-/**
- * @file ed448goldilocks/scalar.c
- * @author Mike Hamburg
+/*
+ * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2015-2016 Cryptography Research, Inc.
*
- * @copyright
- * Copyright (c) 2015-2016 Cryptography Research, Inc. \n
- * Released under the MIT License. See LICENSE.txt for license information.
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
*
- * @brief Decaf high-level functions.
- *
- * @warning This file was automatically generated in Python.
- * Please do not edit it.
+ * Originally written by Mike Hamburg
*/
#include <openssl/crypto.h>
#include "constant_time.h"
#include "point_448.h"
-/* Template stuff */
-#define API_NS(_id) decaf_448_##_id
-#define SCALAR_BITS DECAF_448_SCALAR_BITS
-#define SCALAR_SER_BYTES DECAF_448_SCALAR_BYTES
-#define SCALAR_LIMBS DECAF_448_SCALAR_LIMBS
-#define scalar_t API_NS(scalar_t)
+static const decaf_word_t MONTGOMERY_FACTOR = (decaf_word_t) 0x3bd440fae918bc5;
+static const curve448_scalar_t sc_p = {
+ {
+ {
+ SC_LIMB(0x2378c292ab5844f3), SC_LIMB(0x216cc2728dc58f55),
+ SC_LIMB(0xc44edb49aed63690), SC_LIMB(0xffffffff7cca23e9),
+ SC_LIMB(0xffffffffffffffff), SC_LIMB(0xffffffffffffffff),
+ SC_LIMB(0x3fffffffffffffff)
+ }
+ }
+}, sc_r2 = {
+ {
+ {
-static const decaf_word_t MONTGOMERY_FACTOR = (decaf_word_t)0x3bd440fae918bc5ull;
-static const scalar_t sc_p = {{{
- SC_LIMB(0x2378c292ab5844f3), SC_LIMB(0x216cc2728dc58f55), SC_LIMB(0xc44edb49aed63690), SC_LIMB(0xffffffff7cca23e9), SC_LIMB(0xffffffffffffffff), SC_LIMB(0xffffffffffffffff), SC_LIMB(0x3fffffffffffffff)
-}}}, sc_r2 = {{{
- SC_LIMB(0xe3539257049b9b60), SC_LIMB(0x7af32c4bc1b195d9), SC_LIMB(0x0d66de2388ea1859), SC_LIMB(0xae17cf725ee4d838), SC_LIMB(0x1a9cc14ba3c47c44), SC_LIMB(0x2052bcb7e4d070af), SC_LIMB(0x3402a939f823b729)
-}}};
-/* End of template stuff */
+ SC_LIMB(0xe3539257049b9b60), SC_LIMB(0x7af32c4bc1b195d9),
+ SC_LIMB(0x0d66de2388ea1859), SC_LIMB(0xae17cf725ee4d838),
+ SC_LIMB(0x1a9cc14ba3c47c44), SC_LIMB(0x2052bcb7e4d070af),
+ SC_LIMB(0x3402a939f823b729)
+ }
+ }
+};
-#define WBITS DECAF_WORD_BITS /* NB this may be different from ARCH_WORD_BITS */
+#define WBITS DECAF_WORD_BITS /* NB this may be different from ARCH_WORD_BITS */
-const scalar_t API_NS(scalar_one) = {{{1}}}, API_NS(scalar_zero) = {{{0}}};
+const curve448_scalar_t curve448_scalar_one = {{{1}}};
+const curve448_scalar_t curve448_scalar_zero = {{{0}}};
-/** {extra,accum} - sub +? p
+/*
+ * {extra,accum} - sub +? p
* Must have extra <= 1
*/
-static DECAF_NOINLINE void sc_subx(
- scalar_t out,
- const decaf_word_t accum[SCALAR_LIMBS],
- const scalar_t sub,
- const scalar_t p,
- decaf_word_t extra
-) {
+static void sc_subx(curve448_scalar_t out,
+ const decaf_word_t accum[DECAF_448_SCALAR_LIMBS],
+ const curve448_scalar_t sub,
+ const curve448_scalar_t p, decaf_word_t extra)
+{
decaf_dsword_t chain = 0;
unsigned int i;
- for (i=0; i<SCALAR_LIMBS; i++) {
+ decaf_word_t borrow;
+
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS; i++) {
chain = (chain + accum[i]) - sub->limb[i];
out->limb[i] = chain;
chain >>= WBITS;
}
- decaf_word_t borrow = chain+extra; /* = 0 or -1 */
-
