aboutsummaryrefslogtreecommitdiff
path: root/third_party
diff options
context:
space:
mode:
Diffstat (limited to 'third_party')
-rw-r--r--third_party/openssl-curve25519/LICENSE125
-rwxr-xr-xthird_party/openssl-curve25519/compiler.sh4
-rw-r--r--third_party/openssl-curve25519/crypto_scalarmult_bench.c5
-rw-r--r--third_party/openssl-curve25519/ec_curve25519.c1126
-rw-r--r--third_party/openssl-curve25519/ec_curve25519.h2
-rw-r--r--third_party/openssl-curve25519/measurements.txt1
-rw-r--r--third_party/openssl-nistp256c64/LICENSE125
-rw-r--r--third_party/openssl-nistp256c64/bench_madd.c16
-rwxr-xr-xthird_party/openssl-nistp256c64/compiler.sh4
-rw-r--r--third_party/openssl-nistp256c64/ecp_nistp256.c1314
-rw-r--r--third_party/openssl-nistp256c64/ecp_nistp256.h55
11 files changed, 2777 insertions, 0 deletions
diff --git a/third_party/openssl-curve25519/LICENSE b/third_party/openssl-curve25519/LICENSE
new file mode 100644
index 000000000..8fbabd8af
--- /dev/null
+++ b/third_party/openssl-curve25519/LICENSE
@@ -0,0 +1,125 @@
+
+ LICENSE ISSUES
+ ==============
+
+ The OpenSSL toolkit stays under a double license, i.e. both the conditions of
+ the OpenSSL License and the original SSLeay license apply to the toolkit.
+ See below for the actual license texts.
+
+ OpenSSL License
+ ---------------
+
+/* ====================================================================
+ * Copyright (c) 1998-2017 The OpenSSL Project. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ * software must display the following acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+ Original SSLeay License
+ -----------------------
+
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to. The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code. The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * "This product includes cryptographic software written by
+ * Eric Young (eay@cryptsoft.com)"
+ * The word 'cryptographic' can be left out if the rouines from the library
+ * being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ * the apps directory (application code) you must include an acknowledgement:
+ * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed. i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.]
+ */
+
diff --git a/third_party/openssl-curve25519/compiler.sh b/third_party/openssl-curve25519/compiler.sh
new file mode 100755
index 000000000..29885a152
--- /dev/null
+++ b/third_party/openssl-curve25519/compiler.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+set -eu
+
+gcc -march=native -mtune=native -std=gnu11 -O3 -flto -fomit-frame-pointer -fwrapv -Wno-attributes -lcrypto $@
diff --git a/third_party/openssl-curve25519/crypto_scalarmult_bench.c b/third_party/openssl-curve25519/crypto_scalarmult_bench.c
new file mode 100644
index 000000000..b7d717158
--- /dev/null
+++ b/third_party/openssl-curve25519/crypto_scalarmult_bench.c
@@ -0,0 +1,5 @@
+#include "ec_curve25519.h"
+
+void crypto_scalarmult_bench(unsigned char* buf) {
+ x25519_scalar_mult(buf, buf+32, buf+64);
+}
diff --git a/third_party/openssl-curve25519/ec_curve25519.c b/third_party/openssl-curve25519/ec_curve25519.c
new file mode 100644
index 000000000..7d00cc53f
--- /dev/null
+++ b/third_party/openssl-curve25519/ec_curve25519.c
@@ -0,0 +1,1126 @@
+/*
+ * Copyright 2016 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
+ */
+
+/* This code is mostly taken from the ref10 version of Ed25519 in SUPERCOP
+ * 20141124 (http://bench.cr.yp.to/supercop.html).
+ *
+ * The field functions are shared by Ed25519 and X25519 where possible. */
+
+#include <stdint.h>
+#include <string.h>
+#include "ec_curve25519.h"
+
+
+/* fe means field element. Here the field is \Z/(2^255-19). An element t,
+ * entries t[0]...t[9], represents the integer t[0]+2^26 t[1]+2^51 t[2]+2^77
+ * t[3]+2^102 t[4]+...+2^230 t[9]. Bounds on each t[i] vary depending on
+ * context. */
+typedef int32_t fe[10];
+
+static const int64_t kBottom25Bits = 0x1ffffffLL;
+static const int64_t kBottom26Bits = 0x3ffffffLL;
+static const int64_t kTop39Bits = 0xfffffffffe000000LL;
+static const int64_t kTop38Bits = 0xfffffffffc000000LL;
+
+static uint64_t load_3(const uint8_t *in) {
+ uint64_t result;
+ result = (uint64_t)in[0];
+ result |= ((uint64_t)in[1]) << 8;
+ result |= ((uint64_t)in[2]) << 16;
+ return result;
+}
+
+static uint64_t load_4(const uint8_t *in) {
+ uint64_t result;
+ result = (uint64_t)in[0];
+ result |= ((uint64_t)in[1]) << 8;
+ result |= ((uint64_t)in[2]) << 16;
+ result |= ((uint64_t)in[3]) << 24;
+ return result;
+}
+
+static void fe_frombytes(fe h, const uint8_t *s) {
+ /* Ignores top bit of h. */
+ int64_t h0 = load_4(s);
+ int64_t h1 = load_3(s + 4) << 6;
+ int64_t h2 = load_3(s + 7) << 5;
+ int64_t h3 = load_3(s + 10) << 3;
+ int64_t h4 = load_3(s + 13) << 2;
+ int64_t h5 = load_4(s + 16);
+ int64_t h6 = load_3(s + 20) << 7;
+ int64_t h7 = load_3(s + 23) << 5;
+ int64_t h8 = load_3(s + 26) << 4;
+ int64_t h9 = (load_3(s + 29) & 8388607) << 2;
+ int64_t carry0;
+ int64_t carry1;
+ int64_t carry2;
+ int64_t carry3;
+ int64_t carry4;
+ int64_t carry5;
+ int64_t carry6;
+ int64_t carry7;
+ int64_t carry8;
+ int64_t carry9;
+
+ carry9 = h9 + (1 << 24); h0 += (carry9 >> 25) * 19; h9 -= carry9 & kTop39Bits;
+ carry1 = h1 + (1 << 24); h2 += carry1 >> 25; h1 -= carry1 & kTop39Bits;
+ carry3 = h3 + (1 << 24); h4 += carry3 >> 25; h3 -= carry3 & kTop39Bits;
+ carry5 = h5 + (1 << 24); h6 += carry5 >> 25; h5 -= carry5 & kTop39Bits;
+ carry7 = h7 + (1 << 24); h8 += carry7 >> 25; h7 -= carry7 & kTop39Bits;
+
+ carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & kTop38Bits;
+ carry2 = h2 + (1 << 25); h3 += carry2 >> 26; h2 -= carry2 & kTop38Bits;
+ carry4 = h4 + (1 << 25); h5 += carry4 >> 26; h4 -= carry4 & kTop38Bits;
+ carry6 = h6 + (1 << 25); h7 += carry6 >> 26; h6 -= carry6 & kTop38Bits;
+ carry8 = h8 + (1 << 25); h9 += carry8 >> 26; h8 -= carry8 & kTop38Bits;
+
+ h[0] = h0;
+ h[1] = h1;
+ h[2] = h2;
+ h[3] = h3;
+ h[4] = h4;
+ h[5] = h5;
+ h[6] = h6;
+ h[7] = h7;
+ h[8] = h8;
+ h[9] = h9;
+}
+
+/* Preconditions:
+ * |h| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
+ *
+ * Write p=2^255-19; q=floor(h/p).
+ * Basic claim: q = floor(2^(-255)(h + 19 2^(-25)h9 + 2^(-1))).
+ *
+ * Proof:
+ * Have |h|<=p so |q|<=1 so |19^2 2^(-255) q|<1/4.
+ * Also have |h-2^230 h9|<2^231 so |19 2^(-255)(h-2^230 h9)|<1/4.
+ *
+ * Write y=2^(-1)-19^2 2^(-255)q-19 2^(-255)(h-2^230 h9).
+ * Then 0<y<1.
+ *
+ * Write r=h-pq.
+ * Have 0<=r<=p-1=2^255-20.
+ * Thus 0<=r+19(2^-255)r<r+19(2^-255)2^255<=2^255-1.
+ *
+ * Write x=r+19(2^-255)r+y.
+ * Then 0<x<2^255 so floor(2^(-255)x) = 0 so floor(q+2^(-255)x) = q.
+ *
+ * Have q+2^(-255)x = 2^(-255)(h + 19 2^(-25) h9 + 2^(-1))
+ * so floor(2^(-255)(h + 19 2^(-25) h9 + 2^(-1))) = q. */
+static void fe_tobytes(uint8_t *s, const fe h) {
+ int32_t h0 = h[0];
+ int32_t h1 = h[1];
+ int32_t h2 = h[2];
+ int32_t h3 = h[3];
+ int32_t h4 = h[4];
+ int32_t h5 = h[5];
+ int32_t h6 = h[6];
+ int32_t h7 = h[7];
+ int32_t h8 = h[8];
+ int32_t h9 = h[9];
+ int32_t q;
+
+ q = (19 * h9 + (((int32_t) 1) << 24)) >> 25;
+ q = (h0 + q) >> 26;
+ q = (h1 + q) >> 25;
+ q = (h2 + q) >> 26;
+ q = (h3 + q) >> 25;
+ q = (h4 + q) >> 26;
+ q = (h5 + q) >> 25;
+ q = (h6 + q) >> 26;
+ q = (h7 + q) >> 25;
+ q = (h8 + q) >> 26;
+ q = (h9 + q) >> 25;
+
+ /* Goal: Output h-(2^255-19)q, which is between 0 and 2^255-20. */
+ h0 += 19 * q;
+ /* Goal: Output h-2^255 q, which is between 0 and 2^255-20. */
+
+ h1 += h0 >> 26; h0 &= kBottom26Bits;
+ h2 += h1 >> 25; h1 &= kBottom25Bits;
+ h3 += h2 >> 26; h2 &= kBottom26Bits;
+ h4 += h3 >> 25; h3 &= kBottom25Bits;
+ h5 += h4 >> 26; h4 &= kBottom26Bits;
+ h6 += h5 >> 25; h5 &= kBottom25Bits;
+ h7 += h6 >> 26; h6 &= kBottom26Bits;
+ h8 += h7 >> 25; h7 &= kBottom25Bits;
+ h9 += h8 >> 26; h8 &= kBottom26Bits;
+ h9 &= kBottom25Bits;
+ /* h10 = carry9 */
+
+ /* Goal: Output h0+...+2^255 h10-2^255 q, which is between 0 and 2^255-20.
+ * Have h0+...+2^230 h9 between 0 and 2^255-1;
+ * evidently 2^255 h10-2^255 q = 0.
+ * Goal: Output h0+...+2^230 h9. */
+
+ s[0] = h0 >> 0;
+ s[1] = h0 >> 8;
+ s[2] = h0 >> 16;
+ s[3] = (h0 >> 24) | ((uint32_t)(h1) << 2);
+ s[4] = h1 >> 6;
+ s[5] = h1 >> 14;
+ s[6] = (h1 >> 22) | ((uint32_t)(h2) << 3);
+ s[7] = h2 >> 5;
+ s[8] = h2 >> 13;
+ s[9] = (h2 >> 21) | ((uint32_t)(h3) << 5);
+ s[10] = h3 >> 3;
+ s[11] = h3 >> 11;
+ s[12] = (h3 >> 19) | ((uint32_t)(h4) << 6);
+ s[13] = h4 >> 2;
+ s[14] = h4 >> 10;
+ s[15] = h4 >> 18;
+ s[16] = h5 >> 0;
+ s[17] = h5 >> 8;
+ s[18] = h5 >> 16;
+ s[19] = (h5 >> 24) | ((uint32_t)(h6) << 1);
+ s[20] = h6 >> 7;
+ s[21] = h6 >> 15;
+ s[22] = (h6 >> 23) | ((uint32_t)(h7) << 3);
+ s[23] = h7 >> 5;
+ s[24] = h7 >> 13;
+ s[25] = (h7 >> 21) | ((uint32_t)(h8) << 4);
+ s[26] = h8 >> 4;
+ s[27] = h8 >> 12;
+ s[28] = (h8 >> 20) | ((uint32_t)(h9) << 6);
+ s[29] = h9 >> 2;
+ s[30] = h9 >> 10;
+ s[31] = h9 >> 18;
+}
+
+/* h = f */
+static void fe_copy(fe h, const fe f) {
+ memmove(h, f, sizeof(int32_t) * 10);
+}
+
+/* h = 0 */
+static void fe_0(fe h) { memset(h, 0, sizeof(int32_t) * 10); }
+
+/* h = 1 */
+static void fe_1(fe h) {
+ memset(h, 0, sizeof(int32_t) * 10);
+ h[0] = 1;
+}
+
+/* h = f + g
+ * Can overlap h with f or g.
+ *
+ * Preconditions:
+ * |f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+ * |g| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+ *
+ * Postconditions:
+ * |h| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc. */
+static void fe_add(fe h, const fe f, const fe g) {
+ unsigned i;
+ for (i = 0; i < 10; i++) {
+ h[i] = f[i] + g[i];
+ }
+}
+
+/* h = f - g
+ * Can overlap h with f or g.
+ *
+ * Preconditions:
+ * |f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+ * |g| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+ *
+ * Postconditions:
+ * |h| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc. */
+static void fe_sub(fe h, const fe f, const fe g) {
+ unsigned i;
+ for (i = 0; i < 10; i++) {
+ h[i] = f[i] - g[i];
+ }
+}
+
+/* h = f * g
+ * Can overlap h with f or g.
