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hostap/src/eap_server/eap_ttls.c

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/*
* hostapd / EAP-TTLS (RFC 5281)
* Copyright (c) 2004-2008, 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 "crypto/ms_funcs.h"
#include "crypto/sha1.h"
#include "crypto/tls.h"
#include "eap_server/eap_i.h"
#include "eap_server/eap_tls_common.h"
#include "eap_common/chap.h"
#include "eap_common/eap_ttls.h"
/* Maximum supported TTLS version
* 0 = RFC 5281
* 1 = draft-funk-eap-ttls-v1-00.txt
*/
#ifndef EAP_TTLS_VERSION
#define EAP_TTLS_VERSION 0 /* TTLSv1 implementation is not yet complete */
#endif /* EAP_TTLS_VERSION */
#define MSCHAPV2_KEY_LEN 16
static void eap_ttls_reset(struct eap_sm *sm, void *priv);
struct eap_ttls_data {
struct eap_ssl_data ssl;
enum {
START, PHASE1, PHASE2_START, PHASE2_METHOD,
PHASE2_MSCHAPV2_RESP, PHASE_FINISHED, SUCCESS, FAILURE
} state;
int ttls_version;
int force_version;
const struct eap_method *phase2_method;
void *phase2_priv;
int mschapv2_resp_ok;
u8 mschapv2_auth_response[20];
u8 mschapv2_ident;
int tls_ia_configured;
struct wpabuf *pending_phase2_eap_resp;
int tnc_started;
};
static const char * eap_ttls_state_txt(int state)
{
switch (state) {
case START:
return "START";
case PHASE1:
return "PHASE1";
case PHASE2_START:
return "PHASE2_START";
case PHASE2_METHOD:
return "PHASE2_METHOD";
case PHASE2_MSCHAPV2_RESP:
return "PHASE2_MSCHAPV2_RESP";
case PHASE_FINISHED:
return "PHASE_FINISHED";
case SUCCESS:
return "SUCCESS";
case FAILURE:
return "FAILURE";
default:
return "Unknown?!";
}
}
static void eap_ttls_state(struct eap_ttls_data *data, int state)
{
wpa_printf(MSG_DEBUG, "EAP-TTLS: %s -> %s",
eap_ttls_state_txt(data->state),
eap_ttls_state_txt(state));
data->state = state;
}
static u8 * eap_ttls_avp_hdr(u8 *avphdr, u32 avp_code, u32 vendor_id,
int mandatory, size_t len)
{
struct ttls_avp_vendor *avp;
u8 flags;
size_t hdrlen;
avp = (struct ttls_avp_vendor *) avphdr;
flags = mandatory ? AVP_FLAGS_MANDATORY : 0;
if (vendor_id) {
flags |= AVP_FLAGS_VENDOR;
hdrlen = sizeof(*avp);
avp->vendor_id = host_to_be32(vendor_id);
} else {
hdrlen = sizeof(struct ttls_avp);
}
avp->avp_code = host_to_be32(avp_code);
avp->avp_length = host_to_be32((flags << 24) | (hdrlen + len));
return avphdr + hdrlen;
}
static struct wpabuf * eap_ttls_avp_encapsulate(struct wpabuf *resp,
u32 avp_code, int mandatory)
{
struct wpabuf *avp;
u8 *pos;
avp = wpabuf_alloc(sizeof(struct ttls_avp) + wpabuf_len(resp) + 4);
if (avp == NULL) {
wpabuf_free(resp);
return NULL;
}
pos = eap_ttls_avp_hdr(wpabuf_mhead(avp), avp_code, 0, mandatory,
wpabuf_len(resp));
os_memcpy(pos, wpabuf_head(resp), wpabuf_len(resp));
pos += wpabuf_len(resp);
AVP_PAD((const u8 *) wpabuf_head(avp), pos);
wpabuf_free(resp);
wpabuf_put(avp, pos - (u8 *) wpabuf_head(avp));
return avp;
}
struct eap_ttls_avp {
/* Note: eap is allocated memory; caller is responsible for freeing
* it. All the other pointers are pointing to the packet data, i.e.,
* they must not be freed separately. */
u8 *eap;
size_t eap_len;
u8 *user_name;
size_t user_name_len;
u8 *user_password;
size_t user_password_len;
u8 *chap_challenge;
size_t chap_challenge_len;
u8 *chap_password;
size_t chap_password_len;
u8 *mschap_challenge;
size_t mschap_challenge_len;
u8 *mschap_response;
size_t mschap_response_len;
u8 *mschap2_response;
size_t mschap2_response_len;
};
static int eap_ttls_avp_parse(struct wpabuf *buf, struct eap_ttls_avp *parse)
{
struct ttls_avp *avp;
u8 *pos;
int left;
pos = wpabuf_mhead(buf);
left = wpabuf_len(buf);
os_memset(parse, 0, sizeof(*parse));
while (left > 0) {
u32 avp_code, avp_length, vendor_id = 0;
u8 avp_flags, *dpos;
size_t pad, dlen;
avp = (struct ttls_avp *) pos;
avp_code = be_to_host32(avp->avp_code);
avp_length = be_to_host32(avp->avp_length);
avp_flags = (avp_length >> 24) & 0xff;
avp_length &= 0xffffff;
wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP: code=%d flags=0x%02x "
"length=%d", (int) avp_code, avp_flags,
(int) avp_length);
if ((int) avp_length > left) {
wpa_printf(MSG_WARNING, "EAP-TTLS: AVP overflow "
"(len=%d, left=%d) - dropped",
(int) avp_length, left);
goto fail;
}
if (avp_length < sizeof(*avp)) {
wpa_printf(MSG_WARNING, "EAP-TTLS: Invalid AVP length "
"%d", avp_length);
goto fail;
}
dpos = (u8 *) (avp + 1);
dlen = avp_length - sizeof(*avp);
if (avp_flags & AVP_FLAGS_VENDOR) {
if (dlen < 4) {
wpa_printf(MSG_WARNING, "EAP-TTLS: vendor AVP "
"underflow");
goto fail;
}
vendor_id = be_to_host32(* (be32 *) dpos);
wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP vendor_id %d",
(int) vendor_id);
dpos += 4;
dlen -= 4;
}
wpa_hexdump(MSG_DEBUG, "EAP-TTLS: AVP data", dpos, dlen);
