Mercurial > dropbear
view libtommath/bn_mp_div_2.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_MP_DIV_2_C /* LibTomMath, multiple-precision integer library -- Tom St Denis */ /* SPDX-License-Identifier: Unlicense */ /* b = a/2 */ mp_err mp_div_2(const mp_int *a, mp_int *b) { int x, oldused; mp_digit r, rr, *tmpa, *tmpb; mp_err err; /* copy */ if (b->alloc < a->used) { if ((err = mp_grow(b, a->used)) != MP_OKAY) { return err; } } oldused = b->used; b->used = a->used; /* source alias */ tmpa = a->dp + b->used - 1; /* dest alias */ tmpb = b->dp + b->used - 1; /* carry */ r = 0; for (x = b->used - 1; x >= 0; x--) { /* get the carry for the next iteration */ rr = *tmpa & 1u; /* shift the current digit, add in carry and store */ *tmpb-- = (*tmpa-- >> 1) | (r << (MP_DIGIT_BIT - 1)); /* forward carry to next iteration */ r = rr; } /* zero excess digits */ MP_ZERO_DIGITS(b->dp + b->used, oldused - b->used); b->sign = a->sign; mp_clamp(b); return MP_OKAY; } #endif