added chunk_compare() which compares orders chunks

src/libstrongswan/chunk.c

@@ -230,6 +230,21 @@ chunk_t chunk_skip(chunk_t chunk, size_t bytes)
 	return chunk_empty;
 }
 
+/**
+ * Described in header.
+ */
+int chunk_compare(chunk_t a, chunk_t b)
+{
+	int compare_len = a.len - b.len;
+	int len = (compare_len < 0)? a.len : b.len;
+
+	if (compare_len != 0 || len == 0)
+	{
+		return compare_len;
+	}
+	return memcmp(a.ptr, b.ptr, len);
+};
+
 /**
  * Described in header.
  */

src/libstrongswan/chunk.h

@@ -123,6 +123,12 @@ void chunk_free(chunk_t *chunk);
  */
 chunk_t chunk_skip(chunk_t chunk, size_t bytes);
 
+/**
+ *  Compare two chunks, returns zero if a equals b
+ *  or negative/positive if a is small/greater than b
+ */
+int chunk_compare(chunk_t a, chunk_t b);
+
 /**
  * Compare two chunks for equality,
  * NULL chunks are never equal.