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/*
* rlm_eap_gtc.c Handles that are called from eap
*
* Version: $Id$
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*
* Copyright 2003,2006 The FreeRADIUS server project
*/
RCSID("$Id$")
#include <stdio.h>
#include <stdlib.h>
#include "eap.h"
#include <freeradius-devel/rad_assert.h>
/*
* EAP-GTC is just ASCII data carried inside of the EAP session.
* The length of the data is indicated by the encapsulating EAP
* protocol.
*/
typedef struct rlm_eap_gtc_t {
char const *challenge;
char const *auth_type_name;
int auth_type;
} rlm_eap_gtc_t;
static CONF_PARSER module_config[] = {
{ "challenge", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_eap_gtc_t, challenge), "Password: " },
{ "auth_type", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_eap_gtc_t, auth_type_name), "PAP" },
CONF_PARSER_TERMINATOR
};
/*
* Attach the module.
*/
static int mod_instantiate(CONF_SECTION *cs, void **instance)
{
rlm_eap_gtc_t *inst;
DICT_VALUE *dval;
*instance = inst = talloc_zero(cs, rlm_eap_gtc_t);
if (!inst) return -1;
/*
* Parse the configuration attributes.
*/
if (cf_section_parse(cs, inst, module_config) < 0) {
return -1;
}
if (inst->auth_type_name && *inst->auth_type_name) {
dval = dict_valbyname(PW_AUTH_TYPE, 0, inst->auth_type_name);
if (!dval) {
ERROR("rlm_eap_gtc: Unknown Auth-Type %s",
inst->auth_type_name);
return -1;
}
inst->auth_type = dval->value;
} else {
inst->auth_type = PW_AUTH_TYPE_LOCAL;
}
return 0;
}
/*
* Initiate the EAP-GTC session by sending a challenge to the peer.
*/
static int mod_session_init(void *instance, eap_handler_t *handler)
{
char challenge_str[1024];
int length;
EAP_DS *eap_ds = handler->eap_ds;
rlm_eap_gtc_t *inst = (rlm_eap_gtc_t *) instance;
if (radius_xlat(challenge_str, sizeof(challenge_str), handler->request, inst->challenge, NULL, NULL) < 0) {
return 0;
}
length = strlen(challenge_str);
/*
* We're sending a request...
*/
eap_ds->request->code = PW_EAP_REQUEST;
eap_ds->request->type.data = talloc_array(eap_ds->request,
uint8_t, length);
if (!eap_ds->request->type.data) {
return 0;
}
memcpy(eap_ds->request->type.data, challenge_str, length);
eap_ds->request->type.length = length;
/*
* We don't need to authorize the user at this point.
*
* We also don't need to keep the challenge, as it's
* stored in 'handler->eap_ds', which will be given back
* to us...
*/
handler->stage = PROCESS;
return 1;
}
/*
* Authenticate a previously sent challenge.
*/
static int CC_HINT(nonnull) mod_process(void *instance, eap_handler_t *handler)
{
VALUE_PAIR *vp;
EAP_DS *eap_ds = handler->eap_ds;
rlm_eap_gtc_t *inst = (rlm_eap_gtc_t *) instance;
REQUEST *request = handler->request;
/*
* Get the Cleartext-Password for this user.
*/
rad_assert(handler->stage == PROCESS);
/*
* Sanity check the response. We need at least one byte
* of data.
*/
if (eap_ds->response->length <= 4) {
ERROR("rlm_eap_gtc: corrupted data");
eap_ds->request->code = PW_EAP_FAILURE;
return 0;
}
#if 0
if ((rad_debug_lvl > 2) && fr_log_fp) {
int i;
for (i = 0; i < eap_ds->response->length - 4; i++) {
if ((i & 0x0f) == 0) fprintf(fr_log_fp, "%d: ", i);
fprintf(fr_log_fp, "%02x ", eap_ds->response->type.data[i]);
if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
}
}
#endif
/*
* Handle passwords here.
*/
if (inst->auth_type == PW_AUTH_TYPE_LOCAL) {
/*
* For now, do cleartext password authentication.
*/
vp = fr_pair_find_by_num(request->config, PW_CLEARTEXT_PASSWORD, 0, TAG_ANY);
if (!vp) {
REDEBUG2("Cleartext-Password is required for authentication");
eap_ds->request->code = PW_EAP_FAILURE;
return 0;
}
if (eap_ds->response->type.length != vp->vp_length) {
REDEBUG2("Passwords are of different length. %u %u", (unsigned) eap_ds->response->type.length, (unsigned) vp->vp_length);
eap_ds->request->code = PW_EAP_FAILURE;
return 0;
}
if (memcmp(eap_ds->response->type.data,
vp->vp_strvalue, vp->vp_length) != 0) {
REDEBUG2("Passwords are different");
eap_ds->request->code = PW_EAP_FAILURE;
return 0;
}
/*
* EAP packets can be ~64k long maximum, and
* we don't like that.
*/
} else if (eap_ds->response->type.length <= 128) {
int rcode;
/*
* If there was a User-Password in the request,
* why the heck are they using EAP-GTC?
*/
fr_pair_delete_by_num(&request->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
vp = pair_make_request("User-Password", NULL, T_OP_EQ);
if (!vp) {
return 0;
}
fr_pair_value_bstrncpy(vp, eap_ds->response->type.data, eap_ds->response->type.length);
/*
* Add the password to the request, and allow
* another module to do the work of authenticating it.
*/
request->password = vp;
/*
* This is a wild & crazy hack.
*/
rcode = process_authenticate(inst->auth_type, request);
if (rcode != RLM_MODULE_OK) {
eap_ds->request->code = PW_EAP_FAILURE;
return 0;
}
} else {
ERROR("rlm_eap_gtc: Response is too large to understand");
eap_ds->request->code = PW_EAP_FAILURE;
return 0;
}
eap_ds->request->code = PW_EAP_SUCCESS;
return 1;
}
/*
* The module name should be the only globally exported symbol.
* That is, everything else should be 'static'.
*/
extern rlm_eap_module_t rlm_eap_gtc;
rlm_eap_module_t rlm_eap_gtc = {
.name = "eap_gtc",
.instantiate = mod_instantiate, /* Create new submodule instance */
.session_init = mod_session_init, /* Initialise a new EAP session */
.process = mod_process /* Process next round of EAP method */
};
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