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fragattacks/src/eap_server/eap_server.c
Jouni Malinen c3c5b5fe92 ERP server: Make erp_send_finish_reauth() easier for static analyzers 
The flags argument is used to indicate a failure case (0x80) which
allows erp == NULL. This may be a bit too difficult combination for
static analyzers to understand, so add an explicit check for !erp as
another condition for returning from the function before the erp pointer
gets dereferenced without checking it.

Signed-off-by: Jouni Malinen <j@w1.fi>
2015-06-23 18:27:06 +03:00

2004 lines
51 KiB
C
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/*
* hostapd / EAP Full Authenticator state machine (RFC 4137)
* Copyright (c) 2004-2014, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*
* This state machine is based on the full authenticator state machine defined
* in RFC 4137. However, to support backend authentication in RADIUS
* authentication server functionality, parts of backend authenticator (also
* from RFC 4137) are mixed in. This functionality is enabled by setting
* backend_auth configuration variable to TRUE.
*/
#include "includes.h"
#include "common.h"
#include "crypto/sha256.h"
#include "eap_i.h"
#include "state_machine.h"
#include "common/wpa_ctrl.h"
#define STATE_MACHINE_DATA struct eap_sm
#define STATE_MACHINE_DEBUG_PREFIX "EAP"
#define EAP_MAX_AUTH_ROUNDS 50
static void eap_user_free(struct eap_user *user);
/* EAP state machines are described in RFC 4137 */
static int eap_sm_calculateTimeout(struct eap_sm *sm, int retransCount,
int eapSRTT, int eapRTTVAR,
int methodTimeout);
static void eap_sm_parseEapResp(struct eap_sm *sm, const struct wpabuf *resp);
static int eap_sm_getId(const struct wpabuf *data);
static struct wpabuf * eap_sm_buildSuccess(struct eap_sm *sm, u8 id);
static struct wpabuf * eap_sm_buildFailure(struct eap_sm *sm, u8 id);
static int eap_sm_nextId(struct eap_sm *sm, int id);
static void eap_sm_Policy_update(struct eap_sm *sm, const u8 *nak_list,
size_t len);
static EapType eap_sm_Policy_getNextMethod(struct eap_sm *sm, int *vendor);
static int eap_sm_Policy_getDecision(struct eap_sm *sm);
static Boolean eap_sm_Policy_doPickUp(struct eap_sm *sm, EapType method);
static int eap_get_erp_send_reauth_start(struct eap_sm *sm)
{
if (sm->eapol_cb->get_erp_send_reauth_start)
return sm->eapol_cb->get_erp_send_reauth_start(sm->eapol_ctx);
return 0;
}
static const char * eap_get_erp_domain(struct eap_sm *sm)
{
if (sm->eapol_cb->get_erp_domain)
return sm->eapol_cb->get_erp_domain(sm->eapol_ctx);
return NULL;
}
#ifdef CONFIG_ERP
static struct eap_server_erp_key * eap_erp_get_key(struct eap_sm *sm,
const char *keyname)
{
if (sm->eapol_cb->erp_get_key)
return sm->eapol_cb->erp_get_key(sm->eapol_ctx, keyname);
return NULL;
}
static int eap_erp_add_key(struct eap_sm *sm, struct eap_server_erp_key *erp)
{
if (sm->eapol_cb->erp_add_key)
return sm->eapol_cb->erp_add_key(sm->eapol_ctx, erp);
return -1;
}
#endif /* CONFIG_ERP */
static struct wpabuf * eap_sm_buildInitiateReauthStart(struct eap_sm *sm,
u8 id)
{
const char *domain;
size_t plen = 1;
struct wpabuf *msg;
size_t domain_len = 0;
domain = eap_get_erp_domain(sm);
if (domain) {
domain_len = os_strlen(domain);
plen += 2 + domain_len;
}
msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_ERP_TYPE_REAUTH_START, plen,
EAP_CODE_INITIATE, id);
if (msg == NULL)
return NULL;
wpabuf_put_u8(msg, 0); /* Reserved */
if (domain) {
/* Domain name TLV */
wpabuf_put_u8(msg, EAP_ERP_TLV_DOMAIN_NAME);
wpabuf_put_u8(msg, domain_len);
wpabuf_put_data(msg, domain, domain_len);
}
return msg;
}
static int eap_copy_buf(struct wpabuf **dst, const struct wpabuf *src)
{
if (src == NULL)
return -1;
wpabuf_free(*dst);
*dst = wpabuf_dup(src);
return *dst ? 0 : -1;
}
static int eap_copy_data(u8 **dst, size_t *dst_len,
const u8 *src, size_t src_len)
{
if (src == NULL)
return -1;
os_free(*dst);
*dst = os_malloc(src_len);
if (*dst) {
os_memcpy(*dst, src, src_len);
*dst_len = src_len;
return 0;
} else {
*dst_len = 0;
return -1;
}
}
#define EAP_COPY(dst, src) \
eap_copy_data((dst), (dst ## Len), (src), (src ## Len))
/**
* eap_user_get - Fetch user information from the database
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
* @identity: Identity (User-Name) of the user
* @identity_len: Length of identity in bytes
* @phase2: 0 = EAP phase1 user, 1 = EAP phase2 (tunneled) user
* Returns: 0 on success, or -1 on failure
*
* This function is used to fetch user information for EAP. The user will be
* selected based on the specified identity. sm->user and
* sm->user_eap_method_index are updated for the new user when a matching user
* is found. sm->user can be used to get user information (e.g., password).
*/
int eap_user_get(struct eap_sm *sm, const u8 *identity, size_t identity_len,
int phase2)
{
struct eap_user *user;
if (sm == NULL || sm->eapol_cb == NULL ||
sm->eapol_cb->get_eap_user == NULL)
return -1;
eap_user_free(sm->user);
sm->user = NULL;
user = os_zalloc(sizeof(*user));
if (user == NULL)
return -1;
if (sm->eapol_cb->get_eap_user(sm->eapol_ctx, identity,
identity_len, phase2, user) != 0) {
eap_user_free(user);
return -1;
}
sm->user = user;
sm->user_eap_method_index = 0;
return 0;
}
void eap_log_msg(struct eap_sm *sm, const char *fmt, ...)
{
va_list ap;
char *buf;
int buflen;
if (sm == NULL || sm->eapol_cb == NULL || sm->eapol_cb->log_msg == NULL)
return;
va_start(ap, fmt);
buflen = vsnprintf(NULL, 0, fmt, ap) + 1;
va_end(ap);
buf = os_malloc(buflen);
if (buf == NULL)
return;
va_start(ap, fmt);
vsnprintf(buf, buflen, fmt, ap);
va_end(ap);
sm->eapol_cb->log_msg(sm->eapol_ctx, buf);
os_free(buf);
}
SM_STATE(EAP, DISABLED)
{
SM_ENTRY(EAP, DISABLED);
sm->num_rounds = 0;
}
SM_STATE(EAP, INITIALIZE)
{
SM_ENTRY(EAP, INITIALIZE);
if (sm->eap_if.eapRestart && !sm->eap_server && sm->identity) {
/*
* Need to allow internal Identity method to be used instead
* of passthrough at the beginning of reauthentication.
*/
eap_server_clear_identity(sm);
}
sm->try_initiate_reauth = FALSE;
sm->currentId = -1;
sm->eap_if.eapSuccess = FALSE;
sm->eap_if.eapFail = FALSE;
sm->eap_if.eapTimeout = FALSE;
bin_clear_free(sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
sm->eap_if.eapKeyData = NULL;
sm->eap_if.eapKeyDataLen = 0;
os_free(sm->eap_if.eapSessionId);
sm->eap_if.eapSessionId = NULL;
sm->eap_if.eapSessionIdLen = 0;
sm->eap_if.eapKeyAvailable = FALSE;
sm->eap_if.eapRestart = FALSE;
/*
* This is not defined in RFC 4137, but method state needs to be
* reseted here so that it does not remain in success state when
* re-authentication starts.
