/*
 * Copyright (C) 2008 Martin Willi
 * Hochschule fuer Technik Rapperswil
 *
 * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * 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.
 *
 * $Id$
 */

#include "nm_creds.h"

#include <daemon.h>
#include <utils/mutex.h>

typedef struct private_nm_creds_t private_nm_creds_t;

/**
 * private data of nm_creds
 */
struct private_nm_creds_t {

	/**
	 * public functions
	 */
	nm_creds_t public;
	
	/**
	 * gateway certificate
	 */
	certificate_t *cert;
	
	/**
 	 * User name
 	 */
 	identification_t *user;
	
	/**
	 * User password
	 */
	char *pass;
	
	/**
	 * users certificate
	 */
	certificate_t *usercert;
	
	/**
	 * users private key
	 */
	private_key_t *key;
	
	/**
	 * read/write lock
	 */
	rwlock_t *lock;
};

/**
 * Enumerator for user certificate
 */
static enumerator_t *create_usercert_enumerator(private_nm_creds_t *this,
							certificate_type_t cert, key_type_t key)
{
	public_key_t *public;
	
	if (cert != CERT_ANY && cert != this->usercert->get_type(this->usercert))
	{
		return NULL;
	}
	if (key != KEY_ANY)
	{	
		public = this->usercert->get_public_key(this->usercert);
		if (!public)
		{
			return NULL;
		}
		if (public->get_type(public) != key)
		{
			public->destroy(public);
			return NULL;
		}
		public->destroy(public);
	}
	this->lock->read_lock(this->lock);
	return enumerator_create_cleaner(
								enumerator_create_single(this->usercert, NULL),
								(void*)this->lock->unlock, this->lock);
}

/**
 * Implements credential_set_t.create_cert_enumerator
 */
static enumerator_t* create_cert_enumerator(private_nm_creds_t *this,
							certificate_type_t cert, key_type_t key,
							identification_t *id, bool trusted)
{
	if (id && this->usercert &&
		id->equals(id, this->usercert->get_subject(this->usercert)))
	{
		return create_usercert_enumerator(this, cert, key);
	}

	if (!this->cert)
	{
		return NULL;
	}
	if (cert != CERT_ANY && cert != this->cert->get_type(this->cert))
	{
		return NULL;
	}
	if (id && !this->cert->has_subject(this->cert, id))
	{
		return NULL;
	}
	if (key != KEY_ANY)
	{
		public_key_t *public;
	
		public = this->cert->get_public_key(this->cert);
		if (!public)
		{
			return NULL;
		}
		if (public->get_type(public) != key)
		{
			public->destroy(public);
			return NULL;
		}
		public->destroy(public);
	}
	this->lock->read_lock(this->lock);
	return enumerator_create_cleaner(enumerator_create_single(this->cert, NULL),
									 (void*)this->lock->unlock, this->lock);
}

/**
 * Implements credential_set_t.create_cert_enumerator
 */
static enumerator_t* create_private_enumerator(private_nm_creds_t *this,
										key_type_t type, identification_t *id)
{
	if (this->key == NULL)
	{
		return NULL;
	}
	if (type != KEY_ANY && type != this->key->get_type(this->key))
	{
		return NULL;
	}
	if (id && id->get_type(id) != ID_ANY)
	{
		identification_t *keyid;
		
		keyid = this->key->get_id(this->key, id->get_type(id));
		if (!keyid || !keyid->equals(keyid, id))
		{
			return NULL;
		}
	}
	this->lock->read_lock(this->lock);
	return enumerator_create_cleaner(enumerator_create_single(this->key, NULL),
									 (void*)this->lock->unlock, this->lock);
}

/**
 * shared key enumerator implementation
 */
typedef struct {
	enumerator_t public;
	private_nm_creds_t *this;
	shared_key_t *key;
	bool done;
} shared_enumerator_t;

/**
 * enumerate function for shared enumerator
 */
static bool shared_enumerate(shared_enumerator_t *this, shared_key_t **key,
							 id_match_t *me, id_match_t *other)
{
	if (this->done)
	{
		return FALSE;
	}
	*key = this->key;
	*me = ID_MATCH_PERFECT;
	*other = ID_MATCH_ANY;
	this->done = TRUE;
	return TRUE;
}

