ref: 7be7d0681f567e97fd37f937c2e5e486d6d74eab
dir: /sys/src/ape/lib/openssl/crypto/ex_data.c/
/* crypto/ex_data.c */
/*
* Overhaul notes;
*
* This code is now *mostly* thread-safe. It is now easier to understand in what
* ways it is safe and in what ways it is not, which is an improvement. Firstly,
* all per-class stacks and index-counters for ex_data are stored in the same
* global LHASH table (keyed by class). This hash table uses locking for all
* access with the exception of CRYPTO_cleanup_all_ex_data(), which must only be
* called when no other threads can possibly race against it (even if it was
* locked, the race would mean it's possible the hash table might have been
* recreated after the cleanup). As classes can only be added to the hash table,
* and within each class, the stack of methods can only be incremented, the
* locking mechanics are simpler than they would otherwise be. For example, the
* new/dup/free ex_data functions will lock the hash table, copy the method
* pointers it needs from the relevant class, then unlock the hash table before
* actually applying those method pointers to the task of the new/dup/free
* operations. As they can't be removed from the method-stack, only
* supplemented, there's no race conditions associated with using them outside
* the lock. The get/set_ex_data functions are not locked because they do not
* involve this global state at all - they operate directly with a previously
* obtained per-class method index and a particular "ex_data" variable. These
* variables are usually instantiated per-context (eg. each RSA structure has
* one) so locking on read/write access to that variable can be locked locally
* if required (eg. using the "RSA" lock to synchronise access to a
* per-RSA-structure ex_data variable if required).
* [Geoff]
*/
/* Copyright (C) 1995-1998 Eric Young ([email protected])
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young ([email protected]).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson ([email protected]).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* 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 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 acknowledgement:
* "This product includes cryptographic software written by
* Eric Young ([email protected])"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson ([email protected])"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS 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 AUTHOR OR 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.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2001 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]).
*
*/
#include "cryptlib.h"
#include <openssl/lhash.h>
/* What an "implementation of ex_data functionality" looks like */
struct st_CRYPTO_EX_DATA_IMPL
{
/*********************/
/* GLOBAL OPERATIONS */
/* Return a new class index */
int (*cb_new_class)(void);
/* Cleanup all state used by the implementation */
void (*cb_cleanup)(void);
/************************/
/* PER-CLASS OPERATIONS */
/* Get a new method index within a class */
int (*cb_get_new_index)(int class_index, long argl, void *argp,
CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
CRYPTO_EX_free *free_func);
/* Initialise a new CRYPTO_EX_DATA of a given class */
int (*cb_new_ex_data)(int class_index, void *obj,
CRYPTO_EX_DATA *ad);
/* Duplicate a CRYPTO_EX_DATA of a given class onto a copy */
int (*cb_dup_ex_data)(int class_index, CRYPTO_EX_DATA *to,
CRYPTO_EX_DATA *from);
/* Cleanup a CRYPTO_EX_DATA of a given class */
void (*cb_free_ex_data)(int class_index, void *obj,
CRYPTO_EX_DATA *ad);
};
/* The implementation we use at run-time */
static const CRYPTO_EX_DATA_IMPL *impl = NULL;
/* To call "impl" functions, use this macro rather than referring to 'impl' directly, eg.
* EX_IMPL(get_new_index)(...); */
#define EX_IMPL(a) impl->cb_##a
/* Predeclare the "default" ex_data implementation */
static int int_new_class(void);
static void int_cleanup(void);
static int int_get_new_index(int class_index, long argl, void *argp,
CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
CRYPTO_EX_free *free_func);
static int int_new_ex_data(int class_index, void *obj,
CRYPTO_EX_DATA *ad);
static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
CRYPTO_EX_DATA *from);
static void int_free_ex_data(int class_index, void *obj,
CRYPTO_EX_DATA *ad);
static CRYPTO_EX_DATA_IMPL impl_default =
{
int_new_class,
int_cleanup,
int_get_new_index,
int_new_ex_data,
int_dup_ex_data,
int_free_ex_data
};
/* Internal function that checks whether "impl" is set and if not, sets it to
* the default. */
static void impl_check(void)
{
CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
if(!impl)
impl = &impl_default;
CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
}
/* A macro wrapper for impl_check that first uses a non-locked test before
* invoking the function (which checks again inside a lock). */
#define IMPL_CHECK if(!impl) impl_check();