*/
if (sm->m && sm->eap_method_priv) {
sm->m->reset(sm, sm->eap_method_priv);
sm->eap_method_priv = NULL;
}
sm->m = NULL;
sm->user_eap_method_index = 0;
if (sm->backend_auth) {
sm->currentMethod = EAP_TYPE_NONE;
/* parse rxResp, respId, respMethod */
eap_sm_parseEapResp(sm, sm->eap_if.eapRespData);
if (sm->rxResp) {
sm->currentId = sm->respId;
}
}
sm->num_rounds = 0;
sm->method_pending = METHOD_PENDING_NONE;
wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_STARTED
MACSTR, MAC2STR(sm->peer_addr));
}
SM_STATE(EAP, PICK_UP_METHOD)
{
SM_ENTRY(EAP, PICK_UP_METHOD);
if (eap_sm_Policy_doPickUp(sm, sm->respMethod)) {
sm->currentMethod = sm->respMethod;
if (sm->m && sm->eap_method_priv) {
sm->m->reset(sm, sm->eap_method_priv);
sm->eap_method_priv = NULL;
}
sm->m = eap_server_get_eap_method(EAP_VENDOR_IETF,
sm->currentMethod);
if (sm->m && sm->m->initPickUp) {
sm->eap_method_priv = sm->m->initPickUp(sm);
if (sm->eap_method_priv == NULL) {
wpa_printf(MSG_DEBUG, "EAP: Failed to "
"initialize EAP method %d",
sm->currentMethod);
sm->m = NULL;
sm->currentMethod = EAP_TYPE_NONE;
}
} else {
sm->m = NULL;
sm->currentMethod = EAP_TYPE_NONE;
}
}
wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_PROPOSED_METHOD
"method=%u", sm->currentMethod);
}
SM_STATE(EAP, IDLE)
{
SM_ENTRY(EAP, IDLE);
sm->eap_if.retransWhile = eap_sm_calculateTimeout(
sm, sm->retransCount, sm->eap_if.eapSRTT, sm->eap_if.eapRTTVAR,
sm->methodTimeout);
}
SM_STATE(EAP, RETRANSMIT)
{
SM_ENTRY(EAP, RETRANSMIT);
sm->retransCount++;
if (sm->retransCount <= sm->MaxRetrans && sm->lastReqData) {
if (eap_copy_buf(&sm->eap_if.eapReqData, sm->lastReqData) == 0)
sm->eap_if.eapReq = TRUE;
}
}
SM_STATE(EAP, RECEIVED)
{
SM_ENTRY(EAP, RECEIVED);
/* parse rxResp, respId, respMethod */
eap_sm_parseEapResp(sm, sm->eap_if.eapRespData);
sm->num_rounds++;
}
SM_STATE(EAP, DISCARD)
{
SM_ENTRY(EAP, DISCARD);
sm->eap_if.eapResp = FALSE;
sm->eap_if.eapNoReq = TRUE;
}
SM_STATE(EAP, SEND_REQUEST)
{
SM_ENTRY(EAP, SEND_REQUEST);
sm->retransCount = 0;
if (sm->eap_if.eapReqData) {
if (eap_copy_buf(&sm->lastReqData, sm->eap_if.eapReqData) == 0)
{
sm->eap_if.eapResp = FALSE;
sm->eap_if.eapReq = TRUE;
} else {
sm->eap_if.eapResp = FALSE;
sm->eap_if.eapReq = FALSE;
}
} else {
wpa_printf(MSG_INFO, "EAP: SEND_REQUEST - no eapReqData");
sm->eap_if.eapResp = FALSE;
sm->eap_if.eapReq = FALSE;
sm->eap_if.eapNoReq = TRUE;
}
}
SM_STATE(EAP, INTEGRITY_CHECK)
{
SM_ENTRY(EAP, INTEGRITY_CHECK);
if (!eap_hdr_len_valid(sm->eap_if.eapRespData, 1)) {
sm->ignore = TRUE;
return;
}
if (sm->m->check) {
sm->ignore = sm->m->check(sm, sm->eap_method_priv,
sm->eap_if.eapRespData);
}
}
SM_STATE(EAP, METHOD_REQUEST)
{
SM_ENTRY(EAP, METHOD_REQUEST);
if (sm->m == NULL) {
wpa_printf(MSG_DEBUG, "EAP: method not initialized");
return;
}
sm->currentId = eap_sm_nextId(sm, sm->currentId);
wpa_printf(MSG_DEBUG, "EAP: building EAP-Request: Identifier %d",
sm->currentId);
sm->lastId = sm->currentId;
wpabuf_free(sm->eap_if.eapReqData);
sm->eap_if.eapReqData = sm->m->buildReq(sm, sm->eap_method_priv,
sm->currentId);
if (sm->m->getTimeout)
sm->methodTimeout = sm->m->getTimeout(sm, sm->eap_method_priv);
else
sm->methodTimeout = 0;
}
static void eap_server_erp_init(struct eap_sm *sm)
{
#ifdef CONFIG_ERP
u8 *emsk = NULL;
size_t emsk_len = 0;
u8 EMSKname[EAP_EMSK_NAME_LEN];
u8 len[2];
const char *domain;
size_t domain_len, nai_buf_len;
struct eap_server_erp_key *erp = NULL;
int pos;
domain = eap_get_erp_domain(sm);
if (!domain)
return;
domain_len = os_strlen(domain);
nai_buf_len = 2 * EAP_EMSK_NAME_LEN + 1 + domain_len;
if (nai_buf_len > 253) {
/*
* keyName-NAI has a maximum length of 253 octet to fit in
* RADIUS attributes.
*/
wpa_printf(MSG_DEBUG,
"EAP: Too long realm for ERP keyName-NAI maximum length");
return;
}
nai_buf_len++; /* null termination */
erp = os_zalloc(sizeof(*erp) + nai_buf_len);
if (erp == NULL)
goto fail;
erp->recv_seq = (u32) -1;
emsk = sm->m->get_emsk(sm, sm->eap_method_priv, &emsk_len);
if (!emsk || emsk_len == 0 || emsk_len > ERP_MAX_KEY_LEN) {
wpa_printf(MSG_DEBUG,
"EAP: No suitable EMSK available for ERP");
goto fail;
}
wpa_hexdump_key(MSG_DEBUG, "EAP: EMSK", emsk, emsk_len);
WPA_PUT_BE16(len, 8);
if (hmac_sha256_kdf(sm->eap_if.eapSessionId, sm->eap_if.eapSessionIdLen,
"EMSK", len, sizeof(len),
EMSKname, EAP_EMSK_NAME_LEN) < 0) {
wpa_printf(MSG_DEBUG, "EAP: Could not derive EMSKname");
goto fail;
}
wpa_hexdump(MSG_DEBUG, "EAP: EMSKname", EMSKname, EAP_EMSK_NAME_LEN);
pos = wpa_snprintf_hex(erp->keyname_nai, nai_buf_len,
EMSKname, EAP_EMSK_NAME_LEN);
erp->keyname_nai[pos] = '@';
os_memcpy(&erp->keyname_nai[pos + 1], domain, domain_len);
WPA_PUT_BE16(len, emsk_len);
if (hmac_sha256_kdf(emsk, emsk_len,
"EAP Re-authentication Root Key@ietf.org",
len, sizeof(len), erp->rRK, emsk_len) < 0) {
wpa_printf(MSG_DEBUG, "EAP: Could not derive rRK for ERP");
goto fail;
}
erp->rRK_len = emsk_len;
wpa_hexdump_key(MSG_DEBUG, "EAP: ERP rRK", erp->rRK, erp->rRK_len);
if (hmac_sha256_kdf(erp->rRK, erp->rRK_len,
"EAP Re-authentication Integrity Key@ietf.org",
len, sizeof(len), erp->rIK, erp->rRK_len) < 0) {
wpa_printf(MSG_DEBUG, "EAP: Could not derive rIK for ERP");
goto fail;
}
erp->rIK_len = erp->rRK_len;
wpa_hexdump_key(MSG_DEBUG, "EAP: ERP rIK", erp->rIK, erp->rIK_len);
if (eap_erp_add_key(sm, erp) == 0) {
wpa_printf(MSG_DEBUG, "EAP: Stored ERP keys %s",
erp->keyname_nai);
erp = NULL;
}
fail:
bin_clear_free(emsk, emsk_len);
bin_clear_free(erp, sizeof(*erp));
#endif /* CONFIG_ERP */
}
SM_STATE(EAP, METHOD_RESPONSE)
{
SM_ENTRY(EAP, METHOD_RESPONSE);
if (!eap_hdr_len_valid(sm->eap_if.eapRespData, 1))
return;
sm->m->process(sm, sm->eap_method_priv, sm->eap_if.eapRespData);
if (sm->m->isDone(sm, sm->eap_method_priv)) {
eap_sm_Policy_update(sm, NULL, 0);
bin_clear_free(sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
if (sm->m->getKey) {
sm->eap_if.eapKeyData = sm->m->getKey(
sm, sm->eap_method_priv,
&sm->eap_if.eapKeyDataLen);
} else {
sm->eap_if.eapKeyData = NULL;
sm->eap_if.eapKeyDataLen = 0;
}
os_free(sm->eap_if.eapSessionId);
sm->eap_if.eapSessionId = NULL;
if (sm->m->getSessionId) {
sm->eap_if.eapSessionId = sm->m->getSessionId(
sm, sm->eap_method_priv,
&sm->eap_if.eapSessionIdLen);
wpa_hexdump(MSG_DEBUG, "EAP: Session-Id",
sm->eap_if.eapSessionId,
sm->eap_if.eapSessionIdLen);
}
if (sm->erp && sm->m->get_emsk && sm->eap_if.eapSessionId)
eap_server_erp_init(sm);
sm->methodState = METHOD_END;
} else {
sm->methodState = METHOD_CONTINUE;
}
}
SM_STATE(EAP, PROPOSE_METHOD)
{
int vendor;
EapType type;
SM_ENTRY(EAP, PROPOSE_METHOD);
sm->try_initiate_reauth = FALSE;
try_another_method:
type = eap_sm_Policy_getNextMethod(sm, &vendor);
