/*
 * $Id$
 *
 * Digest Authentication - Radius support
 *
 * Copyright (C) 2001-2003 FhG Fokus
 * Copyright (C) 2010 Juha Heinanen
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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
 *
 * Kamailio 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 Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * History:
 * -------
 * 2003-03-09: Based on authorize.c from radius_auth (janakj)
 * 2006-03-01: pseudo variables support for domain name (bogdan)
 */


#include <string.h>
#include <stdlib.h>
#include "../../mem/mem.h"
#include "../../str.h"
#include "../../parser/hf.h"
#include "../../parser/digest/digest.h"
#include "../../parser/parse_uri.h"
#include "../../parser/parse_from.h"
#include "../../parser/parse_to.h"
#include "../../dprint.h"
#include "../../ut.h"
#include "../../pvar.h"
#include "../../modules/auth/api.h"
#include "authorize.h"
#include "sterman.h"
#include "authrad_mod.h"


/* 
 * Extract URI depending on the request from To or From header 
 */
static inline int get_uri_user(struct sip_msg* _m, str** _uri_user)
{
    struct sip_uri *puri;

    if ((REQ_LINE(_m).method.len == 8) && 
	(memcmp(REQ_LINE(_m).method.s, "REGISTER", 8) == 0)) {
	if ((puri=parse_to_uri(_m))==NULL) {
	    LM_ERR("failed to parse To header\n");
	    return -1;
	}
    } else {
	if ((puri=parse_from_uri(_m))==NULL) {
	    LM_ERR("parsing From header\n");
	    return -1;
	}
    }

    *_uri_user = &(puri->user);

    return 0;
}


/*
 * Authorize digest credentials
 */
static inline int authorize(struct sip_msg* _msg, pv_elem_t* _realm,
			    pv_spec_t * _uri_user, hdr_types_t _hftype)
{
    int res;
    auth_cfg_result_t ret;
    struct hdr_field* h;
    auth_body_t* cred;
    str *uri_user;
    str user, domain;
    pv_value_t pv_val;

    cred = 0;
    ret = -1;
    user.s = 0;

    /* get pre_auth domain from _realm pvar (if exists) */
    if (_realm) {
	if (pv_printf_s(_msg, _realm, &domain) != 0) {
	    LM_ERR("pv_printf_s failed\n");
	    return -5;
	}
    } else {
	domain.len = 0;
	domain.s = 0;
    }

    switch(auth_api.pre_auth(_msg, &domain, _hftype, &h, NULL)) {
    default:
	BUG("unexpected reply '%d'.\n",
	    auth_api.pre_auth(_msg, &domain, _hftype, &h, NULL));
#ifdef EXTRA_DEBUG
	abort();
#endif
	ret = -7;
	goto end;

    case NONCE_REUSED:
	ret = AUTH_NONCE_REUSED;
	goto end;

    case STALE_NONCE:
	ret = AUTH_STALE_NONCE;
	goto end;
	
    case ERROR:
    case BAD_CREDENTIALS:
    case NOT_AUTHENTICATED:
	ret = AUTH_ERROR;
	goto end;

    case NO_CREDENTIALS:
	ret = AUTH_NO_CREDENTIALS;
	goto end;
	
    case DO_AUTHENTICATION:
	break;
	
    case AUTHENTICATED:
	ret = AUTH_OK;
	goto end;
    }

    cred = (auth_body_t*)h->parsed;

    /* get uri_user from _uri_user pvap (if exists) or
       from To/From URI */
    if (_uri_user) {
	if (pv_get_spec_value(_msg, _uri_user, &pv_val) == 0) {
	    if (pv_val.flags & PV_VAL_STR) {
		res = radius_authorize_sterman(_msg, &cred->digest, 
					       &_msg->
					       first_line.u.request.method,
					       &pv_val.rs);
	    } else {
		LM_ERR("uri_user pvar value is not string\n");
		ret = AUTH_ERROR;
		goto end;
	    }
	} else {
	    LM_ERR("cannot get uri_user pvar value\n");
	    ret = AUTH_ERROR;
	    goto end;
	}
    } else {
	if (get_uri_user(_msg, &uri_user) < 0) {
	    LM_ERR("To/From URI not found\n");
	    ret = AUTH_ERROR;;
	    goto end;
	}
	user.s = (char *)pkg_malloc(uri_user->len);
	if (user.s == NULL) {
	    LM_ERR("no pkg memory left for user\n");
	    ret = -7;
	    goto end;
	}
	un_escape(uri_user, &user);
	res = radius_authorize_sterman(_msg, &cred->digest, 
				       &_msg->first_line.u.request.method,
				       &user);
    }

    if (res == 1) {
	switch(auth_api.post_auth(_msg, h)) {
	default:
	    BUG("unexpected reply '%d'.\n",
		auth_api.pre_auth(_msg, &domain, _hftype, &h, NULL));
#ifdef EXTRA_DEBUG
	    abort();
#endif
	    ret = -7;
	    break;
	case ERROR:             
	case NOT_AUTHENTICATED:
	    ret = AUTH_ERROR;
	    break;
	case AUTHENTICATED:
	    ret = AUTH_OK;
	    break;
	}
    } else {
	ret = AUTH_INVALID_PASSWORD;
    }

 end:
    if (user.s) pkg_free(user.s);
    if (ret < 0) {
	if (auth_api.build_challenge(_msg, (cred ? cred->stale : 0), &domain,
				     NULL, NULL, _hftype) < 0) {
	    LM_ERR("while creating challenge\n");
	    ret = -7;
	}
    }
    return ret;
}


/*
 * Authorize using Proxy-Authorize header field (no URI user parameter given)
 */
int radius_proxy_authorize_1(struct sip_msg* _msg, char* _realm, char* _s2)
{
	/* realm parameter is converted in fixup */
	return authorize(_msg, (pv_elem_t*)_realm, (pv_spec_t *)0,
		HDR_PROXYAUTH_T);
}


/*
 * Authorize using Proxy-Authorize header field (URI user parameter given)
 */
int radius_proxy_authorize_2(struct sip_msg* _msg, char* _realm,
														char* _uri_user)
{
	return authorize(_msg, (pv_elem_t*)_realm, (pv_spec_t *)_uri_user,
		HDR_PROXYAUTH_T);
}


/*
 * Authorize using WWW-Authorize header field (no URI user parameter given)
 */
int radius_www_authorize_1(struct sip_msg* _msg, char* _realm, char* _s2)
{
	return authorize(_msg, (pv_elem_t*)_realm, (pv_spec_t *)0,
			 HDR_AUTHORIZATION_T);
}


/*
 * Authorize using WWW-Authorize header field (URI user parameter given)
 */
int radius_www_authorize_2(struct sip_msg* _msg, char* _realm, char* _uri_user)
{
	return authorize(_msg, (pv_elem_t*)_realm, (pv_spec_t *)_uri_user,
			 HDR_AUTHORIZATION_T);
}