Allow EC_GROUP objects to share precomputation for improved memory

efficiency (EC_PRE_COMP objects are now constant once completed).

Extend 'extra_data' API to support arbitrarily many slots (although we
need only one at the moment).

Modify EC internal 'extra_data' API: EC_GROUP_[clear_]free_extra_data
now frees only a single slot (the previous functions are available as
EC_GROUP_[clear_]free_all_extra_data).

Submitted by: Nils Larsch
Reviewed by: Bodo Moeller

1 files changed, 132 insertions, 55 deletions

diff --git a/crypto/ec/ec_lib.c b/crypto/ec/ec_lib.c
index 5e3fb5c20b..c00875cd73 100644
--- a/crypto/ec/ec_lib.c
+++ b/crypto/ec/ec_lib.c
@@ -98,9 +98,6 @@ EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
 	ret->meth = meth;
 
 	ret->extra_data = NULL;
-	ret->extra_data_dup_func = 0;
-	ret->extra_data_free_func = 0;
-	ret->extra_data_clear_free_func = 0;
 
 	ret->generator = NULL;
 	BN_init(&ret->order);
@@ -130,7 +127,7 @@ void EC_GROUP_free(EC_GROUP *group)
 	if (group->meth->group_finish != 0)
 		group->meth->group_finish(group);
 
-	EC_GROUP_free_extra_data(group);
+	EC_GROUP_free_all_extra_data(group);
 
 	if (group->generator != NULL)
 		EC_POINT_free(group->generator);
@@ -153,7 +150,7 @@ void EC_GROUP_clear_free(EC_GROUP *group)
 	else if (group->meth != NULL && group->meth->group_finish != 0)
 		group->meth->group_finish(group);
 
-	EC_GROUP_clear_free_extra_data(group);
+	EC_GROUP_clear_free_all_extra_data(group);
 
 	if (group->generator != NULL)
 		EC_POINT_clear_free(group->generator);
@@ -173,6 +170,8 @@ void EC_GROUP_clear_free(EC_GROUP *group)
 
 int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
 	{
+	EC_EXTRA_DATA *d;
+
 	if (dest->meth->group_copy == 0)
 		{
 		ECerr(EC_F_EC_GROUP_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
@@ -186,19 +185,16 @@ int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
 	if (dest == src)
 		return 1;
 	
-	EC_GROUP_clear_free_extra_data(dest);
-	if (src->extra_data_dup_func)
-		{
-		if (src->extra_data != NULL)
-			{
-			dest->extra_data = src->extra_data_dup_func(src->extra_data);
-			if (dest->extra_data == NULL)
-				return 0;
-			}
+	EC_GROUP_free_all_extra_data(dest);
 
-		dest->extra_data_dup_func = src->extra_data_dup_func;
-		dest->extra_data_free_func = src->extra_data_free_func;
-		dest->extra_data_clear_free_func = src->extra_data_clear_free_func;
+	for (d = src->extra_data; d != NULL; d = d->next)
+		{
+		void *t = d->dup_func(d->data);
+		
+		if (t == NULL)
+			return 0;
+		if (!EC_GROUP_set_extra_data(dest, t, d->dup_func, d->free_func, d->clear_free_func))
+			return 0;
 		}
 
 	if (src->generator != NULL)
@@ -475,67 +471,148 @@ int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
 
 
 /* this has 'package' visibility */
-int EC_GROUP_set_extra_data(EC_GROUP *group, void *extra_data, void *(*extra_data_dup_func)(void *),
-	void (*extra_data_free_func)(void *), void (*extra_data_clear_free_func)(void *))
+int EC_GROUP_set_extra_data(EC_GROUP *group, void *data,
+	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
 	{
-	if ((group->extra_data != NULL)
-		|| (group->extra_data_dup_func != 0)
-		|| (group->extra_data_free_func != 0)
-		|| (group->extra_data_clear_free_func != 0))
-		{
-		ECerr(EC_F_EC_GROUP_SET_EXTRA_DATA, EC_R_SLOT_FULL);
+	EC_EXTRA_DATA *d;
+
+	if (group == NULL)
 		return 0;
+
+	for (d = group->extra_data; d != NULL; d = d->next)
+		{
+		if (d->dup_func == dup_func && d->free_func == free_func && d->clear_free_func == clear_free_func)
+			{
+			ECerr(EC_F_EC_GROUP_SET_EXTRA_DATA, EC_R_SLOT_FULL);
+			return 0;
+			}
 		}
 