+ borrow = chain + extra; /* = 0 or -1 */
+
chain = 0;
- for (i=0; i<SCALAR_LIMBS; i++) {
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS; i++) {
chain = (chain + out->limb[i]) + (p->limb[i] & borrow);
out->limb[i] = chain;
chain >>= WBITS;
}
}
-static DECAF_NOINLINE void sc_montmul (
- scalar_t out,
- const scalar_t a,
- const scalar_t b
-) {
- unsigned int i,j;
- decaf_word_t accum[SCALAR_LIMBS+1] = {0};
+static void sc_montmul(curve448_scalar_t out, const curve448_scalar_t a,
+ const curve448_scalar_t b)
+{
+ unsigned int i, j;
+ decaf_word_t accum[DECAF_448_SCALAR_LIMBS + 1] = { 0 };
decaf_word_t hi_carry = 0;
-
- for (i=0; i<SCALAR_LIMBS; i++) {
+
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS; i++) {
decaf_word_t mand = a->limb[i];
const decaf_word_t *mier = b->limb;
-
+
decaf_dword_t chain = 0;
- for (j=0; j<SCALAR_LIMBS; j++) {
- chain += ((decaf_dword_t)mand)*mier[j] + accum[j];
+ for (j = 0; j < DECAF_448_SCALAR_LIMBS; j++) {
+ chain += ((decaf_dword_t) mand) * mier[j] + accum[j];
accum[j] = chain;
chain >>= WBITS;
}
accum[j] = chain;
-
+
mand = accum[0] * MONTGOMERY_FACTOR;
chain = 0;
mier = sc_p->limb;
- for (j=0; j<SCALAR_LIMBS; j++) {
- chain += (decaf_dword_t)mand*mier[j] + accum[j];
- if (j) accum[j-1] = chain;
+ for (j = 0; j < DECAF_448_SCALAR_LIMBS; j++) {
+ chain += (decaf_dword_t) mand *mier[j] + accum[j];
+ if (j)
+ accum[j - 1] = chain;
chain >>= WBITS;
}
chain += accum[j];
chain += hi_carry;
- accum[j-1] = chain;
+ accum[j - 1] = chain;
hi_carry = chain >> WBITS;
}
-
- sc_subx(out, accum, sc_p, sc_p, hi_carry);
-}
-void API_NS(scalar_mul) (
- scalar_t out,
- const scalar_t a,
- const scalar_t b
-) {
- sc_montmul(out,a,b);
- sc_montmul(out,out,sc_r2);
+ sc_subx(out, accum, sc_p, sc_p, hi_carry);
}
-/* PERF: could implement this */
-static DECAF_INLINE void sc_montsqr (scalar_t out, const scalar_t a) {
- sc_montmul(out,a,a);
+void curve448_scalar_mul(curve448_scalar_t out, const curve448_scalar_t a,
+ const curve448_scalar_t b)
+{
+ sc_montmul(out, a, b);
+ sc_montmul(out, out, sc_r2);
}
-decaf_error_t API_NS(scalar_invert) (
- scalar_t out,
- const scalar_t a
-) {
- /* Fermat's little theorem, sliding window.
- * Sliding window is fine here because the modulus isn't secret.
- */
- const int SCALAR_WINDOW_BITS = 3;
- scalar_t precmp[1<<SCALAR_WINDOW_BITS];
- const int LAST = (1<<SCALAR_WINDOW_BITS)-1;
-
- /* Precompute precmp = [a^1,a^3,...] */
- sc_montmul(precmp[0],a,sc_r2);
- if (LAST > 0) sc_montmul(precmp[LAST],precmp[0],precmp[0]);
-
- int i;
- for (i=1; i<=LAST; i++) {
- sc_montmul(precmp[i],precmp[i-1],precmp[LAST]);
- }
-
- /* Sliding window */
- unsigned residue = 0, trailing = 0, started = 0;
- for (i=SCALAR_BITS-1; i>=-SCALAR_WINDOW_BITS; i--) {
-
- if (started) sc_montsqr(out,out);
-
- decaf_word_t w = (i>=0) ? sc_p->limb[i/WBITS] : 0;
- if (i >= 0 && i<WBITS) {
- assert(w >= 2);
- w-=2;
- }
-
- residue = (residue<<1) | ((w>>(i%WBITS))&1);
- if (residue>>SCALAR_WINDOW_BITS != 0) {
- assert(trailing == 0);
- trailing = residue;
- residue = 0;
- }
-
- if (trailing > 0 && (trailing & ((1<<SCALAR_WINDOW_BITS)-1)) == 0) {
- if (started) {
