Mercurial > dropbear
view libtommath/bn_mp_montgomery_calc_normalization.c @ 1921:284c3837891c
Allow user space file locations (rootless support)
Why:
Running dropbear as a user (rootless) is aided if
files and programs can be saved/removed without
needing sudo.
What:
Use the same convention as DROPBEAR_DEFAULT_CLI_AUTHKEY;
if not starting with '/', then is relative to hedge's /home/hedge:
*_PRIV_FILENAME
DROPBEAR_PIDFILE
SFTPSERVER_PATH
default_options.h commentary added.
Changes kept to a minimum, so log entry in svr_kex.c#163
is refactored.
From:
Generated hostkey is <path> ... <finger-print>
to:
Generated hostkey path is <path>
Generated hostkey fingerprint is <fp>
Otherwise the unexpanded path was reported.
Patch modified by Matt Johnston
Signed-off-by: Begley Brothers Inc <[email protected]>
author | Begley Brothers Inc <begleybrothers@gmail.com> |
---|---|
date | Thu, 09 Jul 2020 17:47:58 +1000 |
parents | 1051e4eea25a |
children |
line wrap: on
line source
#include "tommath_private.h" #ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_C /* LibTomMath, multiple-precision integer library -- Tom St Denis */ /* SPDX-License-Identifier: Unlicense */ /* * shifts with subtractions when the result is greater than b. * * The method is slightly modified to shift B unconditionally upto just under * the leading bit of b. This saves alot of multiple precision shifting. */ mp_err mp_montgomery_calc_normalization(mp_int *a, const mp_int *b) { int x, bits; mp_err err; /* how many bits of last digit does b use */ bits = mp_count_bits(b) % MP_DIGIT_BIT; if (b->used > 1) { if ((err = mp_2expt(a, ((b->used - 1) * MP_DIGIT_BIT) + bits - 1)) != MP_OKAY) { return err; } } else { mp_set(a, 1uL); bits = 1; } /* now compute C = A * B mod b */ for (x = bits - 1; x < (int)MP_DIGIT_BIT; x++) { if ((err = mp_mul_2(a, a)) != MP_OKAY) { return err; } if (mp_cmp_mag(a, b) != MP_LT) { if ((err = s_mp_sub(a, b, a)) != MP_OKAY) { return err; } } } return MP_OKAY; } #endif