/*
 * Copyright (C) 2012 Smile Communications, jason.penton@smilecoms.com
 * Copyright (C) 2012 Smile Communications, richard.good@smilecoms.com
 *
 * The initial version of this code was written by Dragos Vingarzan
 * (dragos(dot)vingarzan(at)fokus(dot)fraunhofer(dot)de and the
 * Fruanhofer Institute. It was and still is maintained in a separate
 * branch of the original SER. We are therefore migrating it to
 * Kamailio/SR and look forward to maintaining it from here on out.
 * 2011/2012 Smile Communications, Pty. Ltd.
 * ported/maintained/improved by
 * Jason Penton (jason(dot)penton(at)smilecoms.com and
 * Richard Good (richard(dot)good(at)smilecoms.com) as part of an
 * effort to add full IMS support to Kamailio/SR using a new and
 * improved architecture
 *
 * NB: Alot of this code was originally part of OpenIMSCore,
 * FhG Fokus.
 * Copyright (C) 2004-2006 FhG Fokus
 * Thanks for great work! This is an effort to
 * break apart the various CSCF functions into logically separate
 * components. We hope this will drive wider use. We also feel
 * that in this way the architecture is more complete and thereby easier
 * to manage in the Kamailio/SR environment
 *
 * 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
 *
 */

#include <string.h>
#include "../../core/ut.h"
#include "../../core/str.h"
#include "../../core/basex.h"
#include "../../core/hashes.h"
#include "../../lib/srdb1/db.h"
#include "../../lib/srdb1/db_ut.h"
#include "../../core/dprint.h"
#include "../../core/parser/digest/digest.h"
#include "../../core/parser/hf.h"
#include "../../core/parser/parser_f.h"
#include "../../core/usr_avp.h"
#include "../../core/mod_fix.h"
#include "../../core/mem/mem.h"
#include "../../core/rand/kam_rand.h"
#include "../cdp/diameter.h"
#include "../cdp/diameter_ims_code_result.h"

#include "cxdx_mar.h"
#include "cxdx_avp.h"


#include "../../lib/ims/ims_getters.h"
#include "../tm/tm_load.h"
#include "api.h"
#include "ims_auth_mod.h"
#include "authorize.h"
#include "utils.h"
#include "../../core/action.h" /* run_actions */

extern unsigned char
		registration_default_algorithm_type; /**< fixed default algorithm for registration (if none present)	*/
extern struct tm_binds tmb;
extern struct cdp_binds cdpb;

extern str
		registration_qop_str; /**< the qop options to put in the authorization challenges */
extern str
		invite_qop_str; /**< the qop options to put in the authorization challenges for INVITE*/
extern int
		av_request_at_sync; /**< how many auth vectors to request in a sync MAR 		*/
extern int
		av_request_at_once; /**< how many auth vectors to request in a MAR 				*/
extern int auth_vector_timeout;
extern int
		auth_data_timeout; /**< timeout for a hash entry to expire when empty in sec 	*/
extern int auth_used_vector_timeout;
extern int add_authinfo_hdr;
extern int max_nonce_reuse;
extern str scscf_name_str;
extern int ignore_failed_auth;
extern int av_check_only_impu;

auth_hash_slot_t *auth_data; /**< Authentication vector hash table */
static int act_auth_data_hash_size =
		0; /**< authentication vector hash table size */

static str empty_s = {0, 0};

str S_WWW = {"WWW", 3};
str S_Proxy = {"Proxy", 5};
str S_Authorization_AKA = {
		"%.*s-Authenticate: Digest realm=\"%.*s\","
		" nonce=\"%.*s\", algorithm=%.*s, ck=\"%.*s\", ik=\"%.*s\"%.*s\r\n",
		107};
str S_Authorization_MD5 = {"%.*s-Authenticate: Digest realm=\"%.*s\","
						   " nonce=\"%.*s\", algorithm=%.*s%.*s\r\n",
		102};

str algorithm_types[] = {{"unknown", 7}, {"AKAv1-MD5", 9}, {"AKAv2-MD5", 9},
		{"Early-IMS", 9}, {"MD5", 3}, {"CableLabs-Digest", 16},
		{"3GPP-Digest", 11}, {"TISPAN-HTTP_DIGEST_MD5", 22},
		{"NASS-Bundled", 12}, {0, 0}};

str auth_scheme_types[] = {{"unknown", 7}, {"Digest-AKAv1-MD5", 16},
		{"Digest-AKAv2-MD5", 16}, {"Early-IMS-Security", 18},
		{"Digest-MD5", 10}, {"Digest", 6}, {"SIP Digest", 10},
		{"HTTP_DIGEST_MD5", 15}, {"NASS-Bundled", 12}, {0, 0}};

/**
 * Convert the SIP Algorithm to its type
 * @param algorithm - the SIP Algorithm
 * @returns the algorithm type
 */
unsigned char get_algorithm_type(str algorithm)
{
	int i;
	for(i = 0; algorithm_types[i].len > 0; i++)
		if(algorithm_types[i].len == algorithm.len
				&& strncasecmp(algorithm_types[i].s, algorithm.s, algorithm.len)
						   == 0)
			return i;
	return AUTH_UNKNOWN;
}

/**
 * Convert the Diameter Authorization Scheme to its type
 * @param scheme - the Diameter Authorization Scheme
 * @returns the SIP Algorithm
 */
unsigned char get_auth_scheme_type(str scheme)
{
	int i;
	for(i = 0; auth_scheme_types[i].len > 0; i++)
		if(auth_scheme_types[i].len == scheme.len
				&& strncasecmp(auth_scheme_types[i].s, scheme.s, scheme.len)
						   == 0)
			return i;
	return AUTH_UNKNOWN;
}

/*
 * Authorize digest credentials
 */
static int digest_authenticate(
		struct sip_msg *msg, str *realm, str *table, hdr_types_t hftype)
{
	return 0;
}

/**
 * Starts the reg_await_timer for an authentication vector.
 * @param av - the authentication vector
 */
void start_reg_await_timer(auth_vector *av)
{
	av->expires = get_ticks() + auth_vector_timeout;
	av->status = AUTH_VECTOR_SENT;
}

/**
 * Timer callback for reg await timers.
 * Drops the auth vectors that have been sent and are expired
 * Also drops the useless auth vectors - used and no longer needed
 * @param ticks - what's the time
 * @param param - a given parameter to be called with
 */
void reg_await_timer(unsigned int ticks, void *param)
{
	auth_userdata *aud, *aud_next;
	auth_vector *av, *av_next;
	int i;

	LM_DBG("Looking for expired/useless at %d\n", ticks);
	for(i = 0; i < act_auth_data_hash_size; i++) {
		auth_data_lock(i);
		aud = auth_data[i].head;
		while(aud) {
			LM_DBG("Slot %4d <%.*s>\n", aud->hash, aud->private_identity.len,
					aud->private_identity.s);
			aud_next = aud->next;
			av = aud->head;
			while(av) {
				LM_DBG(".. AV %4d - %d Exp %3d  %p\n", av->item_number,
						av->status, (int)av->expires, av);
				av_next = av->next;
				if(av->status == AUTH_VECTOR_USELESS
						|| ((av->status == AUTH_VECTOR_USED
									|| av->status == AUTH_VECTOR_SENT)
								&& av->expires < ticks)) {
					LM_DBG("... dropping av %d - %d\n", av->item_number,
							av->status);
					if(av->prev)
						av->prev->next = av->next;
					else
						aud->head = av->next;
					if(av->next)
						av->next->prev = av->prev;
					else
						aud->tail = av->prev;
					free_auth_vector(av);
				}
				av = av_next;
			}
			if(!aud->head) {
				if(aud->expires == 0) {
					LM_DBG("... started empty aud drop timer\n");
					aud->expires = ticks + auth_data_timeout;
				} else if(aud->expires < ticks) {
					LM_DBG("... dropping aud \n");
					if(aud->prev)
						aud->prev->next = aud->next;
					else
						auth_data[i].head = aud->next;
					if(aud->next)
						aud->next->prev = aud->prev;
					else
						auth_data[i].tail = aud->prev;
					free_auth_userdata(aud);
				}
			} else
				aud->expires = 0;

			aud = aud_next;
		}
		auth_data_unlock(i);
	}
	LM_DBG("[DONE] Looking for expired/useless at %d\n", ticks);
}