/* API functions to get/set the "ex_data" implementation */
const CRYPTO_EX_DATA_IMPL *CRYPTO_get_ex_data_implementation(void)
{
IMPL_CHECK
return impl;
}
int CRYPTO_set_ex_data_implementation(const CRYPTO_EX_DATA_IMPL *i)
{
int toret = 0;
CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
if(!impl)
{
impl = i;
toret = 1;
}
CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
return toret;
}
/****************************************************************************/
/* Interal (default) implementation of "ex_data" support. API functions are
* further down. */
/* The type that represents what each "class" used to implement locally. A STACK
* of CRYPTO_EX_DATA_FUNCS plus a index-counter. The 'class_index' is the global
* value representing the class that is used to distinguish these items. */
typedef struct st_ex_class_item {
int class_index;
STACK_OF(CRYPTO_EX_DATA_FUNCS) *meth;
int meth_num;
} EX_CLASS_ITEM;
/* When assigning new class indexes, this is our counter */
static int ex_class = CRYPTO_EX_INDEX_USER;
/* The global hash table of EX_CLASS_ITEM items */
static LHASH *ex_data = NULL;
/* The callbacks required in the "ex_data" hash table */
static unsigned long ex_hash_cb(const void *a_void)
{
return ((const EX_CLASS_ITEM *)a_void)->class_index;
}
static int ex_cmp_cb(const void *a_void, const void *b_void)
{
return (((const EX_CLASS_ITEM *)a_void)->class_index -
((const EX_CLASS_ITEM *)b_void)->class_index);
}
/* Internal functions used by the "impl_default" implementation to access the
* state */
static int ex_data_check(void)
{
int toret = 1;
CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
if(!ex_data && ((ex_data = lh_new(ex_hash_cb, ex_cmp_cb)) == NULL))
toret = 0;
CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
return toret;
}
/* This macros helps reduce the locking from repeated checks because the
* ex_data_check() function checks ex_data again inside a lock. */
#define EX_DATA_CHECK(iffail) if(!ex_data && !ex_data_check()) {iffail}
/* This "inner" callback is used by the callback function that follows it */
static void def_cleanup_util_cb(CRYPTO_EX_DATA_FUNCS *funcs)
{
OPENSSL_free(funcs);
}
/* This callback is used in lh_doall to destroy all EX_CLASS_ITEM values from
* "ex_data" prior to the ex_data hash table being itself destroyed. Doesn't do
* any locking. */
static void def_cleanup_cb(void *a_void)
{
EX_CLASS_ITEM *item = (EX_CLASS_ITEM *)a_void;
sk_CRYPTO_EX_DATA_FUNCS_pop_free(item->meth, def_cleanup_util_cb);
OPENSSL_free(item);
}
/* Return the EX_CLASS_ITEM from the "ex_data" hash table that corresponds to a
* given class. Handles locking. */
static EX_CLASS_ITEM *def_get_class(int class_index)
{
EX_CLASS_ITEM d, *p, *gen;
EX_DATA_CHECK(return NULL;)
d.class_index = class_index;
CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
p = lh_retrieve(ex_data, &d);
if(!p)
{
gen = OPENSSL_malloc(sizeof(EX_CLASS_ITEM));
if(gen)
{
gen->class_index = class_index;
gen->meth_num = 0;
gen->meth = sk_CRYPTO_EX_DATA_FUNCS_new_null();
if(!gen->meth)
OPENSSL_free(gen);
else
{
/* Because we're inside the ex_data lock, the
* return value from the insert will be NULL */
lh_insert(ex_data, gen);
p = gen;
}
}
}
CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
if(!p)
CRYPTOerr(CRYPTO_F_DEF_GET_CLASS,ERR_R_MALLOC_FAILURE);
return p;
}
/* Add a new method to the given EX_CLASS_ITEM and return the corresponding
* index (or -1 for error). Handles locking. */
static int def_add_index(EX_CLASS_ITEM *item, long argl, void *argp,
CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
CRYPTO_EX_free *free_func)
{
int toret = -1;
CRYPTO_EX_DATA_FUNCS *a = (CRYPTO_EX_DATA_FUNCS *)OPENSSL_malloc(
sizeof(CRYPTO_EX_DATA_FUNCS));
if(!a)
{
CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX,ERR_R_MALLOC_FAILURE);
return -1;
}
a->argl=argl;
a->argp=argp;
a->new_func=new_func;
a->dup_func=dup_func;
a->free_func=free_func;
CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
while (sk_CRYPTO_EX_DATA_FUNCS_num(item->meth) <= item->meth_num)
{
if (!sk_CRYPTO_EX_DATA_FUNCS_push(item->meth, NULL))
{
CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX,ERR_R_MALLOC_FAILURE);
OPENSSL_free(a);
goto err;
}
}
toret = item->meth_num++;
(void)sk_CRYPTO_EX_DATA_FUNCS_set(item->meth, toret, a);
err:
CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
return toret;
}
/**************************************************************/
/* The functions in the default CRYPTO_EX_DATA_IMPL structure */
static int int_new_class(void)
{
int toret;
CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
toret = ex_class++;
CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
return toret;
}
static void int_cleanup(void)
{
EX_DATA_CHECK(return;)
lh_doall(ex_data, def_cleanup_cb);
lh_free(ex_data);
ex_data = NULL;
impl = NULL;
}
static int int_get_new_index(int class_index, long argl, void *argp,
CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
CRYPTO_EX_free *free_func)
{