+ *
+ * Preconditions:
+ * |f| bounded by 1.65*2^26,1.65*2^25,1.65*2^26,1.65*2^25,etc.
+ * |g| bounded by 1.65*2^26,1.65*2^25,1.65*2^26,1.65*2^25,etc.
+ *
+ * Postconditions:
+ * |h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc.
+ *
+ * Notes on implementation strategy:
+ *
+ * Using schoolbook multiplication.
+ * Karatsuba would save a little in some cost models.
+ *
+ * Most multiplications by 2 and 19 are 32-bit precomputations;
+ * cheaper than 64-bit postcomputations.
+ *
+ * There is one remaining multiplication by 19 in the carry chain;
+ * one *19 precomputation can be merged into this,
+ * but the resulting data flow is considerably less clean.
+ *
+ * There are 12 carries below.
+ * 10 of them are 2-way parallelizable and vectorizable.
+ * Can get away with 11 carries, but then data flow is much deeper.
+ *
+ * With tighter constraints on inputs can squeeze carries into int32. */
+static void fe_mul(fe h, const fe f, const fe g) {
+ int32_t f0 = f[0];
+ int32_t f1 = f[1];
+ int32_t f2 = f[2];
+ int32_t f3 = f[3];
+ int32_t f4 = f[4];
+ int32_t f5 = f[5];
+ int32_t f6 = f[6];
+ int32_t f7 = f[7];
+ int32_t f8 = f[8];
+ int32_t f9 = f[9];
+ int32_t g0 = g[0];
+ int32_t g1 = g[1];
+ int32_t g2 = g[2];
+ int32_t g3 = g[3];
+ int32_t g4 = g[4];
+ int32_t g5 = g[5];
+ int32_t g6 = g[6];
+ int32_t g7 = g[7];
+ int32_t g8 = g[8];
+ int32_t g9 = g[9];
+ int32_t g1_19 = 19 * g1; /* 1.959375*2^29 */
+ int32_t g2_19 = 19 * g2; /* 1.959375*2^30; still ok */
+ int32_t g3_19 = 19 * g3;
+ int32_t g4_19 = 19 * g4;
+ int32_t g5_19 = 19 * g5;
+ int32_t g6_19 = 19 * g6;
+ int32_t g7_19 = 19 * g7;
+ int32_t g8_19 = 19 * g8;
+ int32_t g9_19 = 19 * g9;
+ int32_t f1_2 = 2 * f1;
+ int32_t f3_2 = 2 * f3;
+ int32_t f5_2 = 2 * f5;
+ int32_t f7_2 = 2 * f7;
+ int32_t f9_2 = 2 * f9;
+ int64_t f0g0 = f0 * (int64_t) g0;
+ int64_t f0g1 = f0 * (int64_t) g1;
+ int64_t f0g2 = f0 * (int64_t) g2;
+ int64_t f0g3 = f0 * (int64_t) g3;
+ int64_t f0g4 = f0 * (int64_t) g4;
+ int64_t f0g5 = f0 * (int64_t) g5;
+ int64_t f0g6 = f0 * (int64_t) g6;
+ int64_t f0g7 = f0 * (int64_t) g7;
+ int64_t f0g8 = f0 * (int64_t) g8;
+ int64_t f0g9 = f0 * (int64_t) g9;
+ int64_t f1g0 = f1 * (int64_t) g0;
+ int64_t f1g1_2 = f1_2 * (int64_t) g1;
+ int64_t f1g2 = f1 * (int64_t) g2;
+ int64_t f1g3_2 = f1_2 * (int64_t) g3;
+ int64_t f1g4 = f1 * (int64_t) g4;
+ int64_t f1g5_2 = f1_2 * (int64_t) g5;
+ int64_t f1g6 = f1 * (int64_t) g6;
+ int64_t f1g7_2 = f1_2 * (int64_t) g7;
+ int64_t f1g8 = f1 * (int64_t) g8;
+ int64_t f1g9_38 = f1_2 * (int64_t) g9_19;
+ int64_t f2g0 = f2 * (int64_t) g0;
+ int64_t f2g1 = f2 * (int64_t) g1;
+ int64_t f2g2 = f2 * (int64_t) g2;
+ int64_t f2g3 = f2 * (int64_t) g3;
+ int64_t f2g4 = f2 * (int64_t) g4;
+ int64_t f2g5 = f2 * (int64_t) g5;
+ int64_t f2g6 = f2 * (int64_t) g6;
+ int64_t f2g7 = f2 * (int64_t) g7;
+ int64_t f2g8_19 = f2 * (int64_t) g8_19;
+ int64_t f2g9_19 = f2 * (int64_t) g9_19;
+ int64_t f3g0 = f3 * (int64_t) g0;
+ int64_t f3g1_2 = f3_2 * (int64_t) g1;
+ int64_t f3g2 = f3 * (int64_t) g2;
+ int64_t f3g3_2 = f3_2 * (int64_t) g3;
+ int64_t f3g4 = f3 * (int64_t) g4;
+ int64_t f3g5_2 = f3_2 * (int64_t) g5;
+ int64_t f3g6 = f3 * (int64_t) g6;
+ int64_t f3g7_38 = f3_2 * (int64_t) g7_19;
+ int64_t f3g8_19 = f3 * (int64_t) g8_19;
+ int64_t f3g9_38 = f3_2 * (int64_t) g9_19;
+ int64_t f4g0 = f4 * (int64_t) g0;
+ int64_t f4g1 = f4 * (int64_t) g1;
+ int64_t f4g2 = f4 * (int64_t) g2;
+ int64_t f4g3 = f4 * (int64_t) g3;
+ int64_t f4g4 = f4 * (int64_t) g4;
+ int64_t f4g5 = f4 * (int64_t) g5;
+ int64_t f4g6_19 = f4 * (int64_t) g6_19;
+ int64_t f4g7_19 = f4 * (int64_t) g7_19;
+ int64_t f4g8_19 = f4 * (int64_t) g8_19;
+ int64_t f4g9_19 = f4 * (int64_t) g9_19;
+ int64_t f5g0 = f5 * (int64_t) g0;
+ int64_t f5g1_2 = f5_2 * (int64_t) g1;
+ int64_t f5g2 = f5 * (int64_t) g2;
+ int64_t f5g3_2 = f5_2 * (int64_t) g3;
+ int64_t f5g4 = f5 * (int64_t) g4;
+ int64_t f5g5_38 = f5_2 * (int64_t) g5_19;
+ int64_t f5g6_19 = f5 * (int64_t) g6_19;
+ int64_t f5g7_38 = f5_2 * (int64_t) g7_19;
+ int64_t f5g8_19 = f5 * (int64_t) g8_19;
+ int64_t f5g9_38 = f5_2 * (int64_t) g9_19;
+ int64_t f6g0 = f6 * (int64_t) g0;
+ int64_t f6g1 = f6 * (int64_t) g1;
+ int64_t f6g2 = f6 * (int64_t) g2;
+ int64_t f6g3 = f6 * (int64_t) g3;
+ int64_t f6g4_19 = f6 * (int64_t) g4_19;
+ int64_t f6g5_19 = f6 * (int64_t) g5_19;
+ int64_t f6g6_19 = f6 * (int64_t) g6_19;
+ int64_t f6g7_19 = f6 * (int64_t) g7_19;
+ int64_t f6g8_19 = f6 * (int64_t) g8_19;
+ int64_t f6g9_19 = f6 * (int64_t) g9_19;
+ int64_t f7g0 = f7 * (int64_t) g0;
+ int64_t f7g1_2 = f7_2 * (int64_t) g1;
+ int64_t f7g2 = f7 * (int64_t) g2;
+ int64_t f7g3_38 = f7_2 * (int64_t) g3_19;
+ int64_t f7g4_19 = f7 * (int64_t) g4_19;
+ int64_t f7g5_38 = f7_2 * (int64_t) g5_19;
+ int64_t f7g6_19 = f7 * (int64_t) g6_19;
+ int64_t f7g7_38 = f7_2 * (int64_t) g7_19;
+ int64_t f7g8_19 = f7 * (int64_t) g8_19;
+ int64_t f7g9_38 = f7_2 * (int64_t) g9_19;
+ int64_t f8g0 = f8 * (int64_t) g0;
+ int64_t f8g1 = f8 * (int64_t) g1;
+ int64_t f8g2_19 = f8 * (int64_t) g2_19;
+ int64_t f8g3_19 = f8 * (int64_t) g3_19;
+ int64_t f8g4_19 = f8 * (int64_t) g4_19;
+ int64_t f8g5_19 = f8 * (int64_t) g5_19;
+ int64_t f8g6_19 = f8 * (int64_t) g6_19;
+ int64_t f8g7_19 = f8 * (int64_t) g7_19;
+ int64_t f8g8_19 = f8 * (int64_t) g8_19;
+ int64_t f8g9_19 = f8 * (int64_t) g9_19;
+ int64_t f9g0 = f9 * (int64_t) g0;
+ int64_t f9g1_38 = f9_2 * (int64_t) g1_19;
+ int64_t f9g2_19 = f9 * (int64_t) g2_19;
+ int64_t f9g3_38 = f9_2 * (int64_t) g3_19;
+ int64_t f9g4_19 = f9 * (int64_t) g4_19;
+ int64_t f9g5_38 = f9_2 * (int64_t) g5_19;
+ int64_t f9g6_19 = f9 * (int64_t) g6_19;
+ int64_t f9g7_38 = f9_2 * (int64_t) g7_19;
+ int64_t f9g8_19 = f9 * (int64_t) g8_19;
+ int64_t f9g9_38 = f9_2 * (int64_t) g9_19;
+ int64_t h0 = f0g0+f1g9_38+f2g8_19+f3g7_38+f4g6_19+f5g5_38+f6g4_19+f7g3_38+f8g2_19+f9g1_38;
+ int64_t h1 = f0g1+f1g0 +f2g9_19+f3g8_19+f4g7_19+f5g6_19+f6g5_19+f7g4_19+f8g3_19+f9g2_19;
+ int64_t h2 = f0g2+f1g1_2 +f2g0 +f3g9_38+f4g8_19+f5g7_38+f6g6_19+f7g5_38+f8g4_19+f9g3_38;
+ int64_t h3 = f0g3+f1g2 +f2g1 +f3g0 +f4g9_19+f5g8_19+f6g7_19+f7g6_19+f8g5_19+f9g4_19;
+ int64_t h4 = f0g4+f1g3_2 +f2g2 +f3g1_2 +f4g0 +f5g9_38+f6g8_19+f7g7_38+f8g6_19+f9g5_38;
+ int64_t h5 = f0g5+f1g4 +f2g3 +f3g2 +f4g1 +f5g0 +f6g9_19+f7g8_19+f8g7_19+f9g6_19;
+ int64_t h6 = f0g6+f1g5_2 +f2g4 +f3g3_2 +f4g2 +f5g1_2 +f6g0 +f7g9_38+f8g8_19+f9g7_38;
+ int64_t h7 = f0g7+f1g6 +f2g5 +f3g4 +f4g3 +f5g2 +f6g1 +f7g0 +f8g9_19+f9g8_19;
+ int64_t h8 = f0g8+f1g7_2 +f2g6 +f3g5_2 +f4g4 +f5g3_2 +f6g2 +f7g1_2 +f8g0 +f9g9_38;
+ int64_t h9 = f0g9+f1g8 +f2g7 +f3g6 +f4g5 +f5g4 +f6g3 +f7g2 +f8g1 +f9g0 ;
+ int64_t carry0;
+ int64_t carry1;
+ int64_t carry2;
+ int64_t carry3;
+ int64_t carry4;
+ int64_t carry5;
+ int64_t carry6;
+ int64_t carry7;
+ int64_t carry8;
+ int64_t carry9;
+
+ /* |h0| <= (1.65*1.65*2^52*(1+19+19+19+19)+1.65*1.65*2^50*(38+38+38+38+38))
+ * i.e. |h0| <= 1.4*2^60; narrower ranges for h2, h4, h6, h8
+ * |h1| <= (1.65*1.65*2^51*(1+1+19+19+19+19+19+19+19+19))
+ * i.e. |h1| <= 1.7*2^59; narrower ranges for h3, h5, h7, h9 */
+
+ carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & kTop38Bits;
+ carry4 = h4 + (1 << 25); h5 += carry4 >> 26; h4 -= carry4 & kTop38Bits;
+ /* |h0| <= 2^25 */
+ /* |h4| <= 2^25 */
+ /* |h1| <= 1.71*2^59 */
+ /* |h5| <= 1.71*2^59 */
+
+ carry1 = h1 + (1 << 24); h2 += carry1 >> 25; h1 -= carry1 & kTop39Bits;
+ carry5 = h5 + (1 << 24); h6 += carry5 >> 25; h5 -= carry5 & kTop39Bits;
+ /* |h1| <= 2^24; from now on fits into int32 */
+ /* |h5| <= 2^24; from now on fits into int32 */
+ /* |h2| <= 1.41*2^60 */
+ /* |h6| <= 1.41*2^60 */
+
+ carry2 = h2 + (1 << 25); h3 += carry2 >> 26; h2 -= carry2 & kTop38Bits;
+ carry6 = h6 + (1 << 25); h7 += carry6 >> 26; h6 -= carry6 & kTop38Bits;
+ /* |h2| <= 2^25; from now on fits into int32 unchanged */
+ /* |h6| <= 2^25; from now on fits into int32 unchanged */
+ /* |h3| <= 1.71*2^59 */
+ /* |h7| <= 1.71*2^59 */
+
+ carry3 = h3 + (1 << 24); h4 += carry3 >> 25; h3 -= carry3 & kTop39Bits;
+ carry7 = h7 + (1 << 24); h8 += carry7 >> 25; h7 -= carry7 & kTop39Bits;
+ /* |h3| <= 2^24; from now on fits into int32 unchanged */
+ /* |h7| <= 2^24; from now on fits into int32 unchanged */
+ /* |h4| <= 1.72*2^34 */
+ /* |h8| <= 1.41*2^60 */
+
+ carry4 = h4 + (1 << 25); h5 += carry4 >> 26; h4 -= carry4 & kTop38Bits;
+ carry8 = h8 + (1 << 25); h9 += carry8 >> 26; h8 -= carry8 & kTop38Bits;
+ /* |h4| <= 2^25; from now on fits into int32 unchanged */
+ /* |h8| <= 2^25; from now on fits into int32 unchanged */
+ /* |h5| <= 1.01*2^24 */
+ /* |h9| <= 1.71*2^59 */
+
+ carry9 = h9 + (1 << 24); h0 += (carry9 >> 25) * 19; h9 -= carry9 & kTop39Bits;
+ /* |h9| <= 2^24; from now on fits into int32 unchanged */
+ /* |h0| <= 1.1*2^39 */
+
+ carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & kTop38Bits;
+ /* |h0| <= 2^25; from now on fits into int32 unchanged */
+ /* |h1| <= 1.01*2^24 */
+
+ h[0] = h0;
+ h[1] = h1;
+ h[2] = h2;
+ h[3] = h3;
+ h[4] = h4;
+ h[5] = h5;
+ h[6] = h6;
+ h[7] = h7;
+ h[8] = h8;
+ h[9] = h9;
+}
+
+/* h = f * f
+ * Can overlap h with f.