/**
 * Destroy function for shared enumerator
 */
static void shared_destroy(shared_enumerator_t *this)
{
	this->key->destroy(this->key);
	this->this->lock->unlock(this->this->lock);
	free(this);
}
/**
 * Implements credential_set_t.create_cert_enumerator
 */
static enumerator_t* create_shared_enumerator(private_nm_creds_t *this, 
							shared_key_type_t type,	identification_t *me,
							identification_t *other)
{
	shared_enumerator_t *enumerator;

	if (!this->pass || !this->user)
	{
		return NULL;
	}
	if (type != SHARED_EAP && type != SHARED_IKE)
	{
		return NULL;
	}
	if (me && !me->equals(me, this->user))
	{
		return NULL;
	}
	
	enumerator = malloc_thing(shared_enumerator_t);
	enumerator->public.enumerate = (void*)shared_enumerate;
	enumerator->public.destroy = (void*)shared_destroy;
	enumerator->this = this;
	enumerator->done = FALSE;
	this->lock->read_lock(this->lock);
	enumerator->key = shared_key_create(type,
										chunk_clone(chunk_create(this->pass,
													strlen(this->pass))));
	return &enumerator->public;
}

/**
 * Implementation of nm_creds_t.set_certificate
 */
static void set_certificate(private_nm_creds_t *this, certificate_t *cert)
{
	this->lock->write_lock(this->lock);
	DESTROY_IF(this->cert);
	this->cert = cert;
	this->lock->unlock(this->lock);
}

/**
 * Implementation of nm_creds_t.set_password
 */
static void set_username_password(private_nm_creds_t *this, identification_t *id,
						 char *password)
{
	this->lock->write_lock(this->lock);
	DESTROY_IF(this->user);
	/* for EAP authentication, we use always use ID_EAP type */
	this->user = identification_create_from_encoding(ID_EAP,
													 id->get_encoding(id));
	free(this->pass);
	this->pass = password ? strdup(password) : NULL;
	this->lock->unlock(this->lock);
}

/**
 * Implementation of nm_creds_t.set_cert_and_key
 */
static void set_cert_and_key(private_nm_creds_t *this, certificate_t *cert,	
							 private_key_t *key)
{
	this->lock->write_lock(this->lock);
	DESTROY_IF(this->key);
	DESTROY_IF(this->usercert);
	this->key = key;
	this->usercert = cert;
	this->lock->unlock(this->lock);
}	

/**
 * Implementation of nm_creds_t.clear
 */
static void clear(private_nm_creds_t *this)
{
	DESTROY_IF(this->cert);
	DESTROY_IF(this->user);
	free(this->pass);
	DESTROY_IF(this->usercert);
	DESTROY_IF(this->key);
	this->key = NULL;
	this->usercert = NULL;
	this->pass = NULL;
	this->cert = NULL;
	this->user = NULL;
}

/**
 * Implementation of nm_creds_t.destroy
 */
static void destroy(private_nm_creds_t *this)
{
	clear(this);
	this->lock->destroy(this->lock);
	free(this);
}

/*
 * see header file
 */
nm_creds_t *nm_creds_create()
{
	private_nm_creds_t *this = malloc_thing(private_nm_creds_t);
	
	this->public.set.create_private_enumerator = (void*)create_private_enumerator;
	this->public.set.create_cert_enumerator = (void*)create_cert_enumerator;
	this->public.set.create_shared_enumerator = (void*)create_shared_enumerator;
	this->public.set.create_cdp_enumerator = (void*)return_null;
	this->public.set.cache_cert = (void*)nop;
	this->public.set_certificate = (void(*)(nm_creds_t*, certificate_t *cert))set_certificate;
	this->public.set_username_password = (void(*)(nm_creds_t*, identification_t *id, char *password))set_username_password;
	this->public.set_cert_and_key = (void(*)(nm_creds_t*, certificate_t *cert, private_key_t *key))set_cert_and_key;
	this->public.clear = (void(*)(nm_creds_t*))clear;
	this->public.destroy = (void(*)(nm_creds_t*))destroy;
	
	this->lock = rwlock_create(RWLOCK_DEFAULT);
	
	this->cert = NULL;
	this->user = NULL;
	this->pass = NULL;
	this->usercert = NULL;
	this->key = NULL;
	
	return &this->public;
}