/*
 * Authenticate using Proxy-Authorize header field
 */

/*
int proxy_authenticate(struct sip_msg* _m, char* _realm, char* _table) {
    str srealm;
    str stable;

    if (_table == NULL) {
        LM_ERR("invalid table parameter\n");
        return -1;
    }

    stable.s = _table;
    stable.len = strlen(stable.s);

    if (get_str_fparam(&srealm, _m, (fparam_t*) _realm) < 0) {
        LM_ERR("failed to get realm value\n");
        return -1; //AUTH_ERROR;
    }

    if (srealm.len == 0) {
        LM_ERR("invalid realm parameter - empty value\n");
        return -1; //AUTH_ERROR;
    }
    LM_DBG("realm value [%.*s]\n", srealm.len, srealm.s);

    return digest_authenticate(_m, &srealm, &stable, HDR_PROXYAUTH_T);
}
 */
int challenge(struct sip_msg *msg, char *str1, char *alg, int is_proxy_auth,
		char *route)
{

	str realm = {0, 0}, algo = {0, 0};
	unsigned int aud_hash;
	str private_identity, public_identity, auts = {0, 0}, nonce = {0, 0};
	auth_vector *av = 0;
	int algo_type = 0;
	str route_name;

	saved_transaction_t *saved_t;
	tm_cell_t *t = 0;
	cfg_action_t *cfg_action;

	if(fixup_get_svalue(msg, (gparam_t *)route, &route_name) != 0) {
		LM_ERR("no async route block for assign_server_unreg\n");
		return -1;
	}

	if(!alg) {
		LM_DBG("no algorithm specified in cfg... using default\n");
	} else {
		if(get_str_fparam(&algo, msg, (fparam_t *)alg) < 0) {
			LM_ERR("failed to get auth algorithm\n");
			return -1;
		}
	}

	LM_DBG("Looking for route block [%.*s]\n", route_name.len, route_name.s);
	int ri = route_get(&main_rt, route_name.s);
	if(ri < 0) {
		LM_ERR("unable to find route block [%.*s]\n", route_name.len,
				route_name.s);
		return -1;
	}
	cfg_action = main_rt.rlist[ri];
	if(cfg_action == NULL) {
		LM_ERR("empty action lists in route block [%.*s]\n", route_name.len,
				route_name.s);
		return -1;
	}

	if(get_str_fparam(&realm, msg, (fparam_t *)str1) < 0) {
		LM_ERR("failed to get realm value\n");
		return CSCF_RETURN_ERROR;
	}

	if(realm.len == 0) {
		LM_ERR("invalid realm value - empty content\n");
		return CSCF_RETURN_ERROR;
	}

	create_return_code(CSCF_RETURN_ERROR);

	LM_DBG("Need to challenge for realm [%.*s]\n", realm.len, realm.s);

	if(msg->first_line.type != SIP_REQUEST) {
		LM_ERR("This message is not a request\n");
		return CSCF_RETURN_ERROR;
	}
	if(!is_proxy_auth) {
		LM_DBG("Checking if REGISTER is authorized for realm [%.*s]...\n",
				realm.len, realm.s);

		/* First check the parameters */
		if(msg->first_line.u.request.method.len != 8
				|| memcmp(msg->first_line.u.request.method.s, "REGISTER", 8)
						   != 0) {
			LM_ERR("This message is not a REGISTER request\n");
			return CSCF_RETURN_ERROR;
		}
	}

	/* get the private_identity */
	if(is_proxy_auth)
		private_identity = cscf_get_private_identity_from(msg, realm);
	else
		private_identity = cscf_get_private_identity(msg, realm);
	if(!private_identity.len) {
		LM_ERR("No private identity specified (Authorization: username)\n");
		stateful_request_reply(msg, 403, MSG_403_NO_PRIVATE);
		return CSCF_RETURN_BREAK;
	}
	/* get the public_identity */
	if(is_proxy_auth)
		public_identity = cscf_get_public_identity_from(msg);
	else
		public_identity = cscf_get_public_identity(msg);

	if(!public_identity.len) {
		LM_ERR("No public identity specified (To:)\n");
		stateful_request_reply(msg, 403, MSG_403_NO_PUBLIC);
		return CSCF_RETURN_BREAK;
	}

	if(algo.len > 0) {
		algo_type = get_algorithm_type(algo);
	} else {
		algo_type = registration_default_algorithm_type;
	}

	//    /* check if it is a synchronization request */
	//    //TODO this is MAR syncing - have removed it currently - TOD maybe put back in
	//    auts = ims_get_auts(msg, realm, is_proxy_auth);
	//    if (auts.len) {
	//        LM_DBG("IMS Auth Synchronization requested <%.*s>\n", auts.len, auts.s);
	//
	//        nonce = ims_get_nonce(msg, realm);
	//        if (nonce.len == 0) {
	//            LM_DBG("Nonce not found (Authorization: nonce)\n");
	//            stateful_request_reply(msg, 403, MSG_403_NO_NONCE);
	//            return CSCF_RETURN_BREAK;
	//        }
	//        av = get_auth_vector(private_identity, public_identity, AUTH_VECTOR_USED, &nonce, &aud_hash);
	//        if (!av)
	//            av = get_auth_vector(private_identity, public_identity, AUTH_VECTOR_SENT, &nonce, &aud_hash);
	//
	//        if (!av) {
	//            LM_ERR("nonce not recognized as sent, no sync!\n");
	//            auts.len = 0;
	//            auts.s = 0;
	//        } else {
	//            av->status = AUTH_VECTOR_USELESS;
	//            auth_data_unlock(aud_hash);
	//            av = 0;
	//            resync = 1;
	//        }
	//    }

	//RICHARD changed this
	//Previous approach sent MAR, got MAA then put auth vectors into queue
	//Then we try and get that auth vector out the queue (it might be used by someone else so we loop)
	//new approach
	//we do MAR get MAA (asynchronously) get auth vector use it to pack the vector etc.
	//set it to sent and set an expires on it
	//then add it to the queue!

	/* loop because some other process might steal the auth_vector that we just retrieved */
	//while (!(av = get_auth_vector(private_identity, public_identity, AUTH_VECTOR_UNUSED, 0, &aud_hash))) {

	if((av = get_auth_vector(private_identity, public_identity,
				AUTH_VECTOR_UNUSED, 0, &aud_hash))) {
		if(!av) {
			LM_ERR("Error retrieving an auth vector\n");
			return CSCF_RETURN_ERROR;
		}

		if(!pack_challenge(msg, realm, av, is_proxy_auth)) {
			stateful_request_reply(msg, 500, MSG_500_PACK_AV);
			auth_data_unlock(aud_hash);
			return CSCF_RETURN_ERROR;
		}

		start_reg_await_timer(
				av); //start the timer to remove stale or unused Auth Vectors
		if(is_proxy_auth) {
			stateful_request_reply(msg, 407, MSG_407_CHALLENGE);
		} else {
			stateful_request_reply(msg, 401, MSG_401_CHALLENGE);
		}
		auth_data_unlock(aud_hash);

