d1f89dd732
This extends EAP server implementation to derive Session-Id similarly to the existing EAP peer implementation. Signed-off-by: Jouni Malinen <j@w1.fi>
545 lines
13 KiB
C
545 lines
13 KiB
C
/*
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* hostapd / EAP-SAKE (RFC 4763) server
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* Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
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*
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* This software may be distributed under the terms of the BSD license.
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* See README for more details.
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*/
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#include "includes.h"
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#include "common.h"
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#include "crypto/random.h"
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#include "eap_server/eap_i.h"
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#include "eap_common/eap_sake_common.h"
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struct eap_sake_data {
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enum { IDENTITY, CHALLENGE, CONFIRM, SUCCESS, FAILURE } state;
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u8 rand_s[EAP_SAKE_RAND_LEN];
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u8 rand_p[EAP_SAKE_RAND_LEN];
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struct {
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u8 auth[EAP_SAKE_TEK_AUTH_LEN];
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u8 cipher[EAP_SAKE_TEK_CIPHER_LEN];
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} tek;
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u8 msk[EAP_MSK_LEN];
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u8 emsk[EAP_EMSK_LEN];
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u8 session_id;
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u8 *peerid;
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size_t peerid_len;
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};
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static const char * eap_sake_state_txt(int state)
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{
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switch (state) {
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case IDENTITY:
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return "IDENTITY";
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case CHALLENGE:
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return "CHALLENGE";
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case CONFIRM:
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return "CONFIRM";
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case SUCCESS:
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return "SUCCESS";
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case FAILURE:
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return "FAILURE";
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default:
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return "?";
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}
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}
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static void eap_sake_state(struct eap_sake_data *data, int state)
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{
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wpa_printf(MSG_DEBUG, "EAP-SAKE: %s -> %s",
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eap_sake_state_txt(data->state),
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eap_sake_state_txt(state));
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data->state = state;
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}
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static void * eap_sake_init(struct eap_sm *sm)
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{
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struct eap_sake_data *data;
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data = os_zalloc(sizeof(*data));
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if (data == NULL)
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return NULL;
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data->state = CHALLENGE;
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if (os_get_random(&data->session_id, 1)) {
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wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
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os_free(data);
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return NULL;
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}
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Initialized Session ID %d",
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data->session_id);
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return data;
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}
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static void eap_sake_reset(struct eap_sm *sm, void *priv)
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{
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struct eap_sake_data *data = priv;
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os_free(data->peerid);
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bin_clear_free(data, sizeof(*data));
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}
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static struct wpabuf * eap_sake_build_msg(struct eap_sake_data *data,
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u8 id, size_t length, u8 subtype)
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{
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struct eap_sake_hdr *sake;
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struct wpabuf *msg;
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size_t plen;
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plen = sizeof(struct eap_sake_hdr) + length;
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msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_SAKE, plen,
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EAP_CODE_REQUEST, id);
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if (msg == NULL) {
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wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to allocate memory "
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"request");
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return NULL;
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}
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sake = wpabuf_put(msg, sizeof(*sake));
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sake->version = EAP_SAKE_VERSION;
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sake->session_id = data->session_id;
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sake->subtype = subtype;
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return msg;
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}
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static struct wpabuf * eap_sake_build_identity(struct eap_sm *sm,
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struct eap_sake_data *data,
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u8 id)
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{
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struct wpabuf *msg;
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size_t plen;
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Identity");
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plen = 4;
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plen += 2 + sm->server_id_len;
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msg = eap_sake_build_msg(data, id, plen, EAP_SAKE_SUBTYPE_IDENTITY);
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if (msg == NULL) {
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data->state = FAILURE;
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return NULL;
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}
