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* hostapd / EAP-SIM (RFC 4186)
3
* Copyright (c) 2005-2007, Jouni Malinen <j@w1.fi>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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* Alternatively, this software may be distributed under the terms of BSD
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* See README and COPYING for more details.
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#include "eap_server/eap_i.h"
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#include "eap_common/eap_sim_common.h"
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#include "eap_server/eap_sim_db.h"
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u8 mk[EAP_SIM_MK_LEN];
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u8 nonce_mt[EAP_SIM_NONCE_MT_LEN];
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u8 nonce_s[EAP_SIM_NONCE_S_LEN];
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u8 k_aut[EAP_SIM_K_AUT_LEN];
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u8 k_encr[EAP_SIM_K_ENCR_LEN];
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u8 msk[EAP_SIM_KEYING_DATA_LEN];
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u8 emsk[EAP_EMSK_LEN];
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u8 kc[EAP_SIM_MAX_CHAL][EAP_SIM_KC_LEN];
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u8 sres[EAP_SIM_MAX_CHAL][EAP_SIM_SRES_LEN];
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u8 rand[EAP_SIM_MAX_CHAL][GSM_RAND_LEN];
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enum { START, CHALLENGE, REAUTH, SUCCESS, FAILURE } state;
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struct eap_sim_reauth *reauth;
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static const char * eap_sim_state_txt(int state)
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static void eap_sim_state(struct eap_sim_data *data, int state)
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wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
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eap_sim_state_txt(data->state),
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eap_sim_state_txt(state));
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static void * eap_sim_init(struct eap_sm *sm)
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struct eap_sim_data *data;
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if (sm->eap_sim_db_priv == NULL) {
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wpa_printf(MSG_WARNING, "EAP-SIM: eap_sim_db not configured");
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data = os_zalloc(sizeof(*data));
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static void eap_sim_reset(struct eap_sm *sm, void *priv)
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struct eap_sim_data *data = priv;
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free(data->next_pseudonym);
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free(data->next_reauth_id);
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static u8 * eap_sim_build_start(struct eap_sm *sm, struct eap_sim_data *data,
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int id, size_t *reqDataLen)
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struct eap_sim_msg *msg;
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wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Start");
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msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
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EAP_SIM_SUBTYPE_START);
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if (eap_sim_db_identity_known(sm->eap_sim_db_priv, sm->identity,
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wpa_printf(MSG_DEBUG, " AT_PERMANENT_ID_REQ");
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eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0);
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wpa_printf(MSG_DEBUG, " AT_VERSION_LIST");
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ver[1] = EAP_SIM_VERSION;
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eap_sim_msg_add(msg, EAP_SIM_AT_VERSION_LIST, sizeof(ver),
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return eap_sim_msg_finish(msg, reqDataLen, NULL, NULL, 0);
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static int eap_sim_build_encr(struct eap_sm *sm, struct eap_sim_data *data,
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struct eap_sim_msg *msg, u16 counter,
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free(data->next_pseudonym);
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data->next_pseudonym =
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eap_sim_db_get_next_pseudonym(sm->eap_sim_db_priv, 0);
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free(data->next_reauth_id);
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if (data->counter <= EAP_SIM_MAX_FAST_REAUTHS) {
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data->next_reauth_id =
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eap_sim_db_get_next_reauth_id(sm->eap_sim_db_priv, 0);
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wpa_printf(MSG_DEBUG, "EAP-SIM: Max fast re-authentication "
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"count exceeded - force full authentication");
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data->next_reauth_id = NULL;
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if (data->next_pseudonym == NULL && data->next_reauth_id == NULL &&
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counter == 0 && nonce_s == NULL)
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wpa_printf(MSG_DEBUG, " AT_IV");
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wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
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eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
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wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)", counter);
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eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
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wpa_printf(MSG_DEBUG, " *AT_NONCE_S");
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eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_S, 0, nonce_s,
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EAP_SIM_NONCE_S_LEN);
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if (data->next_pseudonym) {
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wpa_printf(MSG_DEBUG, " *AT_NEXT_PSEUDONYM (%s)",
