chunk_equals_ptr added to compare chunks given as pointers.

src/libstrongswan/chunk.h

@@ -250,6 +250,15 @@ static inline bool chunk_equals(chunk_t a, chunk_t b)
 			a.len == b.len && memeq(a.ptr, b.ptr, a.len);
 }
 
+/**
+ * Compare two chunks (given as pointers) for equality (useful as callback),
+ * NULL chunks are never equal.
+ */
+static inline bool chunk_equals_ptr(chunk_t *a, chunk_t *b)
+{
+	return a != NULL && b != NULL && chunk_equals(*a, *b);
+}
+
 /**
  * Increment a chunk, as it would reprensent a network order integer.
  *