/* 
 * $Id: sterman.c,v 1.7 2006/02/10 18:55:44 miconda Exp $
 *
 * Digest Authentication - Radius support
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of openser, a free SIP server.
 *
 * openser 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
 *
 * openser 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * History:
 * -------
 * 2003-03-09: Based on digest.c from radius_auth module (janakj)
 * 2005-07-08: Radius AVP may contain any kind of OpenSER AVP - ID/name or
 *             int/str value (bogdan)
 * 2005-07-08: old RPID RADIUS AVP compatibility droped (bogdan)
 */


#include "../../mem/mem.h"
#include "../../dprint.h"
#include "../auth/api.h"
#include "../../modules/acc/dict.h"
#include "../../usr_avp.h"
#include "../../ut.h"
#include "sterman.h"
#include "authrad_mod.h"

#include <stdlib.h>
#include <string.h>
#include <radiusclient-ng.h>


static inline int extract_avp(VALUE_PAIR* vp, unsigned short *flags,
										int_str *name, int_str *value)
{
	static str names, values;
	unsigned int r;
	char *p;
	char *end;

	/* empty? */
	if (vp->lvalue==0 || vp->strvalue==0)
		goto error;

	p = vp->strvalue;
	end = vp->strvalue + vp->lvalue;

	DBG("DEBUG:auth_radius:extract_avp: string is <%.*s>\n",
		(int)(long)(end-p), p);

	/* get name */
	if (*p!='#') {
		/* name AVP */
		*flags |= AVP_NAME_STR;
		names.s = p;
	} else {
		names.s = ++p;
	}

	names.len = 0;
	while( p<end && *p!=':' && *p!='#')
		p++;
	if (names.s==p || p==end) {
		LOG(L_ERR,"ERROR:auth_radius:extract_avp: empty AVP name\n");
		goto error;
	}
	names.len = p - names.s;
	DBG("DEBUG:auth_radius:extract_avp: AVP name is <%.*s>\n",
		names.len, names.s);

	/* get value */
	if (*p!='#') {
		/* string value */
		*flags |= AVP_VAL_STR;
	}
	values.s = ++p;
	values.len = end-values.s;
	if (values.len==0) {
		LOG(L_ERR,"ERROR:auth_radius:extract_avp: empty AVP value\n");
		goto error;
	}
	DBG("DEBUG:auth_radius:extract_avp: AVP val is <%.*s>\n",
		values.len, values.s);

	if ( !((*flags)&AVP_NAME_STR) ) {
		/* convert name to id*/
		if (str2int(&names,&r)!=0 ) {
			LOG(L_ERR,"ERROR:auth_radius:extract_avp: invalid AVP ID '%.*s'\n",
				names.len,names.s);
			goto error;
		}
		name->n = (int)r;
	} else {
		name->s = names;
	}

	if ( !((*flags)&AVP_VAL_STR) ) {
		/* convert value to integer */
		if (str2int(&values,&r)!=0 ) {
			LOG(L_ERR,"ERROR:auth_radius:extract_avp: invalid AVP numrical "
				"value '%.*s'\n", values.len,values.s);
			goto error;
		}
		value->n = (int)r;
	} else {
		value->s = values;
	}

	return 0;
error:
	return -1;
}


/*
 * Generate AVPs from the database result
 */
static int generate_avps(VALUE_PAIR* received)
{
	int_str name, val;
	unsigned short flags;
	VALUE_PAIR *vp;

	vp = received;