if (vendor_id == 0 && avp_code == RADIUS_ATTR_EAP_MESSAGE) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP - EAP Message");
if (parse->eap == NULL) {
parse->eap = os_malloc(dlen);
if (parse->eap == NULL) {
wpa_printf(MSG_WARNING, "EAP-TTLS: "
"failed to allocate memory "
"for Phase 2 EAP data");
goto fail;
}
os_memcpy(parse->eap, dpos, dlen);
parse->eap_len = dlen;
} else {
u8 *neweap = os_realloc(parse->eap,
parse->eap_len + dlen);
if (neweap == NULL) {
wpa_printf(MSG_WARNING, "EAP-TTLS: "
"failed to allocate memory "
"for Phase 2 EAP data");
goto fail;
}
os_memcpy(neweap + parse->eap_len, dpos, dlen);
parse->eap = neweap;
parse->eap_len += dlen;
}
} else if (vendor_id == 0 &&
avp_code == RADIUS_ATTR_USER_NAME) {
wpa_hexdump_ascii(MSG_DEBUG, "EAP-TTLS: User-Name",
dpos, dlen);
parse->user_name = dpos;
parse->user_name_len = dlen;
} else if (vendor_id == 0 &&
avp_code == RADIUS_ATTR_USER_PASSWORD) {
u8 *password = dpos;
size_t password_len = dlen;
while (password_len > 0 &&
password[password_len - 1] == '\0') {
password_len--;
}
wpa_hexdump_ascii_key(MSG_DEBUG, "EAP-TTLS: "
"User-Password (PAP)",
password, password_len);
parse->user_password = password;
parse->user_password_len = password_len;
} else if (vendor_id == 0 &&
avp_code == RADIUS_ATTR_CHAP_CHALLENGE) {
wpa_hexdump(MSG_DEBUG,
"EAP-TTLS: CHAP-Challenge (CHAP)",
dpos, dlen);
parse->chap_challenge = dpos;
parse->chap_challenge_len = dlen;
} else if (vendor_id == 0 &&
avp_code == RADIUS_ATTR_CHAP_PASSWORD) {
wpa_hexdump(MSG_DEBUG,
"EAP-TTLS: CHAP-Password (CHAP)",
dpos, dlen);
parse->chap_password = dpos;
parse->chap_password_len = dlen;
} else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
avp_code == RADIUS_ATTR_MS_CHAP_CHALLENGE) {
wpa_hexdump(MSG_DEBUG,
"EAP-TTLS: MS-CHAP-Challenge",
dpos, dlen);
parse->mschap_challenge = dpos;
parse->mschap_challenge_len = dlen;
} else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
avp_code == RADIUS_ATTR_MS_CHAP_RESPONSE) {
wpa_hexdump(MSG_DEBUG,
"EAP-TTLS: MS-CHAP-Response (MSCHAP)",
dpos, dlen);
parse->mschap_response = dpos;
parse->mschap_response_len = dlen;
} else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
avp_code == RADIUS_ATTR_MS_CHAP2_RESPONSE) {
wpa_hexdump(MSG_DEBUG,
"EAP-TTLS: MS-CHAP2-Response (MSCHAPV2)",
dpos, dlen);
parse->mschap2_response = dpos;
parse->mschap2_response_len = dlen;
} else if (avp_flags & AVP_FLAGS_MANDATORY) {
wpa_printf(MSG_WARNING, "EAP-TTLS: Unsupported "
"mandatory AVP code %d vendor_id %d - "
"dropped", (int) avp_code, (int) vendor_id);
goto fail;
} else {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Ignoring unsupported "
"AVP code %d vendor_id %d",
(int) avp_code, (int) vendor_id);
}
pad = (4 - (avp_length & 3)) & 3;
pos += avp_length + pad;
left -= avp_length + pad;
}
return 0;
fail:
os_free(parse->eap);
parse->eap = NULL;
return -1;
}
static u8 * eap_ttls_implicit_challenge(struct eap_sm *sm,
struct eap_ttls_data *data, size_t len)
{
struct tls_keys keys;
u8 *challenge, *rnd;
if (data->ttls_version == 0) {
return eap_server_tls_derive_key(sm, &data->ssl,
"ttls challenge", len);
}
os_memset(&keys, 0, sizeof(keys));
if (tls_connection_get_keys(sm->ssl_ctx, data->ssl.conn, &keys) ||
keys.client_random == NULL || keys.server_random == NULL ||
keys.inner_secret == NULL) {
wpa_printf(MSG_INFO, "EAP-TTLS: Could not get inner secret, "
"client random, or server random to derive "
"implicit challenge");
return NULL;
}
rnd = os_malloc(keys.client_random_len + keys.server_random_len);
challenge = os_malloc(len);
if (rnd == NULL || challenge == NULL) {
wpa_printf(MSG_INFO, "EAP-TTLS: No memory for implicit "
"challenge derivation");
os_free(rnd);
os_free(challenge);
return NULL;
}
os_memcpy(rnd, keys.server_random, keys.server_random_len);
os_memcpy(rnd + keys.server_random_len, keys.client_random,
keys.client_random_len);
if (tls_prf(keys.inner_secret, keys.inner_secret_len,
"inner application challenge", rnd,
keys.client_random_len + keys.server_random_len,
challenge, len)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to derive implicit "
"challenge");
os_free(rnd);
os_free(challenge);
return NULL;
}
os_free(rnd);
wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Derived implicit challenge",
challenge, len);
return challenge;
}
static void * eap_ttls_init(struct eap_sm *sm)
{
struct eap_ttls_data *data;
data = os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
data->ttls_version = EAP_TTLS_VERSION;
data->force_version = -1;
if (sm->user && sm->user->force_version >= 0) {
data->force_version = sm->user->force_version;
wpa_printf(MSG_DEBUG, "EAP-TTLS: forcing version %d",
data->force_version);