	} else {

		//before we send lets suspend the transaction
		t = tmb.t_gett();
		if(t == NULL || t == T_UNDEFINED) {
			if(tmb.t_newtran(msg) < 0) {
				LM_ERR("cannot create the transaction for MAR async\n");
				stateful_request_reply(msg, 480, MSG_480_DIAMETER_ERROR);
				return CSCF_RETURN_BREAK;
			}
			t = tmb.t_gett();
			if(t == NULL || t == T_UNDEFINED) {
				LM_ERR("cannot lookup the transaction\n");
				stateful_request_reply(msg, 480, MSG_480_DIAMETER_ERROR);
				return CSCF_RETURN_BREAK;
			}
		}

		saved_t = shm_malloc(sizeof(saved_transaction_t));
		if(!saved_t) {
			LM_ERR("no more memory trying to save transaction state\n");
			return CSCF_RETURN_ERROR;
		}
		memset(saved_t, 0, sizeof(saved_transaction_t));
		saved_t->act = cfg_action;

		saved_t->realm.s = (char *)shm_malloc(realm.len + 1);
		if(!saved_t->realm.s) {
			LM_ERR("no more memory trying to save transaction state : "
				   "callid\n");
			shm_free(saved_t);
			return CSCF_RETURN_ERROR;
		}
		memset(saved_t->realm.s, 0, realm.len + 1);
		memcpy(saved_t->realm.s, realm.s, realm.len);
		saved_t->realm.len = realm.len;

		saved_t->is_proxy_auth = is_proxy_auth;

		LM_DBG("Suspending SIP TM transaction\n");
		if(tmb.t_suspend(msg, &saved_t->tindex, &saved_t->tlabel) != 0) {
			LM_ERR("failed to suspend the TM processing\n");
			free_saved_transaction_data(saved_t);
			stateful_request_reply(msg, 480, MSG_480_DIAMETER_ERROR);
			return CSCF_RETURN_BREAK;
		}

		if(multimedia_auth_request(msg, public_identity, private_identity,
				   av_request_at_once, auth_scheme_types[algo_type], nonce,
				   auts, scscf_name_str, saved_t)
				!= 0) {
			LM_ERR("ERR:I_MAR: Error sending MAR or MAR time-out\n");
			tmb.t_cancel_suspend(saved_t->tindex, saved_t->tlabel);
			free_saved_transaction_data(saved_t);
			stateful_request_reply(msg, 480, MSG_480_DIAMETER_ERROR);
			return CSCF_RETURN_BREAK;
		}
	}
	return CSCF_RETURN_BREAK;
}
int www_challenge2(struct sip_msg *msg, char *_route, char *str1, char *str2)
{
	return challenge(msg, str1, 0, 0, _route);
}

int www_challenge3(struct sip_msg *msg, char *_route, char *str1, char *str2)
{
	return challenge(msg, str1, str2, 0, _route);
}

int www_resync_auth(struct sip_msg *msg, char *_route, char *str1, char *str2)
{

	str realm = {0, 0};
	unsigned int aud_hash;
	str private_identity, public_identity, auts = {0, 0}, nonce = {0, 0};
	auth_vector *av = 0;
	int algo_type;
	int is_proxy_auth = 0;
	str route_name;

	saved_transaction_t *saved_t;
	tm_cell_t *t = 0;
	cfg_action_t *cfg_action;

	if(fixup_get_svalue(msg, (gparam_t *)_route, &route_name) != 0) {
		LM_ERR("no async route block for assign_server_unreg\n");
		return -1;
	}

	LM_DBG("Looking for route block [%.*s]\n", route_name.len, route_name.s);
	int ri = route_get(&main_rt, route_name.s);
	if(ri < 0) {
		LM_ERR("unable to find route block [%.*s]\n", route_name.len,
				route_name.s);
		return -1;
	}
	cfg_action = main_rt.rlist[ri];
	if(cfg_action == NULL) {
		LM_ERR("empty action lists in route block [%.*s]\n", route_name.len,
				route_name.s);
		return -1;
	}

	if(get_str_fparam(&realm, msg, (fparam_t *)str1) < 0) {
		LM_ERR("failed to get realm value\n");
		return CSCF_RETURN_ERROR;
	}

	if(realm.len == 0) {
		LM_ERR("invalid realm value - empty content\n");
		return CSCF_RETURN_ERROR;
	}

	create_return_code(CSCF_RETURN_ERROR);

	if(msg->first_line.type != SIP_REQUEST) {
		LM_ERR("This message is not a request\n");
		return CSCF_RETURN_ERROR;
	}

	/* get the private_identity */
	private_identity = cscf_get_private_identity(msg, realm);
	if(!private_identity.len) {
		LM_ERR("No private identity specified (Authorization: username)\n");
		stateful_request_reply(msg, 403, MSG_403_NO_PRIVATE);
		return CSCF_RETURN_BREAK;
	}
	/* get the public_identity */
	public_identity = cscf_get_public_identity(msg);
	if(!public_identity.len) {
		LM_ERR("No public identity specified (To:)\n");
		stateful_request_reply(msg, 403, MSG_403_NO_PUBLIC);
		return CSCF_RETURN_BREAK;
	}

	algo_type = registration_default_algorithm_type;

	/* check if it is a synchronization request */
	//TODO this is MAR syncing - have removed it currently - TOD maybe put back in
	auts = ims_get_auts(msg, realm, is_proxy_auth);
	if(auts.len) {
		LM_DBG("IMS Auth Synchronization requested <%.*s>\n", auts.len, auts.s);

		nonce = ims_get_nonce(msg, realm);
		if(nonce.len == 0) {
			LM_DBG("Nonce not found (Authorization: nonce)\n");
			stateful_request_reply(msg, 403, MSG_403_NO_NONCE);
			return CSCF_RETURN_BREAK;
		}
		av = get_auth_vector(private_identity, public_identity,
				AUTH_VECTOR_USED, &nonce, &aud_hash);
		if(!av)
			av = get_auth_vector(private_identity, public_identity,
					AUTH_VECTOR_SENT, &nonce, &aud_hash);

		if(!av) {
			LM_ERR("nonce not recognized as sent, no sync!\n");
			auts.len = 0;
			auts.s = 0;
		} else {
			av->status = AUTH_VECTOR_USELESS;
			auth_data_unlock(aud_hash);
			av = 0;
		}
	}

	//before we send lets suspend the transaction
	t = tmb.t_gett();
	if(t == NULL || t == T_UNDEFINED) {
		if(tmb.t_newtran(msg) < 0) {
			LM_ERR("cannot create the transaction for MAR async\n");
			stateful_request_reply(msg, 480, MSG_480_DIAMETER_ERROR);
			return CSCF_RETURN_BREAK;
		}
		t = tmb.t_gett();
		if(t == NULL || t == T_UNDEFINED) {
			LM_ERR("cannot lookup the transaction\n");
			stateful_request_reply(msg, 480, MSG_480_DIAMETER_ERROR);
			return CSCF_RETURN_BREAK;
		}
	}

	saved_t = shm_malloc(sizeof(saved_transaction_t));
	if(!saved_t) {
		LM_ERR("no more memory trying to save transaction state\n");
		return CSCF_RETURN_ERROR;
	}
	memset(saved_t, 0, sizeof(saved_transaction_t));
	saved_t->act = cfg_action;

	saved_t->realm.s = (char *)shm_malloc(realm.len + 1);
	if(!saved_t->realm.s) {
		LM_ERR("no more memory trying to save transaction state : callid\n");
		shm_free(saved_t);
		return CSCF_RETURN_ERROR;
	}
	memset(saved_t->realm.s, 0, realm.len + 1);
	memcpy(saved_t->realm.s, realm.s, realm.len);
	saved_t->realm.len = realm.len;

	saved_t->is_proxy_auth = is_proxy_auth;
	saved_t->is_resync = 1;