-	group->extra_data = extra_data;
-	group->extra_data_dup_func = extra_data_dup_func;
-	group->extra_data_free_func = extra_data_free_func;
-	group->extra_data_clear_free_func = extra_data_clear_free_func;
+	if (data == NULL)
+		/* no explicit entry needed */
+		return 1;
+
+	d = OPENSSL_malloc(sizeof *d);
+	if (d == NULL)
+		return 0;
+
+	d->data = data;
+	d->dup_func = dup_func;
+	d->free_func = free_func;
+	d->clear_free_func = clear_free_func;
+
+	d->next = group->extra_data;
+	group->extra_data = d;
+
 	return 1;
 	}
 
-
 /* this has 'package' visibility */
-void *EC_GROUP_get_extra_data(const EC_GROUP *group, void *(*extra_data_dup_func)(void *),
-	void (*extra_data_free_func)(void *), void (*extra_data_clear_free_func)(void *))
+void *EC_GROUP_get_extra_data(const EC_GROUP *group,
+	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
 	{
-	if ((group->extra_data_dup_func != extra_data_dup_func)
-		|| (group->extra_data_free_func != extra_data_free_func)
-		|| (group->extra_data_clear_free_func != extra_data_clear_free_func))
-		{
-#if 0 /* this was an error in 0.9.7, but that does not make a lot of sense */
-		ECerr(EC_F_EC_GROUP_GET_EXTRA_DATA, EC_R_NO_SUCH_EXTRA_DATA);
-#endif
+	EC_EXTRA_DATA *d;
+
+	if (group == NULL)
 		return NULL;
+
+	for (d = group->extra_data; d != NULL; d = d->next)
+		{
+		if (d->dup_func == dup_func && d->free_func == free_func && d->clear_free_func == clear_free_func)
+			return d->data;
 		}
+	
+	return NULL;
+	}
 
-	return group->extra_data;
+/* this has 'package' visibility */
+void EC_GROUP_free_extra_data(EC_GROUP *group,
+	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
+	{
+	EC_EXTRA_DATA **p;
+
+	if (group == NULL)
+		return;
+
+	for (p = &group->extra_data; *p != NULL; p = &((*p)->next))
+		{
+		if ((*p)->dup_func == dup_func && (*p)->free_func == free_func && (*p)->clear_free_func == clear_free_func)
+			{
+			EC_EXTRA_DATA *next = (*p)->next;
+
+			(*p)->free_func((*p)->data);
+			OPENSSL_free(*p);
+			
+			*p = next;
+			return;
+			}
+		}
 	}
 
+/* this has 'package' visibility */
+void EC_GROUP_clear_free_extra_data(EC_GROUP *group,
+	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
+	{
+	EC_EXTRA_DATA **p;
+
+	if (group == NULL)
+		return;
+
+	for (p = &group->extra_data; *p != NULL; p = &((*p)->next))
+		{
+		if ((*p)->dup_func == dup_func && (*p)->free_func == free_func && (*p)->clear_free_func == clear_free_func)
+			{
+			EC_EXTRA_DATA *next = (*p)->next;
+
+			(*p)->clear_free_func((*p)->data);
+			OPENSSL_free(*p);
+			
+			*p = next;
+			return;
+			}
+		}
+	}
 
 /* this has 'package' visibility */
-void EC_GROUP_free_extra_data(EC_GROUP *group)
+void EC_GROUP_free_all_extra_data(EC_GROUP *group)
 	{
-	if (group->extra_data_free_func)
-		group->extra_data_free_func(group->extra_data);
+	EC_EXTRA_DATA *d;
+
+	if (group == NULL)
+		return;
+
+	d = group->extra_data;
+	while (d)
+		{
+		EC_EXTRA_DATA *next = d->next;
+		
+		d->free_func(d->data);
+		OPENSSL_free(d);
+		
+		d = next;
+		}
 	group->extra_data = NULL;
-	group->extra_data_dup_func = 0;
-	group->extra_data_free_func = 0;
-	group->extra_data_clear_free_func = 0;
 	}
 
-
 /* this has 'package' visibility */
-void EC_GROUP_clear_free_extra_data(EC_GROUP *group)
+void EC_GROUP_clear_free_all_extra_data(EC_GROUP *group)
 	{
-	if (group->extra_data_clear_free_func)
-		group->extra_data_clear_free_func(group->extra_data);
-	else if (group->extra_data_free_func)
-		group->extra_data_free_func(group->extra_data);
+	EC_EXTRA_DATA *d;
+
+	if (group == NULL)
+		return;
+
+	d = group->extra_data;
+	while (d)
+		{
+		EC_EXTRA_DATA *next = d->next;
+		
+		d->clear_free_func(d->data);
+		OPENSSL_free(d);
+		
+		d = next;
+		}
 	group->extra_data = NULL;
-	group->extra_data_dup_func = 0;
-	group->extra_data_free_func = 0;
-	group->extra_data_clear_free_func = 0;
 	}