data->ttls_version = data->force_version;
}
data->state = START;
if (!(tls_capabilities(sm->ssl_ctx) & TLS_CAPABILITY_IA) &&
data->ttls_version > 0) {
if (data->force_version > 0) {
wpa_printf(MSG_INFO, "EAP-TTLS: Forced TTLSv%d and "
"TLS library does not support TLS/IA.",
data->force_version);
eap_ttls_reset(sm, data);
return NULL;
}
data->ttls_version = 0;
}
if (eap_server_tls_ssl_init(sm, &data->ssl, 0)) {
wpa_printf(MSG_INFO, "EAP-TTLS: Failed to initialize SSL.");
eap_ttls_reset(sm, data);
return NULL;
}
return data;
}
static void eap_ttls_reset(struct eap_sm *sm, void *priv)
{
struct eap_ttls_data *data = priv;
if (data == NULL)
return;
if (data->phase2_priv && data->phase2_method)
data->phase2_method->reset(sm, data->phase2_priv);
eap_server_tls_ssl_deinit(sm, &data->ssl);
wpabuf_free(data->pending_phase2_eap_resp);
os_free(data);
}
static struct wpabuf * eap_ttls_build_start(struct eap_sm *sm,
struct eap_ttls_data *data, u8 id)
{
struct wpabuf *req;
req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TTLS, 1,
EAP_CODE_REQUEST, id);
if (req == NULL) {
wpa_printf(MSG_ERROR, "EAP-TTLS: Failed to allocate memory for"
" request");
eap_ttls_state(data, FAILURE);
return NULL;
}
wpabuf_put_u8(req, EAP_TLS_FLAGS_START | data->ttls_version);
eap_ttls_state(data, PHASE1);
return req;
}
static struct wpabuf * eap_ttls_build_phase2_eap_req(
struct eap_sm *sm, struct eap_ttls_data *data, u8 id)
{
struct wpabuf *buf, *encr_req;
buf = data->phase2_method->buildReq(sm, data->phase2_priv, id);
if (buf == NULL)
return NULL;
wpa_hexdump_buf_key(MSG_DEBUG,
"EAP-TTLS/EAP: Encapsulate Phase 2 data", buf);
buf = eap_ttls_avp_encapsulate(buf, RADIUS_ATTR_EAP_MESSAGE, 1);
if (buf == NULL) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: Failed to encapsulate "
"packet");
return NULL;
}
wpa_hexdump_buf_key(MSG_DEBUG, "EAP-TTLS/EAP: Encrypt encapsulated "
"Phase 2 data", buf);
encr_req = eap_server_tls_encrypt(sm, &data->ssl, buf);
wpabuf_free(buf);
return encr_req;
}
static struct wpabuf * eap_ttls_build_phase2_mschapv2(
struct eap_sm *sm, struct eap_ttls_data *data)
{
struct wpabuf *encr_req, msgbuf;
u8 *req, *pos, *end;
int ret;
pos = req = os_malloc(100);
if (req == NULL)
return NULL;
end = req + 100;
if (data->mschapv2_resp_ok) {
pos = eap_ttls_avp_hdr(pos, RADIUS_ATTR_MS_CHAP2_SUCCESS,
RADIUS_VENDOR_ID_MICROSOFT, 1, 43);
*pos++ = data->mschapv2_ident;
ret = os_snprintf((char *) pos, end - pos, "S=");
if (ret >= 0 && ret < end - pos)
pos += ret;
pos += wpa_snprintf_hex_uppercase(
(char *) pos, end - pos, data->mschapv2_auth_response,
sizeof(data->mschapv2_auth_response));
} else {
pos = eap_ttls_avp_hdr(pos, RADIUS_ATTR_MS_CHAP_ERROR,
RADIUS_VENDOR_ID_MICROSOFT, 1, 6);
os_memcpy(pos, "Failed", 6);
pos += 6;
AVP_PAD(req, pos);
}
wpabuf_set(&msgbuf, req, pos - req);
wpa_hexdump_buf_key(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Encrypting Phase 2 "
"data", &msgbuf);
encr_req = eap_server_tls_encrypt(sm, &data->ssl, &msgbuf);
os_free(req);
return encr_req;
}
static struct wpabuf * eap_ttls_build_phase_finished(
struct eap_sm *sm, struct eap_ttls_data *data, int final)
{
return tls_connection_ia_send_phase_finished(sm->ssl_ctx,
data->ssl.conn, final);
}
static struct wpabuf * eap_ttls_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
struct eap_ttls_data *data = priv;
if (data->ssl.state == FRAG_ACK) {
return eap_server_tls_build_ack(id, EAP_TYPE_TTLS,
data->ttls_version);
}
if (data->ssl.state == WAIT_FRAG_ACK) {
return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_TTLS,
data->ttls_version, id);
}
switch (data->state) {
case START:
return eap_ttls_build_start(sm, data, id);
case PHASE1:
if (tls_connection_established(sm->ssl_ctx, data->ssl.conn)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase1 done, "
"starting Phase2");
eap_ttls_state(data, PHASE2_START);
}
break;
case PHASE2_METHOD:
wpabuf_free(data->ssl.tls_out);
data->ssl.tls_out_pos = 0;
data->ssl.tls_out = eap_ttls_build_phase2_eap_req(sm, data,
id);
break;
case PHASE2_MSCHAPV2_RESP:
wpabuf_free(data->ssl.tls_out);
data->ssl.tls_out_pos = 0;
data->ssl.tls_out = eap_ttls_build_phase2_mschapv2(sm, data);
break;
case PHASE_FINISHED:
wpabuf_free(data->ssl.tls_out);
data->ssl.tls_out_pos = 0;
data->ssl.tls_out = eap_ttls_build_phase_finished(sm, data, 1);
break;
default:
wpa_printf(MSG_DEBUG, "EAP-TTLS: %s - unexpected state %d",
__func__, data->state);
return NULL;
}
return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_TTLS,
data->ttls_version, id);
}
static Boolean eap_ttls_check(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
const u8 *pos;
size_t len;
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TTLS, respData, &len);
