X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fex_data.c;h=5b2e345c27b7b7e4f7f3997a9c89d806526cad7e;hp=42b8b9d1baeabc99b58b52f9932807027740c07e;hb=a18894d159651891d11155af2feaadb18b4f256c;hpb=dfeab0689f69c0b4bd3480ffd37a9cacc2f17d9c

diff --git a/crypto/ex_data.c b/crypto/ex_data.c
index 42b8b9d1ba..5b2e345c27 100644
--- a/crypto/ex_data.c
+++ b/crypto/ex_data.c
@@ -1,4 +1,33 @@
 /* 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 (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -55,187 +84,553 @@
  * 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
+ *    openssl-core@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 <stdio.h>
 #include <stdlib.h>
-#include "buffer.h"
-#include "bio.h"
-#include "lhash.h"
+#include <openssl/buffer.h>
+#include <openssl/bio.h>
+#include <openssl/lhash.h>
 #include "cryptlib.h"
 
-int CRYPTO_get_ex_new_index(idx,skp,argl,argp,new_func,dup_func,free_func)
-int idx;
-STACK **skp;
-long argl;
-char *argp;
-int (*new_func)();
-int (*dup_func)();
-void (*free_func)();
+/* 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(const void *a_void)
 	{
-	int ret= -1;
-	CRYPTO_EX_DATA_FUNCS *a;
+	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);
+	}
 
-	MemCheck_off();
-	if (*skp == NULL)
-		*skp=sk_new_null();
-	if (*skp == NULL)
+/* 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)
 		{
-		CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX,ERR_R_MALLOC_FAILURE);
-		goto err;
+		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;
+				}
+			}
 		}
-	a=(CRYPTO_EX_DATA_FUNCS *)Malloc(sizeof(CRYPTO_EX_DATA_FUNCS));
-	if (a == NULL)
+	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_CRYPTO_GET_EX_NEW_INDEX,ERR_R_MALLOC_FAILURE);
-		goto err;
+		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;
-	while (sk_num(*skp) <= idx)
+	CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA);
+	while (sk_CRYPTO_EX_DATA_FUNCS_num(item->meth) <= item->meth_num)
 		{
-		if (!sk_push(*skp,NULL))
+		if (!sk_CRYPTO_EX_DATA_FUNCS_push(item->meth, NULL))
 			{
-			CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX,ERR_R_MALLOC_FAILURE);
-			Free(a);
+			CRYPTOerr(CRYPTO_F_DEF_ADD_INDEX,ERR_R_MALLOC_FAILURE);
+			OPENSSL_free(a);
 			goto err;
 			}
 		}
-	sk_value(*skp,idx)=(char *)a;
-	ret=idx;
+	toret = item->meth_num++;
+	sk_CRYPTO_EX_DATA_FUNCS_set(item->meth, toret, a);
 err:
-	MemCheck_on();
-	return(idx);
+	CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA);
+	return toret;
 	}
 
-int CRYPTO_set_ex_data(ad,idx,val)
-CRYPTO_EX_DATA *ad;
-int idx;
-char *val;
-	{
-	int i;
+/**************************************************************/
+/* The functions in the default CRYPTO_EX_DATA_IMPL structure */
 
-	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);
+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;
+	}
 
-	while (i <= idx)
-		{
-		if (!sk_push(ad->sk,NULL))
-			{
-			CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA,ERR_R_MALLOC_FAILURE);
-			return(0);
-			}
-		i++;
-		}
-	sk_value(ad->sk,idx)=val;
-	return(1);
+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;
 	}
 
-char *CRYPTO_get_ex_data(ad,idx)
-CRYPTO_EX_DATA *ad;
-int idx;
+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)
 	{
-	if (ad->sk == NULL)
-		return(0);
-	else if (idx >= sk_num(ad->sk))
-		return(0);
-	else
-		return(sk_value(ad->sk,idx));
+	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);
 	}
 
-/* The callback is called with the 'object', which is the origional data object
- * being duplicated, a pointer to the
- * 'new' object to be inserted, the index, and the argi/argp
- */
-int CRYPTO_dup_ex_data(meth,to,from)
-STACK *meth;
-CRYPTO_EX_DATA *to,*from;
-	{
-	int i,j,m,r;
-	CRYPTO_EX_DATA_FUNCS *mm;
-	char *from_d;
-
-	if (meth == NULL) return(1);
-	if (from->sk == NULL) return(1);
-	m=sk_num(meth);
-	j=sk_num(from->sk);
-	for (i=0; i<j; i++)
-		{
-		from_d=CRYPTO_get_ex_data(from,i);
-		if (i < m)
+/* 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)
 			{
-			mm=(CRYPTO_EX_DATA_FUNCS *)sk_value(meth,i);
-			if (mm->dup_func != NULL)
-				r=mm->dup_func(to,from,(char **)&from_d,i,
-					mm->argl,mm->argp);
+			ptr = CRYPTO_get_ex_data(ad, i);
+			storage[i]->new_func(obj,ptr,ad,i,
+				storage[i]->argl,storage[i]->argp);
 			}
-		CRYPTO_set_ex_data(to,i,from_d);
 		}
-	return(1);
+	if(storage)
+		OPENSSL_free(storage);
+	return 1;
 	}
 
-/* Call each free callback */
-void CRYPTO_free_ex_data(meth,obj,ad)
-STACK *meth;
-char *obj;
-CRYPTO_EX_DATA *ad;
+/* 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)
 	{
-	CRYPTO_EX_DATA_FUNCS *m;
+	int mx, j, i;
 	char *ptr;
-	int i,max;
+	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;
+	}
 
-	if (meth != NULL)
+/* 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++)
 		{
-		max=sk_num(meth);
-		for (i=0; i<max; i++)
+		if(storage[i] && storage[i]->free_func)
 			{
-			m=(CRYPTO_EX_DATA_FUNCS *)sk_value(meth,i);
-			if ((m != NULL) && (m->free_func != NULL))
-				{
-				ptr=CRYPTO_get_ex_data(ad,i);
-				m->free_func(obj,ptr,ad,i,m->argl,m->argp);
-				}
+			ptr = CRYPTO_get_ex_data(ad,i);
+			storage[i]->free_func(obj,ptr,ad,i,
+				storage[i]->argl,storage[i]->argp);
 			}
 		}
-	if (ad->sk != NULL)
+	if(storage)
+		OPENSSL_free(storage);
+	if(ad->sk)
 		{
 		sk_free(ad->sk);
 		ad->sk=NULL;
 		}
 	}
 
-void CRYPTO_new_ex_data(meth,obj,ad)
-STACK *meth;
-char *obj;
-CRYPTO_EX_DATA *ad;
+/********************************************************************/
+/* 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)
 	{
-	CRYPTO_EX_DATA_FUNCS *m;
-	char *ptr;
-	int i,max;
+	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;
 
-	ad->sk=NULL;
-	if (meth != NULL)
+	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)
 		{
-		max=sk_num(meth);
-		for (i=0; i<max; i++)
+		if ((ad->sk=sk_new_null()) == NULL)
 			{
-			m=(CRYPTO_EX_DATA_FUNCS *)sk_value(meth,i);
-			if ((m != NULL) && (m->new_func != NULL))
-				{
-				ptr=CRYPTO_get_ex_data(ad,i);
-				m->new_func(obj,ptr,ad,i,m->argl,m->argp);
-				}
+			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)