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wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PERM_ID_REQ");
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eap_sake_add_attr(msg, EAP_SAKE_AT_PERM_ID_REQ, NULL, 2);
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wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_SERVERID");
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eap_sake_add_attr(msg, EAP_SAKE_AT_SERVERID,
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sm->server_id, sm->server_id_len);
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return msg;
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}
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static struct wpabuf * eap_sake_build_challenge(struct eap_sm *sm,
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struct eap_sake_data *data,
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u8 id)
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{
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struct wpabuf *msg;
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size_t plen;
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Challenge");
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if (random_get_bytes(data->rand_s, EAP_SAKE_RAND_LEN)) {
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wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
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data->state = FAILURE;
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return NULL;
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}
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wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_S (server rand)",
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data->rand_s, EAP_SAKE_RAND_LEN);
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plen = 2 + EAP_SAKE_RAND_LEN + 2 + sm->server_id_len;
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msg = eap_sake_build_msg(data, id, plen, EAP_SAKE_SUBTYPE_CHALLENGE);
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if (msg == NULL) {
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data->state = FAILURE;
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return NULL;
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}
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wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_RAND_S");
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eap_sake_add_attr(msg, EAP_SAKE_AT_RAND_S,
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data->rand_s, EAP_SAKE_RAND_LEN);
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wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_SERVERID");
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eap_sake_add_attr(msg, EAP_SAKE_AT_SERVERID,
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sm->server_id, sm->server_id_len);
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return msg;
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}
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static struct wpabuf * eap_sake_build_confirm(struct eap_sm *sm,
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struct eap_sake_data *data,
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u8 id)
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{
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struct wpabuf *msg;
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u8 *mic;
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Confirm");
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msg = eap_sake_build_msg(data, id, 2 + EAP_SAKE_MIC_LEN,
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EAP_SAKE_SUBTYPE_CONFIRM);
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if (msg == NULL) {
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data->state = FAILURE;
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return NULL;
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}
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wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_S");
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wpabuf_put_u8(msg, EAP_SAKE_AT_MIC_S);
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wpabuf_put_u8(msg, 2 + EAP_SAKE_MIC_LEN);
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mic = wpabuf_put(msg, EAP_SAKE_MIC_LEN);
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if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
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sm->server_id, sm->server_id_len,
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data->peerid, data->peerid_len, 0,
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wpabuf_head(msg), wpabuf_len(msg), mic, mic))
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{
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wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
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data->state = FAILURE;
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os_free(msg);
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return NULL;
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}
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return msg;
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}
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static struct wpabuf * eap_sake_buildReq(struct eap_sm *sm, void *priv, u8 id)
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{
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struct eap_sake_data *data = priv;
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switch (data->state) {
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case IDENTITY:
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return eap_sake_build_identity(sm, data, id);
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case CHALLENGE:
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return eap_sake_build_challenge(sm, data, id);
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case CONFIRM:
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return eap_sake_build_confirm(sm, data, id);
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default:
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Unknown state %d in buildReq",
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data->state);
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break;
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}
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return NULL;
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}
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static Boolean eap_sake_check(struct eap_sm *sm, void *priv,
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struct wpabuf *respData)
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{
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struct eap_sake_data *data = priv;
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struct eap_sake_hdr *resp;
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size_t len;
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u8 version, session_id, subtype;
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const u8 *pos;
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pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, respData, &len);
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if (pos == NULL || len < sizeof(struct eap_sake_hdr)) {
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wpa_printf(MSG_INFO, "EAP-SAKE: Invalid frame");
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return TRUE;
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}
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resp = (struct eap_sake_hdr *) pos;
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version = resp->version;
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session_id = resp->session_id;
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subtype = resp->subtype;
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if (version != EAP_SAKE_VERSION) {
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wpa_printf(MSG_INFO, "EAP-SAKE: Unknown version %d", version);
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return TRUE;
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}
