[thirdparty/openssl.git] / crypto / engine / eng_list.c

/* crypto/engine/eng_list.c */
/*
 * Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL project
 * 2000.
 */
/* ====================================================================
 * Copyright (c) 1999-2018 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).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * ECDH support in OpenSSL originally developed by
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */

#include "cryptlib.h"
#include "eng_int.h"

/*
 * The linked-list of pointers to engine types. engine_list_head incorporates
 * an implicit structural reference but engine_list_tail does not - the
 * latter is a computational niceity and only points to something that is
 * already pointed to by its predecessor in the list (or engine_list_head
 * itself). In the same way, the use of the "prev" pointer in each ENGINE is
 * to save excessive list iteration, it doesn't correspond to an extra
 * structural reference. Hence, engine_list_head, and each non-null "next"
 * pointer account for the list itself assuming exactly 1 structural
 * reference on each list member.
 */
static ENGINE *engine_list_head = NULL;
static ENGINE *engine_list_tail = NULL;

/*
 * This cleanup function is only needed internally. If it should be called,
 * we register it with the "ENGINE_cleanup()" stack to be called during
 * cleanup.
 */

static void engine_list_cleanup(void)
{
    ENGINE *iterator = engine_list_head;

    while (iterator != NULL) {
        ENGINE_remove(iterator);
        iterator = engine_list_head;
    }
    return;
}

/*
 * These static functions starting with a lower case "engine_" always take
 * place when CRYPTO_LOCK_ENGINE has been locked up.
 */
static int engine_list_add(ENGINE *e)
{
    int conflict = 0;
    ENGINE *iterator = NULL;

    if (e == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    iterator = engine_list_head;
    while (iterator && !conflict) {
        conflict = (strcmp(iterator->id, e->id) == 0);
        iterator = iterator->next;
    }
    if (conflict) {
        ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_CONFLICTING_ENGINE_ID);
        return 0;
    }
    if (engine_list_head == NULL) {
        /* We are adding to an empty list. */
        if (engine_list_tail) {
            ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
            return 0;
        }
        engine_list_head = e;
        e->prev = NULL;
        /*
         * The first time the list allocates, we should register the cleanup.
         */
        engine_cleanup_add_last(engine_list_cleanup);
    } else {
        /* We are adding to the tail of an existing list. */
        if ((engine_list_tail == NULL) || (engine_list_tail->next != NULL)) {
            ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
            return 0;
        }
        engine_list_tail->next = e;
        e->prev = engine_list_tail;
    }
    /*
     * Having the engine in the list assumes a structural reference.
     */
    e->struct_ref++;
    engine_ref_debug(e, 0, 1)
        /* However it came to be, e is the last item in the list. */
        engine_list_tail = e;
    e->next = NULL;
    return 1;
}

static int engine_list_remove(ENGINE *e)
{
    ENGINE *iterator;

    if (e == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    /* We need to check that e is in our linked list! */
    iterator = engine_list_head;
    while (iterator && (iterator != e))
        iterator = iterator->next;
    if (iterator == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE,
                  ENGINE_R_ENGINE_IS_NOT_IN_LIST);
        return 0;
    }
    /* un-link e from the chain. */
    if (e->next)
        e->next->prev = e->prev;
    if (e->prev)
        e->prev->next = e->next;
    /* Correct our head/tail if necessary. */
    if (engine_list_head == e)
        engine_list_head = e->next;
    if (engine_list_tail == e)
        engine_list_tail = e->prev;
    engine_free_util(e, 0);
    return 1;
}

/* Get the first/last "ENGINE" type available. */
ENGINE *ENGINE_get_first(void)
{
    ENGINE *ret;

    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    ret = engine_list_head;
    if (ret) {
        ret->struct_ref++;
        engine_ref_debug(ret, 0, 1)
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    return ret;
}

ENGINE *ENGINE_get_last(void)
{
    ENGINE *ret;

    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    ret = engine_list_tail;
    if (ret) {
        ret->struct_ref++;
        engine_ref_debug(ret, 0, 1)
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    return ret;
}

/* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
ENGINE *ENGINE_get_next(ENGINE *e)
{
    ENGINE *ret = NULL;
    if (e == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_GET_NEXT, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    ret = e->next;
    if (ret) {
        /* Return a valid structural refernce to the next ENGINE */
        ret->struct_ref++;
        engine_ref_debug(ret, 0, 1)
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    /* Release the structural reference to the previous ENGINE */
    ENGINE_free(e);
    return ret;
}

