eng_list.c

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/* crypto/engine/eng_list.c */
/* Written by Geoff Thorpe ([email protected]) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * 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
 *    [email protected].
 *
 * 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
 * ([email protected]).  This product includes software written by Tim
 * Hudson ([email protected]).
 *
 */
/* ====================================================================
 * 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 "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);
        }
    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 = getenv("OPENSSL_ENGINES")) == 0) load_dir = "SSLROOT:[ENGINES]";
#else
        if((load_dir = 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, "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;
    }