+/* Prevent integer overflows when incrementing buffer position/length.
+ * Calling functions should check arguments first, but this provides a
+ * backstop */
+#define BUF_MAX_INCR 1000000000
+#define BUF_MAX_SIZE 1000000000
+
+/* avoid excessively large numbers, > ~8192 bits */
+#define BUF_MAX_MPINT (8240 / 8)
+