	LM_DBG("Suspending SIP TM transaction\n");
	if(tmb.t_suspend(msg, &saved_t->tindex, &saved_t->tlabel) < 0) {
		LM_ERR("failed to suspend the TM processing\n");
		free_saved_transaction_data(saved_t);

		stateful_request_reply(msg, 480, MSG_480_DIAMETER_ERROR);
		return CSCF_RETURN_BREAK;
	}

	if(multimedia_auth_request(msg, public_identity, private_identity,
			   av_request_at_sync, auth_scheme_types[algo_type], nonce, auts,
			   scscf_name_str, saved_t)
			!= 0) {
		LM_ERR("ERR:I_MAR: Error sending MAR or MAR time-out\n");
		tmb.t_cancel_suspend(saved_t->tindex, saved_t->tlabel);
		free_saved_transaction_data(saved_t);
		stateful_request_reply(msg, 480, MSG_480_DIAMETER_ERROR);
		return CSCF_RETURN_BREAK;
	}

	return CSCF_RETURN_BREAK;
}

int proxy_challenge(struct sip_msg *msg, char *_route, char *str1, char *str2)
{
	return challenge(msg, str1, str2, 1, _route);
}

/**
 * Replies to a REGISTER and also adds the need headers
 * Path and Service-Route are added.
 * @param msg - the SIP message to operator on
 * @param code - Reason Code for the response
 * @param text - Reason Phrase for the response
 * @returns #CSCF_RETURN_TRUE on success or #CSCF_RETURN_FALSE if not added
 */
int stateful_request_reply(struct sip_msg *msg, int code, char *text)
{
	unsigned int hash, label;
	struct hdr_field *h;
	str t = {0, 0};
	if(parse_headers(msg, HDR_EOH_F, 0) < 0) {
		LM_ERR("Error parsing headers\n");
		return -1;
	}
	h = msg->headers;
	while(h) {
		if(h->name.len == 4 && strncasecmp(h->name.s, "Path", 4) == 0) {
			t.s = h->name.s;
			t.len = h->len;
			ims_add_header_rpl(msg, &(t));
		}
		h = h->next;
	}

	/*if (code==200){
            ims_add_header_rpl(msg,&scscf_service_route);
    }*/ //TODO: need to get the service route from somewhere - registrar?


	if(tmb.t_get_trans_ident(msg, &hash, &label) < 0) {
		if(tmb.t_newtran(msg) < 0)
			LM_INFO("Failed creating SIP transaction\n");
	}
	return tmb.t_reply(msg, code, text);
}

/**
 * Replies to a REGISTER and also adds the need headers
 * Path and Service-Route are added.
 * @param msg - the SIP message to operator on
 * @param code - Reason Code for the response
 * @param text - Reason Phrase for the response
 * @returns #CSCF_RETURN_TRUE on success or #CSCF_RETURN_FALSE if not added
 */

int stateful_request_reply_async(
		struct cell *t_cell, struct sip_msg *msg, int code, char *text)
{
	struct hdr_field *h;
	str t = {0, 0};
	if(parse_headers(msg, HDR_EOH_F, 0) < 0) {
		LM_ERR("Error parsing headers\n");
		return -1;
	}
	h = msg->headers;
	while(h) {
		if(h->name.len == 4 && strncasecmp(h->name.s, "Path", 4) == 0) {
			t.s = h->name.s;
			t.len = h->len;
			ims_add_header_rpl(msg, &(t));
		}
		h = h->next;
	}

	return tmb.t_reply_trans(t_cell, msg, code, text);
}

int authenticate(
		struct sip_msg *msg, char *_realm, char *str2, int is_proxy_auth)
{
	int ret = -1; //CSCF_RETURN_FALSE;
	unsigned int aud_hash = 0;
	str realm;
	str private_identity, public_identity, username;
	str nonce, response16, nc, cnonce, qop_str = {0, 0}, auts = {0, 0}, body,
									   *next_nonce = &empty_s;
	enum qop_type qop = QOP_UNSPEC;
	str uri = {0, 0};
	HASHHEX expected, ha1, hbody = {0}, rspauth;
	int expected_len = 32;
	int expires = 0;
	auth_vector *av = 0;
	uint32_t nc_parsed = 0; /* the numerical representation of nc */

	LM_DBG("Running authenticate, is_proxy_auth=%d\n", is_proxy_auth);

	ret = AUTH_ERROR;

	if(get_str_fparam(&realm, msg, (fparam_t *)_realm) < 0) {
		LM_ERR("failed to get realm value\n");
		return AUTH_NO_CREDENTIALS;
	}

	if(realm.len == 0) {
		LM_ERR("invalid realm value - empty content\n");
		return AUTH_NO_CREDENTIALS;
	}

	if(msg->first_line.type != SIP_REQUEST) {
		LM_ERR("This message is not a request\n");
		ret = AUTH_ERROR;
		goto end;
	}
	if(!is_proxy_auth) {
		LM_DBG("Checking if REGISTER is authorized for realm [%.*s]...\n",
				realm.len, realm.s);

		/* First check the parameters */
		if(msg->first_line.u.request.method.len != 8
				|| memcmp(msg->first_line.u.request.method.s, "REGISTER", 8)
						   != 0) {
			LM_ERR("This message is not a REGISTER request\n");
			ret = AUTH_ERROR;
			goto end;
		}
	}

	if(!realm.len) {
		LM_ERR("No realm found\n");
		return 0; //CSCF_RETURN_BREAK;
	}

	if(is_proxy_auth) {
		private_identity = cscf_get_private_identity_from(msg, realm);
	} else {
		private_identity = cscf_get_private_identity(msg, realm);
	}
	if(!private_identity.len) {
		LM_ERR("private identity missing\n");
		return AUTH_NO_CREDENTIALS;
	}

	if(is_proxy_auth)
		public_identity = cscf_get_public_identity_from(msg);
	else
		public_identity = cscf_get_public_identity(msg);

	if(!public_identity.len) {
		LM_ERR("public identity missing\n");
		return AUTH_NO_CREDENTIALS;
	}

	if(!get_nonce_response(msg, &username, realm, &nonce, &response16, &qop,
			   &qop_str, &nc, &cnonce, &uri, is_proxy_auth)
			|| !nonce.len || !response16.len) {
		LM_DBG("Nonce or response missing: nonce len [%i], response16 "
			   "len[%i]\n",
				nonce.len, response16.len);
		return AUTH_ERROR;
	}

	if(qop == QOP_AUTHINT) {
		body = ims_get_body(msg);
		calc_H(&body, hbody);
	}

	/* first, look for an already used vector (if nonce reuse is enabled) */
	if(max_nonce_reuse > 0) {
		LM_DBG("look for an already used vector for %.*s\n",
				private_identity.len, private_identity.s);
		av = get_auth_vector(private_identity, public_identity,
				AUTH_VECTOR_USED, &nonce, &aud_hash);
	}

	if(!av) {
		/* if none found, or nonce reuse is disabled, look for a fresh vector
         * We should also drop every other used vector at this point
         * (there souldn't be more than one) */
		LM_DBG("Looking for auth vector based on IMPI: [%.*s] and IMPU: "
			   "[%.*s]\n",
				private_identity.len, private_identity.s, public_identity.len,
				public_identity.s);
		auth_userdata *aud;
		auth_vector *av_it;
		aud = get_auth_userdata(private_identity, public_identity);
		if(aud) {
			av_it = aud->head;
			while(av_it) {
				if(av_it->status == AUTH_VECTOR_USED) {
					LM_DBG("vector %p is marked for deletion\n", av_it);
					av_it->status = AUTH_VECTOR_USELESS;
				}
				av_it = av_it->next;
			}
			auth_data_unlock(aud->hash);
		}

		LM_DBG("look for a fresh vector for %.*s\n", private_identity.len,
				private_identity.s);
		av = get_auth_vector(private_identity, public_identity,
				AUTH_VECTOR_SENT, &nonce, &aud_hash);
	}