ENGINE *ENGINE_get_prev(ENGINE *e)
{
    ENGINE *ret = NULL;
    if (e == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_GET_PREV, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    ret = e->prev;
    if (ret) {
        /* Return a valid structural reference to the next ENGINE */
        ret->struct_ref++;
        engine_ref_debug(ret, 0, 1)
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    /* Release the structural reference to the previous ENGINE */
    ENGINE_free(e);
    return ret;
}

/* Add another "ENGINE" type into the list. */
int ENGINE_add(ENGINE *e)
{
    int to_return = 1;
    if (e == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_ADD, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    if ((e->id == NULL) || (e->name == NULL)) {
        ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_ID_OR_NAME_MISSING);
        return 0;
    }
    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    if (!engine_list_add(e)) {
        ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
        to_return = 0;
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    return to_return;
}

/* Remove an existing "ENGINE" type from the array. */
int ENGINE_remove(ENGINE *e)
{
    int to_return = 1;
    if (e == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    if (!engine_list_remove(e)) {
        ENGINEerr(ENGINE_F_ENGINE_REMOVE, ENGINE_R_INTERNAL_LIST_ERROR);
        to_return = 0;
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    return to_return;
}

static void engine_cpy(ENGINE *dest, const ENGINE *src)
{
    dest->id = src->id;
    dest->name = src->name;
#ifndef OPENSSL_NO_RSA
    dest->rsa_meth = src->rsa_meth;
#endif
#ifndef OPENSSL_NO_DSA
    dest->dsa_meth = src->dsa_meth;
#endif
#ifndef OPENSSL_NO_DH
    dest->dh_meth = src->dh_meth;
#endif
#ifndef OPENSSL_NO_ECDH
    dest->ecdh_meth = src->ecdh_meth;
#endif
#ifndef OPENSSL_NO_ECDSA
    dest->ecdsa_meth = src->ecdsa_meth;
#endif
    dest->rand_meth = src->rand_meth;
    dest->store_meth = src->store_meth;
    dest->ciphers = src->ciphers;
    dest->digests = src->digests;
    dest->pkey_meths = src->pkey_meths;
    dest->destroy = src->destroy;
    dest->init = src->init;
    dest->finish = src->finish;
    dest->ctrl = src->ctrl;
    dest->load_privkey = src->load_privkey;
    dest->load_pubkey = src->load_pubkey;
    dest->cmd_defns = src->cmd_defns;
    dest->flags = src->flags;
}

ENGINE *ENGINE_by_id(const char *id)
{
    ENGINE *iterator;
    char *load_dir = NULL;
    if (id == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_PASSED_NULL_PARAMETER);
        return NULL;
    }
    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    iterator = engine_list_head;
    while (iterator && (strcmp(id, iterator->id) != 0))
        iterator = iterator->next;
    if (iterator) {
        /*
         * We need to return a structural reference. If this is an ENGINE
         * type that returns copies, make a duplicate - otherwise increment
         * the existing ENGINE's reference count.
         */
        if (iterator->flags & ENGINE_FLAGS_BY_ID_COPY) {
            ENGINE *cp = ENGINE_new();
            if (!cp)
                iterator = NULL;
            else {
                engine_cpy(cp, iterator);
                iterator = cp;
            }
        } else {
            iterator->struct_ref++;
            engine_ref_debug(iterator, 0, 1)
        }
    }
    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
#if 0
    if (iterator == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE);
        ERR_add_error_data(2, "id=", id);
    }
    return iterator;
#else
    /* EEK! Experimental code starts */
    if (iterator)
        return iterator;
    /*
     * Prevent infinite recusrion if we're looking for the dynamic engine.
     */
    if (strcmp(id, "dynamic")) {
# ifdef OPENSSL_SYS_VMS
        if ((load_dir = ossl_safe_getenv("OPENSSL_ENGINES")) == 0)
            load_dir = "SSLROOT:[ENGINES]";
# else
        if ((load_dir = ossl_safe_getenv("OPENSSL_ENGINES")) == 0)
            load_dir = ENGINESDIR;
# endif
        iterator = ENGINE_by_id("dynamic");
        if (!iterator || !ENGINE_ctrl_cmd_string(iterator, "ID", id, 0) ||
            !ENGINE_ctrl_cmd_string(iterator, "DIR_LOAD", "2", 0) ||
            !ENGINE_ctrl_cmd_string(iterator, "DIR_ADD",
                                    load_dir, 0) ||
            !ENGINE_ctrl_cmd_string(iterator, "LIST_ADD", "1", 0) ||
            !ENGINE_ctrl_cmd_string(iterator, "LOAD", NULL, 0))
            goto notfound;
        return iterator;
    }
 notfound:
    ENGINE_free(iterator);
    ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE);
    ERR_add_error_data(2, "id=", id);
    return NULL;
    /* EEK! Experimental code ends */
#endif
}

