TRUE;
flags = EAP_TNC_VERSION;
send_len = wpabuf_len(data->out_buf) - data->out_used;
if (1 + send_len > data->fragment_size) {
send_len = data->fragment_size - 1;
flags |= EAP_TNC_FLAGS_MORE_FRAGMENTS;
if (data->out_used == 0) {
flags |= EAP_TNC_FLAGS_LENGTH_INCLUDED;
send_len -= 4;
}
}
plen = 1 + send_len;
if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)
plen += 4;
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, plen,
EAP_CODE_RESPONSE, id);
if (resp == NULL)
return NULL;
wpabuf_put_u8(resp, flags); /* Flags */
if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)
wpabuf_put_be32(resp, wpabuf_len(data->out_buf));
wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
send_len);
data->out_used += send_len;
ret->methodState = METHOD_MAY_CONT;
ret->decision = DECISION_FAIL;
if (data->out_used == wpabuf_len(data->out_buf)) {
wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes "
"(message sent completely)",
(unsigned long) send_len);
wpabuf_free(data->out_buf);
data->out_buf = NULL;
data->out_used = 0;
} else {
wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes "
"(%lu more to send)", (unsigned long) send_len,
(unsigned long) wpabuf_len(data->out_buf) -
data->out_used);
data->state = WAIT_FRAG_ACK;
}
return resp;
}
static int eap_tnc_process_cont(struct eap_tnc_data *data,
const u8 *buf, size_t len)
{
/* Process continuation of a pending message */
if (len > wpabuf_tailroom(data->in_buf)) {
wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment overflow");
data->state = FAIL;
return -1;
}
wpabuf_put_data(data->in_buf, buf, len);
wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes, waiting for "
"%lu bytes more", (unsigned long) len,
(unsigned long) wpabuf_tailroom(data->in_buf));
return 0;
}
static struct wpabuf * eap_tnc_process_fragment(struct eap_tnc_data *data,
struct eap_method_ret *ret,
u8 id, u8 flags,
u32 message_length,
const u8 *buf, size_t len)
{
/* Process a fragment that is not the last one of the message */
if (data->in_buf == NULL && !(flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)) {
wpa_printf(MSG_DEBUG, "EAP-TNC: No Message Length field in a "
"fragmented packet");
ret->ignore = TRUE;
return NULL;
}
if (data->in_buf == NULL) {
/* First fragment of the message */
data->in_buf = wpabuf_alloc(message_length);
if (data->in_buf == NULL) {
wpa_printf(MSG_DEBUG, "EAP-TNC: No memory for "
"message");
ret->ignore = TRUE;
return NULL;
}
wpabuf_put_data(data->in_buf, buf, len);
wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes in first "
"fragment, waiting for %lu bytes more",
(unsigned long) len,
(unsigned long) wpabuf_tailroom(data->in_buf));
}
return eap_tnc_build_frag_ack(id, EAP_CODE_RESPONSE);
}
static struct wpabuf * eap_tnc_process(struct eap_sm *sm, void *priv,
struct eap_method_ret *ret,
const struct wpabuf *reqData)
{
struct eap_tnc_data *data = priv;
struct wpabuf *resp;
const u8 *pos, *end;
u8 *rpos, *rpos1;
size_t len, rlen;
size_t imc_len;
char *start_buf, *end_buf;
size_t start_len, end_len;
int tncs_done = 0;
u8 flags, id;
u32 message_length = 0;
struct wpabuf tmpbuf;
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TNC, reqData, &len);
if (pos == NULL) {
wpa_printf(MSG_INFO, "EAP-TNC: Invalid frame (pos=%p len=%lu)",
pos, (unsigned long) len);
ret->ignore = TRUE;
return NULL;
}
id = eap_get_id(reqData);
end = pos + len;
if (len == 0)
flags = 0; /* fragment ack */
else
flags = *pos++;
if (len > 0 && (flags & EAP_TNC_VERSION_MASK) != EAP_TNC_VERSION) {
wpa_printf(MSG_DEBUG, "EAP-TNC: Unsupported version %d",
flags & EAP_TNC_VERSION_MASK);
ret->ignore = TRUE;
return NULL;
}
if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED) {
if (end - pos < 4) {
wpa_printf(MSG_DEBUG, "EAP-TNC: Message underflow");
ret->ignore = TRUE;
return NULL;
}
message_length = WPA_GET_BE32(pos);
pos += 4;
if (message_length < (u32) (end - pos) ||
