db207264ad
The test vectors are taken from the reference implementation, modified to output the results of its random-number generator, and the results of key generation prior to SHA3. This allows the interoperability of the two implementations to be tested somewhat. To accomplish the testing, this commit creates a new, lower-level API that leaves the generation of random numbers and all wire encoding and decoding up to the caller. Change-Id: Ifae3517696dde4be4a0b7c1998bdefb789bac599 Reviewed-on: https://boringssl-review.googlesource.com/8070 Reviewed-by: Adam Langley <agl@google.com>
132 lines
3.5 KiB
C
132 lines
3.5 KiB
C
/* Copyright (c) 2016, Google Inc.
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
|
|
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
|
|
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
|
|
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
|
|
|
|
#include <string.h>
|
|
|
|
#include <openssl/base.h>
|
|
#include <openssl/rand.h>
|
|
|
|
#include "internal.h"
|
|
|
|
|
|
/* See paper for details on the error reconciliation */
|
|
|
|
static int32_t abs_32(int32_t v) {
|
|
int32_t mask = v >> 31;
|
|
return (v ^ mask) - mask;
|
|
}
|
|
|
|
static int32_t f(int32_t* v0, int32_t* v1, int32_t x) {
|
|
int32_t xit, t, r, b;
|
|
|
|
/* Next 6 lines compute t = x/PARAM_Q */
|
|
b = x * 2730;
|
|
t = b >> 25;
|
|
b = x - t * 12289;
|
|
b = 12288 - b;
|
|
b >>= 31;
|
|
t -= b;
|
|
|
|
r = t & 1;
|
|
xit = (t >> 1);
|
|
*v0 = xit + r; /* v0 = round(x/(2*PARAM_Q)) */
|
|
|
|
t -= 1;
|
|
r = t & 1;
|
|
*v1 = (t >> 1) + r;
|
|
|
|
return abs_32(x - ((*v0) * 2 * PARAM_Q));
|
|
}
|
|
|
|
static int32_t g(int32_t x) {
|
|
int32_t t, c, b;
|
|
|
|
/* Next 6 lines compute t = x/(4*PARAM_Q); */
|
|
b = x * 2730;
|
|
t = b >> 27;
|
|
b = x - t * 49156;
|
|
b = 49155 - b;
|
|
b >>= 31;
|
|
t -= b;
|
|
|
|
c = t & 1;
|
|
t = (t >> 1) + c; /* t = round(x/(8*PARAM_Q)) */
|
|
|
|
t *= 8 * PARAM_Q;
|
|
|
|
return abs_32(t - x);
|
|
}
|
|
|
|
static int16_t LDDecode(int32_t xi0, int32_t xi1, int32_t xi2, int32_t xi3) {
|
|
int32_t t;
|
|
|
|
t = g(xi0);
|
|
t += g(xi1);
|
|
t += g(xi2);
|
|
t += g(xi3);
|
|
|
|
t -= 8 * PARAM_Q;
|
|
t >>= 31;
|
|
return t & 1;
|
|
}
|
|
|
|
void newhope_helprec(NEWHOPE_POLY* c, const NEWHOPE_POLY* v,
|
|
const uint8_t rand[32]) {
|
|
int32_t v0[4], v1[4], v_tmp[4], k;
|
|
uint8_t rbit;
|
|
unsigned i;
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
rbit = (rand[i >> 3] >> (i & 7)) & 1;
|
|
|
|
k = f(v0 + 0, v1 + 0, 8 * v->coeffs[0 + i] + 4 * rbit);
|
|
k += f(v0 + 1, v1 + 1, 8 * v->coeffs[256 + i] + 4 * rbit);
|
|
k += f(v0 + 2, v1 + 2, 8 * v->coeffs[512 + i] + 4 * rbit);
|
|
k += f(v0 + 3, v1 + 3, 8 * v->coeffs[768 + i] + 4 * rbit);
|
|
|
|
k = (2 * PARAM_Q - 1 - k) >> 31;
|
|
|
|
v_tmp[0] = ((~k) & v0[0]) ^ (k & v1[0]);
|
|
v_tmp[1] = ((~k) & v0[1]) ^ (k & v1[1]);
|
|
v_tmp[2] = ((~k) & v0[2]) ^ (k & v1[2]);
|
|
v_tmp[3] = ((~k) & v0[3]) ^ (k & v1[3]);
|
|
|
|
c->coeffs[0 + i] = (v_tmp[0] - v_tmp[3]) & 3;
|
|
c->coeffs[256 + i] = (v_tmp[1] - v_tmp[3]) & 3;
|
|
c->coeffs[512 + i] = (v_tmp[2] - v_tmp[3]) & 3;
|
|
c->coeffs[768 + i] = (-k + 2 * v_tmp[3]) & 3;
|
|
}
|
|
}
|
|
|
|
void newhope_reconcile(uint8_t* key, const NEWHOPE_POLY* v,
|
|
const NEWHOPE_POLY* c) {
|
|
int i;
|
|
int32_t tmp[4];
|
|
|
|
memset(key, 0, NEWHOPE_KEY_LENGTH);
|
|
|
|
for (i = 0; i < 256; i++) {
|
|
tmp[0] = 16 * PARAM_Q + 8 * (int32_t)v->coeffs[0 + i] -
|
|
PARAM_Q * (2 * c->coeffs[0 + i] + c->coeffs[768 + i]);
|
|
tmp[1] = 16 * PARAM_Q + 8 * (int32_t)v->coeffs[256 + i] -
|
|
PARAM_Q * (2 * c->coeffs[256 + i] + c->coeffs[768 + i]);
|
|
tmp[2] = 16 * PARAM_Q + 8 * (int32_t)v->coeffs[512 + i] -
|
|
PARAM_Q * (2 * c->coeffs[512 + i] + c->coeffs[768 + i]);
|
|
tmp[3] = 16 * PARAM_Q + 8 * (int32_t)v->coeffs[768 + i] -
|
|
PARAM_Q * (c->coeffs[768 + i]);
|
|
|
|
key[i >> 3] |= LDDecode(tmp[0], tmp[1], tmp[2], tmp[3]) << (i & 7);
|
|
}
|
|
}
|