int ENGINE_up_ref(ENGINE *e)
{
    if (e == NULL) {
        ENGINEerr(ENGINE_F_ENGINE_UP_REF, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    CRYPTO_add(&e->struct_ref, 1, CRYPTO_LOCK_ENGINE);
    return 1;
}
Commit	Line	Data
2b671586	1	/* crypto/engine/eng_list.c */
ae5c8664 MC	2	/*
	3	* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL project
	4	* 2000.
5270e702 RL	5	*/
5270e702 RL	6	/* ====================================================================
8ea16720	7	* Copyright (c) 1999-2018 The OpenSSL Project. All rights reserved.
5270e702 RL	8	*
	9	* Redistribution and use in source and binary forms, with or without
	10	* modification, are permitted provided that the following conditions
	11	* are met:
	12	*
	13	* 1. Redistributions of source code must retain the above copyright
ae5c8664	14	* notice, this list of conditions and the following disclaimer.
5270e702 RL	15	*
	16	* 2. Redistributions in binary form must reproduce the above copyright
	17	* notice, this list of conditions and the following disclaimer in
	18	* the documentation and/or other materials provided with the
	19	* distribution.
	20	*
	21	* 3. All advertising materials mentioning features or use of this
	22	* software must display the following acknowledgment:
	23	* "This product includes software developed by the OpenSSL Project
	24	* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
	25	*
	26	* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
	27	* endorse or promote products derived from this software without
	28	* prior written permission. For written permission, please contact
	29	* licensing@OpenSSL.org.
	30	*
	31	* 5. Products derived from this software may not be called "OpenSSL"
	32	* nor may "OpenSSL" appear in their names without prior written
	33	* permission of the OpenSSL Project.
	34	*
	35	* 6. Redistributions of any form whatsoever must retain the following
	36	* acknowledgment:
	37	* "This product includes software developed by the OpenSSL Project
	38	* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
	39	*
	40	* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
	41	* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	42	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	43	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
	44	* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	45	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	46	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	47	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	48	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	49	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	50	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
	51	* OF THE POSSIBILITY OF SUCH DAMAGE.
	52	* ====================================================================
	53	*
	54	* This product includes cryptographic software written by Eric Young
	55	* (eay@cryptsoft.com). This product includes software written by Tim
	56	* Hudson (tjh@cryptsoft.com).
	57	*
	58	*/
e172d60d BM	59	/* ====================================================================
e172d60d BM	60	* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
ae5c8664	61	* ECDH support in OpenSSL originally developed by
e172d60d BM	62	* SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
e172d60d BM	63	*/
5270e702	64
788d2fa0	65	#include "cryptlib.h"
14cfde9c	66	#include "eng_int.h"
5270e702	67
ae5c8664 MC	68	/*
	69	* The linked-list of pointers to engine types. engine_list_head incorporates
	70	* an implicit structural reference but engine_list_tail does not - the