if (vendor == EAP_VENDOR_IETF)
sm->currentMethod = type;
else
sm->currentMethod = EAP_TYPE_EXPANDED;
if (sm->m && sm->eap_method_priv) {
sm->m->reset(sm, sm->eap_method_priv);
sm->eap_method_priv = NULL;
}
sm->m = eap_server_get_eap_method(vendor, type);
if (sm->m) {
sm->eap_method_priv = sm->m->init(sm);
if (sm->eap_method_priv == NULL) {
wpa_printf(MSG_DEBUG, "EAP: Failed to initialize EAP "
"method %d", sm->currentMethod);
sm->m = NULL;
sm->currentMethod = EAP_TYPE_NONE;
goto try_another_method;
}
}
if (sm->m == NULL) {
wpa_printf(MSG_DEBUG, "EAP: Could not find suitable EAP method");
eap_log_msg(sm, "Could not find suitable EAP method");
sm->decision = DECISION_FAILURE;
return;
}
if (sm->currentMethod == EAP_TYPE_IDENTITY ||
sm->currentMethod == EAP_TYPE_NOTIFICATION)
sm->methodState = METHOD_CONTINUE;
else
sm->methodState = METHOD_PROPOSED;
wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_PROPOSED_METHOD
"vendor=%u method=%u", vendor, sm->currentMethod);
eap_log_msg(sm, "Propose EAP method vendor=%u method=%u",
vendor, sm->currentMethod);
}
SM_STATE(EAP, NAK)
{
const struct eap_hdr *nak;
size_t len = 0;
const u8 *pos;
const u8 *nak_list = NULL;
SM_ENTRY(EAP, NAK);
if (sm->eap_method_priv) {
sm->m->reset(sm, sm->eap_method_priv);
sm->eap_method_priv = NULL;
}
sm->m = NULL;
if (!eap_hdr_len_valid(sm->eap_if.eapRespData, 1))
return;
nak = wpabuf_head(sm->eap_if.eapRespData);
if (nak && wpabuf_len(sm->eap_if.eapRespData) > sizeof(*nak)) {
len = be_to_host16(nak->length);
if (len > wpabuf_len(sm->eap_if.eapRespData))
len = wpabuf_len(sm->eap_if.eapRespData);
pos = (const u8 *) (nak + 1);
len -= sizeof(*nak);
if (*pos == EAP_TYPE_NAK) {
pos++;
len--;
nak_list = pos;
}
}
eap_sm_Policy_update(sm, nak_list, len);
}
SM_STATE(EAP, SELECT_ACTION)
{
SM_ENTRY(EAP, SELECT_ACTION);
sm->decision = eap_sm_Policy_getDecision(sm);
}
SM_STATE(EAP, TIMEOUT_FAILURE)
{
SM_ENTRY(EAP, TIMEOUT_FAILURE);
sm->eap_if.eapTimeout = TRUE;
}
SM_STATE(EAP, FAILURE)
{
SM_ENTRY(EAP, FAILURE);
wpabuf_free(sm->eap_if.eapReqData);
sm->eap_if.eapReqData = eap_sm_buildFailure(sm, sm->currentId);
wpabuf_free(sm->lastReqData);
sm->lastReqData = NULL;
sm->eap_if.eapFail = TRUE;
wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_FAILURE
MACSTR, MAC2STR(sm->peer_addr));
}
SM_STATE(EAP, SUCCESS)
{
SM_ENTRY(EAP, SUCCESS);
wpabuf_free(sm->eap_if.eapReqData);
sm->eap_if.eapReqData = eap_sm_buildSuccess(sm, sm->currentId);
wpabuf_free(sm->lastReqData);
sm->lastReqData = NULL;
if (sm->eap_if.eapKeyData)
sm->eap_if.eapKeyAvailable = TRUE;
sm->eap_if.eapSuccess = TRUE;
wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_SUCCESS
MACSTR, MAC2STR(sm->peer_addr));
}
SM_STATE(EAP, INITIATE_REAUTH_START)
{
SM_ENTRY(EAP, INITIATE_REAUTH_START);
sm->initiate_reauth_start_sent = TRUE;
sm->try_initiate_reauth = TRUE;
sm->currentId = eap_sm_nextId(sm, sm->currentId);
wpa_printf(MSG_DEBUG,
"EAP: building EAP-Initiate-Re-auth-Start: Identifier %d",
sm->currentId);
sm->lastId = sm->currentId;
wpabuf_free(sm->eap_if.eapReqData);
sm->eap_if.eapReqData = eap_sm_buildInitiateReauthStart(sm,
sm->currentId);
wpabuf_free(sm->lastReqData);
sm->lastReqData = NULL;
}
#ifdef CONFIG_ERP
static void erp_send_finish_reauth(struct eap_sm *sm,
struct eap_server_erp_key *erp, u8 id,
u8 flags, u16 seq, const char *nai)
{
size_t plen;
struct wpabuf *msg;
u8 hash[SHA256_MAC_LEN];
size_t hash_len;
u8 seed[4];
if (erp) {
switch (erp->cryptosuite) {
case EAP_ERP_CS_HMAC_SHA256_256:
hash_len = 32;
break;
case EAP_ERP_CS_HMAC_SHA256_128:
hash_len = 16;
break;
default:
return;
}
} else
hash_len = 0;
plen = 1 + 2 + 2 + os_strlen(nai);
if (hash_len)
plen += 1 + hash_len;
msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_ERP_TYPE_REAUTH, plen,
EAP_CODE_FINISH, id);
if (msg == NULL)
return;
wpabuf_put_u8(msg, flags);
wpabuf_put_be16(msg, seq);
wpabuf_put_u8(msg, EAP_ERP_TLV_KEYNAME_NAI);
wpabuf_put_u8(msg, os_strlen(nai));
wpabuf_put_str(msg, nai);
if (erp) {
wpabuf_put_u8(msg, erp->cryptosuite);
if (hmac_sha256(erp->rIK, erp->rIK_len,
wpabuf_head(msg), wpabuf_len(msg), hash) < 0) {
wpabuf_free(msg);
return;
}
wpabuf_put_data(msg, hash, hash_len);
}
wpa_printf(MSG_DEBUG, "EAP: Send EAP-Finish/Re-auth (%s)",
flags & 0x80 ? "failure" : "success");
sm->lastId = sm->currentId;
sm->currentId = id;
wpabuf_free(sm->eap_if.eapReqData);
sm->eap_if.eapReqData = msg;
wpabuf_free(sm->lastReqData);
sm->lastReqData = NULL;
if ((flags & 0x80) || !erp) {
sm->eap_if.eapFail = TRUE;
wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_FAILURE
MACSTR, MAC2STR(sm->peer_addr));
return;
}
bin_clear_free(sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
sm->eap_if.eapKeyDataLen = 0;
sm->eap_if.eapKeyData = os_malloc(erp->rRK_len);
if (!sm->eap_if.eapKeyData)
return;
WPA_PUT_BE16(seed, seq);
WPA_PUT_BE16(&seed[2], erp->rRK_len);
if (hmac_sha256_kdf(erp->rRK, erp->rRK_len,
"Re-authentication Master Session Key@ietf.org",
seed, sizeof(seed),
sm->eap_if.eapKeyData, erp->rRK_len) < 0) {
wpa_printf(MSG_DEBUG, "EAP: Could not derive rMSK for ERP");
bin_clear_free(sm->eap_if.eapKeyData, erp->rRK_len);
sm->eap_if.eapKeyData = NULL;
return;
}
sm->eap_if.eapKeyDataLen = erp->rRK_len;
sm->eap_if.eapKeyAvailable = TRUE;
wpa_hexdump_key(MSG_DEBUG, "EAP: ERP rMSK",
sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
sm->eap_if.eapSuccess = TRUE;
wpa_msg(sm->msg_ctx, MSG_INFO, WPA_EVENT_EAP_SUCCESS
MACSTR, MAC2STR(sm->peer_addr));
}
SM_STATE(EAP, INITIATE_RECEIVED)
{
const u8 *pos, *end, *start, *tlvs, *hdr;
const struct eap_hdr *ehdr;
size_t len;
u8 flags;
u16 seq;
char nai[254];
struct eap_server_erp_key *erp;
int max_len;
u8 hash[SHA256_MAC_LEN];
size_t hash_len;
struct erp_tlvs parse;
u8 resp_flags = 0x80; /* default to failure; cleared on success */
SM_ENTRY(EAP, INITIATE_RECEIVED);
sm->rxInitiate = FALSE;
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_ERP_TYPE_REAUTH,
sm->eap_if.eapRespData, &len);
if (pos == NULL) {
wpa_printf(MSG_INFO, "EAP-Initiate: Invalid frame");
goto fail;
}
hdr = wpabuf_head(sm->eap_if.eapRespData);
ehdr = wpabuf_head(sm->eap_if.eapRespData);
wpa_hexdump(MSG_DEBUG, "EAP: EAP-Initiate/Re-Auth", pos, len);
if (len < 4) {
wpa_printf(MSG_INFO, "EAP: Too short EAP-Initiate/Re-auth");
goto fail;
}
end = pos + len;
flags = *pos++;
seq = WPA_GET_BE16(pos);
pos += 2;
wpa_printf(MSG_DEBUG, "EAP: Flags=0x%x SEQ=%u", flags, seq);
tlvs = pos;
/*
* Parse TVs/TLVs. Since we do not yet know the length of the
* Authentication Tag, stop parsing if an unknown TV/TLV is seen and
* just try to find the keyName-NAI first so that we can check the
* Authentication Tag.