- sc_montmul(out,out,precmp[trailing>>(SCALAR_WINDOW_BITS+1)]);
- } else {
- API_NS(scalar_copy)(out,precmp[trailing>>(SCALAR_WINDOW_BITS+1)]);
- started = 1;
- }
- trailing = 0;
- }
- trailing <<= 1;
-
- }
- assert(residue==0);
- assert(trailing==0);
-
- /* Demontgomerize */
- sc_montmul(out,out,API_NS(scalar_one));
- OPENSSL_cleanse(precmp, sizeof(precmp));
- return decaf_succeed_if(~API_NS(scalar_eq)(out,API_NS(scalar_zero)));
-}
-
-void API_NS(scalar_sub) (
- scalar_t out,
- const scalar_t a,
- const scalar_t b
-) {
+void curve448_scalar_sub(curve448_scalar_t out, const curve448_scalar_t a,
+ const curve448_scalar_t b)
+{
sc_subx(out, a->limb, b, sc_p, 0);
}
-void API_NS(scalar_add) (
- scalar_t out,
- const scalar_t a,
- const scalar_t b
-) {
+void curve448_scalar_add(curve448_scalar_t out, const curve448_scalar_t a,
+ const curve448_scalar_t b)
+{
decaf_dword_t chain = 0;
unsigned int i;
- for (i=0; i<SCALAR_LIMBS; i++) {
+
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS; i++) {
chain = (chain + a->limb[i]) + b->limb[i];
out->limb[i] = chain;
chain >>= WBITS;
sc_subx(out, out->limb, sc_p, sc_p, chain);
}
-void
-API_NS(scalar_set_unsigned) (
- scalar_t out,
- uint64_t w
-) {
- memset(out,0,sizeof(scalar_t));
- unsigned int i = 0;
- for (; i<sizeof(uint64_t)/sizeof(decaf_word_t); i++) {
- out->limb[i] = w;
-#if DECAF_WORD_BITS < 64
- w >>= 8*sizeof(decaf_word_t);
-#endif
- }
-}
-
-decaf_bool_t
-API_NS(scalar_eq) (
- const scalar_t a,
- const scalar_t b
-) {
- decaf_word_t diff = 0;
- unsigned int i;
- for (i=0; i<SCALAR_LIMBS; i++) {
- diff |= a->limb[i] ^ b->limb[i];
- }
- return mask_to_bool(word_is_zero(diff));
-}
+static ossl_inline void scalar_decode_short(curve448_scalar_t s,
+ const unsigned char *ser,
+ unsigned int nbytes)
+{
+ unsigned int i, j, k = 0;
-static DECAF_INLINE void scalar_decode_short (
- scalar_t s,
- const unsigned char *ser,
- unsigned int nbytes
-) {
- unsigned int i,j,k=0;
- for (i=0; i<SCALAR_LIMBS; i++) {
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS; i++) {
decaf_word_t out = 0;
- for (j=0; j<sizeof(decaf_word_t) && k<nbytes; j++,k++) {
- out |= ((decaf_word_t)ser[k])<<(8*j);
- }
+
+ for (j = 0; j < sizeof(decaf_word_t) && k < nbytes; j++, k++)
+ out |= ((decaf_word_t) ser[k]) << (8 * j);
s->limb[i] = out;
}
}
-decaf_error_t API_NS(scalar_decode)(
- scalar_t s,
- const unsigned char ser[SCALAR_SER_BYTES]
-) {
+decaf_error_t curve448_scalar_decode(
+ curve448_scalar_t s,
+ const unsigned char ser[DECAF_448_SCALAR_BYTES])
+{
unsigned int i;
- scalar_decode_short(s, ser, SCALAR_SER_BYTES);
decaf_dsword_t accum = 0;
- for (i=0; i<SCALAR_LIMBS; i++) {
+
+ scalar_decode_short(s, ser, DECAF_448_SCALAR_BYTES);
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS; i++)
accum = (accum + s->limb[i] - sc_p->limb[i]) >> WBITS;
- }
/* Here accum == 0 or -1 */
-
- API_NS(scalar_mul)(s,s,API_NS(scalar_one)); /* ham-handed reduce */
-
+
+ curve448_scalar_mul(s, s, curve448_scalar_one); /* ham-handed reduce */
+
return decaf_succeed_if(~word_is_zero(accum));
}
-void API_NS(scalar_destroy) (
- scalar_t scalar
-) {
- OPENSSL_cleanse(scalar, sizeof(scalar_t));