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data->next_pseudonym);
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eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_PSEUDONYM,
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strlen(data->next_pseudonym),
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(u8 *) data->next_pseudonym,
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strlen(data->next_pseudonym));
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if (data->next_reauth_id) {
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wpa_printf(MSG_DEBUG, " *AT_NEXT_REAUTH_ID (%s)",
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data->next_reauth_id);
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eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_REAUTH_ID,
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strlen(data->next_reauth_id),
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(u8 *) data->next_reauth_id,
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strlen(data->next_reauth_id));
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if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
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wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
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static u8 * eap_sim_build_challenge(struct eap_sm *sm,
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struct eap_sim_data *data,
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int id, size_t *reqDataLen)
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struct eap_sim_msg *msg;
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wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Challenge");
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msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
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EAP_SIM_SUBTYPE_CHALLENGE);
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wpa_printf(MSG_DEBUG, " AT_RAND");
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eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, (u8 *) data->rand,
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data->num_chal * GSM_RAND_LEN);
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if (eap_sim_build_encr(sm, data, msg, 0, NULL)) {
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eap_sim_msg_free(msg);
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wpa_printf(MSG_DEBUG, " AT_MAC");
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eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
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return eap_sim_msg_finish(msg, reqDataLen, data->k_aut, data->nonce_mt,
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EAP_SIM_NONCE_MT_LEN);
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static u8 * eap_sim_build_reauth(struct eap_sm *sm,
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struct eap_sim_data *data,
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int id, size_t *reqDataLen)
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struct eap_sim_msg *msg;
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wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Re-authentication");
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if (hostapd_get_rand(data->nonce_s, EAP_SIM_NONCE_S_LEN))
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wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: NONCE_S",
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data->nonce_s, EAP_SIM_NONCE_S_LEN);
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eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
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eap_sim_derive_keys_reauth(data->counter, sm->identity,
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sm->identity_len, data->nonce_s, data->mk,
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data->msk, data->emsk);
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msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
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EAP_SIM_SUBTYPE_REAUTHENTICATION);
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if (eap_sim_build_encr(sm, data, msg, data->counter, data->nonce_s)) {
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eap_sim_msg_free(msg);
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wpa_printf(MSG_DEBUG, " AT_MAC");
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eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
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return eap_sim_msg_finish(msg, reqDataLen, data->k_aut, NULL, 0);
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static u8 * eap_sim_buildReq(struct eap_sm *sm, void *priv, int id,
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struct eap_sim_data *data = priv;
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switch (data->state) {
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return eap_sim_build_start(sm, data, id, reqDataLen);
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return eap_sim_build_challenge(sm, data, id, reqDataLen);
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return eap_sim_build_reauth(sm, data, id, reqDataLen);
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wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
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"buildReq", data->state);
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static Boolean eap_sim_check(struct eap_sm *sm, void *priv,
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u8 *respData, size_t respDataLen)
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struct eap_sim_data *data = priv;
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struct eap_hdr *resp;
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resp = (struct eap_hdr *) respData;
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pos = (u8 *) (resp + 1);
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if (respDataLen < sizeof(*resp) + 4 || *pos != EAP_TYPE_SIM ||
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(be_to_host16(resp->length)) > respDataLen) {
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wpa_printf(MSG_INFO, "EAP-SIM: Invalid frame");
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if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR)
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switch (data->state) {
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if (subtype != EAP_SIM_SUBTYPE_START) {
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wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