*/
if (erp_parse_tlvs(tlvs, end, &parse, 1) < 0)
goto fail;
if (!parse.keyname) {
wpa_printf(MSG_DEBUG,
"EAP: No keyName-NAI in EAP-Initiate/Re-auth Packet");
goto fail;
}
wpa_hexdump_ascii(MSG_DEBUG, "EAP: EAP-Initiate/Re-auth - keyName-NAI",
parse.keyname, parse.keyname_len);
if (parse.keyname_len > 253) {
wpa_printf(MSG_DEBUG,
"EAP: Too long keyName-NAI in EAP-Initiate/Re-auth");
goto fail;
}
os_memcpy(nai, parse.keyname, parse.keyname_len);
nai[parse.keyname_len] = '\0';
if (!sm->eap_server) {
/*
* In passthrough case, EAP-Initiate/Re-auth replaces
* EAP Identity exchange. Use keyName-NAI as the user identity
* and forward EAP-Initiate/Re-auth to the backend
* authentication server.
*/
wpa_printf(MSG_DEBUG,
"EAP: Use keyName-NAI as user identity for backend authentication");
eap_server_clear_identity(sm);
sm->identity = (u8 *) dup_binstr(parse.keyname,
parse.keyname_len);
if (!sm->identity)
goto fail;
sm->identity_len = parse.keyname_len;
return;
}
erp = eap_erp_get_key(sm, nai);
if (!erp) {
wpa_printf(MSG_DEBUG, "EAP: No matching ERP key found for %s",
nai);
goto report_error;
}
if (erp->recv_seq != (u32) -1 && erp->recv_seq >= seq) {
wpa_printf(MSG_DEBUG,
"EAP: SEQ=%u replayed (already received SEQ=%u)",
seq, erp->recv_seq);
goto fail;
}
/* Is there enough room for Cryptosuite and Authentication Tag? */
start = parse.keyname + parse.keyname_len;
max_len = end - start;
if (max_len <
1 + (erp->cryptosuite == EAP_ERP_CS_HMAC_SHA256_256 ? 32 : 16)) {
wpa_printf(MSG_DEBUG,
"EAP: Not enough room for Authentication Tag");
goto fail;
}
switch (erp->cryptosuite) {
case EAP_ERP_CS_HMAC_SHA256_256:
if (end[-33] != erp->cryptosuite) {
wpa_printf(MSG_DEBUG,
"EAP: Different Cryptosuite used");
goto fail;
}
hash_len = 32;
break;
case EAP_ERP_CS_HMAC_SHA256_128:
if (end[-17] != erp->cryptosuite) {
wpa_printf(MSG_DEBUG,
"EAP: Different Cryptosuite used");
goto fail;
}
hash_len = 16;
break;
default:
hash_len = 0;
break;
}
if (hash_len) {
if (hmac_sha256(erp->rIK, erp->rIK_len, hdr,
end - hdr - hash_len, hash) < 0)
goto fail;
if (os_memcmp(end - hash_len, hash, hash_len) != 0) {
wpa_printf(MSG_DEBUG,
"EAP: Authentication Tag mismatch");
goto fail;
}
}
/* Check if any supported CS results in matching tag */
if (!hash_len && max_len >= 1 + 32 &&
end[-33] == EAP_ERP_CS_HMAC_SHA256_256) {
if (hmac_sha256(erp->rIK, erp->rIK_len, hdr,
end - hdr - 32, hash) < 0)
goto fail;
if (os_memcmp(end - 32, hash, 32) == 0) {
wpa_printf(MSG_DEBUG,
"EAP: Authentication Tag match using HMAC-SHA256-256");
hash_len = 32;
erp->cryptosuite = EAP_ERP_CS_HMAC_SHA256_256;
}
}
if (!hash_len && end[-17] == EAP_ERP_CS_HMAC_SHA256_128) {
if (hmac_sha256(erp->rIK, erp->rIK_len, hdr,
end - hdr - 16, hash) < 0)
goto fail;
if (os_memcmp(end - 16, hash, 16) == 0) {
wpa_printf(MSG_DEBUG,
"EAP: Authentication Tag match using HMAC-SHA256-128");
hash_len = 16;
erp->cryptosuite = EAP_ERP_CS_HMAC_SHA256_128;
}
}
if (!hash_len) {
wpa_printf(MSG_DEBUG,
"EAP: No supported cryptosuite matched Authentication Tag");
goto fail;
}
end -= 1 + hash_len;
/*
* Parse TVs/TLVs again now that we know the exact part of the buffer
* that contains them.
*/
wpa_hexdump(MSG_DEBUG, "EAP: EAP-Initiate/Re-Auth TVs/TLVs",
tlvs, end - tlvs);
if (erp_parse_tlvs(tlvs, end, &parse, 0) < 0)
goto fail;
wpa_printf(MSG_DEBUG, "EAP: ERP key %s SEQ updated to %u",
erp->keyname_nai, seq);
erp->recv_seq = seq;
resp_flags &= ~0x80; /* R=0 - success */
report_error:
erp_send_finish_reauth(sm, erp, ehdr->identifier, resp_flags, seq, nai);
return;
fail:
sm->ignore = TRUE;
}
#endif /* CONFIG_ERP */
SM_STATE(EAP, INITIALIZE_PASSTHROUGH)
{
SM_ENTRY(EAP, INITIALIZE_PASSTHROUGH);
wpabuf_free(sm->eap_if.aaaEapRespData);
sm->eap_if.aaaEapRespData = NULL;
sm->try_initiate_reauth = FALSE;
}
SM_STATE(EAP, IDLE2)
{
SM_ENTRY(EAP, IDLE2);
sm->eap_if.retransWhile = eap_sm_calculateTimeout(
sm, sm->retransCount, sm->eap_if.eapSRTT, sm->eap_if.eapRTTVAR,
sm->methodTimeout);
}
SM_STATE(EAP, RETRANSMIT2)
{
SM_ENTRY(EAP, RETRANSMIT2);
sm->retransCount++;
if (sm->retransCount <= sm->MaxRetrans && sm->lastReqData) {
if (eap_copy_buf(&sm->eap_if.eapReqData, sm->lastReqData) == 0)
sm->eap_if.eapReq = TRUE;
}
}
SM_STATE(EAP, RECEIVED2)
{
SM_ENTRY(EAP, RECEIVED2);
/* parse rxResp, respId, respMethod */
eap_sm_parseEapResp(sm, sm->eap_if.eapRespData);
}
SM_STATE(EAP, DISCARD2)
{
SM_ENTRY(EAP, DISCARD2);
sm->eap_if.eapResp = FALSE;
sm->eap_if.eapNoReq = TRUE;
}
SM_STATE(EAP, SEND_REQUEST2)
{
SM_ENTRY(EAP, SEND_REQUEST2);
sm->retransCount = 0;
if (sm->eap_if.eapReqData) {
if (eap_copy_buf(&sm->lastReqData, sm->eap_if.eapReqData) == 0)
{
sm->eap_if.eapResp = FALSE;
sm->eap_if.eapReq = TRUE;
} else {
sm->eap_if.eapResp = FALSE;
sm->eap_if.eapReq = FALSE;
}
} else {
wpa_printf(MSG_INFO, "EAP: SEND_REQUEST2 - no eapReqData");
sm->eap_if.eapResp = FALSE;
sm->eap_if.eapReq = FALSE;
sm->eap_if.eapNoReq = TRUE;
}
}
SM_STATE(EAP, AAA_REQUEST)
{
SM_ENTRY(EAP, AAA_REQUEST);
if (sm->eap_if.eapRespData == NULL) {
wpa_printf(MSG_INFO, "EAP: AAA_REQUEST - no eapRespData");
return;
}
/*
* if (respMethod == IDENTITY)
* aaaIdentity = eapRespData
* This is already taken care of by the EAP-Identity method which
* stores the identity into sm->identity.
