-/* crypto/ec/ecp_nistp521.c */
/*
- * Written by Adam Langley (Google) for the OpenSSL project
+ * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * 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
*/
+
/* Copyright 2011 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* work which got its smarts from Daniel J. Bernstein's work on the same.
*/
-#include <openssl/opensslconf.h>
-#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
-
-# ifndef OPENSSL_SYS_VMS
-# include <stdint.h>
-# else
-# include <inttypes.h>
-# endif
+#include <openssl/e_os2.h>
+#ifdef OPENSSL_NO_EC_NISTP_64_GCC_128
+NON_EMPTY_TRANSLATION_UNIT
+#else
# include <string.h>
# include <openssl/err.h>
# include "ec_lcl.h"
-# if defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
+# if defined(__SIZEOF_INT128__) && __SIZEOF_INT128__==16
/* even with gcc, the typedef won't work for 32-bit platforms */
typedef __uint128_t uint128_t; /* nonstandard; implemented by gcc on 64-bit
* platforms */
# else
-# error "Need GCC 3.1 or later to define type uint128_t"
+# error "Your compiler doesn't appear to support 128-bit integer types"
# endif
typedef uint8_t u8;
typedef uint64_t u64;
-typedef int64_t s64;
/*
* The underlying field. P521 operates over GF(2^521-1). We can serialise an
/* BN_bn2bin eats leading zeroes */
memset(b_out, 0, sizeof(b_out));
num_bytes = BN_num_bytes(bn);
- if (num_bytes > sizeof b_out) {
+ if (num_bytes > sizeof(b_out)) {
ECerr(EC_F_BN_TO_FELEM, EC_R_BIGNUM_OUT_OF_RANGE);
return 0;
}
{
felem_bytearray b_in, b_out;
felem_to_bin66(b_in, in);
- flip_endian(b_out, b_in, sizeof b_out);
- return BN_bin2bn(b_out, sizeof b_out, out);
+ flip_endian(b_out, b_in, sizeof(b_out));
+ return BN_bin2bn(b_out, sizeof(b_out), out);
}
/*-
* We know that ftmp[i] < 2^63, therefore the only way that the top bit
* can be set is if is_zero was 0 before the decrement.
*/
- is_zero = ((s64) is_zero) >> 63;
+ is_zero = 0 - (is_zero >> 63);
is_p = ftmp[0] ^ kPrime[0];
is_p |= ftmp[1] ^ kPrime[1];
is_p |= ftmp[8] ^ kPrime[8];
is_p--;
- is_p = ((s64) is_p) >> 63;
+ is_p = 0 - (is_p >> 63);
is_zero |= is_p;
return is_zero;
}
-static int felem_is_zero_int(const felem in)
+static int felem_is_zero_int(const void *in)
{
return (int)(felem_is_zero(in) & ((limb) 1));
}
is_p &= is_p << 4;
is_p &= is_p << 2;
is_p &= is_p << 1;
- is_p = ((s64) is_p) >> 63;
+ is_p = 0 - (is_p >> 63);
is_p = ~is_p;
/* is_p is 0 iff |out| == 2^521-1 and all ones otherwise */
is_greater |= is_greater << 4;
is_greater |= is_greater << 2;
is_greater |= is_greater << 1;
- is_greater = ((s64) is_greater) >> 63;
+ is_greater = 0 - (is_greater >> 63);
out[0] -= kPrime[0] & is_greater;
out[1] -= kPrime[1] & is_greater;
* coordinates */
/*-
- * point_double calcuates 2*(x_in, y_in, z_in)
+ * point_double calculates 2*(x_in, y_in, z_in)
*
* The method is taken from:
* http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-3.html#doubling-dbl-2001-b
}
/*-
- * point_add calcuates (x1, y1, z1) + (x2, y2, z2)
+ * point_add calculates (x1, y1, z1) + (x2, y2, z2)
*
* The method is taken from
* http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-3.html#addition-add-2007-bl,
* adapted for mixed addition (z2 = 1, or z2 = 0 for the point at infinity).
*
* This function includes a branch for checking whether the two input points
- * are equal (while not equal to the point at infinity). This case never
- * happens during single point multiplication, so there is no timing leak for
- * ECDH or ECDSA signing. */
+ * are equal (while not equal to the point at infinity). See comment below
+ * on constant-time.
+ */
static void point_add(felem x3, felem y3, felem z3,
const felem x1, const felem y1, const felem z1,
const int mixed, const felem x2, const felem y2,
/* ftmp5[i] < 2^61 */
if (x_equal && y_equal && !z1_is_zero && !z2_is_zero) {
+ /*
+ * This is obviously not constant-time but it will almost-never happen
+ * for ECDH / ECDSA. The case where it can happen is during scalar-mult
+ * where the intermediate value gets very close to the group order.
+ * Since |ec_GFp_nistp_recode_scalar_bits| produces signed digits for
+ * the scalar, it's possible for the intermediate value to be a small
+ * negative multiple of the base point, and for the final signed digit
+ * to be the same value. We believe that this only occurs for the scalar
+ * 1fffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
+ * ffffffa51868783bf2f966b7fcc0148f709a5d03bb5c9b8899c47aebb6fb
+ * 71e913863f7, in that case the penultimate intermediate is -9G and
+ * the final digit is also -9G. Since this only happens for a single
+ * scalar, the timing leak is irrelevent. (Any attacker who wanted to
+ * check whether a secret scalar was that exact value, can already do
+ * so.)