	LM_INFO("uri=%.*s nonce=%.*s response=%.*s qop=%.*s nc=%.*s cnonce=%.*s "
			"hbody=%.*s\n",
			uri.len, uri.s, nonce.len, nonce.s, response16.len, response16.s,
			qop_str.len, qop_str.s, nc.len, nc.s, cnonce.len, cnonce.s, 32,
			hbody);

	if(!av) {
		LM_DBG("no matching auth vector found - maybe timer expired\n");

		if(ignore_failed_auth) {
			LM_WARN("NB: Ignoring all failed auth - check your config if you "
					"don't expect this\n");
			ret = AUTH_OK;
		}

		goto end;
	}

	if(qop != QOP_UNSPEC) {
		/* if QOP is sent, nc must be specified */
		/* the expected nc is the last used one plus 1 */
		int p;
		if(!nc.s || nc.len < 8) {
			LM_ERR("qop specified with no nonce count... failing\n");
			goto cleanup;
		}
		for(p = 0; p < 8; ++p) { /* nc is 8LHEX (RFC 2617 §3.2.2) */
			nc_parsed = (nc_parsed << 4) | UNHEX((int)nc.s[p]);
		}
		LM_DBG("nc is %08x, expected: %08x\n", nc_parsed, av->use_nb + 1);
		if(nc_parsed <= av->use_nb) { /* nc is lower than expected */
			ret = AUTH_NONCE_REUSED;
			av->status =
					AUTH_VECTOR_USELESS; /* invalidate this vector if any mistake/error occurs */
			goto cleanup;
		} else if(nc_parsed > av->use_nb + 1) { /* nc is bigger than expected */
			ret = AUTH_ERROR;
			av->status = AUTH_VECTOR_USELESS;
			goto cleanup;
		}
	}

	switch(av->type) {
		case AUTH_AKAV1_MD5:
		case AUTH_AKAV2_MD5:
		case AUTH_MD5:
			calc_HA1(HA_MD5, &username /*&private_identity*/, &realm,
					&(av->authorization), &(av->authenticate), &cnonce, ha1);
			calc_response(ha1, &(av->authenticate), &nc, &cnonce, &qop_str,
					qop == QOP_AUTHINT, &msg->first_line.u.request.method, &uri,
					hbody, expected);
			LM_INFO("UE said: %.*s and we expect %.*s ha1 %.*s (%.*s)\n",
					response16.len, response16.s,
					/*av->authorization.len,av->authorization.s,*/ 32, expected,
					32, ha1, msg->first_line.u.request.method.len,
					msg->first_line.u.request.method.s);
			break;
		case AUTH_SIP_DIGEST:
		case AUTH_DIGEST:
			// memcpy of received HA1
			memcpy(ha1, av->authorization.s, HASHHEXLEN);
			calc_response(ha1, &(av->authenticate), &nc, &cnonce, &qop_str,
					qop == QOP_AUTHINT, &msg->first_line.u.request.method, &uri,
					hbody, expected);
			LM_INFO("UE said: %.*s and we expect %.*s ha1 %.*s (%.*s)\n",
					response16.len, response16.s, 32, expected, 32, ha1,
					msg->first_line.u.request.method.len,
					msg->first_line.u.request.method.s);
			break;
		default:
			LM_ERR("algorithm %.*s is not handled.\n",
					algorithm_types[av->type].len, algorithm_types[av->type].s);
			ret = AUTH_ERROR;
			goto cleanup; /* release aud before returning */
	}

	expires = cscf_get_max_expires(msg, 0);

	if(response16.len == expected_len
			&& strncasecmp(response16.s, expected, response16.len) == 0) {
		if(max_nonce_reuse > 0 && av->status == AUTH_VECTOR_SENT) {
			/* first use of a reusable vector */
			/* set the vector's new timeout */
			LM_DBG("vector %p now expires in %d seconds\n", av,
					auth_used_vector_timeout);
			av->expires = get_ticks() + auth_used_vector_timeout;
		}
		av->use_nb++;
		LM_DBG("vector %p successfully used %d time(s)\n", av, av->use_nb);

		if(av->use_nb == max_nonce_reuse + 1) {
			LM_DBG("vector %p isn't fresh anymore, recycle it with a new "
				   "nonce\n",
					av);

			int i;
			char y[NONCE_LEN];
			for(i = 0; i < NONCE_LEN; i++)
				y[i] = (unsigned char)((
						int)(256.0 * kam_rand() / (KAM_RAND_MAX + 1.0)));

			if(unlikely((av->authenticate.len < 2 * NONCE_LEN))) {
				if(av->authenticate.s) {
					shm_free(av->authenticate.s);
				}
				av->authenticate.len = 2 * NONCE_LEN;
				av->authenticate.s = shm_malloc(av->authenticate.len);
			}

			if(!av->authenticate.s) {
				LM_ERR("new_auth_vector: failed allocating %d bytes!\n",
						av->authenticate.len);
				av->authenticate.len = 0;
				goto cleanup;
			}

			av->authenticate.len =
					bin_to_base16(y, NONCE_LEN, av->authenticate.s);

			next_nonce = &(av->authenticate);
			av->status = AUTH_VECTOR_USED;
			av->use_nb = 0;
			av->expires = get_ticks()
						  + auth_used_vector_timeout; /* reset the timer */

		} else if(expires == 0) { /* de-registration */
			LM_DBG("de-registration, vector %p isn't needed anymore\n", av);
			av->status = AUTH_VECTOR_USELESS;
		} else {
			av->status = AUTH_VECTOR_USED;
			/* nextnonce is the current nonce */
			next_nonce = &nonce;
		}
		ret = AUTH_OK;

		if(add_authinfo_hdr
				&& expires != 0 /* don't add auth. info if de-registation */) {
			/* calculate rspauth */
			calc_response(ha1, &nonce, &nc, &cnonce, &qop_str,
					qop == QOP_AUTHINT, 0, &uri, hbody, rspauth);

			add_authinfo_resp_hdr(
					msg, *next_nonce, qop_str, rspauth, cnonce, nc);
		}


	} else {
		char authorise[200];
		char authenticate_bin[200];
		char authenticate_hex[200];
		memset(authorise, 0, 200);
		memset(authenticate_bin, 0, 200);
		memset(authenticate_hex, 0, 200);

		int authorise_len = bin_to_base16(
				av->authorization.s, av->authorization.len, authorise);
		int authenticate_len = base64_to_bin(
				av->authenticate.s, av->authenticate.len, authenticate_bin);
		int authenticate_hex_len = bin_to_base16(
				authenticate_bin, authenticate_len, authenticate_hex);
		av->status =
				AUTH_VECTOR_USELESS; /* first mistake, you're out! (but maybe it's synchronization) */
		LM_DBG("UE said: %.*s, but we expect %.*s : authenticate(b64) is "
			   "[%.*s], authenticate(hex) is [%.*s], authorise is [%d] "
			   "[%.*s]\n",
				response16.len, response16.s, 32, expected,
				av->authenticate.len, av->authenticate.s, authenticate_hex_len,
				authenticate_hex, authorise_len, authorise_len, authorise);
		//        /* check for auts in authorization header - if it is then we need to resync */
		auts = ims_get_auts(msg, realm, is_proxy_auth);
		if(auts.len) {
			LM_DBG("IMS Auth Synchronization requested <%.*s>\n", auts.len,
					auts.s);
			ret = AUTH_RESYNC_REQUESTED;
			av->status = AUTH_VECTOR_SENT;
		} else {
			ret = AUTH_INVALID_PASSWORD;
		}
	}

	if(ignore_failed_auth) {
		LM_WARN("NB: Ignoring all failed auth - check your config if you don't "
				"expect this\n");
		ret = AUTH_OK;
	}

cleanup:
	auth_data_unlock(aud_hash);
end:
	return ret;
}

/*
 * Authenticate using WWW-Authorize header field
 */
int www_authenticate(struct sip_msg *msg, char *_realm, char *str2)
{
	return authenticate(msg, _realm, str2, 0);
}

/*
 * Authenticate using WWW-Authorize header field
 */
int proxy_authenticate(struct sip_msg *msg, char *_realm, char *str2)
{
	return authenticate(msg, _realm, str2, 1);
}