+ *
+ * Preconditions:
+ * |f| bounded by 1.65*2^26,1.65*2^25,1.65*2^26,1.65*2^25,etc.
+ *
+ * Postconditions:
+ * |h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc.
+ *
+ * See fe_mul.c for discussion of implementation strategy. */
+static void fe_sq(fe h, const fe f) {
+ int32_t f0 = f[0];
+ int32_t f1 = f[1];
+ int32_t f2 = f[2];
+ int32_t f3 = f[3];
+ int32_t f4 = f[4];
+ int32_t f5 = f[5];
+ int32_t f6 = f[6];
+ int32_t f7 = f[7];
+ int32_t f8 = f[8];
+ int32_t f9 = f[9];
+ int32_t f0_2 = 2 * f0;
+ int32_t f1_2 = 2 * f1;
+ int32_t f2_2 = 2 * f2;
+ int32_t f3_2 = 2 * f3;
+ int32_t f4_2 = 2 * f4;
+ int32_t f5_2 = 2 * f5;
+ int32_t f6_2 = 2 * f6;
+ int32_t f7_2 = 2 * f7;
+ int32_t f5_38 = 38 * f5; /* 1.959375*2^30 */
+ int32_t f6_19 = 19 * f6; /* 1.959375*2^30 */
+ int32_t f7_38 = 38 * f7; /* 1.959375*2^30 */
+ int32_t f8_19 = 19 * f8; /* 1.959375*2^30 */
+ int32_t f9_38 = 38 * f9; /* 1.959375*2^30 */
+ int64_t f0f0 = f0 * (int64_t) f0;
+ int64_t f0f1_2 = f0_2 * (int64_t) f1;
+ int64_t f0f2_2 = f0_2 * (int64_t) f2;
+ int64_t f0f3_2 = f0_2 * (int64_t) f3;
+ int64_t f0f4_2 = f0_2 * (int64_t) f4;
+ int64_t f0f5_2 = f0_2 * (int64_t) f5;
+ int64_t f0f6_2 = f0_2 * (int64_t) f6;
+ int64_t f0f7_2 = f0_2 * (int64_t) f7;
+ int64_t f0f8_2 = f0_2 * (int64_t) f8;
+ int64_t f0f9_2 = f0_2 * (int64_t) f9;
+ int64_t f1f1_2 = f1_2 * (int64_t) f1;
+ int64_t f1f2_2 = f1_2 * (int64_t) f2;
+ int64_t f1f3_4 = f1_2 * (int64_t) f3_2;
+ int64_t f1f4_2 = f1_2 * (int64_t) f4;
+ int64_t f1f5_4 = f1_2 * (int64_t) f5_2;
+ int64_t f1f6_2 = f1_2 * (int64_t) f6;
+ int64_t f1f7_4 = f1_2 * (int64_t) f7_2;
+ int64_t f1f8_2 = f1_2 * (int64_t) f8;
+ int64_t f1f9_76 = f1_2 * (int64_t) f9_38;
+ int64_t f2f2 = f2 * (int64_t) f2;
+ int64_t f2f3_2 = f2_2 * (int64_t) f3;
+ int64_t f2f4_2 = f2_2 * (int64_t) f4;
+ int64_t f2f5_2 = f2_2 * (int64_t) f5;
+ int64_t f2f6_2 = f2_2 * (int64_t) f6;
+ int64_t f2f7_2 = f2_2 * (int64_t) f7;
+ int64_t f2f8_38 = f2_2 * (int64_t) f8_19;
+ int64_t f2f9_38 = f2 * (int64_t) f9_38;
+ int64_t f3f3_2 = f3_2 * (int64_t) f3;
+ int64_t f3f4_2 = f3_2 * (int64_t) f4;
+ int64_t f3f5_4 = f3_2 * (int64_t) f5_2;
+ int64_t f3f6_2 = f3_2 * (int64_t) f6;
+ int64_t f3f7_76 = f3_2 * (int64_t) f7_38;
+ int64_t f3f8_38 = f3_2 * (int64_t) f8_19;
+ int64_t f3f9_76 = f3_2 * (int64_t) f9_38;
+ int64_t f4f4 = f4 * (int64_t) f4;
+ int64_t f4f5_2 = f4_2 * (int64_t) f5;
+ int64_t f4f6_38 = f4_2 * (int64_t) f6_19;
+ int64_t f4f7_38 = f4 * (int64_t) f7_38;
+ int64_t f4f8_38 = f4_2 * (int64_t) f8_19;
+ int64_t f4f9_38 = f4 * (int64_t) f9_38;
+ int64_t f5f5_38 = f5 * (int64_t) f5_38;
+ int64_t f5f6_38 = f5_2 * (int64_t) f6_19;
+ int64_t f5f7_76 = f5_2 * (int64_t) f7_38;
+ int64_t f5f8_38 = f5_2 * (int64_t) f8_19;
+ int64_t f5f9_76 = f5_2 * (int64_t) f9_38;
+ int64_t f6f6_19 = f6 * (int64_t) f6_19;
+ int64_t f6f7_38 = f6 * (int64_t) f7_38;
+ int64_t f6f8_38 = f6_2 * (int64_t) f8_19;
+ int64_t f6f9_38 = f6 * (int64_t) f9_38;
+ int64_t f7f7_38 = f7 * (int64_t) f7_38;
+ int64_t f7f8_38 = f7_2 * (int64_t) f8_19;
+ int64_t f7f9_76 = f7_2 * (int64_t) f9_38;
+ int64_t f8f8_19 = f8 * (int64_t) f8_19;
+ int64_t f8f9_38 = f8 * (int64_t) f9_38;
+ int64_t f9f9_38 = f9 * (int64_t) f9_38;
+ int64_t h0 = f0f0 +f1f9_76+f2f8_38+f3f7_76+f4f6_38+f5f5_38;
+ int64_t h1 = f0f1_2+f2f9_38+f3f8_38+f4f7_38+f5f6_38;
+ int64_t h2 = f0f2_2+f1f1_2 +f3f9_76+f4f8_38+f5f7_76+f6f6_19;
+ int64_t h3 = f0f3_2+f1f2_2 +f4f9_38+f5f8_38+f6f7_38;
+ int64_t h4 = f0f4_2+f1f3_4 +f2f2 +f5f9_76+f6f8_38+f7f7_38;
+ int64_t h5 = f0f5_2+f1f4_2 +f2f3_2 +f6f9_38+f7f8_38;
+ int64_t h6 = f0f6_2+f1f5_4 +f2f4_2 +f3f3_2 +f7f9_76+f8f8_19;
+ int64_t h7 = f0f7_2+f1f6_2 +f2f5_2 +f3f4_2 +f8f9_38;
+ int64_t h8 = f0f8_2+f1f7_4 +f2f6_2 +f3f5_4 +f4f4 +f9f9_38;
+ int64_t h9 = f0f9_2+f1f8_2 +f2f7_2 +f3f6_2 +f4f5_2;
+ int64_t carry0;
+ int64_t carry1;
+ int64_t carry2;
+ int64_t carry3;
+ int64_t carry4;
+ int64_t carry5;
+ int64_t carry6;
+ int64_t carry7;
+ int64_t carry8;
+ int64_t carry9;
+
+ carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & kTop38Bits;
+ carry4 = h4 + (1 << 25); h5 += carry4 >> 26; h4 -= carry4 & kTop38Bits;
+
+ carry1 = h1 + (1 << 24); h2 += carry1 >> 25; h1 -= carry1 & kTop39Bits;
+ carry5 = h5 + (1 << 24); h6 += carry5 >> 25; h5 -= carry5 & kTop39Bits;
+
+ carry2 = h2 + (1 << 25); h3 += carry2 >> 26; h2 -= carry2 & kTop38Bits;
+ carry6 = h6 + (1 << 25); h7 += carry6 >> 26; h6 -= carry6 & kTop38Bits;
+
+ carry3 = h3 + (1 << 24); h4 += carry3 >> 25; h3 -= carry3 & kTop39Bits;
+ carry7 = h7 + (1 << 24); h8 += carry7 >> 25; h7 -= carry7 & kTop39Bits;
+
+ carry4 = h4 + (1 << 25); h5 += carry4 >> 26; h4 -= carry4 & kTop38Bits;
+ carry8 = h8 + (1 << 25); h9 += carry8 >> 26; h8 -= carry8 & kTop38Bits;
+
+ carry9 = h9 + (1 << 24); h0 += (carry9 >> 25) * 19; h9 -= carry9 & kTop39Bits;
+
+ carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & kTop38Bits;
+
+ h[0] = h0;
+ h[1] = h1;
+ h[2] = h2;
+ h[3] = h3;
+ h[4] = h4;
+ h[5] = h5;
+ h[6] = h6;
+ h[7] = h7;
+ h[8] = h8;
+ h[9] = h9;
+}
+
+static void fe_invert(fe out, const fe z) {
+ fe t0;
+ fe t1;
+ fe t2;
+ fe t3;
+ int i;
+
+ /*
+ * Compute z ** -1 = z ** (2 ** 255 - 19 - 2) with the exponent as
+ * 2 ** 255 - 21 = (2 ** 5) * (2 ** 250 - 1) + 11.
+ */
+
+ /* t0 = z ** 2 */
+ fe_sq(t0, z);
+
+ /* t1 = t0 ** (2 ** 2) = z ** 8 */
+ fe_sq(t1, t0);
+ fe_sq(t1, t1);
+
+ /* t1 = z * t1 = z ** 9 */
+ fe_mul(t1, z, t1);
+ /* t0 = t0 * t1 = z ** 11 -- stash t0 away for the end. */
+ fe_mul(t0, t0, t1);
+
+ /* t2 = t0 ** 2 = z ** 22 */
+ fe_sq(t2, t0);
+
+ /* t1 = t1 * t2 = z ** (2 ** 5 - 1) */
+ fe_mul(t1, t1, t2);
+
+ /* t2 = t1 ** (2 ** 5) = z ** ((2 ** 5) * (2 ** 5 - 1)) */
+ fe_sq(t2, t1);
+ for (i = 1; i < 5; ++i) {
+ fe_sq(t2, t2);
+ }
+
+ /* t1 = t1 * t2 = z ** ((2 ** 5 + 1) * (2 ** 5 - 1)) = z ** (2 ** 10 - 1) */
+ fe_mul(t1, t2, t1);
+
+ /* Continuing similarly... */
+
+ /* t2 = z ** (2 ** 20 - 1) */
+ fe_sq(t2, t1);
+ for (i = 1; i < 10; ++i) {
+ fe_sq(t2, t2);
+ }
+ fe_mul(t2, t2, t1);
+
+ /* t2 = z ** (2 ** 40 - 1) */
+ fe_sq(t3, t2);
+ for (i = 1; i < 20; ++i) {
+ fe_sq(t3, t3);
+ }
+ fe_mul(t2, t3, t2);
+
+ /* t2 = z ** (2 ** 10) * (2 ** 40 - 1) */
+ for (i = 0; i < 10; ++i) {
+ fe_sq(t2, t2);
+ }
+ /* t1 = z ** (2 ** 50 - 1) */
+ fe_mul(t1, t2, t1);
+
+ /* t2 = z ** (2 ** 100 - 1) */
+ fe_sq(t2, t1);
+ for (i = 1; i < 50; ++i) {
+ fe_sq(t2, t2);
+ }
+ fe_mul(t2, t2, t1);
+
+ /* t2 = z ** (2 ** 200 - 1) */
+ fe_sq(t3, t2);
+ for (i = 1; i < 100; ++i) {
+ fe_sq(t3, t3);
+ }
+ fe_mul(t2, t3, t2);
+
+ /* t2 = z ** ((2 ** 50) * (2 ** 200 - 1) */
+ fe_sq(t2, t2);
+ for (i = 1; i < 50; ++i) {
+ fe_sq(t2, t2);
+ }
+
+ /* t1 = z ** (2 ** 250 - 1) */
+ fe_mul(t1, t2, t1);
+
+ /* t1 = z ** ((2 ** 5) * (2 ** 250 - 1)) */
+ fe_sq(t1, t1);
+ for (i = 1; i < 5; ++i) {
+ fe_sq(t1, t1);
+ }
+
+ /* Recall t0 = z ** 11; out = z ** (2 ** 255 - 21) */
+ fe_mul(out, t1, t0);
+}
+
+/* h = -f
+ *
+ * Preconditions:
+ * |f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+ *
+ * Postconditions:
+ * |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc. */
+static void fe_neg(fe h, const fe f) {
+ unsigned i;
+ for (i = 0; i < 10; i++) {
+ h[i] = -f[i];
+ }
+}
+
+/* Replace (f,g) with (g,g) if b == 1;
+ * replace (f,g) with (f,g) if b == 0.
