Handle ecdsa-sk flags, reject no-touch For the time being Dropbear will only allow SK auth with default parameters, user-presence needs to be set. In future handling of authorized_keys option "no-touch-required" can be added. This code would also be refactored to share between ecdsa and ed25519 once I get hardware/emulation to test ed25519.

#include "tommath_private.h"
#ifdef BN_MP_ISEVEN_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */

mp_bool mp_iseven(const mp_int *a)
{
   return MP_IS_EVEN(a) ? MP_YES : MP_NO;
}
#endif