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"subtype %d", subtype);
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if (subtype != EAP_SIM_SUBTYPE_CHALLENGE) {
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wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
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"subtype %d", subtype);
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if (subtype != EAP_SIM_SUBTYPE_REAUTHENTICATION) {
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wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
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"subtype %d", subtype);
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wpa_printf(MSG_INFO, "EAP-SIM: Unexpected state (%d) for "
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"processing a response", data->state);
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static int eap_sim_supported_ver(struct eap_sim_data *data, int version)
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return version == EAP_SIM_VERSION;
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static void eap_sim_process_start(struct eap_sm *sm,
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struct eap_sim_data *data,
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u8 *respData, size_t respDataLen,
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struct eap_sim_attrs *attr)
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wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response");
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if (attr->nonce_mt == NULL || attr->selected_version < 0) {
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wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing "
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"required attributes");
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eap_sim_state(data, FAILURE);
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if (!eap_sim_supported_ver(data, attr->selected_version)) {
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wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported "
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"version %d", attr->selected_version);
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eap_sim_state(data, FAILURE);
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if (attr->identity) {
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sm->identity = malloc(attr->identity_len);
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memcpy(sm->identity, attr->identity,
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sm->identity_len = attr->identity_len;
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if (sm->identity && sm->identity_len > 0 &&
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sm->identity[0] == EAP_SIM_PERMANENT_PREFIX) {
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identity = sm->identity;
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identity_len = sm->identity_len;
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identity = eap_sim_db_get_permanent(sm->eap_sim_db_priv,
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if (identity == NULL) {
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data->reauth = eap_sim_db_get_reauth_entry(
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sm->eap_sim_db_priv, sm->identity,
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wpa_printf(MSG_DEBUG, "EAP-SIM: Using fast "
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"re-authentication");
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identity = data->reauth->identity;
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identity_len = data->reauth->identity_len;
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data->counter = data->reauth->counter;
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memcpy(data->mk, data->reauth->mk,
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if (identity == NULL) {
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wpa_printf(MSG_DEBUG, "EAP-SIM: Could not get proper permanent"
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eap_sim_state(data, FAILURE);
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wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
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identity, identity_len);
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eap_sim_state(data, REAUTH);
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data->counter = 0; /* reset re-auth counter since this is full auth */
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data->num_chal = eap_sim_db_get_gsm_triplets(
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sm->eap_sim_db_priv, identity, identity_len,
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(u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres, sm);
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if (data->num_chal == EAP_SIM_DB_PENDING) {
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wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication triplets "
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"not yet available - pending request");
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sm->method_pending = METHOD_PENDING_WAIT;
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if (data->num_chal < 2) {
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wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM "
414
"authentication triplets for the peer");
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eap_sim_state(data, FAILURE);
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wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity for MK derivation",
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sm->identity, sm->identity_len);
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memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN);
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WPA_PUT_BE16(ver_list, EAP_SIM_VERSION);
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eap_sim_derive_mk(sm->identity, sm->identity_len, attr->nonce_mt,
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attr->selected_version, ver_list, sizeof(ver_list),
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data->num_chal, (const u8 *) data->kc, data->mk);
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eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
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eap_sim_state(data, CHALLENGE);
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static void eap_sim_process_challenge(struct eap_sm *sm,