+ *
+ * Preconditions: b in {0,1}. */
+static void fe_cmov(fe f, const fe g, unsigned b) {
+ size_t i;
+ b = 0-b;
+ for (i = 0; i < 10; i++) {
+ int32_t x = f[i] ^ g[i];
+ x &= b;
+ f[i] ^= x;
+ }
+}
+
+/* return 0 if f == 0
+ * return 1 if f != 0
+ *
+ * Preconditions:
+ * |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc. */
+static int fe_isnonzero(const fe f) {
+ uint8_t s[32];
+ static const uint8_t zero[32] = {0};
+ fe_tobytes(s, f);
+
+ return CRYPTO_memcmp(s, zero, sizeof(zero)) != 0;
+}
+
+/* return 1 if f is in {1,3,5,...,q-2}
+ * return 0 if f is in {0,2,4,...,q-1}
+ *
+ * Preconditions:
+ * |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc. */
+static int fe_isnegative(const fe f) {
+ uint8_t s[32];
+ fe_tobytes(s, f);
+ return s[0] & 1;
+}
+
+/* h = 2 * f * f
+ * Can overlap h with f.
+ *
+ * Preconditions:
+ * |f| bounded by 1.65*2^26,1.65*2^25,1.65*2^26,1.65*2^25,etc.
+ *
+ * Postconditions:
+ * |h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc.
+ *
+ * See fe_mul.c for discussion of implementation strategy. */
+static void fe_sq2(fe h, const fe f) {
+ int32_t f0 = f[0];
+ int32_t f1 = f[1];
+ int32_t f2 = f[2];
+ int32_t f3 = f[3];
+ int32_t f4 = f[4];
+ int32_t f5 = f[5];
+ int32_t f6 = f[6];
+ int32_t f7 = f[7];
+ int32_t f8 = f[8];
+ int32_t f9 = f[9];
+ int32_t f0_2 = 2 * f0;
+ int32_t f1_2 = 2 * f1;
+ int32_t f2_2 = 2 * f2;
+ int32_t f3_2 = 2 * f3;
+ int32_t f4_2 = 2 * f4;
+ int32_t f5_2 = 2 * f5;
+ int32_t f6_2 = 2 * f6;
+ int32_t f7_2 = 2 * f7;
+ int32_t f5_38 = 38 * f5; /* 1.959375*2^30 */
+ int32_t f6_19 = 19 * f6; /* 1.959375*2^30 */
+ int32_t f7_38 = 38 * f7; /* 1.959375*2^30 */
+ int32_t f8_19 = 19 * f8; /* 1.959375*2^30 */
+ int32_t f9_38 = 38 * f9; /* 1.959375*2^30 */
+ int64_t f0f0 = f0 * (int64_t) f0;
+ int64_t f0f1_2 = f0_2 * (int64_t) f1;
+ int64_t f0f2_2 = f0_2 * (int64_t) f2;
+ int64_t f0f3_2 = f0_2 * (int64_t) f3;
+ int64_t f0f4_2 = f0_2 * (int64_t) f4;
+ int64_t f0f5_2 = f0_2 * (int64_t) f5;
+ int64_t f0f6_2 = f0_2 * (int64_t) f6;
+ int64_t f0f7_2 = f0_2 * (int64_t) f7;
+ int64_t f0f8_2 = f0_2 * (int64_t) f8;
+ int64_t f0f9_2 = f0_2 * (int64_t) f9;
+ int64_t f1f1_2 = f1_2 * (int64_t) f1;
+ int64_t f1f2_2 = f1_2 * (int64_t) f2;
+ int64_t f1f3_4 = f1_2 * (int64_t) f3_2;
+ int64_t f1f4_2 = f1_2 * (int64_t) f4;
+ int64_t f1f5_4 = f1_2 * (int64_t) f5_2;
+ int64_t f1f6_2 = f1_2 * (int64_t) f6;
+ int64_t f1f7_4 = f1_2 * (int64_t) f7_2;
+ int64_t f1f8_2 = f1_2 * (int64_t) f8;
+ int64_t f1f9_76 = f1_2 * (int64_t) f9_38;
+ int64_t f2f2 = f2 * (int64_t) f2;
+ int64_t f2f3_2 = f2_2 * (int64_t) f3;
+ int64_t f2f4_2 = f2_2 * (int64_t) f4;
+ int64_t f2f5_2 = f2_2 * (int64_t) f5;
+ int64_t f2f6_2 = f2_2 * (int64_t) f6;
+ int64_t f2f7_2 = f2_2 * (int64_t) f7;
+ int64_t f2f8_38 = f2_2 * (int64_t) f8_19;
+ int64_t f2f9_38 = f2 * (int64_t) f9_38;
+ int64_t f3f3_2 = f3_2 * (int64_t) f3;
+ int64_t f3f4_2 = f3_2 * (int64_t) f4;
+ int64_t f3f5_4 = f3_2 * (int64_t) f5_2;
+ int64_t f3f6_2 = f3_2 * (int64_t) f6;
+ int64_t f3f7_76 = f3_2 * (int64_t) f7_38;
+ int64_t f3f8_38 = f3_2 * (int64_t) f8_19;
+ int64_t f3f9_76 = f3_2 * (int64_t) f9_38;
+ int64_t f4f4 = f4 * (int64_t) f4;
+ int64_t f4f5_2 = f4_2 * (int64_t) f5;
+ int64_t f4f6_38 = f4_2 * (int64_t) f6_19;
+ int64_t f4f7_38 = f4 * (int64_t) f7_38;
+ int64_t f4f8_38 = f4_2 * (int64_t) f8_19;
+ int64_t f4f9_38 = f4 * (int64_t) f9_38;
+ int64_t f5f5_38 = f5 * (int64_t) f5_38;
+ int64_t f5f6_38 = f5_2 * (int64_t) f6_19;
+ int64_t f5f7_76 = f5_2 * (int64_t) f7_38;
+ int64_t f5f8_38 = f5_2 * (int64_t) f8_19;
+ int64_t f5f9_76 = f5_2 * (int64_t) f9_38;
+ int64_t f6f6_19 = f6 * (int64_t) f6_19;
+ int64_t f6f7_38 = f6 * (int64_t) f7_38;
+ int64_t f6f8_38 = f6_2 * (int64_t) f8_19;
+ int64_t f6f9_38 = f6 * (int64_t) f9_38;
+ int64_t f7f7_38 = f7 * (int64_t) f7_38;
+ int64_t f7f8_38 = f7_2 * (int64_t) f8_19;
+ int64_t f7f9_76 = f7_2 * (int64_t) f9_38;
+ int64_t f8f8_19 = f8 * (int64_t) f8_19;
+ int64_t f8f9_38 = f8 * (int64_t) f9_38;
+ int64_t f9f9_38 = f9 * (int64_t) f9_38;
+ int64_t h0 = f0f0 +f1f9_76+f2f8_38+f3f7_76+f4f6_38+f5f5_38;
+ int64_t h1 = f0f1_2+f2f9_38+f3f8_38+f4f7_38+f5f6_38;
+ int64_t h2 = f0f2_2+f1f1_2 +f3f9_76+f4f8_38+f5f7_76+f6f6_19;
+ int64_t h3 = f0f3_2+f1f2_2 +f4f9_38+f5f8_38+f6f7_38;
+ int64_t h4 = f0f4_2+f1f3_4 +f2f2 +f5f9_76+f6f8_38+f7f7_38;
+ int64_t h5 = f0f5_2+f1f4_2 +f2f3_2 +f6f9_38+f7f8_38;
+ int64_t h6 = f0f6_2+f1f5_4 +f2f4_2 +f3f3_2 +f7f9_76+f8f8_19;
+ int64_t h7 = f0f7_2+f1f6_2 +f2f5_2 +f3f4_2 +f8f9_38;
+ int64_t h8 = f0f8_2+f1f7_4 +f2f6_2 +f3f5_4 +f4f4 +f9f9_38;
+ int64_t h9 = f0f9_2+f1f8_2 +f2f7_2 +f3f6_2 +f4f5_2;
+ int64_t carry0;
+ int64_t carry1;
+ int64_t carry2;
+ int64_t carry3;
+ int64_t carry4;
+ int64_t carry5;
+ int64_t carry6;
+ int64_t carry7;
+ int64_t carry8;
+ int64_t carry9;
+
+ h0 += h0;
+ h1 += h1;
+ h2 += h2;
+ h3 += h3;
+ h4 += h4;
+ h5 += h5;
+ h6 += h6;
+ h7 += h7;
+ h8 += h8;
+ h9 += h9;
+
+ carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & kTop38Bits;
+ carry4 = h4 + (1 << 25); h5 += carry4 >> 26; h4 -= carry4 & kTop38Bits;
+
+ carry1 = h1 + (1 << 24); h2 += carry1 >> 25; h1 -= carry1 & kTop39Bits;
+ carry5 = h5 + (1 << 24); h6 += carry5 >> 25; h5 -= carry5 & kTop39Bits;
+
+ carry2 = h2 + (1 << 25); h3 += carry2 >> 26; h2 -= carry2 & kTop38Bits;
+ carry6 = h6 + (1 << 25); h7 += carry6 >> 26; h6 -= carry6 & kTop38Bits;
+
+ carry3 = h3 + (1 << 24); h4 += carry3 >> 25; h3 -= carry3 & kTop39Bits;
+ carry7 = h7 + (1 << 24); h8 += carry7 >> 25; h7 -= carry7 & kTop39Bits;
+
+ carry4 = h4 + (1 << 25); h5 += carry4 >> 26; h4 -= carry4 & kTop38Bits;
+ carry8 = h8 + (1 << 25); h9 += carry8 >> 26; h8 -= carry8 & kTop38Bits;
+
+ carry9 = h9 + (1 << 24); h0 += (carry9 >> 25) * 19; h9 -= carry9 & kTop39Bits;
+
+ carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & kTop38Bits;
+
+ h[0] = h0;
+ h[1] = h1;
+ h[2] = h2;
+ h[3] = h3;
+ h[4] = h4;
+ h[5] = h5;
+ h[6] = h6;
+ h[7] = h7;
+ h[8] = h8;
+ h[9] = h9;
+}
+
+static void fe_pow22523(fe out, const fe z) {
+ fe t0;
+ fe t1;
+ fe t2;
+ int i;
+
+ fe_sq(t0, z);
+ fe_sq(t1, t0);
+ for (i = 1; i < 2; ++i) {
+ fe_sq(t1, t1);
+ }
+ fe_mul(t1, z, t1);
+ fe_mul(t0, t0, t1);
+ fe_sq(t0, t0);
+ fe_mul(t0, t1, t0);
+ fe_sq(t1, t0);
+ for (i = 1; i < 5; ++i) {
+ fe_sq(t1, t1);
+ }
+ fe_mul(t0, t1, t0);
+ fe_sq(t1, t0);
+ for (i = 1; i < 10; ++i) {
+ fe_sq(t1, t1);
+ }
+ fe_mul(t1, t1, t0);
+ fe_sq(t2, t1);
+ for (i = 1; i < 20; ++i) {
+ fe_sq(t2, t2);
+ }
+ fe_mul(t1, t2, t1);
+ fe_sq(t1, t1);
+ for (i = 1; i < 10; ++i) {
+ fe_sq(t1, t1);
+ }
+ fe_mul(t0, t1, t0);
+ fe_sq(t1, t0);
+ for (i = 1; i < 50; ++i) {
+ fe_sq(t1, t1);
+ }
+ fe_mul(t1, t1, t0);
+ fe_sq(t2, t1);
+ for (i = 1; i < 100; ++i) {
+ fe_sq(t2, t2);
+ }
+ fe_mul(t1, t2, t1);
+ fe_sq(t1, t1);
+ for (i = 1; i < 50; ++i) {
+ fe_sq(t1, t1);
+ }
+ fe_mul(t0, t1, t0);
+ fe_sq(t0, t0);
+ for (i = 1; i < 2; ++i) {
+ fe_sq(t0, t0);
+ }
+ fe_mul(out, t0, z);
+}
+
+static uint8_t equal(signed char b, signed char c) {
+ uint8_t ub = b;
+ uint8_t uc = c;
+ uint8_t x = ub ^ uc; /* 0: yes; 1..255: no */
+ uint32_t y = x; /* 0: yes; 1..255: no */
+ y -= 1; /* 4294967295: yes; 0..254: no */
+ y >>= 31; /* 1: yes; 0: no */
+ return y;
+}
+
+/* Replace (f,g) with (g,f) if b == 1;
+ * replace (f,g) with (f,g) if b == 0.