message_length > 75000) {
wpa_printf(MSG_DEBUG, "EAP-TNC: Invalid Message "
"Length (%d; %ld remaining in this msg)",
message_length, (long) (end - pos));
ret->ignore = TRUE;
return NULL;
}
}
wpa_printf(MSG_DEBUG, "EAP-TNC: Received packet: Flags 0x%x "
"Message Length %u", flags, message_length);
if (data->state == WAIT_FRAG_ACK) {
if (len > 1) {
wpa_printf(MSG_DEBUG, "EAP-TNC: Unexpected payload in "
"WAIT_FRAG_ACK state");
ret->ignore = TRUE;
return NULL;
}
wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment acknowledged");
data->state = PROC_MSG;
return eap_tnc_build_msg(data, ret, id);
}
if (data->in_buf && eap_tnc_process_cont(data, pos, end - pos) < 0) {
ret->ignore = TRUE;
return NULL;
}
if (flags & EAP_TNC_FLAGS_MORE_FRAGMENTS) {
return eap_tnc_process_fragment(data, ret, id, flags,
message_length, pos,
end - pos);
}
if (data->in_buf == NULL) {
/* Wrap unfragmented messages as wpabuf without extra copy */
wpabuf_set(&tmpbuf, pos, end - pos);
data->in_buf = &tmpbuf;
}
if (data->state == WAIT_START) {
if (!(flags & EAP_TNC_FLAGS_START)) {
wpa_printf(MSG_DEBUG, "EAP-TNC: Server did not use "
"start flag in the first message");
ret->ignore = TRUE;
goto fail;
}
tncc_init_connection(data->tncc);
data->state = PROC_MSG;
} else {
enum tncc_process_res res;
if (flags & EAP_TNC_FLAGS_START) {
wpa_printf(MSG_DEBUG, "EAP-TNC: Server used start "
"flag again");
ret->ignore = TRUE;
goto fail;
}
res = tncc_process_if_tnccs(data->tncc,
wpabuf_head(data->in_buf),
wpabuf_len(data->in_buf));
switch (res) {
case TNCCS_PROCESS_ERROR:
ret->ignore = TRUE;
goto fail;
case TNCCS_PROCESS_OK_NO_RECOMMENDATION:
case TNCCS_RECOMMENDATION_ERROR:
wpa_printf(MSG_DEBUG, "EAP-TNC: No "
"TNCCS-Recommendation received");
break;
case TNCCS_RECOMMENDATION_ALLOW:
wpa_msg(sm->msg_ctx, MSG_INFO,
"TNC: Recommendation = allow");
tncs_done = 1;
break;
case TNCCS_RECOMMENDATION_NONE:
wpa_msg(sm->msg_ctx, MSG_INFO,
"TNC: Recommendation = none");
tncs_done = 1;
break;
case TNCCS_RECOMMENDATION_ISOLATE:
wpa_msg(sm->msg_ctx, MSG_INFO,
"TNC: Recommendation = isolate");
tncs_done = 1;
break;
}
}
if (data->in_buf != &tmpbuf)
wpabuf_free(data->in_buf);
data->in_buf = NULL;
ret->ignore = FALSE;
ret->methodState = METHOD_MAY_CONT;
ret->decision = DECISION_UNCOND_SUCC;
ret->allowNotifications = TRUE;
if (data->out_buf) {
data->state = PROC_MSG;
return eap_tnc_build_msg(data, ret, id);
}
if (tncs_done) {
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1,
EAP_CODE_RESPONSE, eap_get_id(reqData));
if (resp == NULL)
return NULL;
wpabuf_put_u8(resp, EAP_TNC_VERSION);
wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS done - reply with an "
"empty ACK message");
return resp;
}
imc_len = tncc_total_send_len(data->tncc);
start_buf = tncc_if_tnccs_start(data->tncc);
if (start_buf == NULL)
return NULL;
start_len = os_strlen(start_buf);
end_buf = tncc_if_tnccs_end();
if (end_buf == NULL) {
os_free(start_buf);
return NULL;
}
end_len = os_strlen(end_buf);
rlen = start_len + imc_len + end_len;
resp = wpabuf_alloc(rlen);
if (resp == NULL) {
os_free(start_buf);
os_free(end_buf);
return NULL;
}
wpabuf_put_data(resp, start_buf, start_len);
os_free(start_buf);
rpos1 = wpabuf_put(resp, 0);
rpos = tncc_copy_send_buf(data->tncc, rpos1);
wpabuf_put(resp, rpos - rpos1);
wpabuf_put_data(resp, end_buf, end_len);
os_free(end_buf);
wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-TNC: Response",
wpabuf_head(resp), wpabuf_len(resp));
data->out_buf = resp;
data->state = PROC_MSG;
return eap_tnc_build_msg(data, ret, id);
fail:
if (data->in_buf == &tmpbuf)
data->in_buf = NULL;
return NULL;
}
int eap_peer_tnc_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_TNC, "TNC");
if (eap == NULL)
return -1;
eap->init = eap_tnc_init;
eap->deinit = eap_tnc_deinit;
eap->process = eap_tnc_process;
ret = eap_peer_method_register(eap);
if (ret)
eap_peer_method_free(eap);
return ret;
}