	71	* latter is a computational niceity and only points to something that is
	72	* already pointed to by its predecessor in the list (or engine_list_head
	73	* itself). In the same way, the use of the "prev" pointer in each ENGINE is
	74	* to save excessive list iteration, it doesn't correspond to an extra
	75	* structural reference. Hence, engine_list_head, and each non-null "next"
	76	* pointer account for the list itself assuming exactly 1 structural
	77	* reference on each list member.
	78	*/
5270e702 RL	79	static ENGINE *engine_list_head = NULL;
5270e702 RL	80	static ENGINE *engine_list_tail = NULL;
b6d1e52d	81
ae5c8664 MC	82	/*
	83	* This cleanup function is only needed internally. If it should be called,
	84	* we register it with the "ENGINE_cleanup()" stack to be called during
	85	* cleanup.
	86	*/
b6d1e52d GT	87
b6d1e52d GT	88	static void engine_list_cleanup(void)
ae5c8664 MC	89	{
ae5c8664 MC	90	ENGINE *iterator = engine_list_head;
b6d1e52d	91
ae5c8664 MC	92	while (iterator != NULL) {
	93	ENGINE_remove(iterator);
	94	iterator = engine_list_head;
	95	}
	96	return;
	97	}
5270e702	98
ae5c8664 MC	99	/*
	100	* These static functions starting with a lower case "engine_" always take
	101	* place when CRYPTO_LOCK_ENGINE has been locked up.
	102	*/
5270e702	103	static int engine_list_add(ENGINE *e)
ae5c8664 MC	104	{
	105	int conflict = 0;
	106	ENGINE *iterator = NULL;
5270e702	107
ae5c8664 MC	108	if (e == NULL) {
	109	ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ERR_R_PASSED_NULL_PARAMETER);
	110	return 0;
	111	}
	112	iterator = engine_list_head;
	113	while (iterator && !conflict) {
	114	conflict = (strcmp(iterator->id, e->id) == 0);
	115	iterator = iterator->next;
	116	}
	117	if (conflict) {
	118	ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_CONFLICTING_ENGINE_ID);
	119	return 0;
	120	}
	121	if (engine_list_head == NULL) {
	122	/* We are adding to an empty list. */
	123	if (engine_list_tail) {
	124	ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
	125	return 0;
	126	}
	127	engine_list_head = e;
	128	e->prev = NULL;
	129	/*
	130	* The first time the list allocates, we should register the cleanup.
	131	*/
	132	engine_cleanup_add_last(engine_list_cleanup);
	133	} else {
	134	/* We are adding to the tail of an existing list. */
	135	if ((engine_list_tail == NULL) \|\| (engine_list_tail->next != NULL)) {
	136	ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
	137	return 0;
	138	}
	139	engine_list_tail->next = e;
	140	e->prev = engine_list_tail;
	141	}
	142	/*
	143	* Having the engine in the list assumes a structural reference.
	144	*/
	145	e->struct_ref++;
	146	engine_ref_debug(e, 0, 1)
	147	/* However it came to be, e is the last item in the list. */
	148	engine_list_tail = e;
	149	e->next = NULL;
	150	return 1;
	151	}
5270e702 RL	152
5270e702 RL	153	static int engine_list_remove(ENGINE *e)
ae5c8664 MC	154	{
ae5c8664 MC	155	ENGINE *iterator;
5270e702	156
ae5c8664 MC	157	if (e == NULL) {
	158	ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
	159	return 0;
	160	}
	161	/* We need to check that e is in our linked list! */
	162	iterator = engine_list_head;
	163	while (iterator && (iterator != e))
	164	iterator = iterator->next;
	165	if (iterator == NULL) {
	166	ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE,
	167	ENGINE_R_ENGINE_IS_NOT_IN_LIST);
	168	return 0;
	169	}
	170	/* un-link e from the chain. */
	171	if (e->next)
	172	e->next->prev = e->prev;
	173	if (e->prev)
	174	e->prev->next = e->next;
	175	/* Correct our head/tail if necessary. */
	176	if (engine_list_head == e)
	177	engine_list_head = e->next;
	178	if (engine_list_tail == e)