+ *
+ * Preconditions: b in {0,1}. */
+static void fe_cswap(fe f, fe g, unsigned int b) {
+ size_t i;
+ b = 0-b;
+ for (i = 0; i < 10; i++) {
+ int32_t x = f[i] ^ g[i];
+ x &= b;
+ f[i] ^= x;
+ g[i] ^= x;
+ }
+}
+
+/* h = f * 121666
+ * Can overlap h with f.
+ *
+ * Preconditions:
+ * |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
+ *
+ * Postconditions:
+ * |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc. */
+static void fe_mul121666(fe h, fe f) {
+ int32_t f0 = f[0];
+ int32_t f1 = f[1];
+ int32_t f2 = f[2];
+ int32_t f3 = f[3];
+ int32_t f4 = f[4];
+ int32_t f5 = f[5];
+ int32_t f6 = f[6];
+ int32_t f7 = f[7];
+ int32_t f8 = f[8];
+ int32_t f9 = f[9];
+ int64_t h0 = f0 * (int64_t) 121666;
+ int64_t h1 = f1 * (int64_t) 121666;
+ int64_t h2 = f2 * (int64_t) 121666;
+ int64_t h3 = f3 * (int64_t) 121666;
+ int64_t h4 = f4 * (int64_t) 121666;
+ int64_t h5 = f5 * (int64_t) 121666;
+ int64_t h6 = f6 * (int64_t) 121666;
+ int64_t h7 = f7 * (int64_t) 121666;
+ int64_t h8 = f8 * (int64_t) 121666;
+ int64_t h9 = f9 * (int64_t) 121666;
+ int64_t carry0;
+ int64_t carry1;
+ int64_t carry2;
+ int64_t carry3;
+ int64_t carry4;
+ int64_t carry5;
+ int64_t carry6;
+ int64_t carry7;
+ int64_t carry8;
+ int64_t carry9;
+
+ carry9 = h9 + (1 << 24); h0 += (carry9 >> 25) * 19; h9 -= carry9 & kTop39Bits;
+ carry1 = h1 + (1 << 24); h2 += carry1 >> 25; h1 -= carry1 & kTop39Bits;
+ carry3 = h3 + (1 << 24); h4 += carry3 >> 25; h3 -= carry3 & kTop39Bits;
+ carry5 = h5 + (1 << 24); h6 += carry5 >> 25; h5 -= carry5 & kTop39Bits;
+ carry7 = h7 + (1 << 24); h8 += carry7 >> 25; h7 -= carry7 & kTop39Bits;
+
+ carry0 = h0 + (1 << 25); h1 += carry0 >> 26; h0 -= carry0 & kTop38Bits;
+ carry2 = h2 + (1 << 25); h3 += carry2 >> 26; h2 -= carry2 & kTop38Bits;
+ carry4 = h4 + (1 << 25); h5 += carry4 >> 26; h4 -= carry4 & kTop38Bits;
+ carry6 = h6 + (1 << 25); h7 += carry6 >> 26; h6 -= carry6 & kTop38Bits;
+ carry8 = h8 + (1 << 25); h9 += carry8 >> 26; h8 -= carry8 & kTop38Bits;
+
+ h[0] = h0;
+ h[1] = h1;
+ h[2] = h2;
+ h[3] = h3;
+ h[4] = h4;
+ h[5] = h5;
+ h[6] = h6;
+ h[7] = h7;
+ h[8] = h8;
+ h[9] = h9;
+}
+
+static void x25519_scalar_mult_generic(uint8_t out[32],
+ const uint8_t scalar[32],
+ const uint8_t point[32]) {
+ fe x1, x2, z2, x3, z3, tmp0, tmp1;
+ uint8_t e[32];
+ unsigned swap = 0;
+ int pos;
+
+ memcpy(e, scalar, 32);
+ e[0] &= 248;
+ e[31] &= 127;
+ e[31] |= 64;
+ fe_frombytes(x1, point);
+ fe_1(x2);
+ fe_0(z2);
+ fe_copy(x3, x1);
+ fe_1(z3);
+
+ for (pos = 254; pos >= 0; --pos) {
+ unsigned b = 1 & (e[pos / 8] >> (pos & 7));
+ swap ^= b;
+ fe_cswap(x2, x3, swap);
+ fe_cswap(z2, z3, swap);
+ swap = b;
+ fe_sub(tmp0, x3, z3);
+ fe_sub(tmp1, x2, z2);
+ fe_add(x2, x2, z2);
+ fe_add(z2, x3, z3);
+ fe_mul(z3, tmp0, x2);
+ fe_mul(z2, z2, tmp1);
+ fe_sq(tmp0, tmp1);
+ fe_sq(tmp1, x2);
+ fe_add(x3, z3, z2);
+ fe_sub(z2, z3, z2);
+ fe_mul(x2, tmp1, tmp0);
+ fe_sub(tmp1, tmp1, tmp0);
+ fe_sq(z2, z2);
+ fe_mul121666(z3, tmp1);
+ fe_sq(x3, x3);
+ fe_add(tmp0, tmp0, z3);
+ fe_mul(z3, x1, z2);
+ fe_mul(z2, tmp1, tmp0);
+ }
+ fe_cswap(x2, x3, swap);
+ fe_cswap(z2, z3, swap);
+
+ fe_invert(z2, z2);
+ fe_mul(x2, x2, z2);
+ fe_tobytes(out, x2);
+}
+
+void x25519_scalar_mult(uint8_t out[32], const uint8_t scalar[32],
+ const uint8_t point[32]) {
+ x25519_scalar_mult_generic(out, scalar, point);
+}
diff --git a/third_party/openssl-curve25519/ec_curve25519.h b/third_party/openssl-curve25519/ec_curve25519.h
new file mode 100644
index 000000000..60dc86e75
--- /dev/null
+++ b/third_party/openssl-curve25519/ec_curve25519.h
@@ -0,0 +1,2 @@
+#include <stdint.h>
+void x25519_scalar_mult(uint8_t out[32], const uint8_t scalar[32], const uint8_t point[32]);
diff --git a/third_party/openssl-curve25519/measurements.txt b/third_party/openssl-curve25519/measurements.txt
new file mode 100644
index 000000000..b28317900
--- /dev/null
+++ b/third_party/openssl-curve25519/measurements.txt
@@ -0,0 +1 @@
+359336 ashryn-noht-notb-ac-broadwell 2.50ghz 7.1.1 56d7eec6
diff --git a/third_party/openssl-nistp256c64/LICENSE b/third_party/openssl-nistp256c64/LICENSE
new file mode 100644
index 000000000..8fbabd8af
--- /dev/null
+++ b/third_party/openssl-nistp256c64/LICENSE
@@ -0,0 +1,125 @@
+
+ LICENSE ISSUES
+ ==============
+
+ The OpenSSL toolkit stays under a double license, i.e. both the conditions of
+ the OpenSSL License and the original SSLeay license apply to the toolkit.
+ See below for the actual license texts.
+
+ OpenSSL License
+ ---------------
+
+/* ====================================================================
+ * Copyright (c) 1998-2017 The OpenSSL Project. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ * software must display the following acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+ Original SSLeay License
+ -----------------------
+
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to. The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code. The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * "This product includes cryptographic software written by
+ * Eric Young (eay@cryptsoft.com)"
+ * The word 'cryptographic' can be left out if the rouines from the library
+ * being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ * the apps directory (application code) you must include an acknowledgement:
+ * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed. i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.]
+ */
+
diff --git a/third_party/openssl-nistp256c64/bench_madd.c b/third_party/openssl-nistp256c64/bench_madd.c
new file mode 100644
index 000000000..e2dc8e880
--- /dev/null
+++ b/third_party/openssl-nistp256c64/bench_madd.c
@@ -0,0 +1,16 @@
+#include <stdint.h>
+#include "ecp_nistp256.h"
+
+void bench_madd(unsigned char* buf) {
+ uint128_t* x3 = (uint128_t*) buf;
+ uint128_t* y3 = (uint128_t*) (buf + 1*sizeof(felem));
+ uint128_t* z3 = (uint128_t*) (buf + 2*sizeof(felem));
+ uint128_t* x1 = (uint128_t*) (buf + 3*sizeof(felem));
+ uint128_t* y1 = (uint128_t*) (buf + 4*sizeof(felem));
+ uint128_t* z1 = (uint128_t*) (buf + 5*sizeof(felem));
+ int mixed = 1;
+ uint64_t* x2 = (uint64_t*) (buf + 6*sizeof(felem));
+ uint64_t* y2 = (uint64_t*) (buf + 6*sizeof(felem) + sizeof(smallfelem));
+ smallfelem z2 = {1, 0, 0, 0};
+ point_add(x3, y3, z3, x1, y1, z1, mixed, x2, y2, z2);
+}
diff --git a/third_party/openssl-nistp256c64/compiler.sh b/third_party/openssl-nistp256c64/compiler.sh
new file mode 100755
index 000000000..e64df574a
--- /dev/null
+++ b/third_party/openssl-nistp256c64/compiler.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+set -eu
+
+gcc -march=native -mtune=native -std=gnu11 -O3 -flto -fomit-frame-pointer -fwrapv -Wno-attributes $@
diff --git a/third_party/openssl-nistp256c64/ecp_nistp256.c b/third_party/openssl-nistp256c64/ecp_nistp256.c
new file mode 100644
index 000000000..9d5f36905
--- /dev/null
+++ b/third_party/openssl-nistp256c64/ecp_nistp256.c
@@ -0,0 +1,1314 @@
+/*
+ * Copyright 2011-2016 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");
+ *
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * A 64-bit implementation of the NIST P-256 elliptic curve point multiplication
+ *
+ * OpenSSL integration was taken from Emilia Kasper's work in ecp_nistp224.c.
+ * Otherwise based on Emilia's P224 work, which was inspired by my curve25519
+ * work which got its smarts from Daniel J. Bernstein's work on the same.
+ */
+
+# include <stdint.h>
+# include <string.h>
+# include <openssl/err.h>
+# include "ecp_nistp256.h"
+
+
+/*
+ * These are the parameters of P256, taken from FIPS 186-3, page 86. These
+ * values are big-endian.
+ */
+static const felem_bytearray nistp256_curve_params[5] = {
+ {0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x01, /* p */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
+ {0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x01, /* a = -3 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfc}, /* b */
+ {0x5a, 0xc6, 0x35, 0xd8, 0xaa, 0x3a, 0x93, 0xe7,
+ 0xb3, 0xeb, 0xbd, 0x55, 0x76, 0x98, 0x86, 0xbc,
+ 0x65, 0x1d, 0x06, 0xb0, 0xcc, 0x53, 0xb0, 0xf6,
+ 0x3b, 0xce, 0x3c, 0x3e, 0x27, 0xd2, 0x60, 0x4b},
+ {0x6b, 0x17, 0xd1, 0xf2, 0xe1, 0x2c, 0x42, 0x47, /* x */
+ 0xf8, 0xbc, 0xe6, 0xe5, 0x63, 0xa4, 0x40, 0xf2,
+ 0x77, 0x03, 0x7d, 0x81, 0x2d, 0xeb, 0x33, 0xa0,
+ 0xf4, 0xa1, 0x39, 0x45, 0xd8, 0x98, 0xc2, 0x96},
+ {0x4f, 0xe3, 0x42, 0xe2, 0xfe, 0x1a, 0x7f, 0x9b, /* y */
+ 0x8e, 0xe7, 0xeb, 0x4a, 0x7c, 0x0f, 0x9e, 0x16,
+ 0x2b, 0xce, 0x33, 0x57, 0x6b, 0x31, 0x5e, 0xce,
+ 0xcb, 0xb6, 0x40, 0x68, 0x37, 0xbf, 0x51, 0xf5}
+};
+
+/*-
+
+/* This is the value of the prime as four 64-bit words, little-endian. */
+static const u64 kPrime[4] =
+ { 0xfffffffffffffffful, 0xffffffff, 0, 0xffffffff00000001ul };
+static const u64 bottom63bits = 0x7ffffffffffffffful;
+
+/*
+ * bin32_to_felem takes a little-endian byte array and converts it into felem
+ * form. This assumes that the CPU is little-endian.
+ */
+static void bin32_to_felem(felem out, const u8 in[32])
+{
+ out[0] = *((u64 *)&in[0]);
+ out[1] = *((u64 *)&in[8]);
+ out[2] = *((u64 *)&in[16]);
+ out[3] = *((u64 *)&in[24]);
+}
+
+/*
+ * smallfelem_to_bin32 takes a smallfelem and serialises into a little
+ * endian, 32 byte array. This assumes that the CPU is little-endian.
