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/* crypto/engine/engine_list.c */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
* project 2000.
*/
/* ====================================================================
* Copyright (c) 1999 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 <openssl/crypto.h>
#include "cryptlib.h"
#include "engine_int.h"
#include <openssl/engine.h>
/* Weird "ex_data" handling. Some have suggested there's some problems with the
* CRYPTO_EX_DATA code (or model), but for now I'm implementing it exactly as
* it's done in crypto/rsa/. That way the usage and documentation of that can be
* used to assist here, and any changes or fixes made there should similarly map
* over here quite straightforwardly. */
static int engine_ex_data_num = 0;
static STACK_OF(CRYPTO_EX_DATA_FUNCS) *engine_ex_data_stack = NULL;
/* 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;
/* A boolean switch, used to ensure we only initialise once. This
* is needed because the engine list may genuinely become empty during
* use (so we can't use engine_list_head as an indicator for example. */
static int engine_list_flag = 0;
/* 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;
}
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++;
/* 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;
/* remove our structural reference. */
e->struct_ref--;
return 1;
}
/* This check always takes place with CRYPTO_LOCK_ENGINE locked up
* so we're synchronised, but we can't call anything that tries to
* lock it again! :-) NB: For convenience (and code-clarity) we
* don't output errors for failures of the engine_list_add function
* as it will generate errors itself. */
static int engine_internal_check(void)
{
if(engine_list_flag)
return 1;
/* This is our first time up, we need to populate the list
* with our statically compiled-in engines. */
if(!engine_list_add(ENGINE_openssl()))
return 0;
engine_list_flag = 1;
return 1;
}
/* Get the first/last "ENGINE" type available. */
ENGINE *ENGINE_get_first(void)
{
ENGINE *ret = NULL;
CRYPTO_r_lock(CRYPTO_LOCK_ENGINE);
if(engine_internal_check())
{
ret = engine_list_head;
if(ret)
ret->struct_ref++;
}
CRYPTO_r_unlock(CRYPTO_LOCK_ENGINE);
return ret;
}
ENGINE *ENGINE_get_last(void)
{
ENGINE *ret = NULL;
CRYPTO_r_lock(CRYPTO_LOCK_ENGINE);
if(engine_internal_check())
{
ret = engine_list_tail;
if(ret)
ret->struct_ref++;
}
CRYPTO_r_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_r_lock(CRYPTO_LOCK_ENGINE);
ret = e->next;
if(ret)
/* Return a valid structural refernce to the next ENGINE */
ret->struct_ref++;
CRYPTO_r_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_r_lock(CRYPTO_LOCK_ENGINE);
ret = e->prev;
if(ret)
/* Return a valid structural reference to the next ENGINE */
ret->struct_ref++;
CRYPTO_r_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 == N
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