/*
* Copyright 1995-2020 The OpenSSL Project Authors. 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 "crypto/cryptlib.h"
#include "internal/thread_once.h"
/*
* Each structure type (sometimes called a class), that supports
* exdata has a stack of callbacks for each instance.
*/
struct ex_callback_st {
long argl; /* Arbitrary long */
void *argp; /* Arbitrary void * */
CRYPTO_EX_new *new_func;
CRYPTO_EX_free *free_func;
CRYPTO_EX_dup *dup_func;
};
/*
* The state for each class. This could just be a typedef, but
* a structure allows future changes.
*/
typedef struct ex_callbacks_st {
STACK_OF(EX_CALLBACK) *meth;
} EX_CALLBACKS;
static EX_CALLBACKS ex_data[CRYPTO_EX_INDEX__COUNT];
static CRYPTO_RWLOCK *ex_data_lock = NULL;
static CRYPTO_ONCE ex_data_init = CRYPTO_ONCE_STATIC_INIT;
DEFINE_RUN_ONCE_STATIC(do_ex_data_init)
{
if (!OPENSSL_init_crypto(0, NULL))
return 0;
ex_data_lock = CRYPTO_THREAD_lock_new();
return ex_data_lock != NULL;
}
/*
* Return the EX_CALLBACKS from the |ex_data| array that corresponds to
* a given class. On success, *holds the lock.*
*/
static EX_CALLBACKS *get_and_lock(int class_index)
{
EX_CALLBACKS *ip;
if (class_index < 0 || class_index >= CRYPTO_EX_INDEX__COUNT) {
CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_PASSED_INVALID_ARGUMENT);
return NULL;
}
if (!RUN_ONCE(&ex_data_init, do_ex_data_init)) {
CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_MALLOC_FAILURE);
return NULL;
}
if (ex_data_lock == NULL) {
/*
* This can happen in normal operation when using CRYPTO_mem_leaks().
* The CRYPTO_mem_leaks() function calls OPENSSL_cleanup() which cleans
* up the locks. Subsequently the BIO that CRYPTO_mem_leaks() uses gets
* freed, which also attempts to free the ex_data. However
* CRYPTO_mem_leaks() ensures that the ex_data is freed early (i.e.
* before OPENSSL_cleanup() is called), so if we get here we can safely
* ignore this operation. We just treat it as an error.
*/
return NULL;
}
ip = &ex_data[class_index];
CRYPTO_THREAD_write_lock(ex_data_lock);
return ip;
}
static void cleanup_cb(EX_CALLBACK *funcs)
{
OPENSSL_free(funcs);
}
/*
* Release all "ex_data" state to prevent memory leaks. This can't be made
* thread-safe without overhauling a lot of stuff, and shouldn't really be
* called under potential race-conditions anyway (it's for program shutdown
* after all).
*/
void crypto_cleanup_all_ex_data_int(void)
{
int i;
for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) {
EX_CALLBACKS *ip = &ex_data[i];
sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);
ip->meth = NULL;
}
CRYPTO_THREAD_lock_free(ex_data_lock);
ex_data_lock = NULL;
}
/*
* Unregister a new index by replacing the callbacks with no-ops.
* Any in-use instances are leaked.
*/
static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
long argl, void *argp)
{
}
static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
long argl, void *argp)
{
}
static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from,
void *from_d, int idx,
long argl, void *argp)
{
return 1;
}
int CRYPTO_free_ex_index(int class_index, int idx)
{
EX_CALLBACKS *ip = get_and_lock(class_index);
EX_CALLBACK *a;
int toret = 0;
if (ip == NULL)
return 0;
if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth))
goto err;
a = sk_EX_CALLBACK_value(ip->meth, idx);
if (a == NULL)
goto err;
a->new_func = dummy_new;
a->dup_func = dummy_dup;
a->free_func = dummy_free;
toret = 1;
err:
CRYPTO_THREAD_unlock(ex_data_lock);
return toret;
}
/*
* Register a new index.
*/
int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
CRYPTO_EX_free *free_func)
{
int toret = -1;
EX_CALLBACK *a;
EX_CALLBACKS *ip = get_and_lock(class_index);
if (ip == NULL)
return -1;
if (ip->meth == NULL) {
ip->meth = sk_EX_CALLBACK_new_null();
/* We push an initial value on the stack because the SSL
* "app_data" routines use ex_data index zero. See RT 3710. */
if (ip->meth == NULL
|| !sk_EX_CALLBACK_push(ip->meth, NULL)) {
CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
goto err;
}
}
a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a));
if (a == NULL) {
CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
goto err;
}
a->argl = argl;
a->argp = argp;
a->new_func = new_func;
a->dup_func = dup_func;
a->free_func = free_func;
if (!sk_EX_CALLBACK_push(ip->meth, NULL)) {
CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
OPENSSL_free(a);
goto err;
}
toret = sk_EX_CALLBACK_num(ip->meth) - 1;
(void)sk_EX_CALLBACK_set(ip->meth, toret, a);
err:
CRYPTO_THREAD_unlock(ex_data_lock);
return toret;
}
/*
* Initialise a new CRYPTO_EX_DATA for use in a particular class - including
* calling new() callbacks for each index in the class used by this variable
* Thread-safe by copying a class's array of "EX_CALLBACK" entries
* in the lock, then using them outside the lock. Note this only applies
* to the global "ex_data" state (ie. class definitions), not 'ad' itself.