if (pos == NULL || len < 1) {
wpa_printf(MSG_INFO, "EAP-TTLS: Invalid frame");
return TRUE;
}
return FALSE;
}
static int eap_ttls_ia_permute_inner_secret(struct eap_sm *sm,
struct eap_ttls_data *data,
const u8 *key, size_t key_len)
{
u8 *buf;
size_t buf_len;
int ret;
if (key) {
buf_len = 2 + key_len;
buf = os_malloc(buf_len);
if (buf == NULL)
return -1;
WPA_PUT_BE16(buf, key_len);
os_memcpy(buf + 2, key, key_len);
} else {
buf = NULL;
buf_len = 0;
}
wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Session keys for TLS/IA inner "
"secret permutation", buf, buf_len);
ret = tls_connection_ia_permute_inner_secret(sm->ssl_ctx,
data->ssl.conn,
buf, buf_len);
os_free(buf);
return ret;
}
static void eap_ttls_process_phase2_pap(struct eap_sm *sm,
struct eap_ttls_data *data,
const u8 *user_password,
size_t user_password_len)
{
if (!sm->user || !sm->user->password || sm->user->password_hash ||
!(sm->user->ttls_auth & EAP_TTLS_AUTH_PAP)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/PAP: No plaintext user "
"password configured");
eap_ttls_state(data, FAILURE);
return;
}
if (sm->user->password_len != user_password_len ||
os_memcmp(sm->user->password, user_password, user_password_len) !=
0) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/PAP: Invalid user password");
eap_ttls_state(data, FAILURE);
return;
}
wpa_printf(MSG_DEBUG, "EAP-TTLS/PAP: Correct user password");
eap_ttls_state(data, data->ttls_version > 0 ? PHASE_FINISHED :
SUCCESS);
}
static void eap_ttls_process_phase2_chap(struct eap_sm *sm,
struct eap_ttls_data *data,
const u8 *challenge,
size_t challenge_len,
const u8 *password,
size_t password_len)
{
u8 *chal, hash[CHAP_MD5_LEN];
if (challenge == NULL || password == NULL ||
challenge_len != EAP_TTLS_CHAP_CHALLENGE_LEN ||
password_len != 1 + EAP_TTLS_CHAP_PASSWORD_LEN) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Invalid CHAP attributes "
"(challenge len %lu password len %lu)",
(unsigned long) challenge_len,
(unsigned long) password_len);
eap_ttls_state(data, FAILURE);
return;
}
if (!sm->user || !sm->user->password || sm->user->password_hash ||
!(sm->user->ttls_auth & EAP_TTLS_AUTH_CHAP)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: No plaintext user "
"password configured");
eap_ttls_state(data, FAILURE);
return;
}
chal = eap_ttls_implicit_challenge(sm, data,
EAP_TTLS_CHAP_CHALLENGE_LEN + 1);
if (chal == NULL) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Failed to generate "
"challenge from TLS data");
eap_ttls_state(data, FAILURE);
return;
}
if (os_memcmp(challenge, chal, EAP_TTLS_CHAP_CHALLENGE_LEN) != 0 ||
password[0] != chal[EAP_TTLS_CHAP_CHALLENGE_LEN]) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Challenge mismatch");
os_free(chal);
eap_ttls_state(data, FAILURE);
return;
}
os_free(chal);
/* MD5(Ident + Password + Challenge) */
chap_md5(password[0], sm->user->password, sm->user->password_len,
challenge, challenge_len, hash);
if (os_memcmp(hash, password + 1, EAP_TTLS_CHAP_PASSWORD_LEN) == 0) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Correct user password");
eap_ttls_state(data, data->ttls_version > 0 ? PHASE_FINISHED :
SUCCESS);
} else {
wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Invalid user password");
eap_ttls_state(data, FAILURE);
}
}
static void eap_ttls_process_phase2_mschap(struct eap_sm *sm,
struct eap_ttls_data *data,
u8 *challenge, size_t challenge_len,
u8 *response, size_t response_len)
{
u8 *chal, nt_response[24];
if (challenge == NULL || response == NULL ||
challenge_len != EAP_TTLS_MSCHAP_CHALLENGE_LEN ||
response_len != EAP_TTLS_MSCHAP_RESPONSE_LEN) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Invalid MS-CHAP "
"attributes (challenge len %lu response len %lu)",
(unsigned long) challenge_len,
(unsigned long) response_len);
eap_ttls_state(data, FAILURE);
return;
}
if (!sm->user || !sm->user->password ||
!(sm->user->ttls_auth & EAP_TTLS_AUTH_MSCHAP)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: No user password "
"configured");
eap_ttls_state(data, FAILURE);
return;
}
chal = eap_ttls_implicit_challenge(sm, data,
EAP_TTLS_MSCHAP_CHALLENGE_LEN + 1);
if (chal == NULL) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Failed to generate "
"challenge from TLS data");
eap_ttls_state(data, FAILURE);
return;
}
if (os_memcmp(challenge, chal, EAP_TTLS_MSCHAP_CHALLENGE_LEN) != 0 ||
response[0] != chal[EAP_TTLS_MSCHAP_CHALLENGE_LEN]) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Challenge mismatch");
os_free(chal);
eap_ttls_state(data, FAILURE);
return;
}
os_free(chal);
if (sm->user->password_hash)
challenge_response(challenge, sm->user->password, nt_response);
else