+ */
point_double(x3, y3, z3, x1, y1, z1);
return;
}
}
/* Precomputation for the group generator. */
-struct nistp512_pre_comp_st {
+struct nistp521_pre_comp_st {
felem g_pre_comp[16][3];
- int references;
+ CRYPTO_REF_COUNT references;
+ CRYPTO_RWLOCK *lock;
};
const EC_METHOD *EC_GFp_nistp521_method(void)
ec_GFp_nistp521_group_set_curve,
ec_GFp_simple_group_get_curve,
ec_GFp_simple_group_get_degree,
+ ec_group_simple_order_bits,
ec_GFp_simple_group_check_discriminant,
ec_GFp_simple_point_init,
ec_GFp_simple_point_finish,
0 /* field_div */ ,
0 /* field_encode */ ,
0 /* field_decode */ ,
- 0 /* field_set_to_one */
+ 0, /* field_set_to_one */
+ ec_key_simple_priv2oct,
+ ec_key_simple_oct2priv,
+ 0, /* set private */
+ ec_key_simple_generate_key,
+ ec_key_simple_check_key,
+ ec_key_simple_generate_public_key,
+ 0, /* keycopy */
+ 0, /* keyfinish */
+ ecdh_simple_compute_key
};
return &ret;
ECerr(EC_F_NISTP521_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE);
return ret;
}
+
ret->references = 1;
+
+ ret->lock = CRYPTO_THREAD_lock_new();
+ if (ret->lock == NULL) {
+ ECerr(EC_F_NISTP521_PRE_COMP_NEW, ERR_R_MALLOC_FAILURE);
+ OPENSSL_free(ret);
+ return NULL;
+ }
return ret;
}
NISTP521_PRE_COMP *EC_nistp521_pre_comp_dup(NISTP521_PRE_COMP *p)
{
+ int i;
if (p != NULL)
- CRYPTO_add(&p->references, 1, CRYPTO_LOCK_EC_PRE_COMP);
+ CRYPTO_UP_REF(&p->references, &i, p->lock);
return p;
}
void EC_nistp521_pre_comp_free(NISTP521_PRE_COMP *p)
{
- if (p == NULL
- || CRYPTO_add(&p->references, -1, CRYPTO_LOCK_EC_PRE_COMP) > 0)
+ int i;
+
+ if (p == NULL)
return;
+
+ CRYPTO_DOWN_REF(&p->references, &i, p->lock);
+ REF_PRINT_COUNT("EC_nistp521", x);
+ if (i > 0)
+ return;
+ REF_ASSERT_ISNT(i < 0);
+
+ CRYPTO_THREAD_lock_free(p->lock);
OPENSSL_free(p);
}
if ((ctx = new_ctx = BN_CTX_new()) == NULL)
return 0;
BN_CTX_start(ctx);
- if (((curve_p = BN_CTX_get(ctx)) == NULL) ||
- ((curve_a = BN_CTX_get(ctx)) == NULL) ||
- ((curve_b = BN_CTX_get(ctx)) == NULL))
+ curve_p = BN_CTX_get(ctx);
+ curve_a = BN_CTX_get(ctx);
+ curve_b = BN_CTX_get(ctx);
+ if (curve_b == NULL)
goto err;
BN_bin2bn(nistp521_curve_params[0], sizeof(felem_bytearray), curve_p);
BN_bin2bn(nistp521_curve_params[1], sizeof(felem_bytearray), curve_a);
sizeof(felem),
tmp_felems,
(void (*)(void *))felem_one,
- (int (*)(const void *))
felem_is_zero_int,
(void (*)(void *, const void *))
felem_assign,
if ((ctx = new_ctx = BN_CTX_new()) == NULL)
return 0;
BN_CTX_start(ctx);
- if (((x = BN_CTX_get(ctx)) == NULL) ||
- ((y = BN_CTX_get(ctx)) == NULL) ||
- ((z = BN_CTX_get(ctx)) == NULL) ||
- ((tmp_scalar = BN_CTX_get(ctx)) == NULL))
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ z = BN_CTX_get(ctx);
+ tmp_scalar = BN_CTX_get(ctx);
+ if (tmp_scalar == NULL)
goto err;
if (scalar != NULL) {
felem tmp_felems[16];
/* throw away old precomputation */
- EC_nistp521_pre_comp_free(group->pre_comp.nistp521);
+ EC_pre_comp_free(group);
if (ctx == NULL)
if ((ctx = new_ctx = BN_CTX_new()) == NULL)
return 0;
BN_CTX_start(ctx);
- if (((x = BN_CTX_get(ctx)) == NULL) || ((y = BN_CTX_get(ctx)) == NULL))
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ if (y == NULL)
goto err;
/* get the generator */
if (group->generator == NULL)
*/
if (0 == EC_POINT_cmp(group, generator, group->generator, ctx)) {
memcpy(pre->g_pre_comp, gmul, sizeof(pre->g_pre_comp));
- ret = 1;
- goto err;
+ goto done;
}
if ((!BN_to_felem(pre->g_pre_comp[1][0], group->generator->X)) ||
(!BN_to_felem(pre->g_pre_comp[1][1], group->generator->Y)) ||
}
make_points_affine(15, &(pre->g_pre_comp[1]), tmp_felems);
+ done:
SETPRECOMP(group, nistp521, pre);
ret = 1;
pre = NULL;
int ec_GFp_nistp521_have_precompute_mult(const EC_GROUP *group)
{
- return HAVEPRECOMP(group, nistp512);
+ return HAVEPRECOMP(group, nistp521);
}
-#else
-static void *dummy = &dummy;
#endif