/* $OpenBSD: eng_init.c,v 1.6 2014/06/12 15:49:29 deraadt Exp $ */
/* ====================================================================
 * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include "eng_int.h"

/* Initialise a engine type for use (or up its functional reference count
 * if it's already in use). This version is only used internally. */
int
engine_unlocked_init(ENGINE *e)
{
	int to_return = 1;

	if ((e->funct_ref == 0) && e->init)
		/* This is the first functional reference and the engine
		 * requires initialisation so we do it now. */
		to_return = e->init(e);
	if (to_return) {
		/* OK, we return a functional reference which is also a
		 * structural reference. */
		e->struct_ref++;
		e->funct_ref++;
		engine_ref_debug(e, 0, 1)
		engine_ref_debug(e, 1, 1)
	}
	return to_return;
}

/* Free a functional reference to a engine type. This version is only used
 * internally. */
int
engine_unlocked_finish(ENGINE *e, int unlock_for_handlers)
{
	int to_return = 1;

	/* Reduce the functional reference count here so if it's the terminating
	 * case, we can release the lock safely and call the finish() handler
	 * without risk of a race. We get a race if we leave the count until
	 * after and something else is calling "finish" at the same time -
	 * there's a chance that both threads will together take the count from
	 * 2 to 0 without either calling finish(). */
	e->funct_ref--;
	engine_ref_debug(e, 1, -1);
	if ((e->funct_ref == 0) && e->finish) {
		if (unlock_for_handlers)
			CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
		to_return = e->finish(e);
		if (unlock_for_handlers)
			CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
		if (!to_return)
			return 0;
	}

	/* Release the structural reference too */
	if (!engine_free_util(e, 0)) {
		ENGINEerr(ENGINE_F_ENGINE_UNLOCKED_FINISH,
		    ENGINE_R_FINISH_FAILED);
		return 0;
	}
	return to_return;
}

/* The API (locked) version of "init" */
int
ENGINE_init(ENGINE *e)
{
	int ret;

	if (e == NULL) {
		ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_PASSED_NULL_PARAMETER);
		return 0;
	}
	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	ret = engine_unlocked_init(e);
	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	return ret;
}

/* The API (locked) version of "finish" */
int
ENGINE_finish(ENGINE *e)
{
	int to_return = 1;

	if (e == NULL) {
		ENGINEerr(ENGINE_F_ENGINE_FINISH, ERR_R_PASSED_NULL_PARAMETER);
		return 0;
	}
	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	to_return = engine_unlocked_finish(e, 1);
	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	if (!to_return) {
		ENGINEerr(ENGINE_F_ENGINE_FINISH, ENGINE_R_FINISH_FAILED);
		return 0;
	}
	return to_return;
}