*/
eap_copy_buf(&sm->eap_if.aaaEapRespData, sm->eap_if.eapRespData);
}
SM_STATE(EAP, AAA_RESPONSE)
{
SM_ENTRY(EAP, AAA_RESPONSE);
eap_copy_buf(&sm->eap_if.eapReqData, sm->eap_if.aaaEapReqData);
sm->currentId = eap_sm_getId(sm->eap_if.eapReqData);
sm->methodTimeout = sm->eap_if.aaaMethodTimeout;
}
SM_STATE(EAP, AAA_IDLE)
{
SM_ENTRY(EAP, AAA_IDLE);
sm->eap_if.aaaFail = FALSE;
sm->eap_if.aaaSuccess = FALSE;
sm->eap_if.aaaEapReq = FALSE;
sm->eap_if.aaaEapNoReq = FALSE;
sm->eap_if.aaaEapResp = TRUE;
}
SM_STATE(EAP, TIMEOUT_FAILURE2)
{
SM_ENTRY(EAP, TIMEOUT_FAILURE2);
sm->eap_if.eapTimeout = TRUE;
}
SM_STATE(EAP, FAILURE2)
{
SM_ENTRY(EAP, FAILURE2);
eap_copy_buf(&sm->eap_if.eapReqData, sm->eap_if.aaaEapReqData);
sm->eap_if.eapFail = TRUE;
}
SM_STATE(EAP, SUCCESS2)
{
SM_ENTRY(EAP, SUCCESS2);
eap_copy_buf(&sm->eap_if.eapReqData, sm->eap_if.aaaEapReqData);
sm->eap_if.eapKeyAvailable = sm->eap_if.aaaEapKeyAvailable;
if (sm->eap_if.aaaEapKeyAvailable) {
EAP_COPY(&sm->eap_if.eapKeyData, sm->eap_if.aaaEapKeyData);
} else {
bin_clear_free(sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
sm->eap_if.eapKeyData = NULL;
sm->eap_if.eapKeyDataLen = 0;
}
sm->eap_if.eapSuccess = TRUE;
/*
* Start reauthentication with identity request even though we know the
* previously used identity. This is needed to get reauthentication
* started properly.
*/
sm->start_reauth = TRUE;
}
SM_STEP(EAP)
{
if (sm->eap_if.eapRestart && sm->eap_if.portEnabled)
SM_ENTER_GLOBAL(EAP, INITIALIZE);
else if (!sm->eap_if.portEnabled)
SM_ENTER_GLOBAL(EAP, DISABLED);
else if (sm->num_rounds > EAP_MAX_AUTH_ROUNDS) {
if (sm->num_rounds == EAP_MAX_AUTH_ROUNDS + 1) {
wpa_printf(MSG_DEBUG, "EAP: more than %d "
"authentication rounds - abort",
EAP_MAX_AUTH_ROUNDS);
sm->num_rounds++;
SM_ENTER_GLOBAL(EAP, FAILURE);
}
} else switch (sm->EAP_state) {
case EAP_INITIALIZE:
if (sm->backend_auth) {
if (!sm->rxResp)
SM_ENTER(EAP, SELECT_ACTION);
else if (sm->rxResp &&
(sm->respMethod == EAP_TYPE_NAK ||
(sm->respMethod == EAP_TYPE_EXPANDED &&
sm->respVendor == EAP_VENDOR_IETF &&
sm->respVendorMethod == EAP_TYPE_NAK)))
SM_ENTER(EAP, NAK);
else
SM_ENTER(EAP, PICK_UP_METHOD);
} else {
SM_ENTER(EAP, SELECT_ACTION);
}
break;
case EAP_PICK_UP_METHOD:
if (sm->currentMethod == EAP_TYPE_NONE) {
SM_ENTER(EAP, SELECT_ACTION);
} else {
SM_ENTER(EAP, METHOD_RESPONSE);
}
break;
case EAP_DISABLED:
if (sm->eap_if.portEnabled)
SM_ENTER(EAP, INITIALIZE);
break;
case EAP_IDLE:
if (sm->eap_if.retransWhile == 0) {
if (sm->try_initiate_reauth) {
sm->try_initiate_reauth = FALSE;
SM_ENTER(EAP, SELECT_ACTION);
} else {
SM_ENTER(EAP, RETRANSMIT);
}
} else if (sm->eap_if.eapResp)
SM_ENTER(EAP, RECEIVED);
break;
case EAP_RETRANSMIT:
if (sm->retransCount > sm->MaxRetrans)
SM_ENTER(EAP, TIMEOUT_FAILURE);
else
SM_ENTER(EAP, IDLE);
break;
case EAP_RECEIVED:
if (sm->rxResp && (sm->respId == sm->currentId) &&
(sm->respMethod == EAP_TYPE_NAK ||
(sm->respMethod == EAP_TYPE_EXPANDED &&
sm->respVendor == EAP_VENDOR_IETF &&
sm->respVendorMethod == EAP_TYPE_NAK))
&& (sm->methodState == METHOD_PROPOSED))
SM_ENTER(EAP, NAK);
else if (sm->rxResp && (sm->respId == sm->currentId) &&
((sm->respMethod == sm->currentMethod) ||
(sm->respMethod == EAP_TYPE_EXPANDED &&
sm->respVendor == EAP_VENDOR_IETF &&
sm->respVendorMethod == sm->currentMethod)))
SM_ENTER(EAP, INTEGRITY_CHECK);
#ifdef CONFIG_ERP
else if (sm->rxInitiate)
SM_ENTER(EAP, INITIATE_RECEIVED);
#endif /* CONFIG_ERP */
else {
wpa_printf(MSG_DEBUG, "EAP: RECEIVED->DISCARD: "
"rxResp=%d respId=%d currentId=%d "
"respMethod=%d currentMethod=%d",
sm->rxResp, sm->respId, sm->currentId,
sm->respMethod, sm->currentMethod);
eap_log_msg(sm, "Discard received EAP message");
SM_ENTER(EAP, DISCARD);
}
break;
case EAP_DISCARD:
SM_ENTER(EAP, IDLE);
break;
case EAP_SEND_REQUEST:
SM_ENTER(EAP, IDLE);
break;
case EAP_INTEGRITY_CHECK:
if (sm->ignore)
SM_ENTER(EAP, DISCARD);
else
SM_ENTER(EAP, METHOD_RESPONSE);
break;
case EAP_METHOD_REQUEST:
if (sm->m == NULL) {
/*
* This transition is not mentioned in RFC 4137, but it
* is needed to handle cleanly a case where EAP method
* initialization fails.
*/
SM_ENTER(EAP, FAILURE);
break;
}
SM_ENTER(EAP, SEND_REQUEST);
break;
case EAP_METHOD_RESPONSE:
/*
* Note: Mechanism to allow EAP methods to wait while going
* through pending processing is an extension to RFC 4137
* which only defines the transits to SELECT_ACTION and
* METHOD_REQUEST from this METHOD_RESPONSE state.