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if (session_id != data->session_id) {
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wpa_printf(MSG_INFO, "EAP-SAKE: Session ID mismatch (%d,%d)",
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session_id, data->session_id);
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return TRUE;
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}
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Received frame: subtype=%d", subtype);
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if (data->state == IDENTITY && subtype == EAP_SAKE_SUBTYPE_IDENTITY)
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return FALSE;
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if (data->state == CHALLENGE && subtype == EAP_SAKE_SUBTYPE_CHALLENGE)
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return FALSE;
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if (data->state == CONFIRM && subtype == EAP_SAKE_SUBTYPE_CONFIRM)
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return FALSE;
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if (subtype == EAP_SAKE_SUBTYPE_AUTH_REJECT)
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return FALSE;
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wpa_printf(MSG_INFO, "EAP-SAKE: Unexpected subtype=%d in state=%d",
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subtype, data->state);
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return TRUE;
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}
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static void eap_sake_process_identity(struct eap_sm *sm,
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struct eap_sake_data *data,
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const struct wpabuf *respData,
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const u8 *payload, size_t payloadlen)
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{
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if (data->state != IDENTITY)
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return;
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Identity");
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/* TODO: update identity and select new user data */
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eap_sake_state(data, CHALLENGE);
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}
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static void eap_sake_process_challenge(struct eap_sm *sm,
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struct eap_sake_data *data,
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const struct wpabuf *respData,
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const u8 *payload, size_t payloadlen)
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{
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struct eap_sake_parse_attr attr;
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u8 mic_p[EAP_SAKE_MIC_LEN];
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if (data->state != CHALLENGE)
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return;
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Challenge");
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if (eap_sake_parse_attributes(payload, payloadlen, &attr))
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return;
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if (!attr.rand_p || !attr.mic_p) {
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wpa_printf(MSG_INFO, "EAP-SAKE: Response/Challenge did not "
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"include AT_RAND_P or AT_MIC_P");
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return;
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}
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os_memcpy(data->rand_p, attr.rand_p, EAP_SAKE_RAND_LEN);
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os_free(data->peerid);
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data->peerid = NULL;
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data->peerid_len = 0;
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if (attr.peerid) {
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data->peerid = os_malloc(attr.peerid_len);
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if (data->peerid == NULL)
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return;
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os_memcpy(data->peerid, attr.peerid, attr.peerid_len);
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data->peerid_len = attr.peerid_len;
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}
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if (sm->user == NULL || sm->user->password == NULL ||
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sm->user->password_len != 2 * EAP_SAKE_ROOT_SECRET_LEN) {
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wpa_printf(MSG_INFO, "EAP-SAKE: Plaintext password with "
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"%d-byte key not configured",
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2 * EAP_SAKE_ROOT_SECRET_LEN);
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data->state = FAILURE;
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return;
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}
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eap_sake_derive_keys(sm->user->password,
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sm->user->password + EAP_SAKE_ROOT_SECRET_LEN,
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data->rand_s, data->rand_p,
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(u8 *) &data->tek, data->msk, data->emsk);
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eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
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sm->server_id, sm->server_id_len,
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data->peerid, data->peerid_len, 1,
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wpabuf_head(respData), wpabuf_len(respData),
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attr.mic_p, mic_p);
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if (os_memcmp_const(attr.mic_p, mic_p, EAP_SAKE_MIC_LEN) != 0) {
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wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_P");
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eap_sake_state(data, FAILURE);
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return;
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}
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eap_sake_state(data, CONFIRM);
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}
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static void eap_sake_process_confirm(struct eap_sm *sm,
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struct eap_sake_data *data,
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const struct wpabuf *respData,
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const u8 *payload, size_t payloadlen)
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{
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struct eap_sake_parse_attr attr;
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u8 mic_p[EAP_SAKE_MIC_LEN];
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if (data->state != CONFIRM)
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return;
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Confirm");
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if (eap_sake_parse_attributes(payload, payloadlen, &attr))
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return;
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if (!attr.mic_p) {
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wpa_printf(MSG_INFO, "EAP-SAKE: Response/Confirm did not "
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"include AT_MIC_P");
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return;
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}
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eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
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sm->server_id, sm->server_id_len,