*/
int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
{
int mx, i;
void *ptr;
EX_CALLBACK **storage = NULL;
EX_CALLBACK *stack[10];
EX_CALLBACKS *ip = get_and_lock(class_index);
if (ip == NULL)
return 0;
ad->sk = NULL;
mx = sk_EX_CALLBACK_num(ip->meth);
if (mx > 0) {
if (mx < (int)OSSL_NELEM(stack))
storage = stack;
else
storage = OPENSSL_malloc(sizeof(*storage) * mx);
if (storage != NULL)
for (i = 0; i < mx; i++)
storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
}
CRYPTO_THREAD_unlock(ex_data_lock);
if (mx > 0 && storage == NULL) {
CRYPTOerr(CRYPTO_F_CRYPTO_NEW_EX_DATA, ERR_R_MALLOC_FAILURE);
return 0;
}
for (i = 0; i < mx; i++) {
if (storage[i] != NULL && storage[i]->new_func != NULL) {
ptr = CRYPTO_get_ex_data(ad, i);
storage[i]->new_func(obj, ptr, ad, i,
storage[i]->argl, storage[i]->argp);
}
}
if (storage != stack)
OPENSSL_free(storage);
return 1;
}
/*
* Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
* for each index in the class used by this variable
*/
int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
const CRYPTO_EX_DATA *from)
{
int mx, j, i;
void *ptr;
EX_CALLBACK *stack[10];
EX_CALLBACK **storage = NULL;
EX_CALLBACKS *ip;
int toret = 0;
if (from->sk == NULL)
/* Nothing to copy over */
return 1;
if ((ip = get_and_lock(class_index)) == NULL)
return 0;
mx = sk_EX_CALLBACK_num(ip->meth);
j = sk_void_num(from->sk);
if (j < mx)
mx = j;
if (mx > 0) {
if (mx < (int)OSSL_NELEM(stack))
storage = stack;
else
storage = OPENSSL_malloc(sizeof(*storage) * mx);
if (storage != NULL)
for (i = 0; i < mx; i++)
storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
}
CRYPTO_THREAD_unlock(ex_data_lock);
if (mx == 0)
return 1;
if (storage == NULL) {
CRYPTOerr(CRYPTO_F_CRYPTO_DUP_EX_DATA, ERR_R_MALLOC_FAILURE);
return 0;
}
/*
* Make sure the ex_data stack is at least |mx| elements long to avoid
* issues in the for loop that follows; so go get the |mx|'th element
* (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign
* to itself. This is normally a no-op; but ensures the stack is the
* proper size
*/
if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))
goto err;
for (i = 0; i < mx; i++) {
ptr = CRYPTO_get_ex_data(from, i);
if (storage[i] != NULL && storage[i]->dup_func != NULL)
if (!storage[i]->dup_func(to, from, &ptr, i,
storage[i]->argl, storage[i]->argp))
goto err;
CRYPTO_set_ex_data(to, i, ptr);
}
toret = 1;
err:
if (storage != stack)
OPENSSL_free(storage);
return toret;
}
/*
* Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
* each index in the class used by this variable
*/
void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
{
int mx, i;
EX_CALLBACKS *ip;
void *ptr;
EX_CALLBACK *f;
EX_CALLBACK *stack[10];
EX_CALLBACK **storage = NULL;
if ((ip = get_and_lock(class_index)) == NULL)
goto err;
mx = sk_EX_CALLBACK_num(ip->meth);
if (mx > 0) {
if (mx < (int)OSSL_NELEM(stack))
storage = stack;
else
storage = OPENSSL_malloc(sizeof(*storage) * mx);
if (storage != NULL)
for (i = 0; i < mx; i++)
storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
}
CRYPTO_THREAD_unlock(ex_data_lock);
for (i = 0; i < mx; i++) {
if (storage != NULL)
f = storage[i];
else {
CRYPTO_THREAD_write_lock(ex_data_lock);
f = sk_EX_CALLBACK_value(ip->meth, i);
CRYPTO_THREAD_unlock(ex_data_lock);
}
if (f != NULL && f->free_func != NULL) {
ptr = CRYPTO_get_ex_data(ad, i);
f->free_func(obj, ptr, ad, i, f->argl, f->argp);
}
}
if (storage != stack)
OPENSSL_free(storage);
err:
sk_void_free(ad->sk);
ad->sk = NULL;
}
/*
* For a given CRYPTO_EX_DATA variable, set the value corresponding to a
* particular index in the class used by this variable
*/
int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
{
int i;
if (ad->sk == NULL) {
if ((ad->sk = sk_void_new_null()) == NULL) {
CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
return 0;
}
}
for (i = sk_void_num(ad->sk); i <= idx; ++i) {
if (!sk_void_push(ad->sk, NULL)) {
CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
return 0;
}
}
sk_void_set(ad->sk, idx, val);
return 1;
}
/*
* For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
* particular index in the class used by this variable
*/
void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
{
if (ad->sk == NULL || idx >= sk_void_num(ad->sk))
return NULL;
return sk_void_value(ad->sk, idx);
}