*/
if (sm->methodState == METHOD_END)
SM_ENTER(EAP, SELECT_ACTION);
else if (sm->method_pending == METHOD_PENDING_WAIT) {
wpa_printf(MSG_DEBUG, "EAP: Method has pending "
"processing - wait before proceeding to "
"METHOD_REQUEST state");
} else if (sm->method_pending == METHOD_PENDING_CONT) {
wpa_printf(MSG_DEBUG, "EAP: Method has completed "
"pending processing - reprocess pending "
"EAP message");
sm->method_pending = METHOD_PENDING_NONE;
SM_ENTER(EAP, METHOD_RESPONSE);
} else
SM_ENTER(EAP, METHOD_REQUEST);
break;
case EAP_PROPOSE_METHOD:
/*
* Note: Mechanism to allow EAP methods to wait while going
* through pending processing is an extension to RFC 4137
* which only defines the transit to METHOD_REQUEST from this
* PROPOSE_METHOD state.
*/
if (sm->method_pending == METHOD_PENDING_WAIT) {
wpa_printf(MSG_DEBUG, "EAP: Method has pending "
"processing - wait before proceeding to "
"METHOD_REQUEST state");
if (sm->user_eap_method_index > 0)
sm->user_eap_method_index--;
} else if (sm->method_pending == METHOD_PENDING_CONT) {
wpa_printf(MSG_DEBUG, "EAP: Method has completed "
"pending processing - reprocess pending "
"EAP message");
sm->method_pending = METHOD_PENDING_NONE;
SM_ENTER(EAP, PROPOSE_METHOD);
} else
SM_ENTER(EAP, METHOD_REQUEST);
break;
case EAP_NAK:
SM_ENTER(EAP, SELECT_ACTION);
break;
case EAP_SELECT_ACTION:
if (sm->decision == DECISION_FAILURE)
SM_ENTER(EAP, FAILURE);
else if (sm->decision == DECISION_SUCCESS)
SM_ENTER(EAP, SUCCESS);
else if (sm->decision == DECISION_PASSTHROUGH)
SM_ENTER(EAP, INITIALIZE_PASSTHROUGH);
else if (sm->decision == DECISION_INITIATE_REAUTH_START)
SM_ENTER(EAP, INITIATE_REAUTH_START);
#ifdef CONFIG_ERP
else if (sm->eap_server && sm->erp && sm->rxInitiate)
SM_ENTER(EAP, INITIATE_RECEIVED);
#endif /* CONFIG_ERP */
else
SM_ENTER(EAP, PROPOSE_METHOD);
break;
case EAP_INITIATE_REAUTH_START:
SM_ENTER(EAP, SEND_REQUEST);
break;
case EAP_INITIATE_RECEIVED:
if (!sm->eap_server)
SM_ENTER(EAP, SELECT_ACTION);
break;
case EAP_TIMEOUT_FAILURE:
break;
case EAP_FAILURE:
break;
case EAP_SUCCESS:
break;
case EAP_INITIALIZE_PASSTHROUGH:
if (sm->currentId == -1)
SM_ENTER(EAP, AAA_IDLE);
else
SM_ENTER(EAP, AAA_REQUEST);
break;
case EAP_IDLE2:
if (sm->eap_if.eapResp)
SM_ENTER(EAP, RECEIVED2);
else if (sm->eap_if.retransWhile == 0)
SM_ENTER(EAP, RETRANSMIT2);
break;
case EAP_RETRANSMIT2:
if (sm->retransCount > sm->MaxRetrans)
SM_ENTER(EAP, TIMEOUT_FAILURE2);
else
SM_ENTER(EAP, IDLE2);
break;
case EAP_RECEIVED2:
if (sm->rxResp && (sm->respId == sm->currentId))
SM_ENTER(EAP, AAA_REQUEST);
else
SM_ENTER(EAP, DISCARD2);
break;
case EAP_DISCARD2:
SM_ENTER(EAP, IDLE2);
break;
case EAP_SEND_REQUEST2:
SM_ENTER(EAP, IDLE2);
break;
case EAP_AAA_REQUEST:
SM_ENTER(EAP, AAA_IDLE);
break;
case EAP_AAA_RESPONSE:
SM_ENTER(EAP, SEND_REQUEST2);
break;
case EAP_AAA_IDLE:
if (sm->eap_if.aaaFail)
SM_ENTER(EAP, FAILURE2);
else if (sm->eap_if.aaaSuccess)
SM_ENTER(EAP, SUCCESS2);
else if (sm->eap_if.aaaEapReq)
SM_ENTER(EAP, AAA_RESPONSE);
else if (sm->eap_if.aaaTimeout)
SM_ENTER(EAP, TIMEOUT_FAILURE2);
break;
case EAP_TIMEOUT_FAILURE2:
break;
case EAP_FAILURE2:
break;
case EAP_SUCCESS2:
break;
}
}
static int eap_sm_calculateTimeout(struct eap_sm *sm, int retransCount,
int eapSRTT, int eapRTTVAR,
int methodTimeout)
{
int rto, i;
if (sm->try_initiate_reauth) {
wpa_printf(MSG_DEBUG,
"EAP: retransmit timeout 1 second for EAP-Initiate-Re-auth-Start");
return 1;
}
if (methodTimeout) {
/*
* EAP method (either internal or through AAA server, provided
* timeout hint. Use that as-is as a timeout for retransmitting
* the EAP request if no response is received.
*/
wpa_printf(MSG_DEBUG, "EAP: retransmit timeout %d seconds "
"(from EAP method hint)", methodTimeout);
return methodTimeout;
}
/*
* RFC 3748 recommends algorithms described in RFC 2988 for estimation
* of the retransmission timeout. This should be implemented once
* round-trip time measurements are available. For nowm a simple
* backoff mechanism is used instead if there are no EAP method
* specific hints.
*
* SRTT = smoothed round-trip time
* RTTVAR = round-trip time variation
* RTO = retransmission timeout
*/
/*
* RFC 2988, 2.1: before RTT measurement, set RTO to 3 seconds for
* initial retransmission and then double the RTO to provide back off
* per 5.5. Limit the maximum RTO to 20 seconds per RFC 3748, 4.3
* modified RTOmax.
*/
rto = 3;
for (i = 0; i < retransCount; i++) {
rto *= 2;
if (rto >= 20) {
rto = 20;
break;
}
}
wpa_printf(MSG_DEBUG, "EAP: retransmit timeout %d seconds "
"(from dynamic back off; retransCount=%d)",
rto, retransCount);
return rto;
}
static void eap_sm_parseEapResp(struct eap_sm *sm, const struct wpabuf *resp)
{
const struct eap_hdr *hdr;
size_t plen;
/* parse rxResp, respId, respMethod */
sm->rxResp = FALSE;
sm->rxInitiate = FALSE;
sm->respId = -1;
sm->respMethod = EAP_TYPE_NONE;
sm->respVendor = EAP_VENDOR_IETF;
sm->respVendorMethod = EAP_TYPE_NONE;
if (resp == NULL || wpabuf_len(resp) < sizeof(*hdr)) {
wpa_printf(MSG_DEBUG, "EAP: parseEapResp: invalid resp=%p "
"len=%lu", resp,
resp ? (unsigned long) wpabuf_len(resp) : 0);
return;
}
hdr = wpabuf_head(resp);
plen = be_to_host16(hdr->length);
if (plen > wpabuf_len(resp)) {
wpa_printf(MSG_DEBUG, "EAP: Ignored truncated EAP-Packet "
"(len=%lu plen=%lu)",
(unsigned long) wpabuf_len(resp),
(unsigned long) plen);
return;
}
sm->respId = hdr->identifier;
if (hdr->code == EAP_CODE_RESPONSE)
sm->rxResp = TRUE;
else if (hdr->code == EAP_CODE_INITIATE)
sm->rxInitiate = TRUE;
if (plen > sizeof(*hdr)) {
u8 *pos = (u8 *) (hdr + 1);
sm->respMethod = *pos++;
if (sm->respMethod == EAP_TYPE_EXPANDED) {
if (plen < sizeof(*hdr) + 8) {
wpa_printf(MSG_DEBUG, "EAP: Ignored truncated "
"expanded EAP-Packet (plen=%lu)",
(unsigned long) plen);
return;
}
sm->respVendor = WPA_GET_BE24(pos);
pos += 3;
sm->respVendorMethod = WPA_GET_BE32(pos);
}
}
wpa_printf(MSG_DEBUG,
"EAP: parseEapResp: rxResp=%d rxInitiate=%d respId=%d respMethod=%u respVendor=%u respVendorMethod=%u",
sm->rxResp, sm->rxInitiate, sm->respId, sm->respMethod,
sm->respVendor, sm->respVendorMethod);
}
static int eap_sm_getId(const struct wpabuf *data)
{
const struct eap_hdr *hdr;
if (data == NULL || wpabuf_len(data) < sizeof(*hdr))
return -1;
hdr = wpabuf_head(data);
wpa_printf(MSG_DEBUG, "EAP: getId: id=%d", hdr->identifier);
return hdr->identifier;
}
static struct wpabuf * eap_sm_buildSuccess(struct eap_sm *sm, u8 id)
{
struct wpabuf *msg;
struct eap_hdr *resp;
wpa_printf(MSG_DEBUG, "EAP: Building EAP-Success (id=%d)", id);
msg = wpabuf_alloc(sizeof(*resp));
if (msg == NULL)
return NULL;
resp = wpabuf_put(msg, sizeof(*resp));
resp->code = EAP_CODE_SUCCESS;
resp->identifier = id;
resp->length = host_to_be16(sizeof(*resp));
return msg;
}
static struct wpabuf * eap_sm_buildFailure(struct eap_sm *sm, u8 id)
{
struct wpabuf *msg;
struct eap_hdr *resp;
wpa_printf(MSG_DEBUG, "EAP: Building EAP-Failure (id=%d)", id);
msg = wpabuf_alloc(sizeof(*resp));
if (msg == NULL)
return NULL;
resp = wpabuf_put(msg, sizeof(*resp));
resp->code = EAP_CODE_FAILURE;
resp->identifier = id;
resp->length = host_to_be16(sizeof(*resp));
return msg;
}
static int eap_sm_nextId(struct eap_sm *sm, int id)
{
if (id < 0) {
/* RFC 3748 Ch 4.1: recommended to initialize Identifier with a
* random number */
id = rand() & 0xff;
if (id != sm->lastId)
return id;
}
return (id + 1) & 0xff;
}
/**
* eap_sm_process_nak - Process EAP-Response/Nak
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
* @nak_list: Nak list (allowed methods) from the supplicant
* @len: Length of nak_list in bytes
*
* This function is called when EAP-Response/Nak is received from the
* supplicant. This can happen for both phase 1 and phase 2 authentications.
