/*
* Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
* Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "eng_local.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 optimization 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_int()" 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 global_engine_lock 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;
if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
ENGINEerr(ENGINE_F_ENGINE_GET_FIRST, ERR_R_MALLOC_FAILURE);
return NULL;
}
CRYPTO_THREAD_write_lock(global_engine_lock);
ret = engine_list_head;
if (ret) {
ret->struct_ref++;
engine_ref_debug(ret, 0, 1);
}
CRYPTO_THREAD_unlock(global_engine_lock);
return ret;
}
ENGINE *ENGINE_get_last(void)
{
ENGINE *ret;
if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
ENGINEerr(ENGINE_F_ENGINE_GET_LAST, ERR_R_MALLOC_FAILURE);
return NULL;
}
CRYPTO_THREAD_write_lock(global_engine_lock);
ret = engine_list_tail;
if (ret) {
ret->struct_ref++;
engine_ref_debug(ret, 0, 1);
}
CRYPTO_THREAD_unlock(global_engine_lock);
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_THREAD_write_lock(global_engine_lock);
ret = e->next;
if (ret) {
/* Return a valid structural reference to the next ENGINE */
ret->struct_ref++;
engine_ref_debug(ret, 0, 1);
}
CRYPTO_THREAD_unlock(global_engine_lock);
/* 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_THREAD_write_lock(global_engine_lock);
ret = e->prev;
if (ret) {
/* Return a valid structural reference to the next ENGINE */
ret->struct_ref++;
engine_ref_debug(ret, 0, 1);
}
CRYPTO_THREAD_unlock(global_engine_lock);
/* 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_THREAD_write_lock(global_engine_lock);
if (!engine_list_add(e)) {
ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
to_return = 0;
}
CRYPTO_THREAD_unlock(global_engine_lock);
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_THREAD_write_lock(global_engine_lock);
if (!engine_list_remove(e)) {
ENGINEerr(ENGINE_F_ENGINE_REMOVE, ENGINE_R_INTERNAL_LIST_ERROR);
to_return = 0;
}
CRYPTO_THREAD_unlock(global_engine_lock);
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_EC
dest->ec_meth = src->ec_meth;
#endif
dest->rand_meth = src->rand_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;
}
if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_MALLOC_FAILURE);
return NULL;
}
CRYPTO_THREAD_write_lock(global_engine_lock);
iterator = engine_list_head;
while (iterator && (strcmp(id, iterator->id) != 0))
iterator = iterator->next;
if (iterator != NULL) {
/*
* 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 == NULL)
iterator = NULL;
else {
engine_cpy(cp, iterator);
iterator = cp;
}
} else {
iterator->struct_ref++;
engine_ref_debug(iterator, 0, 1);
}
}
CRYPTO_THREAD_unlock(global_engine_lock);
if (iterator != NULL)
return iterator;
/*
* Prevent infinite recursion if we're looking for the dynamic engine.
*/
if (strcmp(id, "dynamic")) {
if ((load_dir = ossl_safe_getenv("OPENSSL_ENGINES")) == NULL)
load_dir = ENGINESDIR;
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 */
}
int ENGINE_up_ref(ENGINE *e)
{
int i;
if (e == NULL) {
ENGINEerr(ENGINE_F_ENGINE_UP_REF, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
CRYPTO_UP_REF(&e->struct_ref, &i, global_engine_lock);
return 1;
}