	179	engine_list_tail = e->prev;
	180	engine_free_util(e, 0);
	181	return 1;
	182	}
5270e702 RL	183
	184	/* Get the first/last "ENGINE" type available. */
	185	ENGINE *ENGINE_get_first(void)
ae5c8664 MC	186	{
ae5c8664 MC	187	ENGINE *ret;
5270e702	188
ae5c8664 MC	189	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	190	ret = engine_list_head;
	191	if (ret) {
	192	ret->struct_ref++;
	193	engine_ref_debug(ret, 0, 1)
	194	}
	195	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	196	return ret;
	197	}
b6d1e52d	198
5270e702	199	ENGINE *ENGINE_get_last(void)
ae5c8664 MC	200	{
ae5c8664 MC	201	ENGINE *ret;
5270e702	202
ae5c8664 MC	203	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	204	ret = engine_list_tail;
	205	if (ret) {
	206	ret->struct_ref++;
	207	engine_ref_debug(ret, 0, 1)
	208	}
	209	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	210	return ret;
	211	}
5270e702 RL	212
	213	/* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
	214	ENGINE ENGINE_get_next(ENGINE e)
ae5c8664 MC	215	{
	216	ENGINE *ret = NULL;
	217	if (e == NULL) {
	218	ENGINEerr(ENGINE_F_ENGINE_GET_NEXT, ERR_R_PASSED_NULL_PARAMETER);
	219	return 0;
	220	}
	221	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	222	ret = e->next;
	223	if (ret) {
	224	/* Return a valid structural refernce to the next ENGINE */
	225	ret->struct_ref++;
	226	engine_ref_debug(ret, 0, 1)
	227	}
	228	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	229	/* Release the structural reference to the previous ENGINE */
	230	ENGINE_free(e);
	231	return ret;
	232	}
b6d1e52d	233
5270e702	234	ENGINE ENGINE_get_prev(ENGINE e)
ae5c8664 MC	235	{
	236	ENGINE *ret = NULL;
	237	if (e == NULL) {
	238	ENGINEerr(ENGINE_F_ENGINE_GET_PREV, ERR_R_PASSED_NULL_PARAMETER);
	239	return 0;
	240	}
	241	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	242	ret = e->prev;
	243	if (ret) {
	244	/* Return a valid structural reference to the next ENGINE */
	245	ret->struct_ref++;
	246	engine_ref_debug(ret, 0, 1)
	247	}
	248	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	249	/* Release the structural reference to the previous ENGINE */
	250	ENGINE_free(e);
	251	return ret;
	252	}
5270e702 RL	253
	254	/* Add another "ENGINE" type into the list. */
	255	int ENGINE_add(ENGINE *e)
ae5c8664 MC	256	{
	257	int to_return = 1;
	258	if (e == NULL) {
	259	ENGINEerr(ENGINE_F_ENGINE_ADD, ERR_R_PASSED_NULL_PARAMETER);
	260	return 0;
	261	}
	262	if ((e->id == NULL) \|\| (e->name == NULL)) {
	263	ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_ID_OR_NAME_MISSING);
b0042479	264	return 0;
ae5c8664 MC	265	}
	266	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	267	if (!engine_list_add(e)) {
	268	ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
	269	to_return = 0;
	270	}
	271	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	272	return to_return;
	273	}
5270e702 RL	274
	275	/* Remove an existing "ENGINE" type from the array. */
	276	int ENGINE_remove(ENGINE *e)
ae5c8664 MC	277	{
	278	int to_return = 1;
	279	if (e == NULL) {
	280	ENGINEerr(ENGINE_F_ENGINE_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
	281	return 0;
	282	}
	283	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	284	if (!engine_list_remove(e)) {
	285	ENGINEerr(ENGINE_F_ENGINE_REMOVE, ENGINE_R_INTERNAL_LIST_ERROR);
	286	to_return = 0;
	287	}
	288	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	289	return to_return;
	290	}
5270e702	291
b6d1e52d	292	static void engine_cpy(ENGINE dest, const ENGINE src)
ae5c8664 MC	293	{
	294	dest->id = src->id;
	295	dest->name = src->name;
b6d1e52d	296	#ifndef OPENSSL_NO_RSA
ae5c8664	297	dest->rsa_meth = src->rsa_meth;