	DBG("DEBUG:auth_radius:generate_avps: getting SIP AVPs from avpair %d\n",
		attrs[A_SIP_AVP].v);

	for( ; (vp=rc_avpair_get(vp,attrs[A_SIP_AVP].v,0)) ; vp=vp->next) {
		flags = 0;
		if (extract_avp( vp, &flags, &name, &val)!=0 )
			continue;
		if (add_avp( flags, name, val) < 0) {
			LOG(L_ERR, "ERROR:auth_radius:generate_avps: Unable to create "
				"a new AVP\n");
		} else {
			DBG("DEBUG:auth_radius:generate_avps: "
				"AVP '%.*s'/%d='%.*s'/%d has been added\n",
				(flags&AVP_NAME_STR)?name.s.len:4,
				(flags&AVP_NAME_STR)?name.s.s:"null",
				(flags&AVP_NAME_STR)?0:name.n,
				(flags&AVP_VAL_STR)?val.s.len:4,
				(flags&AVP_VAL_STR)?val.s.s:"null",
				(flags&AVP_VAL_STR)?0:val.n );
		}
	}

	return 0;
}


static int add_cisco_vsa(VALUE_PAIR** send, struct sip_msg* msg)
{
	str callid;

	if (!msg->callid && parse_headers(msg, HDR_CALLID_F, 0) == -1) {
		LOG(L_ERR, "ERROR:auth_radius:add_cisco_vsa: Cannot parse "
			"Call-ID header field\n");
		return -1;
	}

	if (!msg->callid) {
		LOG(L_ERR, "ERROR:auth_radius:add_cisco_vsa: Call-ID header "
			"field not found\n");
		return -1;
	}

	callid.len = msg->callid->body.len + 8;
	callid.s = pkg_malloc(callid.len);
	if (callid.s == NULL) {
		LOG(L_ERR, "ERROR:auth_radius:add_cisco_vsa: No pkg memory left\n");
		return -1;
	}

	memcpy(callid.s, "call-id=", 8);
	memcpy(callid.s + 8, msg->callid->body.s, msg->callid->body.len);

	if (rc_avpair_add(rh, send, attrs[A_CISCO_AVPAIR].v, callid.s,
			callid.len, VENDOR(attrs[A_CISCO_AVPAIR].v)) == 0) {
		LOG(L_ERR, "ERROR:auth_radius:add_cisco_vsa: Unable to add "
			"Cisco-AVPair attribute\n");
		pkg_free(callid.s);
		return -1;
	}

	pkg_free(callid.s);
	return 0;
}


/*
 * This function creates and submits radius authentication request as per
 * draft-sterman-aaa-sip-00.txt.  In addition, _user parameter is included
 * in the request as value of a SER specific attribute type SIP-URI-User,
 * which can be be used as a check item in the request.  Service type of
 * the request is Authenticate-Only.
 */
int radius_authorize_sterman(struct sip_msg* _msg, dig_cred_t* _cred, str* _method, str* _user) 
{
	static char msg[4096];
	VALUE_PAIR *send, *received;
	UINT4 service;
	str method, user, user_name;
	int i;
	
	send = received = 0;

	if (!(_cred && _method && _user)) {
		LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: "
			"Invalid parameter value\n");
		return -1;
	}

	method = *_method;
	user = *_user;
	
	/*
	 * Add all the user digest parameters according to the qop defined.
	 * Most devices tested only offer support for the simplest digest.
	 */
	if (_cred->username.domain.len) {
		if (!rc_avpair_add(rh, &send, attrs[A_USER_NAME].v, _cred->username.whole.s, _cred->username.whole.len, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
				"to add User-Name attribute\n");
			goto err;
		}
	} else {
		user_name.len = _cred->username.user.len + _cred->realm.len + 1;
		user_name.s = pkg_malloc(user_name.len);
		if (!user_name.s) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: "
				"No pkg memory left\n");
			return -3;
		}
		memcpy(user_name.s, _cred->username.whole.s, _cred->username.whole.len);
		user_name.s[_cred->username.whole.len] = '@';
		memcpy(user_name.s + _cred->username.whole.len + 1, _cred->realm.s,
			_cred->realm.len);
		if (!rc_avpair_add(rh, &send, attrs[A_USER_NAME].v, user_name.s,
		user_name.len, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: "
				"Unable to add User-Name attribute\n");
			pkg_free(user_name.s);
			goto err;
		}
		pkg_free(user_name.s);
	}

