Mercurial > dropbear
view libtommath/bn_mp_count_bits.c @ 1861:2b3a8026a6ce
Add re-exec for server
This allows ASLR to re-randomize the address
space for every connection, preventing some
vulnerabilities from being exploitable by
repeated probing.
Overhead (memory and time) is yet to be confirmed.
At present this is only enabled on Linux. Other BSD platforms
with fexecve() would probably also work though have not been tested.
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sun, 30 Jan 2022 10:14:56 +0800 |
parents | 1051e4eea25a |
children |
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#include "tommath_private.h" #ifdef BN_MP_COUNT_BITS_C /* LibTomMath, multiple-precision integer library -- Tom St Denis */ /* SPDX-License-Identifier: Unlicense */ /* returns the number of bits in an int */ int mp_count_bits(const mp_int *a) { int r; mp_digit q; /* shortcut */ if (MP_IS_ZERO(a)) { return 0; } /* get number of digits and add that */ r = (a->used - 1) * MP_DIGIT_BIT; /* take the last digit and count the bits in it */ q = a->dp[a->used - 1]; while (q > 0u) { ++r; q >>= 1u; } return r; } #endif