b6d1e52d GT	298	#endif
b6d1e52d GT	299	#ifndef OPENSSL_NO_DSA
ae5c8664	300	dest->dsa_meth = src->dsa_meth;
b6d1e52d GT	301	#endif
b6d1e52d GT	302	#ifndef OPENSSL_NO_DH
ae5c8664	303	dest->dh_meth = src->dh_meth;
4d94ae00	304	#endif
e172d60d	305	#ifndef OPENSSL_NO_ECDH
ae5c8664	306	dest->ecdh_meth = src->ecdh_meth;
e172d60d	307	#endif
4d94ae00	308	#ifndef OPENSSL_NO_ECDSA
ae5c8664	309	dest->ecdsa_meth = src->ecdsa_meth;
b6d1e52d	310	#endif
ae5c8664 MC	311	dest->rand_meth = src->rand_meth;
	312	dest->store_meth = src->store_meth;
	313	dest->ciphers = src->ciphers;
	314	dest->digests = src->digests;
	315	dest->pkey_meths = src->pkey_meths;
	316	dest->destroy = src->destroy;
	317	dest->init = src->init;
	318	dest->finish = src->finish;
	319	dest->ctrl = src->ctrl;
	320	dest->load_privkey = src->load_privkey;
	321	dest->load_pubkey = src->load_pubkey;
	322	dest->cmd_defns = src->cmd_defns;
	323	dest->flags = src->flags;
	324	}
b6d1e52d	325
5270e702	326	ENGINE ENGINE_by_id(const char id)
ae5c8664 MC	327	{
	328	ENGINE *iterator;
	329	char *load_dir = NULL;
	330	if (id == NULL) {
	331	ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_PASSED_NULL_PARAMETER);
	332	return NULL;
	333	}
	334	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	335	iterator = engine_list_head;
	336	while (iterator && (strcmp(id, iterator->id) != 0))
	337	iterator = iterator->next;
	338	if (iterator) {
	339	/*
	340	* We need to return a structural reference. If this is an ENGINE
	341	* type that returns copies, make a duplicate - otherwise increment
	342	* the existing ENGINE's reference count.
	343	*/
	344	if (iterator->flags & ENGINE_FLAGS_BY_ID_COPY) {
	345	ENGINE *cp = ENGINE_new();
	346	if (!cp)
	347	iterator = NULL;
	348	else {
	349	engine_cpy(cp, iterator);
	350	iterator = cp;
	351	}
	352	} else {
	353	iterator->struct_ref++;
	354	engine_ref_debug(iterator, 0, 1)
	355	}
	356	}
	357	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
aae329c4	358	#if 0
ae5c8664 MC	359	if (iterator == NULL) {
	360	ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE);
	361	ERR_add_error_data(2, "id=", id);
	362	}
	363	return iterator;
aae329c4	364	#else
ae5c8664 MC	365	/* EEK! Experimental code starts */
	366	if (iterator)
	367	return iterator;
	368	/*
	369	* Prevent infinite recusrion if we're looking for the dynamic engine.
	370	*/
	371	if (strcmp(id, "dynamic")) {
	372	# ifdef OPENSSL_SYS_VMS
788d2fa0	373	if ((load_dir = ossl_safe_getenv("OPENSSL_ENGINES")) == 0)
ae5c8664 MC	374	load_dir = "SSLROOT:[ENGINES]";
ae5c8664 MC	375	# else
788d2fa0	376	if ((load_dir = ossl_safe_getenv("OPENSSL_ENGINES")) == 0)
ae5c8664 MC	377	load_dir = ENGINESDIR;
	378	# endif
	379	iterator = ENGINE_by_id("dynamic");
	380	if (!iterator \|\| !ENGINE_ctrl_cmd_string(iterator, "ID", id, 0) \|\|
	381	!ENGINE_ctrl_cmd_string(iterator, "DIR_LOAD", "2", 0) \|\|
	382	!ENGINE_ctrl_cmd_string(iterator, "DIR_ADD",
	383	load_dir, 0) \|\|
	384	!ENGINE_ctrl_cmd_string(iterator, "LIST_ADD", "1", 0) \|\|
	385	!ENGINE_ctrl_cmd_string(iterator, "LOAD", NULL, 0))
	386	goto notfound;
	387	return iterator;
	388	}
	389	notfound:
	390	ENGINE_free(iterator);
	391	ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE);
	392	ERR_add_error_data(2, "id=", id);
	393	return NULL;
	394	/* EEK! Experimental code ends */
aae329c4	395	#endif
ae5c8664	396	}
314c6670 GT	397
314c6670 GT	398	int ENGINE_up_ref(ENGINE *e)
ae5c8664 MC	399	{
	400	if (e == NULL) {
	401	ENGINEerr(ENGINE_F_ENGINE_UP_REF, ERR_R_PASSED_NULL_PARAMETER);
	402	return 0;
	403	}
	404	CRYPTO_add(&e->struct_ref, 1, CRYPTO_LOCK_ENGINE);
	405	return 1;
	406	}