	if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_USER_NAME].v, 
	_cred->username.whole.s, _cred->username.whole.len, 0)) {
		LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: "
			"Unable to add Digest-User-Name attribute\n");
		goto err;
	}

	if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_REALM].v, _cred->realm.s,
	_cred->realm.len, 0)) {
		LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
			"to add Digest-Realm attribute\n");
		goto err;
	}
	if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_NONCE].v, _cred->nonce.s,
	_cred->nonce.len, 0)) {
		LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
			"to add Digest-Nonce attribute\n");
		goto err;
	}
	
	if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_URI].v, _cred->uri.s,
	_cred->uri.len, 0)) {
		LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
				"to add Digest-URI attribute\n");
		goto err;
	}
	if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_METHOD].v, method.s,
	method.len, 0)) {
		LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
			"to add Digest-Method attribute\n");
		goto err;
	}
	
	/* 
	 * Add the additional authentication fields according to the QOP.
	 */
	if (_cred->qop.qop_parsed == QOP_AUTH) {
		if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_QOP].v, "auth", 4, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: "
				"Unable to add Digest-QOP attribute\n");
			goto err;
		}
		if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_NONCE_COUNT].v, 
		_cred->nc.s, _cred->nc.len, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
				"to add Digest-CNonce-Count attribute\n");
			goto err;
		}
		if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_CNONCE].v, 
		_cred->cnonce.s, _cred->cnonce.len, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
				"to add Digest-CNonce attribute\n");
			goto err;
		}
	} else if (_cred->qop.qop_parsed == QOP_AUTHINT) {
		if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_QOP].v,
		"auth-int", 8, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
				"to add Digest-QOP attribute\n");
			goto err;
		}
		if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_NONCE_COUNT].v,
		_cred->nc.s, _cred->nc.len, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
				"to add Digest-Nonce-Count attribute\n");
			goto err;
		}
		if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_CNONCE].v,
		_cred->cnonce.s, _cred->cnonce.len, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
				"to add Digest-CNonce attribute\n");
			goto err;
		}
		if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_BODY_DIGEST].v, 
		_cred->opaque.s, _cred->opaque.len, 0)) {
			LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable "
				"to add Digest-Body-Digest attribute\n");
			goto err;
		}
		
	} else  {
		/* send nothing for qop == "" */
	}

	/* Add the response... What to calculate against... */
	if (!rc_avpair_add(rh, &send, attrs[A_DIGEST_RESPONSE].v, 
	_cred->response.s, _cred->response.len, 0)) {
		LOG(L_ERR, "sterman(): Unable to add Digest-Response attribute\n");
		goto err;
	}

	/* Indicate the service type, Authenticate only in our case */
	service = vals[V_SIP_SESSION].v;
	if (!rc_avpair_add(rh, &send, attrs[A_SERVICE_TYPE].v, &service, -1, 0)) {
		LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable to "
			"add Service-Type attribute\n");
		goto err;
	}

	/* Add SIP URI as a check item */
	if (!rc_avpair_add(rh,&send,attrs[A_SIP_URI_USER].v,user.s,user.len,0)) {
		LOG(L_ERR, "ERROR:auth_radius:radius_authorize_sterman: Unable to "
			"add Sip-URI-User attribute\n");
		goto err;
	}

	if (attrs[A_CISCO_AVPAIR].n != NULL) {
		if (add_cisco_vsa(&send, _msg)) {
			goto err;
		}
	}

	/* Send request */
	if ((i = rc_auth(rh, SIP_PORT, send, &received, msg)) == OK_RC) {
		DBG("DEBUG:auth_radius:radius_authorize_sterman: Success\n");
		rc_avpair_free(send);
		send = 0;

		generate_avps(received);

		rc_avpair_free(received);
		return 1;
	} else {
		LOG(L_ERR,"ERROR:auth_radius:radius_authorize_sterman: "
			"rc_auth failed\n");
		goto err;
	}

 err:
	if (send) rc_avpair_free(send);
	if (received) rc_avpair_free(received);
	return -1;
}