*/
void eap_sm_process_nak(struct eap_sm *sm, const u8 *nak_list, size_t len)
{
int i;
size_t j;
if (sm->user == NULL)
return;
wpa_printf(MSG_MSGDUMP, "EAP: processing NAK (current EAP method "
"index %d)", sm->user_eap_method_index);
wpa_hexdump(MSG_MSGDUMP, "EAP: configured methods",
(u8 *) sm->user->methods,
EAP_MAX_METHODS * sizeof(sm->user->methods[0]));
wpa_hexdump(MSG_MSGDUMP, "EAP: list of methods supported by the peer",
nak_list, len);
i = sm->user_eap_method_index;
while (i < EAP_MAX_METHODS &&
(sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
sm->user->methods[i].method != EAP_TYPE_NONE)) {
if (sm->user->methods[i].vendor != EAP_VENDOR_IETF)
goto not_found;
for (j = 0; j < len; j++) {
if (nak_list[j] == sm->user->methods[i].method) {
break;
}
}
if (j < len) {
/* found */
i++;
continue;
}
not_found:
/* not found - remove from the list */
if (i + 1 < EAP_MAX_METHODS) {
os_memmove(&sm->user->methods[i],
&sm->user->methods[i + 1],
(EAP_MAX_METHODS - i - 1) *
sizeof(sm->user->methods[0]));
}
sm->user->methods[EAP_MAX_METHODS - 1].vendor =
EAP_VENDOR_IETF;
sm->user->methods[EAP_MAX_METHODS - 1].method = EAP_TYPE_NONE;
}
wpa_hexdump(MSG_MSGDUMP, "EAP: new list of configured methods",
(u8 *) sm->user->methods, EAP_MAX_METHODS *
sizeof(sm->user->methods[0]));
}
static void eap_sm_Policy_update(struct eap_sm *sm, const u8 *nak_list,
size_t len)
{
if (nak_list == NULL || sm == NULL || sm->user == NULL)
return;
if (sm->user->phase2) {
wpa_printf(MSG_DEBUG, "EAP: EAP-Nak received after Phase2 user"
" info was selected - reject");
sm->decision = DECISION_FAILURE;
return;
}
eap_sm_process_nak(sm, nak_list, len);
}
static EapType eap_sm_Policy_getNextMethod(struct eap_sm *sm, int *vendor)
{
EapType next;
int idx = sm->user_eap_method_index;
/* In theory, there should be no problems with starting
* re-authentication with something else than EAP-Request/Identity and
* this does indeed work with wpa_supplicant. However, at least Funk
* Supplicant seemed to ignore re-auth if it skipped
* EAP-Request/Identity.
* Re-auth sets currentId == -1, so that can be used here to select
* whether Identity needs to be requested again. */
if (sm->identity == NULL || sm->currentId == -1) {
*vendor = EAP_VENDOR_IETF;
next = EAP_TYPE_IDENTITY;
sm->update_user = TRUE;
} else if (sm->user && idx < EAP_MAX_METHODS &&
(sm->user->methods[idx].vendor != EAP_VENDOR_IETF ||
sm->user->methods[idx].method != EAP_TYPE_NONE)) {
*vendor = sm->user->methods[idx].vendor;
next = sm->user->methods[idx].method;
sm->user_eap_method_index++;
} else {
*vendor = EAP_VENDOR_IETF;
next = EAP_TYPE_NONE;
}
wpa_printf(MSG_DEBUG, "EAP: getNextMethod: vendor %d type %d",
*vendor, next);
return next;
}
static int eap_sm_Policy_getDecision(struct eap_sm *sm)
{
if (!sm->eap_server && sm->identity && !sm->start_reauth) {
wpa_printf(MSG_DEBUG, "EAP: getDecision: -> PASSTHROUGH");
return DECISION_PASSTHROUGH;
}
if (sm->m && sm->currentMethod != EAP_TYPE_IDENTITY &&
sm->m->isSuccess(sm, sm->eap_method_priv)) {
wpa_printf(MSG_DEBUG, "EAP: getDecision: method succeeded -> "
"SUCCESS");
sm->update_user = TRUE;
return DECISION_SUCCESS;
}
if (sm->m && sm->m->isDone(sm, sm->eap_method_priv) &&
!sm->m->isSuccess(sm, sm->eap_method_priv)) {
wpa_printf(MSG_DEBUG, "EAP: getDecision: method failed -> "
"FAILURE");
sm->update_user = TRUE;
return DECISION_FAILURE;
}
if ((sm->user == NULL || sm->update_user) && sm->identity &&
!sm->start_reauth) {
/*
* Allow Identity method to be started once to allow identity
* selection hint to be sent from the authentication server,
* but prevent a loop of Identity requests by only allowing
* this to happen once.
*/
int id_req = 0;
if (sm->user && sm->currentMethod == EAP_TYPE_IDENTITY &&
sm->user->methods[0].vendor == EAP_VENDOR_IETF &&
sm->user->methods[0].method == EAP_TYPE_IDENTITY)
id_req = 1;
if (eap_user_get(sm, sm->identity, sm->identity_len, 0) != 0) {
wpa_printf(MSG_DEBUG, "EAP: getDecision: user not "
"found from database -> FAILURE");
return DECISION_FAILURE;
}
if (id_req && sm->user &&
sm->user->methods[0].vendor == EAP_VENDOR_IETF &&
sm->user->methods[0].method == EAP_TYPE_IDENTITY) {
wpa_printf(MSG_DEBUG, "EAP: getDecision: stop "
"identity request loop -> FAILURE");
sm->update_user = TRUE;
return DECISION_FAILURE;
}
sm->update_user = FALSE;
}
sm->start_reauth = FALSE;
if (sm->user && sm->user_eap_method_index < EAP_MAX_METHODS &&
(sm->user->methods[sm->user_eap_method_index].vendor !=
EAP_VENDOR_IETF ||
sm->user->methods[sm->user_eap_method_index].method !=
EAP_TYPE_NONE)) {
wpa_printf(MSG_DEBUG, "EAP: getDecision: another method "
"available -> CONTINUE");
return DECISION_CONTINUE;
}
if (!sm->identity && eap_get_erp_send_reauth_start(sm) &&
!sm->initiate_reauth_start_sent) {
wpa_printf(MSG_DEBUG,
"EAP: getDecision: send EAP-Initiate/Re-auth-Start");
return DECISION_INITIATE_REAUTH_START;
}
if (sm->identity == NULL || sm->currentId == -1) {
wpa_printf(MSG_DEBUG, "EAP: getDecision: no identity known "
"yet -> CONTINUE");
return DECISION_CONTINUE;
}
wpa_printf(MSG_DEBUG, "EAP: getDecision: no more methods available -> "
"FAILURE");
return DECISION_FAILURE;
}
static Boolean eap_sm_Policy_doPickUp(struct eap_sm *sm, EapType method)
{
return method == EAP_TYPE_IDENTITY ? TRUE : FALSE;
}
/**
* eap_server_sm_step - Step EAP server state machine
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
* Returns: 1 if EAP state was changed or 0 if not
*
* This function advances EAP state machine to a new state to match with the
* current variables. This should be called whenever variables used by the EAP
* state machine have changed.
