+static inline bool is_zero_hash(const u8 hash[SHA1_HASH_SIZE])
+{
+ for (u8 i = 0; i < SHA1_HASH_SIZE / 4; i++)
+ if (((u32*)hash)[i])
+ return false;
+ return true;
+}
+
+static void zero_hash(u8 hash[SHA1_HASH_SIZE])
+{
+ memset(hash, 0, SHA1_HASH_SIZE);
+}
+