nt_challenge_response(challenge, sm->user->password,
sm->user->password_len, nt_response);
if (os_memcmp(nt_response, response + 2 + 24, 24) == 0) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Correct response");
eap_ttls_state(data, data->ttls_version > 0 ? PHASE_FINISHED :
SUCCESS);
} else {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Invalid NT-Response");
wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAP: Received",
response + 2 + 24, 24);
wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAP: Expected",
nt_response, 24);
eap_ttls_state(data, FAILURE);
}
}
static void eap_ttls_process_phase2_mschapv2(struct eap_sm *sm,
struct eap_ttls_data *data,
u8 *challenge,
size_t challenge_len,
u8 *response, size_t response_len)
{
u8 *chal, *username, nt_response[24], *rx_resp, *peer_challenge,
*auth_challenge;
size_t username_len, i;
if (challenge == NULL || response == NULL ||
challenge_len != EAP_TTLS_MSCHAPV2_CHALLENGE_LEN ||
response_len != EAP_TTLS_MSCHAPV2_RESPONSE_LEN) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Invalid MS-CHAP2 "
"attributes (challenge len %lu response len %lu)",
(unsigned long) challenge_len,
(unsigned long) response_len);
eap_ttls_state(data, FAILURE);
return;
}
if (!sm->user || !sm->user->password ||
!(sm->user->ttls_auth & EAP_TTLS_AUTH_MSCHAPV2)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: No user password "
"configured");
eap_ttls_state(data, FAILURE);
return;
}
/* MSCHAPv2 does not include optional domain name in the
* challenge-response calculation, so remove domain prefix
* (if present). */
username = sm->identity;
username_len = sm->identity_len;
for (i = 0; i < username_len; i++) {
if (username[i] == '\\') {
username_len -= i + 1;
username += i + 1;
break;
}
}
chal = eap_ttls_implicit_challenge(
sm, data, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN + 1);
if (chal == NULL) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Failed to generate "
"challenge from TLS data");
eap_ttls_state(data, FAILURE);
return;
}
if (os_memcmp(challenge, chal, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN) != 0 ||
response[0] != chal[EAP_TTLS_MSCHAPV2_CHALLENGE_LEN]) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Challenge mismatch");
os_free(chal);
eap_ttls_state(data, FAILURE);
return;
}
os_free(chal);
auth_challenge = challenge;
peer_challenge = response + 2;
wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: User",
username, username_len);
wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: auth_challenge",
auth_challenge, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN);
wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: peer_challenge",
peer_challenge, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN);
if (sm->user->password_hash) {
generate_nt_response_pwhash(auth_challenge, peer_challenge,
username, username_len,
sm->user->password,
nt_response);
} else {
generate_nt_response(auth_challenge, peer_challenge,
username, username_len,
sm->user->password,
sm->user->password_len,
nt_response);
}
rx_resp = response + 2 + EAP_TTLS_MSCHAPV2_CHALLENGE_LEN + 8;
if (os_memcmp(nt_response, rx_resp, 24) == 0) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Correct "
"NT-Response");
data->mschapv2_resp_ok = 1;
if (data->ttls_version > 0) {
const u8 *pw_hash;
u8 pw_hash_buf[16], pw_hash_hash[16], master_key[16];
u8 session_key[2 * MSCHAPV2_KEY_LEN];
if (sm->user->password_hash)
pw_hash = sm->user->password;
else {
nt_password_hash(sm->user->password,
sm->user->password_len,
pw_hash_buf);
pw_hash = pw_hash_buf;
}
hash_nt_password_hash(pw_hash, pw_hash_hash);
get_master_key(pw_hash_hash, nt_response, master_key);
get_asymetric_start_key(master_key, session_key,
MSCHAPV2_KEY_LEN, 0, 0);
get_asymetric_start_key(master_key,
session_key + MSCHAPV2_KEY_LEN,
MSCHAPV2_KEY_LEN, 1, 0);
eap_ttls_ia_permute_inner_secret(sm, data,
session_key,
sizeof(session_key));
}
if (sm->user->password_hash) {
generate_authenticator_response_pwhash(
sm->user->password,
peer_challenge, auth_challenge,
username, username_len, nt_response,
data->mschapv2_auth_response);
} else {
generate_authenticator_response(
sm->user->password, sm->user->password_len,
peer_challenge, auth_challenge,
username, username_len, nt_response,
data->mschapv2_auth_response);
}
} else {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Invalid "
"NT-Response");
wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: Received",
rx_resp, 24);
wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: Expected",
nt_response, 24);
data->mschapv2_resp_ok = 0;
}
eap_ttls_state(data, PHASE2_MSCHAPV2_RESP);
data->mschapv2_ident = response[0];
}