/**
 * @brief bind functions to IMS AUTH API structure
 */
int bind_ims_auth(ims_auth_api_t *api)
{
	if(!api) {
		ERR("Invalid parameter value\n");
		return -1;
	}
	api->digest_authenticate = digest_authenticate;

	return 0;
}

/**
 * Retrieve an authentication vector.
 * \note returns with a lock, so unlock it when done
 * @param private_identity - the private identity
 * @param public_identity - the public identity
 * @param status - the status of the authentication vector
 * @param nonce - the nonce in the auth vector
 * @param hash - the hash to unlock when done
 * @returns the auth_vector* if found or NULL if not
 */
auth_vector *get_auth_vector(str private_identity, str public_identity,
		int status, str *nonce, unsigned int *hash)
{
	auth_userdata *aud;
	auth_vector *av;
	aud = get_auth_userdata(private_identity, public_identity);
	if(!aud) {
		LM_ERR("no auth userdata\n");
		goto error;
	}

	av = aud->head;
	while(av) {
		LM_DBG("looping through AV status is %d and were looking for %d\n",
				av->status, status);
		if(av->status == status
				&& (nonce == 0
						|| (nonce->len == av->authenticate.len
								&& memcmp(nonce->s, av->authenticate.s,
										   nonce->len)
										   == 0))) {
			LM_DBG("Found result\n");
			*hash = aud->hash;
			return av;
		}
		av = av->next;
	}

error:
	if(aud)
		auth_data_unlock(aud->hash);
	return 0;
}

/**
 * Locks the required slot of the auth_data.
 * @param hash - the index of the slot
 */
void auth_data_lock(unsigned int hash)
{
	lock_get(auth_data[(hash)].lock);
}

/**
 * UnLocks the required slot of the auth_data
 * @param hash - the index of the slot
 */
void auth_data_unlock(unsigned int hash)
{
	lock_release(auth_data[(hash)].lock);
}

/**
 * Initializes the Authorization Data structures.
 * @param size - size of the hash table
 * @returns 1 on success or 0 on error
 */
int auth_data_init(int size)
{
	int i;
	auth_data = shm_malloc(sizeof(auth_hash_slot_t) * size);
	if(!auth_data) {
		LM_ERR("error allocating mem\n");
		return 0;
	}
	memset(auth_data, 0, sizeof(auth_hash_slot_t) * size);
	for(i = 0; i < size; i++) {
		auth_data[i].lock = lock_alloc();
		lock_init(auth_data[i].lock);
	}
	act_auth_data_hash_size = size;
	return 1;
}

/**
 * Destroy the Authorization Data structures */
void auth_data_destroy()
{
	int i;
	auth_userdata *aud, *next;
	for(i = 0; i < act_auth_data_hash_size; i++) {
		auth_data_lock(i);
		lock_destroy(auth_data[i].lock);
		lock_dealloc(auth_data[i].lock);
		aud = auth_data[i].head;
		while(aud) {
			next = aud->next;
			free_auth_userdata(aud);
			aud = next;
		}
	}
	if(auth_data)
		shm_free(auth_data);
}

/**
 * Create new authorization vector
 * @param item_number - number to index it in the vectors list
 * @param auth_scheme - Diameter Authorization Scheme
 * @param authenticate - the challenge
 * @param authorization - the expected response
 * @param ck - the cypher key
 * @param ik - the integrity key
 * @returns the new auth_vector* or NULL on error
 */
auth_vector *new_auth_vector(int item_number, str auth_scheme, str authenticate,
		str authorization, str ck, str ik)
{
	auth_vector *x = 0;
	char base16_ck[32 + 1] = {0};
	int base16_ck_len = 0;
	x = shm_malloc(sizeof(auth_vector));
	if(!x) {
		LM_ERR("error allocating mem\n");
		goto done;
	}
	memset(x, 0, sizeof(auth_vector));
	x->item_number = item_number;
	x->type = get_auth_scheme_type(auth_scheme);
	switch(x->type) {
		case AUTH_AKAV1_MD5:
		case AUTH_AKAV2_MD5:
			/* AKA */
			x->authenticate.len = authenticate.len * 4 / 3 + 4;
			x->authenticate.s = shm_malloc(x->authenticate.len);
			if(!x->authenticate.s) {
				LM_ERR("error allocating mem\n");
				goto done;
			}
			x->authenticate.len = bin_to_base64(
					authenticate.s, authenticate.len, x->authenticate.s);

			x->authorization.len = authorization.len;
			x->authorization.s = shm_malloc(x->authorization.len);
			if(!x->authorization.s) {
				LM_ERR("error allocating mem\n");
				goto done;
			}
			memcpy(x->authorization.s, authorization.s, authorization.len);
			x->ck.len = ck.len;
			x->ck.s = shm_malloc(ck.len);
			if(!x->ck.s) {
				LM_ERR("error allocating mem\n");
				goto done;
			}
			memcpy(x->ck.s, ck.s, ck.len);

			x->ik.len = ik.len;
			x->ik.s = shm_malloc(ik.len);
			if(!x->ik.s) {
				LM_ERR("error allocating mem\n");
				goto done;
			}
			memcpy(x->ik.s, ik.s, ik.len);
			break;

		case AUTH_MD5:
			/* MD5 */
			x->authenticate.len = authenticate.len * 2;
			x->authenticate.s = shm_malloc(x->authenticate.len);
			if(!x->authenticate.s) {
				LM_ERR("new_auth_vector: error allocating mem\n");
				goto done;
			}
			x->authenticate.len = bin_to_base16(
					authenticate.s, authenticate.len, x->authenticate.s);

			x->authorization.len = authorization.len;
			x->authorization.s = shm_malloc(x->authorization.len);
			if(!x->authorization.s) {
				LM_ERR("new_auth_vector: error allocating mem\n");
				goto done;
			}
			memcpy(x->authorization.s, authorization.s, authorization.len);
			x->authorization.len = authorization.len;
			break;
		case AUTH_DIGEST:
		case AUTH_SIP_DIGEST: {
			int i;
			char y[NONCE_LEN];
			for(i = 0; i < NONCE_LEN; i++)
				y[i] = (unsigned char)((
						int)(256.0 * kam_rand() / (KAM_RAND_MAX + 1.0)));
			x->authenticate.len = 2 * NONCE_LEN;
			x->authenticate.s = shm_malloc(x->authenticate.len);
			if(!x->authenticate.s) {
				LM_ERR("new_auth_vector: failed allocating %d bytes!\n",
						x->authenticate.len);
				x->authenticate.len = 0;
				goto done;
			}
			x->authenticate.len =
					bin_to_base16(y, NONCE_LEN, x->authenticate.s);
		}

			x->authorization.len = authorization.len;
			x->authorization.s = shm_malloc(x->authorization.len);
			if(!x->authorization.s) {
				LM_ERR("new_auth_vector: error allocating mem\n");
				x->authorization.len = 0;
				goto done;
			}
			memcpy(x->authorization.s, authorization.s, authorization.len);
			x->authorization.len = authorization.len;

			break;
		case AUTH_HTTP_DIGEST_MD5:
			x->authenticate.len = authenticate.len;
			x->authenticate.s = shm_malloc(x->authenticate.len);
			if(!x->authenticate.s) {
				LM_ERR("new_auth_vector: error allocating mem\n");
				x->authenticate.len = 0;
				goto done;
			}
			memcpy(x->authenticate.s, authenticate.s, authenticate.len);