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data->peerid, data->peerid_len, 1,
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wpabuf_head(respData), wpabuf_len(respData),
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attr.mic_p, mic_p);
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if (os_memcmp_const(attr.mic_p, mic_p, EAP_SAKE_MIC_LEN) != 0) {
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wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_P");
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eap_sake_state(data, FAILURE);
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} else
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eap_sake_state(data, SUCCESS);
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}
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static void eap_sake_process_auth_reject(struct eap_sm *sm,
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struct eap_sake_data *data,
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const struct wpabuf *respData,
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const u8 *payload, size_t payloadlen)
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{
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wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Response/Auth-Reject");
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eap_sake_state(data, FAILURE);
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}
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static void eap_sake_process(struct eap_sm *sm, void *priv,
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struct wpabuf *respData)
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{
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struct eap_sake_data *data = priv;
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struct eap_sake_hdr *resp;
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u8 subtype;
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size_t len;
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const u8 *pos, *end;
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pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, respData, &len);
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if (pos == NULL || len < sizeof(struct eap_sake_hdr))
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return;
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resp = (struct eap_sake_hdr *) pos;
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end = pos + len;
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subtype = resp->subtype;
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pos = (u8 *) (resp + 1);
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wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Received attributes",
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pos, end - pos);
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switch (subtype) {
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case EAP_SAKE_SUBTYPE_IDENTITY:
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eap_sake_process_identity(sm, data, respData, pos, end - pos);
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break;
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case EAP_SAKE_SUBTYPE_CHALLENGE:
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eap_sake_process_challenge(sm, data, respData, pos, end - pos);
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break;
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case EAP_SAKE_SUBTYPE_CONFIRM:
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eap_sake_process_confirm(sm, data, respData, pos, end - pos);
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break;
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case EAP_SAKE_SUBTYPE_AUTH_REJECT:
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eap_sake_process_auth_reject(sm, data, respData, pos,
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end - pos);
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break;
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}
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}
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static Boolean eap_sake_isDone(struct eap_sm *sm, void *priv)
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{
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struct eap_sake_data *data = priv;
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return data->state == SUCCESS || data->state == FAILURE;
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}
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static u8 * eap_sake_getKey(struct eap_sm *sm, void *priv, size_t *len)
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{
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struct eap_sake_data *data = priv;
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u8 *key;
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if (data->state != SUCCESS)
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return NULL;
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key = os_malloc(EAP_MSK_LEN);
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if (key == NULL)
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return NULL;
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os_memcpy(key, data->msk, EAP_MSK_LEN);
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*len = EAP_MSK_LEN;
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return key;
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}
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static u8 * eap_sake_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
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{
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struct eap_sake_data *data = priv;
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u8 *key;
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if (data->state != SUCCESS)
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return NULL;
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key = os_malloc(EAP_EMSK_LEN);
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if (key == NULL)
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return NULL;
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os_memcpy(key, data->emsk, EAP_EMSK_LEN);
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*len = EAP_EMSK_LEN;
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return key;
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}
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static Boolean eap_sake_isSuccess(struct eap_sm *sm, void *priv)
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{
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struct eap_sake_data *data = priv;
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return data->state == SUCCESS;
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}
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|
|
|
|
|
static u8 * eap_sake_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
|
|
{
|
|
struct eap_sake_data *data = priv;
|
|
u8 *id;
|
|
|
|
if (data->state != SUCCESS)
|
|
return NULL;
|
|
|
|
*len = 1 + 2 * EAP_SAKE_RAND_LEN;
|
|
id = os_malloc(*len);
|
|
if (id == NULL)
|
|
return NULL;
|
|
|
|
id[0] = EAP_TYPE_SAKE;
|
|
os_memcpy(id + 1, data->rand_s, EAP_SAKE_RAND_LEN);
|
|
os_memcpy(id + 1 + EAP_SAKE_RAND_LEN, data->rand_s, EAP_SAKE_RAND_LEN);
|
|
wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Derived Session-Id", id, *len);
|
|
|
|
return id;
|
|
}
|
|
|
|
|
|
int eap_server_sake_register(void)
|
|
{
|
|
struct eap_method *eap;
|
|
int ret;
|
|
|
|
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
|
|
EAP_VENDOR_IETF, EAP_TYPE_SAKE, "SAKE");
|
|
if (eap == NULL)
|
|
return -1;
|
|
|
|
eap->init = eap_sake_init;
|
|
eap->reset = eap_sake_reset;
|
|
eap->buildReq = eap_sake_buildReq;
|
|
eap->check = eap_sake_check;
|
|
eap->process = eap_sake_process;
|
|
eap->isDone = eap_sake_isDone;
|
|
eap->getKey = eap_sake_getKey;
|
|
eap->isSuccess = eap_sake_isSuccess;
|
|
eap->get_emsk = eap_sake_get_emsk;
|
|
eap->getSessionId = eap_sake_get_session_id;
|
|
|
|
ret = eap_server_method_register(eap);
|
|
if (ret)
|
|
eap_server_method_free(eap);
|
|
return ret;
|
|
}
|