+ */
+static void smallfelem_to_bin32(u8 out[32], const smallfelem in)
+{
+ *((u64 *)&out[0]) = in[0];
+ *((u64 *)&out[8]) = in[1];
+ *((u64 *)&out[16]) = in[2];
+ *((u64 *)&out[24]) = in[3];
+}
+
+/*-
+ * Field operations
+ * ----------------
+ */
+
+static void smallfelem_one(smallfelem out)
+{
+ out[0] = 1;
+ out[1] = 0;
+ out[2] = 0;
+ out[3] = 0;
+}
+
+static void smallfelem_assign(smallfelem out, const smallfelem in)
+{
+ out[0] = in[0];
+ out[1] = in[1];
+ out[2] = in[2];
+ out[3] = in[3];
+}
+
+static void felem_assign(felem out, const felem in)
+{
+ out[0] = in[0];
+ out[1] = in[1];
+ out[2] = in[2];
+ out[3] = in[3];
+}
+
+/* felem_sum sets out = out + in. */
+static void felem_sum(felem out, const felem in)
+{
+ out[0] += in[0];
+ out[1] += in[1];
+ out[2] += in[2];
+ out[3] += in[3];
+}
+
+/* felem_small_sum sets out = out + in. */
+static void felem_small_sum(felem out, const smallfelem in)
+{
+ out[0] += in[0];
+ out[1] += in[1];
+ out[2] += in[2];
+ out[3] += in[3];
+}
+
+/* felem_scalar sets out = out * scalar */
+static void felem_scalar(felem out, const u64 scalar)
+{
+ out[0] *= scalar;
+ out[1] *= scalar;
+ out[2] *= scalar;
+ out[3] *= scalar;
+}
+
+/* longfelem_scalar sets out = out * scalar */
+static void longfelem_scalar(longfelem out, const u64 scalar)
+{
+ out[0] *= scalar;
+ out[1] *= scalar;
+ out[2] *= scalar;
+ out[3] *= scalar;
+ out[4] *= scalar;
+ out[5] *= scalar;
+ out[6] *= scalar;
+ out[7] *= scalar;
+}
+
+# define two105m41m9 (((limb)1) << 105) - (((limb)1) << 41) - (((limb)1) << 9)
+# define two105 (((limb)1) << 105)
+# define two105m41p9 (((limb)1) << 105) - (((limb)1) << 41) + (((limb)1) << 9)
+
+/* zero105 is 0 mod p */
+static const felem zero105 =
+ { two105m41m9, two105, two105m41p9, two105m41p9 };
+
+/*-
+ * smallfelem_neg sets |out| to |-small|
+ * On exit:
+ * out[i] < out[i] + 2^105
+ */
+static void smallfelem_neg(felem out, const smallfelem small)
+{
+ /* In order to prevent underflow, we subtract from 0 mod p. */
+ out[0] = zero105[0] - small[0];
+ out[1] = zero105[1] - small[1];
+ out[2] = zero105[2] - small[2];
+ out[3] = zero105[3] - small[3];
+}
+
+/*-
+ * felem_diff subtracts |in| from |out|
+ * On entry:
+ * in[i] < 2^104
+ * On exit:
+ * out[i] < out[i] + 2^105
+ */
+static void felem_diff(felem out, const felem in)
+{
+ /*
+ * In order to prevent underflow, we add 0 mod p before subtracting.
+ */
+ out[0] += zero105[0];
+ out[1] += zero105[1];
+ out[2] += zero105[2];
+ out[3] += zero105[3];
+
+ out[0] -= in[0];
+ out[1] -= in[1];
+ out[2] -= in[2];
+ out[3] -= in[3];
+}
+
+# define two107m43m11 (((limb)1) << 107) - (((limb)1) << 43) - (((limb)1) << 11)
+# define two107 (((limb)1) << 107)
+# define two107m43p11 (((limb)1) << 107) - (((limb)1) << 43) + (((limb)1) << 11)
+
+/* zero107 is 0 mod p */
+static const felem zero107 =
+ { two107m43m11, two107, two107m43p11, two107m43p11 };
+
+/*-
+ * An alternative felem_diff for larger inputs |in|
+ * felem_diff_zero107 subtracts |in| from |out|
+ * On entry:
+ * in[i] < 2^106
+ * On exit:
+ * out[i] < out[i] + 2^107
+ */
+static void felem_diff_zero107(felem out, const felem in)
+{
+ /*
+ * In order to prevent underflow, we add 0 mod p before subtracting.
+ */
+ out[0] += zero107[0];
+ out[1] += zero107[1];
+ out[2] += zero107[2];
+ out[3] += zero107[3];
+
+ out[0] -= in[0];
+ out[1] -= in[1];
+ out[2] -= in[2];
+ out[3] -= in[3];
+}
+
+/*-
+ * longfelem_diff subtracts |in| from |out|
+ * On entry:
+ * in[i] < 7*2^67
+ * On exit:
+ * out[i] < out[i] + 2^70 + 2^40
+ */
+static void longfelem_diff(longfelem out, const longfelem in)
+{
+ static const limb two70m8p6 =
+ (((limb) 1) << 70) - (((limb) 1) << 8) + (((limb) 1) << 6);
+ static const limb two70p40 = (((limb) 1) << 70) + (((limb) 1) << 40);
+ static const limb two70 = (((limb) 1) << 70);
+ static const limb two70m40m38p6 =
+ (((limb) 1) << 70) - (((limb) 1) << 40) - (((limb) 1) << 38) +
+ (((limb) 1) << 6);
+ static const limb two70m6 = (((limb) 1) << 70) - (((limb) 1) << 6);
+
+ /* add 0 mod p to avoid underflow */
+ out[0] += two70m8p6;
+ out[1] += two70p40;
+ out[2] += two70;
+ out[3] += two70m40m38p6;
+ out[4] += two70m6;
+ out[5] += two70m6;
+ out[6] += two70m6;
+ out[7] += two70m6;
+
+ /* in[i] < 7*2^67 < 2^70 - 2^40 - 2^38 + 2^6 */
+ out[0] -= in[0];
+ out[1] -= in[1];
+ out[2] -= in[2];
+ out[3] -= in[3];
+ out[4] -= in[4];
+ out[5] -= in[5];
+ out[6] -= in[6];
+ out[7] -= in[7];
+}
+
+# define two64m0 (((limb)1) << 64) - 1
+# define two110p32m0 (((limb)1) << 110) + (((limb)1) << 32) - 1
+# define two64m46 (((limb)1) << 64) - (((limb)1) << 46)
+# define two64m32 (((limb)1) << 64) - (((limb)1) << 32)
+
+/* zero110 is 0 mod p */
+static const felem zero110 = { two64m0, two110p32m0, two64m46, two64m32 };
+
+/*-
+ * felem_shrink converts an felem into a smallfelem. The result isn't quite
+ * minimal as the value may be greater than p.
+ *
+ * On entry:
+ * in[i] < 2^109
+ * On exit:
+ * out[i] < 2^64
+ */
+static void felem_shrink(smallfelem out, const felem in)
+{
+ felem tmp;
+ u64 a, b, mask;
+ s64 high, low;
+ static const u64 kPrime3Test = 0x7fffffff00000001ul; /* 2^63 - 2^32 + 1 */
+
+ /* Carry 2->3 */
+ tmp[3] = zero110[3] + in[3] + ((u64)(in[2] >> 64));
+ /* tmp[3] < 2^110 */
+
+ tmp[2] = zero110[2] + (u64)in[2];
+ tmp[0] = zero110[0] + in[0];
+ tmp[1] = zero110[1] + in[1];
+ /* tmp[0] < 2**110, tmp[1] < 2^111, tmp[2] < 2**65 */
+
+ /*
+ * We perform two partial reductions where we eliminate the high-word of
+ * tmp[3]. We don't update the other words till the end.
+ */
+ a = tmp[3] >> 64; /* a < 2^46 */
+ tmp[3] = (u64)tmp[3];
+ tmp[3] -= a;
+ tmp[3] += ((limb) a) << 32;
+ /* tmp[3] < 2^79 */
+
+ b = a;
+ a = tmp[3] >> 64; /* a < 2^15 */
+ b += a; /* b < 2^46 + 2^15 < 2^47 */
+ tmp[3] = (u64)tmp[3];
+ tmp[3] -= a;
+ tmp[3] += ((limb) a) << 32;
+ /* tmp[3] < 2^64 + 2^47 */
+
+ /*
+ * This adjusts the other two words to complete the two partial
+ * reductions.
+ */
+ tmp[0] += b;
+ tmp[1] -= (((limb) b) << 32);
+
+ /*
+ * In order to make space in tmp[3] for the carry from 2 -> 3, we
+ * conditionally subtract kPrime if tmp[3] is large enough.
+ */
+ high = tmp[3] >> 64;
+ /* As tmp[3] < 2^65, high is either 1 or 0 */
+ high <<= 63;
+ high >>= 63;
+ /*-
+ * high is:
+ * all ones if the high word of tmp[3] is 1
+ * all zeros if the high word of tmp[3] if 0 */
+ low = tmp[3];
+ mask = low >> 63;
+ /*-
+ * mask is:
+ * all ones if the MSB of low is 1
+ * all zeros if the MSB of low if 0 */
+ low &= bottom63bits;
+ low -= kPrime3Test;
+ /* if low was greater than kPrime3Test then the MSB is zero */
+ low = ~low;
+ low >>= 63;
+ /*-
+ * low is:
+ * all ones if low was > kPrime3Test
+ * all zeros if low was <= kPrime3Test */
+ mask = (mask & low) | high;
+ tmp[0] -= mask & kPrime[0];
+ tmp[1] -= mask & kPrime[1];
+ /* kPrime[2] is zero, so omitted */
+ tmp[3] -= mask & kPrime[3];
+ /* tmp[3] < 2**64 - 2**32 + 1 */
+
+ tmp[1] += ((u64)(tmp[0] >> 64));
+ tmp[0] = (u64)tmp[0];
+ tmp[2] += ((u64)(tmp[1] >> 64));
+ tmp[1] = (u64)tmp[1];
+ tmp[3] += ((u64)(tmp[2] >> 64));
+ tmp[2] = (u64)tmp[2];
+ /* tmp[i] < 2^64 */
+
+ out[0] = tmp[0];
+ out[1] = tmp[1];
+ out[2] = tmp[2];
+ out[3] = tmp[3];
+}
+
+/* smallfelem_expand converts a smallfelem to an felem */
+static void smallfelem_expand(felem out, const smallfelem in)
+{
+ out[0] = in[0];
+ out[1] = in[1];
+ out[2] = in[2];
+ out[3] = in[3];
+}
+
+/*-
+ * smallfelem_square sets |out| = |small|^2
+ * On entry:
+ * small[i] < 2^64
+ * On exit:
+ * out[i] < 7 * 2^64 < 2^67
+ */
+static void smallfelem_square(longfelem out, const smallfelem small)
+{
+ limb a;
+ u64 high, low;
+
+ a = ((uint128_t) small[0]) * small[0];
+ low = a;
+ high = a >> 64;
+ out[0] = low;
+ out[1] = high;
+
+ a = ((uint128_t) small[0]) * small[1];
+ low = a;
+ high = a >> 64;
+ out[1] += low;
+ out[1] += low;
+ out[2] = high;
+
+ a = ((uint128_t) small[0]) * small[2];
+ low = a;
+ high = a >> 64;
+ out[2] += low;
+ out[2] *= 2;
+ out[3] = high;
+
+ a = ((uint128_t) small[0]) * small[3];
+ low = a;
+ high = a >> 64;
+ out[3] += low;
+ out[4] = high;
+
+ a = ((uint128_t) small[1]) * small[2];
+ low = a;
+ high = a >> 64;
+ out[3] += low;
+ out[3] *= 2;
+ out[4] += high;
+
+ a = ((uint128_t) small[1]) * small[1];
+ low = a;
+ high = a >> 64;
+ out[2] += low;
+ out[3] += high;
+
+ a = ((uint128_t) small[1]) * small[3];
+ low = a;
+ high = a >> 64;
+ out[4] += low;
+ out[4] *= 2;
+ out[5] = high;
+
+ a = ((uint128_t) small[2]) * small[3];
+ low = a;
+ high = a >> 64;
+ out[5] += low;
+ out[5] *= 2;
+ out[6] = high;
+ out[6] += high;
+
+ a = ((uint128_t) small[2]) * small[2];
+ low = a;
+ high = a >> 64;
+ out[4] += low;
+ out[5] += high;
+
+ a = ((uint128_t) small[3]) * small[3];
+ low = a;
+ high = a >> 64;
+ out[6] += low;
+ out[7] = high;
+}
+
+/*-
+ * felem_square sets |out| = |in|^2
+ * On entry:
+ * in[i] < 2^109
+ * On exit:
+ * out[i] < 7 * 2^64 < 2^67
+ */
+static void felem_square(longfelem out, const felem in)
+{
+ u64 small[4];
+ felem_shrink(small, in);
+ smallfelem_square(out, small);
+}
+
+/*-
+ * smallfelem_mul sets |out| = |small1| * |small2|
+ * On entry:
+ * small1[i] < 2^64
+ * small2[i] < 2^64
+ * On exit:
+ * out[i] < 7 * 2^64 < 2^67
+ */
+static void smallfelem_mul(longfelem out, const smallfelem small1,
+ const smallfelem small2)
+{
+ limb a;
+ u64 high, low;
+
+ a = ((uint128_t) small1[0]) * small2[0];
+ low = a;
+ high = a >> 64;
+ out[0] = low;
+ out[1] = high;
+
+ a = ((uint128_t) small1[0]) * small2[1];
+ low = a;
+ high = a >> 64;
+ out[1] += low;
+ out[2] = high;
+
+ a = ((uint128_t) small1[1]) * small2[0];
+ low = a;
+ high = a >> 64;
+ out[1] += low;
+ out[2] += high;
+
+ a = ((uint128_t) small1[0]) * small2[2];
+ low = a;
+ high = a >> 64;
+ out[2] += low;
+ out[3] = high;
+
+ a = ((uint128_t) small1[1]) * small2[1];
+ low = a;
+ high = a >> 64;
+ out[2] += low;
+ out[3] += high;
+
+ a = ((uint128_t) small1[2]) * small2[0];
+ low = a;
+ high = a >> 64;
+ out[2] += low;
+ out[3] += high;
+
+ a = ((uint128_t) small1[0]) * small2[3];
+ low = a;
+ high = a >> 64;
+ out[3] += low;
+ out[4] = high;
+
+ a = ((uint128_t) small1[1]) * small2[2];
+ low = a;
+ high = a >> 64;
+ out[3] += low;
+ out[4] += high;
+
+ a = ((uint128_t) small1[2]) * small2[1];
+ low = a;
+ high = a >> 64;
+ out[3] += low;
+ out[4] += high;
+
+ a = ((uint128_t) small1[3]) * small2[0];
+ low = a;
+ high = a >> 64;
+ out[3] += low;
+ out[4] += high;
+
+ a = ((uint128_t) small1[1]) * small2[3];
+ low = a;
+ high = a >> 64;
+ out[4] += low;
+ out[5] = high;
+
+ a = ((uint128_t) small1[2]) * small2[2];
+ low = a;
+ high = a >> 64;
+ out[4] += low;
+ out[5] += high;
+
+ a = ((uint128_t) small1[3]) * small2[1];
+ low = a;
+ high = a >> 64;
+ out[4] += low;
+ out[5] += high;
+
+ a = ((uint128_t) small1[2]) * small2[3];
+ low = a;
+ high = a >> 64;
+ out[5] += low;
+ out[6] = high;
+
+ a = ((uint128_t) small1[3]) * small2[2];
+ low = a;
+ high = a >> 64;
+ out[5] += low;
+ out[6] += high;
+
+ a = ((uint128_t) small1[3]) * small2[3];
+ low = a;
+ high = a >> 64;
+ out[6] += low;
+ out[7] = high;
+}
+
+/*-
+ * felem_mul sets |out| = |in1| * |in2|
+ * On entry:
+ * in1[i] < 2^109
+ * in2[i] < 2^109
+ * On exit:
+ * out[i] < 7 * 2^64 < 2^67
+ */
+static void felem_mul(longfelem out, const felem in1, const felem in2)
+{
+ smallfelem small1, small2;
+ felem_shrink(small1, in1);
+ felem_shrink(small2, in2);
+ smallfelem_mul(out, small1, small2);
+}
+
+/*-
+ * felem_small_mul sets |out| = |small1| * |in2|
+ * On entry:
+ * small1[i] < 2^64
+ * in2[i] < 2^109
+ * On exit:
+ * out[i] < 7 * 2^64 < 2^67
+ */
+static void felem_small_mul(longfelem out, const smallfelem small1,
+ const felem in2)
+{
+ smallfelem small2;
+ felem_shrink(small2, in2);
+ smallfelem_mul(out, small1, small2);
+}
+
+# define two100m36m4 (((limb)1) << 100) - (((limb)1) << 36) - (((limb)1) << 4)
+# define two100 (((limb)1) << 100)
+# define two100m36p4 (((limb)1) << 100) - (((limb)1) << 36) + (((limb)1) << 4)
+/* zero100 is 0 mod p */
+static const felem zero100 =
+ { two100m36m4, two100, two100m36p4, two100m36p4 };
+
+/*-
+ * Internal function for the different flavours of felem_reduce.