			x->authorization.len = authorization.len;
			x->authorization.s = shm_malloc(x->authorization.len);
			if(!x->authorization.s) {
				LM_ERR("new_auth_vector: error allocating mem\n");
				x->authorization.len = 0;
				goto done;
			}
			memcpy(x->authorization.s, authorization.s, authorization.len);
			break;
		case AUTH_EARLY_IMS:
			/* early IMS */
			x->authenticate.len = 0;
			x->authenticate.s = 0;
			x->authorization.len = authorization.len;
			x->authorization.s = shm_malloc(x->authorization.len);
			if(!x->authorization.s) {
				LM_ERR("new_auth_vector: error allocating mem\n");
				goto done;
			}
			memcpy(x->authorization.s, authorization.s, authorization.len);
			x->authorization.len = authorization.len;
			break;
		case AUTH_NASS_BUNDLED:
			/* NASS-Bundled */
			x->authenticate.len = 0;
			x->authenticate.s = 0;
			x->authorization.len = authorization.len;
			x->authorization.s = shm_malloc(x->authorization.len);
			if(!x->authorization.s) {
				LM_ERR("new_auth_vector: error allocating mem\n");
				goto done;
			}
			memcpy(x->authorization.s, authorization.s, authorization.len);
			x->authorization.len = authorization.len;
			break;

		default:
			/* all else */
			x->authenticate.len = 0;
			x->authenticate.s = 0;
	}

	x->use_nb = 0;

	x->next = 0;
	x->prev = 0;
	x->status = AUTH_VECTOR_UNUSED;
	x->expires = 0;

	if(x->ck.len > 0 && x->ck.s) {
		base16_ck_len = bin_to_base16(x->ck.s, 16, base16_ck);
		if(base16_ck_len)
			LM_DBG("new auth-vector with ck [%s] with status %d\n", base16_ck,
					x->status);
	}

done:
	return x;
}

/**
 * Frees the memory taken by an authentication vector
 * @param av - the vector to be freed
 */
void free_auth_vector(auth_vector *av)
{
	if(av) {
		if(av->authenticate.s)
			shm_free(av->authenticate.s);
		if(av->authorization.s)
			shm_free(av->authorization.s);
		if(av->ck.s)
			shm_free(av->ck.s);
		if(av->ik.s)
			shm_free(av->ik.s);
		shm_free(av);
	}
}

/**
 * Creates a new Authorization Userdata structure.
 * @param private_identity - the private identity to attach to
 * @param public_identity - the public identity to attach to
 * @returns the new auth_userdata* on success or NULL on error
 */
auth_userdata *new_auth_userdata(str private_identity, str public_identity)
{
	auth_userdata *x = 0;

	x = shm_malloc(sizeof(auth_userdata));
	if(!x) {
		LM_ERR("error allocating mem\n");
		goto done;
	}

	x->private_identity.len = private_identity.len;
	x->private_identity.s = shm_malloc(private_identity.len);
	if(!x) {
		LM_ERR("error allocating mem\n");
		goto done;
	}
	memcpy(x->private_identity.s, private_identity.s, private_identity.len);

	x->public_identity.len = public_identity.len;
	x->public_identity.s = shm_malloc(public_identity.len);
	if(!x) {
		LM_ERR("error allocating mem\n");
		goto done;
	}
	memcpy(x->public_identity.s, public_identity.s, public_identity.len);

	x->head = 0;
	x->tail = 0;

	x->next = 0;
	x->prev = 0;

done:
	return x;
}

/**
 * Deallocates the auth_userdata.
 * @param aud - the auth_userdata to be deallocated
 */
void free_auth_userdata(auth_userdata *aud)
{
	auth_vector *av, *next;
	if(aud) {
		if(aud->private_identity.s)
			shm_free(aud->private_identity.s);
		if(aud->public_identity.s)
			shm_free(aud->public_identity.s);
		av = aud->head;
		while(av) {
			next = av->next;
			free_auth_vector(av);
			av = next;
		}
		shm_free(aud);
	}
}

/**
 * Computes a hash based on the private and public identities
 * @param private_identity - the private identity
 * @param public_identity - the public identity
 * @returns the hash % Auth_data->size
 */
unsigned int get_hash_auth(str private_identity, str public_identity)
{
	if(av_check_only_impu)
		return core_hash(&public_identity, 0, act_auth_data_hash_size);
	else
		return core_hash(&public_identity, 0, act_auth_data_hash_size);
	/*


#define h_inc h+=v^(v>>3)
    char* p;
    register unsigned v;
    register unsigned h;

    h = 0;
    for (p = private_identity.s; p <= (private_identity.s + private_identity.len - 4); p += 4) {
        v = (*p << 24)+(p[1] << 16)+(p[2] << 8) + p[3];
        h_inc;
    }
    v = 0;
    for (; p < (private_identity.s + private_identity.len); p++) {
        v <<= 8;
        v += *p;
    }
    h_inc;
    for (p = public_identity.s; p <= (public_identity.s + public_identity.len - 4); p += 4) {
        v = (*p << 24)+(p[1] << 16)+(p[2] << 8) + p[3];
        h_inc;
    }
    v = 0;
    for (; p < (public_identity.s + public_identity.len); p++) {
        v <<= 8;
        v += *p;
    }

    h = ((h)+(h >> 11))+((h >> 13)+(h >> 23));
    return (h) % auth_data_hash_size;
#undef h_inc
*/
}

/**
 * Retrieve the auth_userdata for a user.
 * \note you will return with lock on the hash slot, so release it!
 * @param private_identity - the private identity
 * @param public_identity - the public identity
 * @returns the auth_userdata* found or newly created on success, NULL on error
 */
auth_userdata *get_auth_userdata(str private_identity, str public_identity)
{

	unsigned int hash = 0;
	auth_userdata *aud = 0;

	hash = get_hash_auth(private_identity, public_identity);
	auth_data_lock(hash);
	aud = auth_data[hash].head;
	if(av_check_only_impu)
		LM_DBG("Searching auth_userdata for IMPU %.*s (Hash %d)\n",
				public_identity.len, public_identity.s, hash);
	else
		LM_DBG("Searching auth_userdata for IMPU %.*s / IMPI %.*s (Hash %d)\n",
				public_identity.len, public_identity.s, private_identity.len,
				private_identity.s, hash);

	while(aud) {
		if(av_check_only_impu) {
			if(aud->public_identity.len == public_identity.len
					&& memcmp(aud->public_identity.s, public_identity.s,
							   public_identity.len)
							   == 0) {
				LM_DBG("Found auth_userdata\n");
				return aud;
			}
		} else {
			if(aud->private_identity.len == private_identity.len
					&& aud->public_identity.len == public_identity.len
					&& memcmp(aud->private_identity.s, private_identity.s,
							   private_identity.len)
							   == 0
					&& memcmp(aud->public_identity.s, public_identity.s,
							   public_identity.len)
							   == 0) {
				LM_DBG("Found auth_userdata\n");
				return aud;
			}
		}

		aud = aud->next;
	}
	/* if we get here, there is no auth_userdata for this user */
	aud = new_auth_userdata(private_identity, public_identity);
	if(!aud) {
		auth_data_unlock(hash);
		return 0;
	}

	aud->prev = auth_data[hash].tail;
	aud->next = 0;
	aud->hash = hash;

	if(!auth_data[hash].head)
		auth_data[hash].head = aud;
	if(auth_data[hash].tail)
		auth_data[hash].tail->next = aud;
	auth_data[hash].tail = aud;

	return aud;
}

/**
 * Sends a Multimedia-Authentication-Response to retrieve some authentication vectors and maybe synchronize.
 * Must respond with a SIP reply every time it returns 0
 * @param msg - the SIP REGISTER message
 * @param public_identity - the public identity
 * @param private_identity - the private identity
 * @param count - how many vectors to request
 * @param algorithm - which algorithm to request
 * @param nonce - the challenge that will be sent
 * @param auts - the AKA synchronization or empty string if not a synchronization
 * @param server_name - the S-CSCF name to be saved on the HSS
 * @returns 1 on success, 0 on failure
 */
int multimedia_auth_request(struct sip_msg *msg, str public_identity,
		str private_identity, int count, str auth_scheme, str nonce, str auts,
		str servername, saved_transaction_t *transaction_data)
{


	str authorization = {0, 0};
	int result = -1;