static int eap_ttls_phase2_eap_init(struct eap_sm *sm,
struct eap_ttls_data *data,
EapType eap_type)
{
if (data->phase2_priv && data->phase2_method) {
data->phase2_method->reset(sm, data->phase2_priv);
data->phase2_method = NULL;
data->phase2_priv = NULL;
}
data->phase2_method = eap_server_get_eap_method(EAP_VENDOR_IETF,
eap_type);
if (!data->phase2_method)
return -1;
sm->init_phase2 = 1;
data->phase2_priv = data->phase2_method->init(sm);
sm->init_phase2 = 0;
return data->phase2_priv == NULL ? -1 : 0;
}
static void eap_ttls_process_phase2_eap_response(struct eap_sm *sm,
struct eap_ttls_data *data,
u8 *in_data, size_t in_len)
{
u8 next_type = EAP_TYPE_NONE;
struct eap_hdr *hdr;
u8 *pos;
size_t left;
struct wpabuf buf;
const struct eap_method *m = data->phase2_method;
void *priv = data->phase2_priv;
if (priv == NULL) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: %s - Phase2 not "
"initialized?!", __func__);
return;
}
hdr = (struct eap_hdr *) in_data;
pos = (u8 *) (hdr + 1);
if (in_len > sizeof(*hdr) && *pos == EAP_TYPE_NAK) {
left = in_len - sizeof(*hdr);
wpa_hexdump(MSG_DEBUG, "EAP-TTLS/EAP: Phase2 type Nak'ed; "
"allowed types", pos + 1, left - 1);
eap_sm_process_nak(sm, pos + 1, left - 1);
if (sm->user && sm->user_eap_method_index < EAP_MAX_METHODS &&
sm->user->methods[sm->user_eap_method_index].method !=
EAP_TYPE_NONE) {
next_type = sm->user->methods[
sm->user_eap_method_index++].method;
wpa_printf(MSG_DEBUG, "EAP-TTLS: try EAP type %d",
next_type);
if (eap_ttls_phase2_eap_init(sm, data, next_type)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to "
"initialize EAP type %d",
next_type);
eap_ttls_state(data, FAILURE);
return;
}
} else {
eap_ttls_state(data, FAILURE);
}
return;
}
wpabuf_set(&buf, in_data, in_len);
if (m->check(sm, priv, &buf)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: Phase2 check() asked to "
"ignore the packet");
return;
}
m->process(sm, priv, &buf);
if (sm->method_pending == METHOD_PENDING_WAIT) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: Phase2 method is in "
"pending wait state - save decrypted response");
wpabuf_free(data->pending_phase2_eap_resp);
data->pending_phase2_eap_resp = wpabuf_dup(&buf);
}
if (!m->isDone(sm, priv))
return;
if (!m->isSuccess(sm, priv)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: Phase2 method failed");
eap_ttls_state(data, FAILURE);
return;
}
switch (data->state) {
case PHASE2_START:
if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
wpa_hexdump_ascii(MSG_DEBUG, "EAP_TTLS: Phase2 "
"Identity not found in the user "
"database",
sm->identity, sm->identity_len);
eap_ttls_state(data, FAILURE);
break;
}
eap_ttls_state(data, PHASE2_METHOD);
next_type = sm->user->methods[0].method;
sm->user_eap_method_index = 1;
wpa_printf(MSG_DEBUG, "EAP-TTLS: try EAP type %d", next_type);
if (eap_ttls_phase2_eap_init(sm, data, next_type)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to initialize "
"EAP type %d", next_type);
eap_ttls_state(data, FAILURE);
}
break;
case PHASE2_METHOD:
if (data->ttls_version > 0) {
if (m->getKey) {
u8 *key;
size_t key_len;
key = m->getKey(sm, priv, &key_len);
eap_ttls_ia_permute_inner_secret(sm, data,
key, key_len);
}
eap_ttls_state(data, PHASE_FINISHED);
} else
eap_ttls_state(data, SUCCESS);
break;
case FAILURE:
break;
default:
wpa_printf(MSG_DEBUG, "EAP-TTLS: %s - unexpected state %d",
__func__, data->state);
break;
}
}
static void eap_ttls_process_phase2_eap(struct eap_sm *sm,
struct eap_ttls_data *data,
const u8 *eap, size_t eap_len)
{
struct eap_hdr *hdr;
size_t len;
if (data->state == PHASE2_START) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: initializing Phase 2");
if (eap_ttls_phase2_eap_init(sm, data, EAP_TYPE_IDENTITY) < 0)
{
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: failed to "
"initialize EAP-Identity");
return;
}
}
if (eap_len < sizeof(*hdr)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: too short Phase 2 EAP "
"packet (len=%lu)", (unsigned long) eap_len);
return;
}
hdr = (struct eap_hdr *) eap;
len = be_to_host16(hdr->length);
wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: received Phase 2 EAP: code=%d "
"identifier=%d length=%lu", hdr->code, hdr->identifier,
(unsigned long) len);
if (len > eap_len) {
wpa_printf(MSG_INFO, "EAP-TTLS/EAP: Length mismatch in Phase 2"
" EAP frame (hdr len=%lu, data len in AVP=%lu)",
(unsigned long) len, (unsigned long) eap_len);
return;
}
switch (hdr->code) {
case EAP_CODE_RESPONSE:
eap_ttls_process_phase2_eap_response(sm, data, (u8 *) hdr,
len);
break;
default:
wpa_printf(MSG_INFO, "EAP-TTLS/EAP: Unexpected code=%d in "
"Phase 2 EAP header", hdr->code);
break;
}
}
static void eap_ttls_process_phase2(struct eap_sm *sm,