+ * felem_reduce_ reduces the higher coefficients in[4]-in[7].
+ * On entry:
+ * out[0] >= in[6] + 2^32*in[6] + in[7] + 2^32*in[7]
+ * out[1] >= in[7] + 2^32*in[4]
+ * out[2] >= in[5] + 2^32*in[5]
+ * out[3] >= in[4] + 2^32*in[5] + 2^32*in[6]
+ * On exit:
+ * out[0] <= out[0] + in[4] + 2^32*in[5]
+ * out[1] <= out[1] + in[5] + 2^33*in[6]
+ * out[2] <= out[2] + in[7] + 2*in[6] + 2^33*in[7]
+ * out[3] <= out[3] + 2^32*in[4] + 3*in[7]
+ */
+static void felem_reduce_(felem out, const longfelem in)
+{
+ int128_t c;
+ /* combine common terms from below */
+ c = in[4] + (in[5] << 32);
+ out[0] += c;
+ out[3] -= c;
+
+ c = in[5] - in[7];
+ out[1] += c;
+ out[2] -= c;
+
+ /* the remaining terms */
+ /* 256: [(0,1),(96,-1),(192,-1),(224,1)] */
+ out[1] -= (in[4] << 32);
+ out[3] += (in[4] << 32);
+
+ /* 320: [(32,1),(64,1),(128,-1),(160,-1),(224,-1)] */
+ out[2] -= (in[5] << 32);
+
+ /* 384: [(0,-1),(32,-1),(96,2),(128,2),(224,-1)] */
+ out[0] -= in[6];
+ out[0] -= (in[6] << 32);
+ out[1] += (in[6] << 33);
+ out[2] += (in[6] * 2);
+ out[3] -= (in[6] << 32);
+
+ /* 448: [(0,-1),(32,-1),(64,-1),(128,1),(160,2),(192,3)] */
+ out[0] -= in[7];
+ out[0] -= (in[7] << 32);
+ out[2] += (in[7] << 33);
+ out[3] += (in[7] * 3);
+}
+
+/*-
+ * felem_reduce converts a longfelem into an felem.
+ * To be called directly after felem_square or felem_mul.
+ * On entry:
+ * in[0] < 2^64, in[1] < 3*2^64, in[2] < 5*2^64, in[3] < 7*2^64
+ * in[4] < 7*2^64, in[5] < 5*2^64, in[6] < 3*2^64, in[7] < 2*64
+ * On exit:
+ * out[i] < 2^101
+ */
+static void felem_reduce(felem out, const longfelem in)
+{
+ out[0] = zero100[0] + in[0];
+ out[1] = zero100[1] + in[1];
+ out[2] = zero100[2] + in[2];
+ out[3] = zero100[3] + in[3];
+
+ felem_reduce_(out, in);
+
+ /*-
+ * out[0] > 2^100 - 2^36 - 2^4 - 3*2^64 - 3*2^96 - 2^64 - 2^96 > 0
+ * out[1] > 2^100 - 2^64 - 7*2^96 > 0
+ * out[2] > 2^100 - 2^36 + 2^4 - 5*2^64 - 5*2^96 > 0
+ * out[3] > 2^100 - 2^36 + 2^4 - 7*2^64 - 5*2^96 - 3*2^96 > 0
+ *
+ * out[0] < 2^100 + 2^64 + 7*2^64 + 5*2^96 < 2^101
+ * out[1] < 2^100 + 3*2^64 + 5*2^64 + 3*2^97 < 2^101
+ * out[2] < 2^100 + 5*2^64 + 2^64 + 3*2^65 + 2^97 < 2^101
+ * out[3] < 2^100 + 7*2^64 + 7*2^96 + 3*2^64 < 2^101
+ */
+}
+
+/*-
+ * felem_reduce_zero105 converts a larger longfelem into an felem.
+ * On entry:
+ * in[0] < 2^71
+ * On exit:
+ * out[i] < 2^106
+ */
+static void felem_reduce_zero105(felem out, const longfelem in)
+{
+ out[0] = zero105[0] + in[0];
+ out[1] = zero105[1] + in[1];
+ out[2] = zero105[2] + in[2];
+ out[3] = zero105[3] + in[3];
+
+ felem_reduce_(out, in);
+
+ /*-
+ * out[0] > 2^105 - 2^41 - 2^9 - 2^71 - 2^103 - 2^71 - 2^103 > 0
+ * out[1] > 2^105 - 2^71 - 2^103 > 0
+ * out[2] > 2^105 - 2^41 + 2^9 - 2^71 - 2^103 > 0
+ * out[3] > 2^105 - 2^41 + 2^9 - 2^71 - 2^103 - 2^103 > 0
+ *
+ * out[0] < 2^105 + 2^71 + 2^71 + 2^103 < 2^106
+ * out[1] < 2^105 + 2^71 + 2^71 + 2^103 < 2^106
+ * out[2] < 2^105 + 2^71 + 2^71 + 2^71 + 2^103 < 2^106
+ * out[3] < 2^105 + 2^71 + 2^103 + 2^71 < 2^106
+ */
+}
+
+/*
+ * subtract_u64 sets *result = *result - v and *carry to one if the
+ * subtraction underflowed.
+ */
+static void subtract_u64(u64 *result, u64 *carry, u64 v)
+{
+ uint128_t r = *result;
+ r -= v;
+ *carry = (r >> 64) & 1;
+ *result = (u64)r;
+}
+
+/*
+ * felem_contract converts |in| to its unique, minimal representation. On
+ * entry: in[i] < 2^109
+ */
+static void felem_contract(smallfelem out, const felem in)
+{
+ unsigned i;
+ u64 all_equal_so_far = 0, result = 0, carry;
+
+ felem_shrink(out, in);
+ /* small is minimal except that the value might be > p */
+
+ all_equal_so_far--;
+ /*
+ * We are doing a constant time test if out >= kPrime. We need to compare
+ * each u64, from most-significant to least significant. For each one, if
+ * all words so far have been equal (m is all ones) then a non-equal
+ * result is the answer. Otherwise we continue.
+ */
+ for (i = 3; i < 4; i--) {
+ u64 equal;
+ uint128_t a = ((uint128_t) kPrime[i]) - out[i];
+ /*
+ * if out[i] > kPrime[i] then a will underflow and the high 64-bits
+ * will all be set.
+ */
+ result |= all_equal_so_far & ((u64)(a >> 64));
+
+ /*
+ * if kPrime[i] == out[i] then |equal| will be all zeros and the
+ * decrement will make it all ones.
+ */
+ equal = kPrime[i] ^ out[i];
+ equal--;
+ equal &= equal << 32;
+ equal &= equal << 16;
+ equal &= equal << 8;
+ equal &= equal << 4;
+ equal &= equal << 2;
+ equal &= equal << 1;
+ equal = ((s64) equal) >> 63;
+
+ all_equal_so_far &= equal;
+ }
+
+ /*
+ * if all_equal_so_far is still all ones then the two values are equal
+ * and so out >= kPrime is true.
+ */
+ result |= all_equal_so_far;
+
+ /* if out >= kPrime then we subtract kPrime. */
+ subtract_u64(&out[0], &carry, result & kPrime[0]);
+ subtract_u64(&out[1], &carry, carry);
+ subtract_u64(&out[2], &carry, carry);
+ subtract_u64(&out[3], &carry, carry);
+
+ subtract_u64(&out[1], &carry, result & kPrime[1]);
+ subtract_u64(&out[2], &carry, carry);
+ subtract_u64(&out[3], &carry, carry);
+
+ subtract_u64(&out[2], &carry, result & kPrime[2]);
+ subtract_u64(&out[3], &carry, carry);
+
+ subtract_u64(&out[3], &carry, result & kPrime[3]);
+}
+
+static void smallfelem_square_contract(smallfelem out, const smallfelem in)
+{
+ longfelem longtmp;
+ felem tmp;
+
+ smallfelem_square(longtmp, in);
+ felem_reduce(tmp, longtmp);
+ felem_contract(out, tmp);
+}
+
+static void smallfelem_mul_contract(smallfelem out, const smallfelem in1,
+ const smallfelem in2)
+{
+ longfelem longtmp;
+ felem tmp;
+
+ smallfelem_mul(longtmp, in1, in2);
+ felem_reduce(tmp, longtmp);
+ felem_contract(out, tmp);
+}
+
+/*-
+ * felem_is_zero returns a limb with all bits set if |in| == 0 (mod p) and 0
+ * otherwise.