*/
int eap_server_sm_step(struct eap_sm *sm)
{
int res = 0;
do {
sm->changed = FALSE;
SM_STEP_RUN(EAP);
if (sm->changed)
res = 1;
} while (sm->changed);
return res;
}
static void eap_user_free(struct eap_user *user)
{
if (user == NULL)
return;
bin_clear_free(user->password, user->password_len);
user->password = NULL;
os_free(user);
}
/**
* eap_server_sm_init - Allocate and initialize EAP server state machine
* @eapol_ctx: Context data to be used with eapol_cb calls
* @eapol_cb: Pointer to EAPOL callback functions
* @conf: EAP configuration
* Returns: Pointer to the allocated EAP state machine or %NULL on failure
*
* This function allocates and initializes an EAP state machine.
*/
struct eap_sm * eap_server_sm_init(void *eapol_ctx,
const struct eapol_callbacks *eapol_cb,
struct eap_config *conf)
{
struct eap_sm *sm;
sm = os_zalloc(sizeof(*sm));
if (sm == NULL)
return NULL;
sm->eapol_ctx = eapol_ctx;
sm->eapol_cb = eapol_cb;
sm->MaxRetrans = 5; /* RFC 3748: max 3-5 retransmissions suggested */
sm->ssl_ctx = conf->ssl_ctx;
sm->msg_ctx = conf->msg_ctx;
sm->eap_sim_db_priv = conf->eap_sim_db_priv;
sm->backend_auth = conf->backend_auth;
sm->eap_server = conf->eap_server;
if (conf->pac_opaque_encr_key) {
sm->pac_opaque_encr_key = os_malloc(16);
if (sm->pac_opaque_encr_key) {
os_memcpy(sm->pac_opaque_encr_key,
conf->pac_opaque_encr_key, 16);
}
}
if (conf->eap_fast_a_id) {
sm->eap_fast_a_id = os_malloc(conf->eap_fast_a_id_len);
if (sm->eap_fast_a_id) {
os_memcpy(sm->eap_fast_a_id, conf->eap_fast_a_id,
conf->eap_fast_a_id_len);
sm->eap_fast_a_id_len = conf->eap_fast_a_id_len;
}
}
if (conf->eap_fast_a_id_info)
sm->eap_fast_a_id_info = os_strdup(conf->eap_fast_a_id_info);
sm->eap_fast_prov = conf->eap_fast_prov;
sm->pac_key_lifetime = conf->pac_key_lifetime;
sm->pac_key_refresh_time = conf->pac_key_refresh_time;
sm->eap_sim_aka_result_ind = conf->eap_sim_aka_result_ind;
sm->tnc = conf->tnc;
sm->wps = conf->wps;
if (conf->assoc_wps_ie)
sm->assoc_wps_ie = wpabuf_dup(conf->assoc_wps_ie);
if (conf->assoc_p2p_ie)
sm->assoc_p2p_ie = wpabuf_dup(conf->assoc_p2p_ie);
if (conf->peer_addr)
os_memcpy(sm->peer_addr, conf->peer_addr, ETH_ALEN);
sm->fragment_size = conf->fragment_size;
sm->pwd_group = conf->pwd_group;
sm->pbc_in_m1 = conf->pbc_in_m1;
sm->server_id = conf->server_id;
sm->server_id_len = conf->server_id_len;
sm->erp = conf->erp;
#ifdef CONFIG_TESTING_OPTIONS
sm->tls_test_flags = conf->tls_test_flags;
#endif /* CONFIG_TESTING_OPTIONS */
wpa_printf(MSG_DEBUG, "EAP: Server state machine created");
return sm;
}
/**
* eap_server_sm_deinit - Deinitialize and free an EAP server state machine
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
*
* This function deinitializes EAP state machine and frees all allocated
* resources.
*/
void eap_server_sm_deinit(struct eap_sm *sm)
{
if (sm == NULL)
return;
wpa_printf(MSG_DEBUG, "EAP: Server state machine removed");
if (sm->m && sm->eap_method_priv)
sm->m->reset(sm, sm->eap_method_priv);
wpabuf_free(sm->eap_if.eapReqData);
bin_clear_free(sm->eap_if.eapKeyData, sm->eap_if.eapKeyDataLen);
os_free(sm->eap_if.eapSessionId);
wpabuf_free(sm->lastReqData);
wpabuf_free(sm->eap_if.eapRespData);
os_free(sm->identity);
os_free(sm->pac_opaque_encr_key);
os_free(sm->eap_fast_a_id);
os_free(sm->eap_fast_a_id_info);
wpabuf_free(sm->eap_if.aaaEapReqData);
wpabuf_free(sm->eap_if.aaaEapRespData);
bin_clear_free(sm->eap_if.aaaEapKeyData, sm->eap_if.aaaEapKeyDataLen);
eap_user_free(sm->user);
wpabuf_free(sm->assoc_wps_ie);
wpabuf_free(sm->assoc_p2p_ie);
os_free(sm);
}
/**
* eap_sm_notify_cached - Notify EAP state machine of cached PMK
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
*
* This function is called when PMKSA caching is used to skip EAP
* authentication.
*/
void eap_sm_notify_cached(struct eap_sm *sm)
{
if (sm == NULL)
return;
sm->EAP_state = EAP_SUCCESS;
}
/**
* eap_sm_pending_cb - EAP state machine callback for a pending EAP request
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
*
* This function is called when data for a pending EAP-Request is received.
*/
void eap_sm_pending_cb(struct eap_sm *sm)
{
if (sm == NULL)
return;
wpa_printf(MSG_DEBUG, "EAP: Callback for pending request received");
if (sm->method_pending == METHOD_PENDING_WAIT)
sm->method_pending = METHOD_PENDING_CONT;
}
/**
* eap_sm_method_pending - Query whether EAP method is waiting for pending data
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
* Returns: 1 if method is waiting for pending data or 0 if not
*/
int eap_sm_method_pending(struct eap_sm *sm)
{
if (sm == NULL)
return 0;
return sm->method_pending == METHOD_PENDING_WAIT;
}
/**
* eap_get_identity - Get the user identity (from EAP-Response/Identity)
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
* @len: Buffer for returning identity length
* Returns: Pointer to the user identity or %NULL if not available
*/
const u8 * eap_get_identity(struct eap_sm *sm, size_t *len)
{
*len = sm->identity_len;
return sm->identity;
}
/**
* eap_get_interface - Get pointer to EAP-EAPOL interface data
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
* Returns: Pointer to the EAP-EAPOL interface data
*/
struct eap_eapol_interface * eap_get_interface(struct eap_sm *sm)
{
return &sm->eap_if;
}
/**
* eap_server_clear_identity - Clear EAP identity information
* @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
*
* This function can be used to clear the EAP identity information in the EAP
* server context. This allows the EAP/Identity method to be used again after
* EAPOL-Start or EAPOL-Logoff.
*/
void eap_server_clear_identity(struct eap_sm *sm)
{
os_free(sm->identity);
sm->identity = NULL;
}
#ifdef CONFIG_TESTING_OPTIONS
void eap_server_mschap_rx_callback(struct eap_sm *sm, const char *source,
const u8 *username, size_t username_len,
const u8 *challenge, const u8 *response)
{
char hex_challenge[30], hex_response[90], user[100];
/* Print out Challenge and Response in format supported by asleap. */
if (username)
printf_encode(user, sizeof(user), username, username_len);
else
user[0] = '\0';
wpa_snprintf_hex_sep(hex_challenge, sizeof(hex_challenge),
challenge, sizeof(challenge), ':');
wpa_snprintf_hex_sep(hex_response, sizeof(hex_response), response, 24,
':');
wpa_printf(MSG_DEBUG, "[%s/user=%s] asleap -C %s -R %s",
source, user, hex_challenge, hex_response);
}
#endif /* CONFIG_TESTING_OPTIONS */
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