proposal: Keep track of contained transform types

src/libstrongswan/crypto/proposal/proposal.c

@@ -57,6 +57,11 @@ struct private_proposal_t {
 	 */
 	array_t *transforms;
 
+	/**
+	 * Types of transforms contained, as transform_type_t
+	 */
+	array_t *types;
+
 	/**
 	 * senders SPI
 	 */
@@ -68,6 +73,57 @@ struct private_proposal_t {
 	u_int number;
 };
 
+/**
+ * Sort transform types
+ */
+static int type_sort(const void *a, const void *b, void *user)
+{
+	const transform_type_t *ta = a, *tb = b;
+	return *ta - *tb;
+}
+
+/**
+ * Find a transform type
+ */
+static int type_find(const void *a, const void *b)
+{
+	return type_sort(a, b, NULL);
+}
+
+/**
+ * Check if the given transform type is already in the set
+ */
+static bool contains_type(private_proposal_t *this, transform_type_t type)
+{
+	return array_bsearch(this->types, &type, type_find, NULL) != -1;
+}
+
+/**
+ * Add the given transform type to the set
+ */
+static void add_type(private_proposal_t *this, transform_type_t type)
+{
+	if (!contains_type(this, type))
+	{
+		array_insert(this->types, ARRAY_TAIL, &type);
+		array_sort(this->types, type_sort, NULL);
+	}
+}
+
+/**
+ * Remove the given transform type from the set
+ */
+static void remove_type(private_proposal_t *this, transform_type_t type)
+{
+	int i;
+
+	i = array_bsearch(this->types, &type, type_find, NULL);
+	if (i >= 0)
+	{
+		array_remove(this->types, i, NULL);
+	}
+}
+
 /**
  * Struct used to store different kinds of algorithms.
  */
@@ -91,6 +147,7 @@ METHOD(proposal_t, add_algorithm, void,
 	};
 
 	array_insert(this->transforms, ARRAY_TAIL, &entry);
+	add_type(this, type);
 }
 
 CALLBACK(alg_filter, bool,
@@ -206,17 +263,29 @@ METHOD(proposal_t, strip_dh, void,
 {
 	enumerator_t *enumerator;
 	entry_t *entry;
+	bool found = FALSE;
 
 	enumerator = array_create_enumerator(this->transforms);
 	while (enumerator->enumerate(enumerator, &entry))
 	{
-		if (entry->type == DIFFIE_HELLMAN_GROUP &&
-			entry->alg != keep)
+		if (entry->type == DIFFIE_HELLMAN_GROUP)
 		{
-			array_remove_at(this->transforms, enumerator);
+			if (entry->alg != keep)
+			{
+				array_remove_at(this->transforms, enumerator);
+			}
+			else
+			{
+				found = TRUE;
+			}
 		}
 	}
 	enumerator->destroy(enumerator);
+
+	if (keep == MODP_NONE || !found)
+	{
+		remove_type(this, DIFFIE_HELLMAN_GROUP);
+	}
 }
 
 /**
@@ -427,6 +496,7 @@ METHOD(proposal_t, clone_, proposal_t*,
 	private_proposal_t *clone;
 	enumerator_t *enumerator;
 	entry_t *entry;
+	transform_type_t *type;
 
 	clone = (private_proposal_t*)proposal_create(this->protocol, 0);
 
@@ -436,6 +506,12 @@ METHOD(proposal_t, clone_, proposal_t*,
 		array_insert(clone->transforms, ARRAY_TAIL, entry);
 	}
 	enumerator->destroy(enumerator);
+	enumerator = array_create_enumerator(this->types);
+	while (enumerator->enumerate(enumerator, &type))
+	{
+		array_insert(clone->types, ARRAY_TAIL, type);
+	}
+	enumerator->destroy(enumerator);
 
 	clone->spi = this->spi;
 	clone->number = this->number;
@@ -479,6 +555,7 @@ static void remove_transform(private_proposal_t *this, transform_type_t type)
 		}
 	}
 	e->destroy(e);
+	remove_type(this, type);
 }
 
 /**
@@ -605,6 +682,7 @@ static bool check_proposal(private_proposal_t *this)
 			}
 		}
 		e->destroy(e);
+		remove_type(this, ENCRYPTION_ALGORITHM);
 
 		if (!get_algorithm(this, INTEGRITY_ALGORITHM, NULL, NULL))
 		{
@@ -730,6 +808,7 @@ METHOD(proposal_t, destroy, void,
 	private_proposal_t *this)
 {
 	array_destroy(this->transforms);
+	array_destroy(this->types);
 	free(this);
 }
 
@@ -760,6 +839,7 @@ proposal_t *proposal_create(protocol_id_t protocol, u_int number)
 		.protocol = protocol,
 		.number = number,
 		.transforms = array_create(sizeof(entry_t), 0),
+		.types = array_create(sizeof(transform_type_t), 0),
 	);
 
 	return &this->public;