+void curve448_scalar_destroy(curve448_scalar_t scalar)
+{
+ OPENSSL_cleanse(scalar, sizeof(curve448_scalar_t));
}
-void API_NS(scalar_decode_long)(
- scalar_t s,
- const unsigned char *ser,
- size_t ser_len
-) {
+void curve448_scalar_decode_long(curve448_scalar_t s,
+ const unsigned char *ser, size_t ser_len)
+{
+ size_t i;
+ curve448_scalar_t t1, t2;
+
if (ser_len == 0) {
- API_NS(scalar_copy)(s, API_NS(scalar_zero));
+ curve448_scalar_copy(s, curve448_scalar_zero);
return;
}
-
- size_t i;
- scalar_t t1, t2;
- i = ser_len - (ser_len%SCALAR_SER_BYTES);
- if (i==ser_len) i -= SCALAR_SER_BYTES;
-
- scalar_decode_short(t1, &ser[i], ser_len-i);
+ i = ser_len - (ser_len % DECAF_448_SCALAR_BYTES);
+ if (i == ser_len)
+ i -= DECAF_448_SCALAR_BYTES;
- if (ser_len == sizeof(scalar_t)) {
- assert(i==0);
+ scalar_decode_short(t1, &ser[i], ser_len - i);
+
+ if (ser_len == sizeof(curve448_scalar_t)) {
+ assert(i == 0);
/* ham-handed reduce */
- API_NS(scalar_mul)(s,t1,API_NS(scalar_one));
- API_NS(scalar_destroy)(t1);
+ curve448_scalar_mul(s, t1, curve448_scalar_one);
+ curve448_scalar_destroy(t1);
return;
}
while (i) {
- i -= SCALAR_SER_BYTES;
- sc_montmul(t1,t1,sc_r2);
- ignore_result( API_NS(scalar_decode)(t2, ser+i) );
- API_NS(scalar_add)(t1, t1, t2);
+ i -= DECAF_448_SCALAR_BYTES;
+ sc_montmul(t1, t1, sc_r2);
+ ignore_result(curve448_scalar_decode(t2, ser + i));
+ curve448_scalar_add(t1, t1, t2);
}
- API_NS(scalar_copy)(s, t1);
- API_NS(scalar_destroy)(t1);
- API_NS(scalar_destroy)(t2);
+ curve448_scalar_copy(s, t1);
+ curve448_scalar_destroy(t1);
+ curve448_scalar_destroy(t2);
}
-void API_NS(scalar_encode)(
- unsigned char ser[SCALAR_SER_BYTES],
- const scalar_t s
-) {
- unsigned int i,j,k=0;
- for (i=0; i<SCALAR_LIMBS; i++) {
- for (j=0; j<sizeof(decaf_word_t); j++,k++) {
- ser[k] = s->limb[i] >> (8*j);
- }
- }
-}
+void curve448_scalar_encode(unsigned char ser[DECAF_448_SCALAR_BYTES],
+ const curve448_scalar_t s)
+{
+ unsigned int i, j, k = 0;
-void API_NS(scalar_cond_sel) (
- scalar_t out,
- const scalar_t a,
- const scalar_t b,
- decaf_bool_t pick_b
-) {
- constant_time_select(out,a,b,sizeof(scalar_t),bool_to_mask(pick_b),sizeof(out->limb[0]));
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS; i++) {
+ for (j = 0; j < sizeof(decaf_word_t); j++, k++)
+ ser[k] = s->limb[i] >> (8 * j);
+ }
}
-void API_NS(scalar_halve) (
- scalar_t out,
- const scalar_t a
-) {
+void curve448_scalar_halve(curve448_scalar_t out, const curve448_scalar_t a)
+{
decaf_word_t mask = -(a->limb[0] & 1);
decaf_dword_t chain = 0;
unsigned int i;
- for (i=0; i<SCALAR_LIMBS; i++) {
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS; i++) {
chain = (chain + a->limb[i]) + (sc_p->limb[i] & mask);
out->limb[i] = chain;
chain >>= DECAF_WORD_BITS;
}
- for (i=0; i<SCALAR_LIMBS-1; i++) {
- out->limb[i] = out->limb[i]>>1 | out->limb[i+1]<<(WBITS-1);
- }
- out->limb[i] = out->limb[i]>>1 | chain<<(WBITS-1);
+ for (i = 0; i < DECAF_448_SCALAR_LIMBS - 1; i++)
+ out->limb[i] = out->limb[i] >> 1 | out->limb[i + 1] << (WBITS - 1);
+ out->limb[i] = out->limb[i] >> 1 | chain << (WBITS - 1);
}
-