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mirror of https://github.com/openssl/openssl.git synced 2025-03-07 19:38:33 +08:00
openssl/crypto/engine/eng_list.c
Bernd Edlinger e2571e02d2 Avoid loading of a dynamic engine twice
Use the address of the bind function as a DYNAMIC_ID,
since the true name of the engine is not known
before the bind function returns,
but invoking the bind function before the engine
is unloaded results in memory corruption.

Fixes 

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/17073)
2021-11-23 06:08:16 +01:00

445 lines
13 KiB
C

/*
* Copyright 2001-2021 The OpenSSL Project Authors. All Rights Reserved.
* Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
*
* Licensed under the Apache License 2.0 (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
*/
/* We need to use some engine deprecated APIs */
#define OPENSSL_SUPPRESS_DEPRECATED
#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;
/*
* The linked list of currently loaded dynamic engines.
*/
static ENGINE *engine_dyn_list_head = NULL;
static ENGINE *engine_dyn_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) {
ERR_raise(ERR_LIB_ENGINE, 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) {
ERR_raise(ERR_LIB_ENGINE, ENGINE_R_CONFLICTING_ENGINE_ID);
return 0;
}
if (engine_list_head == NULL) {
/* We are adding to an empty list. */
if (engine_list_tail) {
ERR_raise(ERR_LIB_ENGINE, 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)) {
ERR_raise(ERR_LIB_ENGINE, 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_PRINT(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) {
ERR_raise(ERR_LIB_ENGINE, 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) {
ERR_raise(ERR_LIB_ENGINE, 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;
}
/* Add engine to dynamic engine list. */
int engine_add_dynamic_id(ENGINE *e, ENGINE_DYNAMIC_ID dynamic_id,
int not_locked)
{
int result = 0;
ENGINE *iterator = NULL;
if (e == NULL)
return 0;
if (e->dynamic_id == NULL && dynamic_id == NULL)
return 0;
if (not_locked && !CRYPTO_THREAD_write_lock(global_engine_lock))
return 0;
if (dynamic_id != NULL) {
iterator = engine_dyn_list_head;
while (iterator != NULL) {
if (iterator->dynamic_id == dynamic_id)
goto err;
iterator = iterator->next;
}
if (e->dynamic_id != NULL)
goto err;
e->dynamic_id = dynamic_id;
}
if (engine_dyn_list_head == NULL) {
/* We are adding to an empty list. */
if (engine_dyn_list_tail != NULL)
goto err;
engine_dyn_list_head = e;
e->prev_dyn = NULL;
} else {
/* We are adding to the tail of an existing list. */
if (engine_dyn_list_tail == NULL
|| engine_dyn_list_tail->next_dyn != NULL)
goto err;
engine_dyn_list_tail->next_dyn = e;
e->prev_dyn = engine_dyn_list_tail;
}
engine_dyn_list_tail = e;
e->next_dyn = NULL;
result = 1;
err:
if (not_locked)
CRYPTO_THREAD_unlock(global_engine_lock);
return result;
}
/* Remove engine from dynamic engine list. */
void engine_remove_dynamic_id(ENGINE *e, int not_locked)
{
if (e == NULL || e->dynamic_id == NULL)
return;
if (not_locked && !CRYPTO_THREAD_write_lock(global_engine_lock))
return;
e->dynamic_id = NULL;
/* un-link e from the chain. */
if (e->next_dyn != NULL)
e->next_dyn->prev_dyn = e->prev_dyn;
if (e->prev_dyn != NULL)
e->prev_dyn->next_dyn = e->next_dyn;
/* Correct our head/tail if necessary. */
if (engine_dyn_list_head == e)
engine_dyn_list_head = e->next_dyn;
if (engine_dyn_list_tail == e)
engine_dyn_list_tail = e->prev_dyn;
if (not_locked)
CRYPTO_THREAD_unlock(global_engine_lock);
}
/* Get the first/last "ENGINE" type available. */
ENGINE *ENGINE_get_first(void)
{
ENGINE *ret;
if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_MALLOC_FAILURE);
return NULL;
}
if (!CRYPTO_THREAD_write_lock(global_engine_lock))
return NULL;
ret = engine_list_head;
if (ret) {
ret->struct_ref++;
ENGINE_REF_PRINT(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)) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_MALLOC_FAILURE);
return NULL;
}
if (!CRYPTO_THREAD_write_lock(global_engine_lock))
return NULL;
ret = engine_list_tail;
if (ret) {
ret->struct_ref++;
ENGINE_REF_PRINT(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) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
return NULL;
}
if (!CRYPTO_THREAD_write_lock(global_engine_lock))
return NULL;
ret = e->next;
if (ret) {
/* Return a valid structural reference to the next ENGINE */
ret->struct_ref++;
ENGINE_REF_PRINT(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) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
return NULL;
}
if (!CRYPTO_THREAD_write_lock(global_engine_lock))
return NULL;
ret = e->prev;
if (ret) {
/* Return a valid structural reference to the next ENGINE */
ret->struct_ref++;
ENGINE_REF_PRINT(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) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if ((e->id == NULL) || (e->name == NULL)) {
ERR_raise(ERR_LIB_ENGINE, ENGINE_R_ID_OR_NAME_MISSING);
return 0;
}
if (!CRYPTO_THREAD_write_lock(global_engine_lock))
return 0;
if (!engine_list_add(e)) {
ERR_raise(ERR_LIB_ENGINE, 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) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if (!CRYPTO_THREAD_write_lock(global_engine_lock))
return 0;
if (!engine_list_remove(e)) {
ERR_raise(ERR_LIB_ENGINE, 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;
dest->rsa_meth = src->rsa_meth;
#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;
dest->dynamic_id = src->dynamic_id;
engine_add_dynamic_id(dest, NULL, 0);
}
ENGINE *ENGINE_by_id(const char *id)
{
ENGINE *iterator;
char *load_dir = NULL;
if (id == NULL) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
return NULL;
}
ENGINE_load_builtin_engines();
if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_MALLOC_FAILURE);
return NULL;
}
if (!CRYPTO_THREAD_write_lock(global_engine_lock))
return NULL;
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_PRINT(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);
ERR_raise_data(ERR_LIB_ENGINE, ENGINE_R_NO_SUCH_ENGINE, "id=%s", id);
return NULL;
/* EEK! Experimental code ends */
}
int ENGINE_up_ref(ENGINE *e)
{
int i;
if (e == NULL) {
ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
CRYPTO_UP_REF(&e->struct_ref, &i, global_engine_lock);
return 1;
}