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struct eap_sim_data *data,
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u8 *respData, size_t respDataLen,
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struct eap_sim_attrs *attr)
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if (attr->mac == NULL ||
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eap_sim_verify_mac(data->k_aut, respData, respDataLen, attr->mac,
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data->num_chal * EAP_SIM_SRES_LEN)) {
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wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
447
"did not include valid AT_MAC");
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eap_sim_state(data, FAILURE);
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wpa_printf(MSG_DEBUG, "EAP-SIM: Challenge response includes the "
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eap_sim_state(data, SUCCESS);
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identity = eap_sim_db_get_permanent(sm->eap_sim_db_priv, sm->identity,
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sm->identity_len, &identity_len);
458
if (identity == NULL) {
459
identity = sm->identity;
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identity_len = sm->identity_len;
463
if (data->next_pseudonym) {
464
eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, identity,
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data->next_pseudonym);
467
data->next_pseudonym = NULL;
469
if (data->next_reauth_id) {
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eap_sim_db_add_reauth(sm->eap_sim_db_priv, identity,
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data->next_reauth_id, data->counter + 1,
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data->next_reauth_id = NULL;
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static void eap_sim_process_reauth(struct eap_sm *sm,
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struct eap_sim_data *data,
481
u8 *respData, size_t respDataLen,
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struct eap_sim_attrs *attr)
484
struct eap_sim_attrs eattr;
485
u8 *decrypted = NULL;
486
const u8 *identity, *id2;
487
size_t identity_len, id2_len;
489
if (attr->mac == NULL ||
490
eap_sim_verify_mac(data->k_aut, respData, respDataLen, attr->mac,
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data->nonce_s, EAP_SIM_NONCE_S_LEN)) {
492
wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
493
"did not include valid AT_MAC");
497
if (attr->encr_data == NULL || attr->iv == NULL) {
498
wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
499
"message did not include encrypted data");
503
decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
504
attr->encr_data_len, attr->iv, &eattr,
506
if (decrypted == NULL) {
507
wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
508
"data from reauthentication message");
512
if (eattr.counter != data->counter) {
513
wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
514
"used incorrect counter %u, expected %u",
515
eattr.counter, data->counter);
521
wpa_printf(MSG_DEBUG, "EAP-SIM: Re-authentication response includes "
522
"the correct AT_MAC");
523
eap_sim_state(data, SUCCESS);
526
identity = data->reauth->identity;
527
identity_len = data->reauth->identity_len;
529
identity = sm->identity;
530
identity_len = sm->identity_len;
533
id2 = eap_sim_db_get_permanent(sm->eap_sim_db_priv, identity,
534
identity_len, &id2_len);
537
identity_len = id2_len;
540
if (data->next_pseudonym) {
541
eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, identity,
542
identity_len, data->next_pseudonym);
543
data->next_pseudonym = NULL;
545
if (data->next_reauth_id) {
546
eap_sim_db_add_reauth(sm->eap_sim_db_priv, identity,
547
identity_len, data->next_reauth_id,
548
data->counter + 1, data->mk);
549
data->next_reauth_id = NULL;
551
eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
558
eap_sim_state(data, FAILURE);
559
eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
565
static void eap_sim_process_client_error(struct eap_sm *sm,
566
struct eap_sim_data *data,
567
u8 *respData, size_t respDataLen,
568
struct eap_sim_attrs *attr)
570
wpa_printf(MSG_DEBUG, "EAP-SIM: Client reported error %d",
571
attr->client_error_code);
572
eap_sim_state(data, FAILURE);
576
static void eap_sim_process(struct eap_sm *sm, void *priv,
577
u8 *respData, size_t respDataLen)
579
struct eap_sim_data *data = priv;
580
struct eap_hdr *resp;
583
struct eap_sim_attrs attr;
585
resp = (struct eap_hdr *) respData;
586
pos = (u8 *) (resp + 1);
588
len = be_to_host16(resp->length);
591
if (eap_sim_parse_attr(pos, respData + len, &attr, 0, 0)) {
592
wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to parse attributes");
593
eap_sim_state(data, FAILURE);
597
if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) {
598
eap_sim_process_client_error(sm, data, respData, len, &attr);
602
switch (data->state) {
604
eap_sim_process_start(sm, data, respData, len, &attr);
607
eap_sim_process_challenge(sm, data, respData, len, &attr);
610
eap_sim_process_reauth(sm, data, respData, len, &attr);
613
wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
614
"process", data->state);
620
static Boolean eap_sim_isDone(struct eap_sm *sm, void *priv)
622
struct eap_sim_data *data = priv;
623
return data->state == SUCCESS || data->state == FAILURE;
627
static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
629
struct eap_sim_data *data = priv;
632
if (data->state != SUCCESS)
635
key = malloc(EAP_SIM_KEYING_DATA_LEN);
638
memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
639
*len = EAP_SIM_KEYING_DATA_LEN;
644
static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
646
struct eap_sim_data *data = priv;
649
if (data->state != SUCCESS)
652
key = malloc(EAP_EMSK_LEN);
655
memcpy(key, data->emsk, EAP_EMSK_LEN);
661
static Boolean eap_sim_isSuccess(struct eap_sm *sm, void *priv)
663
struct eap_sim_data *data = priv;
664
return data->state == SUCCESS;
668
int eap_server_sim_register(void)
670
struct eap_method *eap;
673
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
674
EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
678
eap->init = eap_sim_init;
679
eap->reset = eap_sim_reset;
680
eap->buildReq = eap_sim_buildReq;
681
eap->check = eap_sim_check;
682
eap->process = eap_sim_process;
683
eap->isDone = eap_sim_isDone;
684
eap->getKey = eap_sim_getKey;
685
eap->isSuccess = eap_sim_isSuccess;
686
eap->get_emsk = eap_sim_get_emsk;
688
ret = eap_server_method_register(eap);
690
eap_server_method_free(eap);
added
removed
src/eap_server/eap_sim.c