struct eap_ttls_data *data,
struct wpabuf *in_buf)
{
struct wpabuf *in_decrypted;
struct eap_ttls_avp parse;
wpa_printf(MSG_DEBUG, "EAP-TTLS: received %lu bytes encrypted data for"
" Phase 2", (unsigned long) wpabuf_len(in_buf));
if (data->pending_phase2_eap_resp) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Pending Phase 2 EAP response "
"- skip decryption and use old data");
eap_ttls_process_phase2_eap(
sm, data, wpabuf_head(data->pending_phase2_eap_resp),
wpabuf_len(data->pending_phase2_eap_resp));
wpabuf_free(data->pending_phase2_eap_resp);
data->pending_phase2_eap_resp = NULL;
return;
}
in_decrypted = tls_connection_decrypt(sm->ssl_ctx, data->ssl.conn,
in_buf);
if (in_decrypted == NULL) {
wpa_printf(MSG_INFO, "EAP-TTLS: Failed to decrypt Phase 2 "
"data");
eap_ttls_state(data, FAILURE);
return;
}
if (data->state == PHASE_FINISHED) {
if (wpabuf_len(in_decrypted) == 0 &&
tls_connection_ia_final_phase_finished(sm->ssl_ctx,
data->ssl.conn)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: FinalPhaseFinished "
"received");
eap_ttls_state(data, SUCCESS);
} else {
wpa_printf(MSG_INFO, "EAP-TTLS: Did not receive valid "
"FinalPhaseFinished");
eap_ttls_state(data, FAILURE);
}
wpabuf_free(in_decrypted);
return;
}
wpa_hexdump_buf_key(MSG_DEBUG, "EAP-TTLS: Decrypted Phase 2 EAP",
in_decrypted);
if (eap_ttls_avp_parse(in_decrypted, &parse) < 0) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to parse AVPs");
wpabuf_free(in_decrypted);
eap_ttls_state(data, FAILURE);
return;
}
if (parse.user_name) {
os_free(sm->identity);
sm->identity = os_malloc(parse.user_name_len);
if (sm->identity) {
os_memcpy(sm->identity, parse.user_name,
parse.user_name_len);
sm->identity_len = parse.user_name_len;
}
if (eap_user_get(sm, parse.user_name, parse.user_name_len, 1)
!= 0) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase2 Identity not "
"found in the user database");
eap_ttls_state(data, FAILURE);
goto done;
}
}
#ifdef EAP_SERVER_TNC
if (data->tnc_started && parse.eap == NULL) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: TNC started but no EAP "
"response from peer");
eap_ttls_state(data, FAILURE);
goto done;
}
#endif /* EAP_SERVER_TNC */
if (parse.eap) {
eap_ttls_process_phase2_eap(sm, data, parse.eap,
parse.eap_len);
} else if (parse.user_password) {
eap_ttls_process_phase2_pap(sm, data, parse.user_password,
parse.user_password_len);
} else if (parse.chap_password) {
eap_ttls_process_phase2_chap(sm, data,
parse.chap_challenge,
parse.chap_challenge_len,
parse.chap_password,
parse.chap_password_len);
} else if (parse.mschap_response) {
eap_ttls_process_phase2_mschap(sm, data,
parse.mschap_challenge,
parse.mschap_challenge_len,
parse.mschap_response,
parse.mschap_response_len);
} else if (parse.mschap2_response) {
eap_ttls_process_phase2_mschapv2(sm, data,
parse.mschap_challenge,
parse.mschap_challenge_len,
parse.mschap2_response,
parse.mschap2_response_len);
}
done:
wpabuf_free(in_decrypted);
os_free(parse.eap);
}
static void eap_ttls_start_tnc(struct eap_sm *sm, struct eap_ttls_data *data)
{
#ifdef EAP_SERVER_TNC
if (!sm->tnc || data->state != SUCCESS || data->tnc_started)
return;
wpa_printf(MSG_DEBUG, "EAP-TTLS: Initialize TNC");
if (eap_ttls_phase2_eap_init(sm, data, EAP_TYPE_TNC)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to initialize TNC");
eap_ttls_state(data, FAILURE);
return;
}
data->tnc_started = 1;
eap_ttls_state(data, PHASE2_METHOD);
#endif /* EAP_SERVER_TNC */
}
static int eap_ttls_process_version(struct eap_sm *sm, void *priv,
int peer_version)
{
struct eap_ttls_data *data = priv;
if (peer_version < data->ttls_version) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: peer ver=%d, own ver=%d; "
"use version %d",
peer_version, data->ttls_version, peer_version);
data->ttls_version = peer_version;
}
if (data->ttls_version > 0 && !data->tls_ia_configured) {
if (tls_connection_set_ia(sm->ssl_ctx, data->ssl.conn, 1)) {
wpa_printf(MSG_INFO, "EAP-TTLS: Failed to enable "
"TLS/IA");
return -1;
}
data->tls_ia_configured = 1;
}
return 0;
}
static void eap_ttls_process_msg(struct eap_sm *sm, void *priv,
const struct wpabuf *respData)
{
struct eap_ttls_data *data = priv;
switch (data->state) {
case PHASE1:
if (eap_server_tls_phase1(sm, &data->ssl) < 0)
eap_ttls_state(data, FAILURE);
break;
case PHASE2_START:
case PHASE2_METHOD:
case PHASE_FINISHED:
eap_ttls_process_phase2(sm, data, data->ssl.tls_in);
eap_ttls_start_tnc(sm, data);
break;
case PHASE2_MSCHAPV2_RESP:
if (data->mschapv2_resp_ok && wpabuf_len(data->ssl.tls_in) ==
0) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Peer "
"acknowledged response");
eap_ttls_state(data, data->ttls_version > 0 ?
