+ * It is up to the implementation to decide whether the crypt operation is
+ * performed in place. The caller can tell by looking if the buffers given by
+ * \a src and \a dst coincide after the call. If (and only if) the crypt
+ * operation was not performed in place, the function allocated a new buffer
+ * for the result, so dst->iov_base is different from src->iov_base. In this
+ * case, the destination buffer must be freed by the caller when it is no
+ * longer needed.