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Diffstat (limited to 'contrib/hostapd/eap_sim.c')
| -rw-r--r-- | contrib/hostapd/eap_sim.c | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/contrib/hostapd/eap_sim.c b/contrib/hostapd/eap_sim.c new file mode 100644 index 000000000000..aade18161d1d --- /dev/null +++ b/contrib/hostapd/eap_sim.c @@ -0,0 +1,431 @@ +/* + * hostapd / EAP-SIM (draft-haverinen-pppext-eap-sim-15.txt) + * Copyright (c) 2005, Jouni Malinen <jkmaline@cc.hut.fi> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Alternatively, this software may be distributed under the terms of BSD + * license. + * + * See README and COPYING for more details. + */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <netinet/in.h> + +#include "hostapd.h" +#include "common.h" +#include "sha1.h" +#include "eap_i.h" +#include "eap_sim_common.h" +#include "eap_sim_db.h" + + +#define EAP_SIM_VERSION 1 + +/* EAP-SIM Subtypes */ +#define EAP_SIM_SUBTYPE_START 10 +#define EAP_SIM_SUBTYPE_CHALLENGE 11 +#define EAP_SIM_SUBTYPE_NOTIFICATION 12 +#define EAP_SIM_SUBTYPE_REAUTHENTICATION 13 +#define EAP_SIM_SUBTYPE_CLIENT_ERROR 14 + +/* AT_CLIENT_ERROR_CODE error codes */ +#define EAP_SIM_UNABLE_TO_PROCESS_PACKET 0 +#define EAP_SIM_UNSUPPORTED_VERSION 1 +#define EAP_SIM_INSUFFICIENT_NUM_OF_CHAL 2 +#define EAP_SIM_RAND_NOT_FRESH 3 + +#define KC_LEN 8 +#define SRES_LEN 4 +#define EAP_SIM_MAX_FAST_REAUTHS 1000 + +#define EAP_SIM_MAX_CHAL 3 + +struct eap_sim_data { + u8 mk[EAP_SIM_MK_LEN]; + u8 nonce_mt[EAP_SIM_NONCE_MT_LEN]; + u8 k_aut[EAP_SIM_K_AUT_LEN]; + u8 k_encr[EAP_SIM_K_ENCR_LEN]; + u8 msk[EAP_SIM_KEYING_DATA_LEN]; + u8 kc[EAP_SIM_MAX_CHAL][KC_LEN]; + u8 sres[EAP_SIM_MAX_CHAL][SRES_LEN]; + u8 rand[EAP_SIM_MAX_CHAL][GSM_RAND_LEN]; + int num_chal; + enum { START, CHALLENGE, SUCCESS, FAILURE } state; +}; + + +static const char * eap_sim_state_txt(int state) +{ + switch (state) { + case START: + return "START"; + case CHALLENGE: + return "CHALLENGE"; + case SUCCESS: + return "SUCCESS"; + case FAILURE: + return "FAILURE"; + default: + return "Unknown?!"; + } +} + + +static void eap_sim_state(struct eap_sim_data *data, int state) +{ + wpa_printf(MSG_DEBUG, "EAP-SIM %s -> %s", + eap_sim_state_txt(data->state), + eap_sim_state_txt(state)); + data->state = state; +} + + +static void * eap_sim_init(struct eap_sm *sm) +{ + struct eap_sim_data *data; + + if (sm->eap_sim_db_priv == NULL) { + wpa_printf(MSG_WARNING, "EAP-SIM: eap_sim_db not configured"); + return NULL; + } + + data = malloc(sizeof(*data)); + if (data == NULL) + return data; + memset(data, 0, sizeof(*data)); + data->state = START; + + return data; +} + + +static void eap_sim_reset(struct eap_sm *sm, void *priv) +{ + struct eap_sim_data *data = priv; + free(data); +} + + +static u8 * eap_sim_build_start(struct eap_sm *sm, struct eap_sim_data *data, + int id, size_t *reqDataLen) +{ + struct eap_sim_msg *msg; + u8 ver[2]; + + msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM, + EAP_SIM_SUBTYPE_START); + if (eap_sim_db_identity_known(sm->eap_sim_db_priv, sm->identity, + sm->identity_len)) { + eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0); + } + ver[0] = 0; + ver[1] = EAP_SIM_VERSION; + eap_sim_msg_add(msg, EAP_SIM_AT_VERSION_LIST, sizeof(ver), + ver, sizeof(ver)); + return eap_sim_msg_finish(msg, reqDataLen, NULL, NULL, 0); +} + + +static u8 * eap_sim_build_challenge(struct eap_sm *sm, + struct eap_sim_data *data, + int id, size_t *reqDataLen) +{ + struct eap_sim_msg *msg; + + msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM, + EAP_SIM_SUBTYPE_CHALLENGE); + eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, (u8 *) data->rand, + data->num_chal * GSM_RAND_LEN); + eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC); + return eap_sim_msg_finish(msg, reqDataLen, data->k_aut, data->nonce_mt, + EAP_SIM_NONCE_MT_LEN); +} + + +static u8 * eap_sim_buildReq(struct eap_sm *sm, void *priv, int id, + size_t *reqDataLen) +{ + struct eap_sim_data *data = priv; + + switch (data->state) { + case START: + return eap_sim_build_start(sm, data, id, reqDataLen); + case CHALLENGE: + return eap_sim_build_challenge(sm, data, id, reqDataLen); + default: + wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in " + "buildReq", data->state); + break; + } + return NULL; +} + + +static Boolean eap_sim_check(struct eap_sm *sm, void *priv, + u8 *respData, size_t respDataLen) +{ + struct eap_sim_data *data = priv; + struct eap_hdr *resp; + u8 *pos, subtype; + size_t len; + + resp = (struct eap_hdr *) respData; + pos = (u8 *) (resp + 1); + if (respDataLen < sizeof(*resp) + 4 || *pos != EAP_TYPE_SIM || + (len = ntohs(resp->length)) > respDataLen) { + wpa_printf(MSG_INFO, "EAP-SIM: Invalid frame"); + return TRUE; + } + subtype = pos[1]; + + if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) + return FALSE; + + switch (data->state) { + case START: + if (subtype != EAP_SIM_SUBTYPE_START) { + wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response " + "subtype %d", subtype); + return TRUE; + } + break; + case CHALLENGE: + if (subtype != EAP_SIM_SUBTYPE_CHALLENGE) { + wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response " + "subtype %d", subtype); + return TRUE; + } + break; + default: + wpa_printf(MSG_INFO, "EAP-SIM: Unexpected state (%d) for " + "processing a response", data->state); + return TRUE; + } + + return FALSE; +} + + +static int eap_sim_supported_ver(struct eap_sim_data *data, int version) +{ + return version == EAP_SIM_VERSION; +} + + +static void eap_sim_derive_mk(struct eap_sim_data *data, + const u8 *identity, size_t identity_len, + const u8 *nonce_mt, int selected_version, + int num_chal, const u8 *kc) +{ + u8 sel_ver[2], ver_list[2]; + const unsigned char *addr[5]; + size_t len[5]; + + addr[0] = identity; + addr[1] = kc; + addr[2] = nonce_mt; + addr[3] = ver_list; + addr[4] = sel_ver; + + len[0] = identity_len; + len[1] = num_chal * KC_LEN; + len[2] = EAP_SIM_NONCE_MT_LEN; + len[3] = sizeof(ver_list); + len[4] = sizeof(sel_ver); + + ver_list[0] = 0; + ver_list[1] = EAP_SIM_VERSION; + sel_ver[0] = selected_version >> 8; + sel_ver[1] = selected_version & 0xff; + + /* MK = SHA1(Identity|n*Kc|NONCE_MT|Version List|Selected Version) */ + sha1_vector(5, addr, len, data->mk); + wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: MK", data->mk, EAP_SIM_MK_LEN); +} + + +static void eap_sim_process_start(struct eap_sm *sm, + struct eap_sim_data *data, + u8 *respData, size_t respDataLen, + struct eap_sim_attrs *attr) +{ + wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response"); + + if (attr->nonce_mt == NULL || attr->selected_version < 0) { + wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing " + "required attributes"); + eap_sim_state(data, FAILURE); + return; + } + + if (!eap_sim_supported_ver(data, attr->selected_version)) { + wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported " + "version %d", attr->selected_version); + eap_sim_state(data, FAILURE); + return; + } + + if (attr->identity) { + free(sm->identity); + sm->identity = malloc(attr->identity_len); + if (sm->identity) { + memcpy(sm->identity, attr->identity, + attr->identity_len); + sm->identity_len = attr->identity_len; + } + } + + if (sm->identity == NULL || sm->identity_len < 1 || + sm->identity[0] != '1') { + wpa_printf(MSG_DEBUG, "EAP-SIM: Could not get proper