PHASE_FINISHED : SUCCESS);
} else if (!data->mschapv2_resp_ok) {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Peer "
"acknowledged error");
eap_ttls_state(data, FAILURE);
} else {
wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Unexpected "
"frame from peer (payload len %lu, "
"expected empty frame)",
(unsigned long)
wpabuf_len(data->ssl.tls_in));
eap_ttls_state(data, FAILURE);
}
eap_ttls_start_tnc(sm, data);
break;
default:
wpa_printf(MSG_DEBUG, "EAP-TTLS: Unexpected state %d in %s",
data->state, __func__);
break;
}
}
static void eap_ttls_process(struct eap_sm *sm, void *priv,
struct wpabuf *respData)
{
struct eap_ttls_data *data = priv;
if (eap_server_tls_process(sm, &data->ssl, respData, data,
EAP_TYPE_TTLS, eap_ttls_process_version,
eap_ttls_process_msg) < 0)
eap_ttls_state(data, FAILURE);
}
static Boolean eap_ttls_isDone(struct eap_sm *sm, void *priv)
{
struct eap_ttls_data *data = priv;
return data->state == SUCCESS || data->state == FAILURE;
}
static u8 * eap_ttls_v1_derive_key(struct eap_sm *sm,
struct eap_ttls_data *data)
{
struct tls_keys keys;
u8 *rnd, *key;
os_memset(&keys, 0, sizeof(keys));
if (tls_connection_get_keys(sm->ssl_ctx, data->ssl.conn, &keys) ||
keys.client_random == NULL || keys.server_random == NULL ||
keys.inner_secret == NULL) {
wpa_printf(MSG_INFO, "EAP-TTLS: Could not get inner secret, "
"client random, or server random to derive keying "
"material");
return NULL;
}
rnd = os_malloc(keys.client_random_len + keys.server_random_len);
key = os_malloc(EAP_TLS_KEY_LEN);
if (rnd == NULL || key == NULL) {
wpa_printf(MSG_INFO, "EAP-TTLS: No memory for key derivation");
os_free(rnd);
os_free(key);
return NULL;
}
os_memcpy(rnd, keys.client_random, keys.client_random_len);
os_memcpy(rnd + keys.client_random_len, keys.server_random,
keys.server_random_len);
if (tls_prf(keys.inner_secret, keys.inner_secret_len,
"ttls v1 keying material", rnd, keys.client_random_len +
keys.server_random_len, key, EAP_TLS_KEY_LEN)) {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to derive key");
os_free(rnd);
os_free(key);
return NULL;
}
wpa_hexdump(MSG_DEBUG, "EAP-TTLS: client/server random",
rnd, keys.client_random_len + keys.server_random_len);
wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: TLS/IA inner secret",
keys.inner_secret, keys.inner_secret_len);
os_free(rnd);
return key;
}
static u8 * eap_ttls_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
struct eap_ttls_data *data = priv;
u8 *eapKeyData;
if (data->state != SUCCESS)
return NULL;
if (data->ttls_version == 0) {
eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
"ttls keying material",
EAP_TLS_KEY_LEN);
} else {
eapKeyData = eap_ttls_v1_derive_key(sm, data);
}
if (eapKeyData) {
*len = EAP_TLS_KEY_LEN;
wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Derived key",
eapKeyData, EAP_TLS_KEY_LEN);
} else {
wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to derive key");
}
return eapKeyData;
}
static Boolean eap_ttls_isSuccess(struct eap_sm *sm, void *priv)
{
struct eap_ttls_data *data = priv;
return data->state == SUCCESS;
}
int eap_server_ttls_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_TTLS, "TTLS");
if (eap == NULL)
return -1;
eap->init = eap_ttls_init;
eap->reset = eap_ttls_reset;
eap->buildReq = eap_ttls_buildReq;
eap->check = eap_ttls_check;
eap->process = eap_ttls_process;
eap->isDone = eap_ttls_isDone;
eap->getKey = eap_ttls_getKey;
eap->isSuccess = eap_ttls_isSuccess;
ret = eap_server_method_register(eap);
if (ret)
eap_server_method_free(eap);
return ret;
}
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