	int is_sync = 0;
	if(auts.len) {
		authorization.s = pkg_malloc(nonce.len * 3 / 4 + auts.len * 3 / 4 + 8);
		if(!authorization.s) {
			LM_ERR("no more pkg mem\n");
			return result;
		}
		authorization.len = base64_to_bin(nonce.s, nonce.len, authorization.s);
		authorization.len = RAND_LEN;
		authorization.len += base64_to_bin(
				auts.s, auts.len, authorization.s + authorization.len);
		is_sync = 1;
	}

	if(is_sync) {
		drop_auth_userdata(private_identity, public_identity);
	}


	LM_DBG("Sending MAR\n");
	result = cxdx_send_mar(msg, public_identity, private_identity, count,
			auth_scheme, authorization, servername, transaction_data);
	if(authorization.s)
		pkg_free(authorization.s);

	return result;
}

/**
 * Adds the WWW-Authenticate header for challenge, based on the authentication vector.
 * @param msg - SIP message to add the header to
 * @param realm - the realm
 * @param av - the authentication vector
 * @returns 1 on success, 0 on error
 */
int pack_challenge(
		struct sip_msg *msg, str realm, auth_vector *av, int is_proxy_auth)
{
	str x = {0, 0};
	char ck[32], ik[32];
	int ck_len, ik_len;
	str *auth_prefix = is_proxy_auth ? &S_Proxy : &S_WWW;
	str qop;
	int is_invite;

	is_invite =
			(msg->first_line.u.request.method_value == METHOD_INVITE) ? 1 : 0;
	if(is_invite) {
		qop.s = invite_qop_str.s;
		qop.len = invite_qop_str.len;
		LM_DBG("setting QOP str used is [%.*s]\n", invite_qop_str.len,
				invite_qop_str.s);
		//		av->type = AUTH_MD5;
	} else {
		qop.s = registration_qop_str.s;
		qop.len = registration_qop_str.len;
		LM_DBG("setting QOP str used is [%.*s]\n", registration_qop_str.len,
				registration_qop_str.s);
	}
	LM_DBG("QOP str used is [%.*s]\n", qop.len, qop.s);


	switch(av->type) {
		case AUTH_AKAV1_MD5:
		case AUTH_AKAV2_MD5:
			/* AKA */
			ck_len = bin_to_base16(av->ck.s, 16, ck);
			ik_len = bin_to_base16(av->ik.s, 16, ik);
			x.len = S_Authorization_AKA.len + auth_prefix->len + realm.len
					+ av->authenticate.len + algorithm_types[av->type].len
					+ ck_len + ik_len + qop.len;
			x.s = pkg_malloc(x.len);
			if(!x.s) {
				LM_ERR("Error allocating %d bytes\n", x.len);
				goto error;
			}
			sprintf(x.s, S_Authorization_AKA.s, auth_prefix->len,
					auth_prefix->s, realm.len, realm.s, av->authenticate.len,
					av->authenticate.s, algorithm_types[av->type].len,
					algorithm_types[av->type].s, ck_len, ck, ik_len, ik,
					qop.len, qop.s);
			x.len = strlen(x.s);
			break;
		case AUTH_HTTP_DIGEST_MD5:
			/* ETSI HTTP_DIGEST MD5 */
			/* this one continues into the next one */
		case AUTH_DIGEST:
			/* Cable-Labs MD5 */
			/* this one continues into the next one */
		case AUTH_SIP_DIGEST:
			/* 3GPP MD5 */
			/* this one continues into the next one */
		case AUTH_MD5:
			/* FOKUS MD5 */
			x.len = S_Authorization_MD5.len + auth_prefix->len + realm.len
					+ av->authenticate.len + algorithm_types[av->type].len
					+ qop.len;
			x.s = pkg_malloc(x.len);
			if(!x.s) {
				LM_ERR("pack_challenge: Error allocating %d bytes\n", x.len);
				goto error;
			}
			sprintf(x.s, S_Authorization_MD5.s, auth_prefix->len,
					auth_prefix->s, realm.len, realm.s, av->authenticate.len,
					av->authenticate.s, algorithm_types[AUTH_MD5].len,
					algorithm_types[AUTH_MD5].s, qop.len, qop.s);
			x.len = strlen(x.s);
			break;

		default:
			LM_CRIT("not implemented for algorithm %.*s\n",
					algorithm_types[av->type].len, algorithm_types[av->type].s);
			goto error;
	}

	if(ims_add_header_rpl(msg, &x)) {
		pkg_free(x.s);
		return 1;
	}

error:
	if(x.s)
		pkg_free(x.s);

	return 0;
}

/**
 * Adds the Authentication-Info header for, based on the credentials sent by a successful REGISTER.
 * @param msg - SIP message to add the header to
 * @returns 1 on success, 0 on error
 */
int add_authinfo_resp_hdr(struct sip_msg *msg, str nextnonce, str qop,
		HASHHEX rspauth, str cnonce, str nc)
{

	str authinfo_hdr;
	static const char authinfo_fmt[] = "Authentication-Info: "
									   "nextnonce=\"%.*s\","
									   "qop=%.*s,"
									   "rspauth=\"%.*s\","
									   "cnonce=\"%.*s\","
									   "nc=%.*s\r\n";

	authinfo_hdr.len =
			sizeof(authinfo_fmt) + nextnonce.len + qop.len + HASHHEXLEN
			+ cnonce.len + nc.len
			- 20 /* format string parameters */ - 1 /* trailing \0 */;
	authinfo_hdr.s = pkg_malloc(authinfo_hdr.len + 1);

	if(!authinfo_hdr.s) {
		LM_ERR("add_authinfo_resp_hdr: Error allocating %d bytes\n",
				authinfo_hdr.len);
		goto error;
	}
	snprintf(authinfo_hdr.s, authinfo_hdr.len + 1, authinfo_fmt, nextnonce.len,
			nextnonce.s, qop.len, qop.s, HASHHEXLEN, rspauth, cnonce.len,
			cnonce.s, nc.len, nc.s);
	LM_DBG("authinfo hdr built: %.*s", authinfo_hdr.len, authinfo_hdr.s);
	if(ims_add_header_rpl(msg, &authinfo_hdr)) {
		LM_DBG("authinfo hdr added");
		pkg_free(authinfo_hdr.s);
		return 1;
	}
error:
	if(authinfo_hdr.s)
		pkg_free(authinfo_hdr.s);

	return 0;
}

/**
 * Add an authentication vector to the authentication userdata storage.
 * @param private_identity - the private identity
 * @param public_identity - the public identity
 * @param av - the authentication vector
 * @returns 1 on success or 0 on error
 */
int add_auth_vector(str private_identity, str public_identity, auth_vector *av)
{
	auth_userdata *aud;
	aud = get_auth_userdata(private_identity, public_identity);
	if(!aud)
		goto error;

	LM_DBG("Adding auth_vector (status %d) for IMPU %.*s / IMPI %.*s (Hash "
		   "%d)\n",
			av->status, public_identity.len, public_identity.s,
			private_identity.len, private_identity.s, aud->hash);


	av->prev = 0;
	if(aud->head) {
		av->next = aud->head;
		aud->head->prev = av;
	}

	aud->head = av;

	auth_data_unlock(aud->hash);
	return 1;
error:

	return 0;
}

/**
 * Declares all auth vectors as useless when we do a synchronization
 * @param private_identity - the private identity
 * @param public_identity - the public identity
 * @returns 1 on success, 0 on error
 */
int drop_auth_userdata(str private_identity, str public_identity)
{
	auth_userdata *aud;
	auth_vector *av;
	aud = get_auth_userdata(private_identity, public_identity);
	if(!aud)
		goto error;

	av = aud->head;
	while(av) {
		LM_DBG("dropping auth vector that was in status %d\n", av->status);
		av->status = AUTH_VECTOR_USELESS;
		av = av->next;
	}
	auth_data_unlock(aud->hash);
	return 1;
error:
	LM_DBG("no authdata to drop any auth vectors\n");
	if(aud)
		auth_data_unlock(aud->hash);
	return 0;
}
