Introduce extra delay before closing unauthenticated sessions To make it harder for attackers, introduce a delay to keep an unauthenticated session open a bit longer, thus blocking a connection slot until after the delay. Without this, while there is a limit on the amount of attempts an attacker can make at the same time (MAX_UNAUTH_PER_IP), the time taken by dropbear to handle one attempt is still short and thus for each of the allowed parallel attempts many attempts can be chained one after the other. The attempt rate is then: "MAX_UNAUTH_PER_IP / <process time of one attempt>". With the delay, this rate becomes: "MAX_UNAUTH_PER_IP / UNAUTH_CLOSE_DELAY".

/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/*
   Current values evaluated on an AMD A8-6600K (64-bit).
   Type "make tune" to optimize them for your machine but
   be aware that it may take a long time. It took 2:30 minutes
   on the aforementioned machine for example.
 */

#define MP_DEFAULT_KARATSUBA_MUL_CUTOFF 80
#define MP_DEFAULT_KARATSUBA_SQR_CUTOFF 120
#define MP_DEFAULT_TOOM_MUL_CUTOFF      350
#define MP_DEFAULT_TOOM_SQR_CUTOFF      400