permanent" + " user name"); + eap_sim_state(data, FAILURE); + return; + } + + wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity", + sm->identity, sm->identity_len); + + data->num_chal = eap_sim_db_get_gsm_triplets( + sm->eap_sim_db_priv, sm->identity, sm->identity_len, + EAP_SIM_MAX_CHAL, + (u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres); + if (data->num_chal < 2) { + wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM " + "authentication triplets for the peer"); + eap_sim_state(data, FAILURE); + return; + } + + memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN); + eap_sim_derive_mk(data, sm->identity, sm->identity_len, attr->nonce_mt, + attr->selected_version, data->num_chal, + (u8 *) data->kc); + eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk); + + eap_sim_state(data, CHALLENGE); +} + + +static void eap_sim_process_challenge(struct eap_sm *sm, + struct eap_sim_data *data, + u8 *respData, size_t respDataLen, + struct eap_sim_attrs *attr) +{ + if (attr->mac == NULL || + eap_sim_verify_mac(data->k_aut, respData, respDataLen, attr->mac, + (u8 *) data->sres, data->num_chal * SRES_LEN)) { + wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message " + "did not include valid AT_MAC"); + eap_sim_state(data, FAILURE); + return; + } + + wpa_printf(MSG_DEBUG, "EAP-SIM: Challenge response includes the " + "correct AT_MAC"); + eap_sim_state(data, SUCCESS); +} + + +static void eap_sim_process_client_error(struct eap_sm *sm, + struct eap_sim_data *data, + u8 *respData, size_t respDataLen, + struct eap_sim_attrs *attr) +{ + wpa_printf(MSG_DEBUG, "EAP-SIM: Client reported error %d", + attr->client_error_code); + eap_sim_state(data, FAILURE); +} + + +static void eap_sim_process(struct eap_sm *sm, void *priv, + u8 *respData, size_t respDataLen) +{ + struct eap_sim_data *data = priv; + struct eap_hdr *resp; + u8 *pos, subtype; + size_t len; + struct eap_sim_attrs attr; + + resp = (struct eap_hdr *) respData; + pos = (u8 *) (resp + 1); + subtype = pos[1]; + len = ntohs(resp->length); + pos += 4; + + if (eap_sim_parse_attr(pos, respData + len, &attr, 0, 0)) { + wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to parse attributes"); + eap_sim_state(data, FAILURE); + return; + } + + if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) { + eap_sim_process_client_error(sm, data, respData, len, &attr); + return; + } + + switch (data->state) { + case START: + eap_sim_process_start(sm, data, respData, len, &attr); + break; + case CHALLENGE: + eap_sim_process_challenge(sm, data, respData, len, &attr); + break; + default: + wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in " + "process", data->state); + break; + } +} + + +static Boolean eap_sim_isDone(struct eap_sm *sm, void *priv) +{ + struct eap_sim_data *data = priv; + return data->state == SUCCESS || data->state == FAILURE; +} + + +static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len) +{ + struct eap_sim_data *data = priv; + u8 *key; + + if (data->state != SUCCESS) + return NULL; + + key = malloc(EAP_SIM_KEYING_DATA_LEN); + if (key == NULL) + return NULL; + memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN); + *len = EAP_SIM_KEYING_DATA_LEN; + return key; +} + + +static Boolean eap_sim_isSuccess(struct eap_sm *sm, void *priv) +{ + struct eap_sim_data *data = priv; + return data->state == SUCCESS; +} + + +const struct eap_method eap_method_sim = +{ + .method = EAP_TYPE_SIM, + .name = "SIM", + .init = eap_sim_init, + .reset = eap_sim_reset, + .buildReq = eap_sim_buildReq, + .check = eap_sim_check, + .process = eap_sim_process, + .isDone = eap_sim_isDone, + .getKey = eap_sim_getKey, + .isSuccess = eap_sim_isSuccess, +}; |