Mercurial > dropbear
view libtommath/bn_s_mp_sqr.c @ 1855:35d504d59c05
Implement server-side support for sk-ecdsa U2F-backed keys (#142)
* Implement server-side support for sk-ecdsa U2F-backed keys
* Fix out-of-bounds read on normal ecdsa-sha2-[identifier] keys
* Fix one more potential out-of-bounds read
* Check if nistp256 curve is used in sk-ecdsa-sha2- key
It's the only allowed curve per PROTOCOL.u2f specification
* Implement server-side support for sk-ed25519 FIDO2-backed keys
* Keys with type sk-* make no sense as host keys, so they should be
disabled
* fix typo
* Make sk-ecdsa call buf_ecdsa_verify
This reduces code duplication, the SK code just handles the
different message format.
* Reduce sk specific code
The application id can be stored in signkey, then we don't need
to call sk-specific functions from svr-authpubkey
* Remove debugging output, which causes compilation errors with DEBUG_TRACE disabled
* Proper cleanup of sk_app
Co-authored-by: Matt Johnston <[email protected]>
author | egor-duda <egor-duda@users.noreply.github.com> |
---|---|
date | Sat, 22 Jan 2022 16:53:04 +0300 |
parents | 1051e4eea25a |
children |
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#include "tommath_private.h" #ifdef BN_S_MP_SQR_C /* LibTomMath, multiple-precision integer library -- Tom St Denis */ /* SPDX-License-Identifier: Unlicense */ /* low level squaring, b = a*a, HAC pp.596-597, Algorithm 14.16 */ mp_err s_mp_sqr(const mp_int *a, mp_int *b) { mp_int t; int ix, iy, pa; mp_err err; mp_word r; mp_digit u, tmpx, *tmpt; pa = a->used; if ((err = mp_init_size(&t, (2 * pa) + 1)) != MP_OKAY) { return err; } /* 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)MP_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)MP_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)MP_DIGIT_BIT); } } mp_clamp(&t); mp_exch(&t, b); mp_clear(&t); return MP_OKAY; } #endif