Mercurial > dropbear
view libtommath/bn_s_mp_sqr.c @ 1665:7c17995bcdfb
Improve address logging on early exit messages (#83)
Change 'Early exit' and 'Exit before auth' messages to include the IP
address & port as part of the message.
This allows log scanning utilities such as 'fail2ban' to obtain the
offending IP address as part of the failure event instead of extracting
the PID from the message and then scanning the log again for match
'child connection from' messages
Signed-off-by: Kevin Darbyshire-Bryant <[email protected]>
author | Kevin Darbyshire-Bryant <6500011+ldir-EDB0@users.noreply.github.com> |
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date | Wed, 18 Mar 2020 15:28:56 +0000 |
parents | f52919ffd3b1 |
children | 1051e4eea25a |
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#include "tommath_private.h" #ifdef BN_S_MP_SQR_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * * LibTomMath is a library that provides multiple-precision * integer arithmetic as well as number theoretic functionality. * * The library was designed directly after the MPI library by * Michael Fromberger but has been written from scratch with * additional optimizations in place. * * SPDX-License-Identifier: Unlicense */ /* low level squaring, b = a*a, HAC pp.596-597, Algorithm 14.16 */ int s_mp_sqr(const mp_int *a, mp_int *b) { mp_int t; int res, ix, iy, pa; mp_word r; mp_digit u, tmpx, *tmpt; pa = a->used; if ((res = mp_init_size(&t, (2 * pa) + 1)) != MP_OKAY) { return res; } /* default used is maximum possible size */ t.used = (2 * pa) + 1; for (ix = 0; ix < pa; ix++) { /* first calculate the digit at 2*ix */ /* calculate double precision result */ r = (mp_word)t.dp[2*ix] + ((mp_word)a->dp[ix] * (mp_word)a->dp[ix]); /* store lower part in result */ t.dp[ix+ix] = (mp_digit)(r & (mp_word)MP_MASK); /* get the carry */ u = (mp_digit)(r >> (mp_word)DIGIT_BIT); /* left hand side of A[ix] * A[iy] */ tmpx = a->dp[ix]; /* alias for where to store the results */ tmpt = t.dp + ((2 * ix) + 1); for (iy = ix + 1; iy < pa; iy++) { /* first calculate the product */ r = (mp_word)tmpx * (mp_word)a->dp[iy]; /* now calculate the double precision result, note we use * addition instead of *2 since it's easier to optimize */ r = (mp_word)*tmpt + r + r + (mp_word)u; /* store lower part */ *tmpt++ = (mp_digit)(r & (mp_word)MP_MASK); /* get carry */ u = (mp_digit)(r >> (mp_word)DIGIT_BIT); } /* propagate upwards */ while (u != 0uL) { r = (mp_word)*tmpt + (mp_word)u; *tmpt++ = (mp_digit)(r & (mp_word)MP_MASK); u = (mp_digit)(r >> (mp_word)DIGIT_BIT); } } mp_clamp(&t); mp_exch(&t, b); mp_clear(&t); return MP_OKAY; } #endif /* ref: HEAD -> master, tag: v1.1.0 */ /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ /* commit time: 2019-01-28 20:32:32 +0100 */