EX_CLASS_ITEM *item = def_get_class(class_index);
if(!item)
return -1;
return def_add_index(item, argl, argp, new_func, dup_func, free_func);
}
/* Thread-safe by copying a class's array of "CRYPTO_EX_DATA_FUNCS" entries in
* the lock, then using them outside the lock. NB: Thread-safety only applies to
* the global "ex_data" state (ie. class definitions), not thread-safe on 'ad'
* itself. */
static int int_new_ex_data(int class_index, void *obj,
CRYPTO_EX_DATA *ad)
{
int mx,i;
void *ptr;
CRYPTO_EX_DATA_FUNCS **storage = NULL;
EX_CLASS_ITEM *item = def_get_class(class_index);
if(!item)
/* error is already set */
return 0;
ad->sk = NULL;
CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
if(mx > 0)
{
storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
if(!storage)
goto skip;
for(i = 0; i < mx; i++)
storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
}
skip:
CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
if((mx > 0) && !storage)
{
CRYPTOerr(CRYPTO_F_INT_NEW_EX_DATA,ERR_R_MALLOC_FAILURE);
return 0;
}
for(i = 0; i < mx; i++)
{
if(storage[i] && storage[i]->new_func)
{
ptr = CRYPTO_get_ex_data(ad, i);
storage[i]->new_func(obj,ptr,ad,i,
storage[i]->argl,storage[i]->argp);
}
}
if(storage)
OPENSSL_free(storage);
return 1;
}
/* Same thread-safety notes as for "int_new_ex_data" */
static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
CRYPTO_EX_DATA *from)
{
int mx, j, i;
char *ptr;
CRYPTO_EX_DATA_FUNCS **storage = NULL;
EX_CLASS_ITEM *item;
if(!from->sk)
/* 'to' should be "blank" which *is* just like 'from' */
return 1;
if((item = def_get_class(class_index)) == NULL)
return 0;
CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
j = sk_num(from->sk);
if(j < mx)
mx = j;
if(mx > 0)
{
storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
if(!storage)
goto skip;
for(i = 0; i < mx; i++)
storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
}
skip:
CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
if((mx > 0) && !storage)
{
CRYPTOerr(CRYPTO_F_INT_DUP_EX_DATA,ERR_R_MALLOC_FAILURE);
return 0;
}
for(i = 0; i < mx; i++)
{
ptr = CRYPTO_get_ex_data(from, i);
if(storage[i] && storage[i]->dup_func)
storage[i]->dup_func(to,from,&ptr,i,
storage[i]->argl,storage[i]->argp);
CRYPTO_set_ex_data(to,i,ptr);
}
if(storage)
OPENSSL_free(storage);
return 1;
}
/* Same thread-safety notes as for "int_new_ex_data" */
static void int_free_ex_data(int class_index, void *obj,
CRYPTO_EX_DATA *ad)
{
int mx,i;
EX_CLASS_ITEM *item;
void *ptr;
CRYPTO_EX_DATA_FUNCS **storage = NULL;
if((item = def_get_class(class_index)) == NULL)
return;
CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA);
mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth);
if(mx > 0)
{
storage = OPENSSL_malloc(mx * sizeof(CRYPTO_EX_DATA_FUNCS*));
if(!storage)
goto skip;
for(i = 0; i < mx; i++)
storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value(item->meth,i);
}
skip:
CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA);
if((mx > 0) && !storage)
{
CRYPTOerr(CRYPTO_F_INT_FREE_EX_DATA,ERR_R_MALLOC_FAILURE);
return;
}
for(i = 0; i < mx; i++)
{
if(storage[i] && storage[i]->free_func)
{
ptr = CRYPTO_get_ex_data(ad,i);
storage[i]->free_func(obj,ptr,ad,i,
storage[i]->argl,storage[i]->argp);
}
}
if(storage)
OPENSSL_free(storage);
if(ad->sk)
{
sk_free(ad->sk);
ad->sk=NULL;
}
}
/********************************************************************/
/* API functions that defer all "state" operations to the "ex_data"
* implementation we have set. */
/* Obtain an index for a new class (not the same as getting a new index within
* an existing class - this is actually getting a new *class*) */
int CRYPTO_ex_data_new_class(void)
{
IMPL_CHECK
return EX_IMPL(new_class)();
}
/* 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(void)
{
IMPL_CHECK
EX_IMPL(cleanup)();
}
/* Inside an existing class, get/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 ret = -1;
IMPL_CHECK
ret = EX_IMPL(get_new_index)(class_index,
argl, argp, new_func, dup_func, free_func);
return ret;
}
/* 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 */
int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
{
IMPL_CHECK
return EX_IMPL(new_ex_data)(class_index, obj, ad);
}
/* 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,
CRYPTO_EX_DATA *from)
{
IMPL_CHECK
return EX_IMPL(dup_ex_data)(class_index, to, from);
}
/* 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)
{
IMPL_CHECK
EX_IMPL(free_ex_data)(class_index, obj, ad);
}
/* 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_new_null()) == NULL)
{
CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA,ERR_R_MALLOC_FAILURE);
return(0);
}
}
i=sk_num(ad->sk);
while (i <= idx)
{
if (!sk_push(ad->sk,NULL))
{
CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA,ERR_R_MALLOC_FAILURE);
return(0);
}
i++;
}
sk_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)
return(0);
else if (idx >= sk_num(ad->sk))
return(0);
else
return(sk_value(ad->sk,idx));
}
IMPLEMENT_STACK_OF(CRYPTO_EX_DATA_FUNCS)