+ * On entry:
+ * small[i] < 2^64
+ */
+static limb smallfelem_is_zero(const smallfelem small)
+{
+ limb result;
+ u64 is_p;
+
+ u64 is_zero = small[0] | small[1] | small[2] | small[3];
+ is_zero--;
+ is_zero &= is_zero << 32;
+ is_zero &= is_zero << 16;
+ is_zero &= is_zero << 8;
+ is_zero &= is_zero << 4;
+ is_zero &= is_zero << 2;
+ is_zero &= is_zero << 1;
+ is_zero = ((s64) is_zero) >> 63;
+
+ is_p = (small[0] ^ kPrime[0]) |
+ (small[1] ^ kPrime[1]) |
+ (small[2] ^ kPrime[2]) | (small[3] ^ kPrime[3]);
+ is_p--;
+ is_p &= is_p << 32;
+ is_p &= is_p << 16;
+ is_p &= is_p << 8;
+ is_p &= is_p << 4;
+ is_p &= is_p << 2;
+ is_p &= is_p << 1;
+ is_p = ((s64) is_p) >> 63;
+
+ is_zero |= is_p;
+
+ result = is_zero;
+ result |= ((limb) is_zero) << 64;
+ return result;
+}
+
+static int smallfelem_is_zero_int(const smallfelem small)
+{
+ return (int)(smallfelem_is_zero(small) & ((limb) 1));
+}
+
+/*-
+ * felem_inv calculates |out| = |in|^{-1}
+ *
+ * Based on Fermat's Little Theorem:
+ * a^p = a (mod p)
+ * a^{p-1} = 1 (mod p)
+ * a^{p-2} = a^{-1} (mod p)
+ */
+static void felem_inv(felem out, const felem in)
+{
+ felem ftmp, ftmp2;
+ /* each e_I will hold |in|^{2^I - 1} */
+ felem e2, e4, e8, e16, e32, e64;
+ longfelem tmp;
+ unsigned i;
+
+ felem_square(tmp, in);
+ felem_reduce(ftmp, tmp); /* 2^1 */
+ felem_mul(tmp, in, ftmp);
+ felem_reduce(ftmp, tmp); /* 2^2 - 2^0 */
+ felem_assign(e2, ftmp);
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp); /* 2^3 - 2^1 */
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp); /* 2^4 - 2^2 */
+ felem_mul(tmp, ftmp, e2);
+ felem_reduce(ftmp, tmp); /* 2^4 - 2^0 */
+ felem_assign(e4, ftmp);
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp); /* 2^5 - 2^1 */
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp); /* 2^6 - 2^2 */
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp); /* 2^7 - 2^3 */
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp); /* 2^8 - 2^4 */
+ felem_mul(tmp, ftmp, e4);
+ felem_reduce(ftmp, tmp); /* 2^8 - 2^0 */
+ felem_assign(e8, ftmp);
+ for (i = 0; i < 8; i++) {
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp);
+ } /* 2^16 - 2^8 */
+ felem_mul(tmp, ftmp, e8);
+ felem_reduce(ftmp, tmp); /* 2^16 - 2^0 */
+ felem_assign(e16, ftmp);
+ for (i = 0; i < 16; i++) {
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp);
+ } /* 2^32 - 2^16 */
+ felem_mul(tmp, ftmp, e16);
+ felem_reduce(ftmp, tmp); /* 2^32 - 2^0 */
+ felem_assign(e32, ftmp);
+ for (i = 0; i < 32; i++) {
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp);
+ } /* 2^64 - 2^32 */
+ felem_assign(e64, ftmp);
+ felem_mul(tmp, ftmp, in);
+ felem_reduce(ftmp, tmp); /* 2^64 - 2^32 + 2^0 */
+ for (i = 0; i < 192; i++) {
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp);
+ } /* 2^256 - 2^224 + 2^192 */
+
+ felem_mul(tmp, e64, e32);
+ felem_reduce(ftmp2, tmp); /* 2^64 - 2^0 */
+ for (i = 0; i < 16; i++) {
+ felem_square(tmp, ftmp2);
+ felem_reduce(ftmp2, tmp);
+ } /* 2^80 - 2^16 */
+ felem_mul(tmp, ftmp2, e16);
+ felem_reduce(ftmp2, tmp); /* 2^80 - 2^0 */
+ for (i = 0; i < 8; i++) {
+ felem_square(tmp, ftmp2);
+ felem_reduce(ftmp2, tmp);
+ } /* 2^88 - 2^8 */
+ felem_mul(tmp, ftmp2, e8);
+ felem_reduce(ftmp2, tmp); /* 2^88 - 2^0 */
+ for (i = 0; i < 4; i++) {
+ felem_square(tmp, ftmp2);
+ felem_reduce(ftmp2, tmp);
+ } /* 2^92 - 2^4 */
+ felem_mul(tmp, ftmp2, e4);
+ felem_reduce(ftmp2, tmp); /* 2^92 - 2^0 */
+ felem_square(tmp, ftmp2);
+ felem_reduce(ftmp2, tmp); /* 2^93 - 2^1 */
+ felem_square(tmp, ftmp2);
+ felem_reduce(ftmp2, tmp); /* 2^94 - 2^2 */
+ felem_mul(tmp, ftmp2, e2);
+ felem_reduce(ftmp2, tmp); /* 2^94 - 2^0 */
+ felem_square(tmp, ftmp2);
+ felem_reduce(ftmp2, tmp); /* 2^95 - 2^1 */
+ felem_square(tmp, ftmp2);
+ felem_reduce(ftmp2, tmp); /* 2^96 - 2^2 */
+ felem_mul(tmp, ftmp2, in);
+ felem_reduce(ftmp2, tmp); /* 2^96 - 3 */
+
+ felem_mul(tmp, ftmp2, ftmp);
+ felem_reduce(out, tmp); /* 2^256 - 2^224 + 2^192 + 2^96 - 3 */
+}
+
+static void smallfelem_inv_contract(smallfelem out, const smallfelem in)
+{
+ felem tmp;
+
+ smallfelem_expand(tmp, in);
+ felem_inv(tmp, tmp);
+ felem_contract(out, tmp);
+}
+
+/*-
+ * Group operations
+ * ----------------
+ *
+ * Building on top of the field operations we have the operations on the
+ * elliptic curve group itself. Points on the curve are represented in Jacobian
+ * coordinates
+ */
+
+/*-
+ * 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
+ *
+ * Outputs can equal corresponding inputs, i.e., x_out == x_in is allowed.
+ * while x_out == y_in is not (maybe this works, but it's not tested).
+ */
+static void
+point_double(felem x_out, felem y_out, felem z_out,
+ const felem x_in, const felem y_in, const felem z_in)
+{
+ longfelem tmp, tmp2;
+ felem delta, gamma, beta, alpha, ftmp, ftmp2;
+ smallfelem small1, small2;
+
+ felem_assign(ftmp, x_in);
+ /* ftmp[i] < 2^106 */
+ felem_assign(ftmp2, x_in);
+ /* ftmp2[i] < 2^106 */
+
+ /* delta = z^2 */
+ felem_square(tmp, z_in);
+ felem_reduce(delta, tmp);
+ /* delta[i] < 2^101 */
+
+ /* gamma = y^2 */
+ felem_square(tmp, y_in);
+ felem_reduce(gamma, tmp);
+ /* gamma[i] < 2^101 */
+ felem_shrink(small1, gamma);
+
+ /* beta = x*gamma */
+ felem_small_mul(tmp, small1, x_in);
+ felem_reduce(beta, tmp);
+ /* beta[i] < 2^101 */
+
+ /* alpha = 3*(x-delta)*(x+delta) */
+ felem_diff(ftmp, delta);
+ /* ftmp[i] < 2^105 + 2^106 < 2^107 */
+ felem_sum(ftmp2, delta);
+ /* ftmp2[i] < 2^105 + 2^106 < 2^107 */
+ felem_scalar(ftmp2, 3);
+ /* ftmp2[i] < 3 * 2^107 < 2^109 */
+ felem_mul(tmp, ftmp, ftmp2);
+ felem_reduce(alpha, tmp);
+ /* alpha[i] < 2^101 */
+ felem_shrink(small2, alpha);
+
+ /* x' = alpha^2 - 8*beta */
+ smallfelem_square(tmp, small2);
+ felem_reduce(x_out, tmp);
+ felem_assign(ftmp, beta);
+ felem_scalar(ftmp, 8);
+ /* ftmp[i] < 8 * 2^101 = 2^104 */
+ felem_diff(x_out, ftmp);
+ /* x_out[i] < 2^105 + 2^101 < 2^106 */
+
+ /* z' = (y + z)^2 - gamma - delta */
+ felem_sum(delta, gamma);
+ /* delta[i] < 2^101 + 2^101 = 2^102 */
+ felem_assign(ftmp, y_in);
+ felem_sum(ftmp, z_in);
+ /* ftmp[i] < 2^106 + 2^106 = 2^107 */
+ felem_square(tmp, ftmp);
+ felem_reduce(z_out, tmp);
+ felem_diff(z_out, delta);
+ /* z_out[i] < 2^105 + 2^101 < 2^106 */
+
+ /* y' = alpha*(4*beta - x') - 8*gamma^2 */
+ felem_scalar(beta, 4);
+ /* beta[i] < 4 * 2^101 = 2^103 */
+ felem_diff_zero107(beta, x_out);
+ /* beta[i] < 2^107 + 2^103 < 2^108 */
+ felem_small_mul(tmp, small2, beta);
+ /* tmp[i] < 7 * 2^64 < 2^67 */
+ smallfelem_square(tmp2, small1);
+ /* tmp2[i] < 7 * 2^64 */
+ longfelem_scalar(tmp2, 8);
+ /* tmp2[i] < 8 * 7 * 2^64 = 7 * 2^67 */
+ longfelem_diff(tmp, tmp2);
+ /* tmp[i] < 2^67 + 2^70 + 2^40 < 2^71 */
+ felem_reduce_zero105(y_out, tmp);
+ /* y_out[i] < 2^106 */
+}
+
+/*
+ * point_double_small is the same as point_double, except that it operates on
+ * smallfelems
+ */
+static void
+point_double_small(smallfelem x_out, smallfelem y_out, smallfelem z_out,
+ const smallfelem x_in, const smallfelem y_in,
+ const smallfelem z_in)
+{
+ felem felem_x_out, felem_y_out, felem_z_out;
+ felem felem_x_in, felem_y_in, felem_z_in;
+
+ smallfelem_expand(felem_x_in, x_in);
+ smallfelem_expand(felem_y_in, y_in);
+ smallfelem_expand(felem_z_in, z_in);
+ point_double(felem_x_out, felem_y_out, felem_z_out,
+ felem_x_in, felem_y_in, felem_z_in);
+ felem_shrink(x_out, felem_x_out);
+ felem_shrink(y_out, felem_y_out);
+ felem_shrink(z_out, felem_z_out);
+}
+
+/* copy_conditional copies in to out iff mask is all ones. */
+static void copy_conditional(felem out, const felem in, limb mask)
+{
+ unsigned i;
+ for (i = 0; i < NLIMBS; ++i) {
+ const limb tmp = mask & (in[i] ^ out[i]);
+ out[i] ^= tmp;
+ }
+}
+
+/* copy_small_conditional copies in to out iff mask is all ones. */
+static void copy_small_conditional(felem out, const smallfelem in, limb mask)
+{
+ unsigned i;
+ const u64 mask64 = mask;
+ for (i = 0; i < NLIMBS; ++i) {
+ out[i] = ((limb) (in[i] & mask64)) | (out[i] & ~mask);
+ }
+}
+
+/*-
+ * 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.
+ */
+void point_add(felem x3, felem y3, felem z3,
+ const felem x1, const felem y1, const felem z1,
+ const int mixed, const smallfelem x2,
+ const smallfelem y2, const smallfelem z2)
+{
+ felem ftmp, ftmp2, ftmp3, ftmp4, ftmp5, ftmp6, x_out, y_out, z_out;
+ longfelem tmp, tmp2;
+ smallfelem small1, small2, small3, small4, small5;
+ limb x_equal, y_equal, z1_is_zero, z2_is_zero;
+
+ felem_shrink(small3, z1);
+
+ z1_is_zero = smallfelem_is_zero(small3);
+ z2_is_zero = smallfelem_is_zero(z2);
+
+ /* ftmp = z1z1 = z1**2 */
+ smallfelem_square(tmp, small3);
+ felem_reduce(ftmp, tmp);
+ /* ftmp[i] < 2^101 */
+ felem_shrink(small1, ftmp);
+
+ if (!mixed) {
+ /* ftmp2 = z2z2 = z2**2 */
+ smallfelem_square(tmp, z2);
+ felem_reduce(ftmp2, tmp);
+ /* ftmp2[i] < 2^101 */
+ felem_shrink(small2, ftmp2);
+
+ felem_shrink(small5, x1);
+
+ /* u1 = ftmp3 = x1*z2z2 */
+ smallfelem_mul(tmp, small5, small2);
+ felem_reduce(ftmp3, tmp);
+ /* ftmp3[i] < 2^101 */
+
+ /* ftmp5 = z1 + z2 */
+ felem_assign(ftmp5, z1);
+ felem_small_sum(ftmp5, z2);
+ /* ftmp5[i] < 2^107 */
+
+ /* ftmp5 = (z1 + z2)**2 - (z1z1 + z2z2) = 2z1z2 */
+ felem_square(tmp, ftmp5);
+ felem_reduce(ftmp5, tmp);
+ /* ftmp2 = z2z2 + z1z1 */
+ felem_sum(ftmp2, ftmp);
+ /* ftmp2[i] < 2^101 + 2^101 = 2^102 */
+ felem_diff(ftmp5, ftmp2);
+ /* ftmp5[i] < 2^105 + 2^101 < 2^106 */
+
+ /* ftmp2 = z2 * z2z2 */
+ smallfelem_mul(tmp, small2, z2);
+ felem_reduce(ftmp2, tmp);
+
+ /* s1 = ftmp2 = y1 * z2**3 */
+ felem_mul(tmp, y1, ftmp2);
+ felem_reduce(ftmp6, tmp);
+ /* ftmp6[i] < 2^101 */
+ } else {
+ /*
+ * We'll assume z2 = 1 (special case z2 = 0 is handled later)
+ */
+
+ /* u1 = ftmp3 = x1*z2z2 */
+ felem_assign(ftmp3, x1);
+ /* ftmp3[i] < 2^106 */
+
+ /* ftmp5 = 2z1z2 */
+ felem_assign(ftmp5, z1);
+ felem_scalar(ftmp5, 2);
+ /* ftmp5[i] < 2*2^106 = 2^107 */
+
+ /* s1 = ftmp2 = y1 * z2**3 */
+ felem_assign(ftmp6, y1);
+ /* ftmp6[i] < 2^106 */
+ }
+
+ /* u2 = x2*z1z1 */
+ smallfelem_mul(tmp, x2, small1);
+ felem_reduce(ftmp4, tmp);
+
+ /* h = ftmp4 = u2 - u1 */
+ felem_diff_zero107(ftmp4, ftmp3);
+ /* ftmp4[i] < 2^107 + 2^101 < 2^108 */
+ felem_shrink(small4, ftmp4);
+
+ x_equal = smallfelem_is_zero(small4);
+
+ /* z_out = ftmp5 * h */
+ felem_small_mul(tmp, small4, ftmp5);
+ felem_reduce(z_out, tmp);
+ /* z_out[i] < 2^101 */
+
+ /* ftmp = z1 * z1z1 */
+ smallfelem_mul(tmp, small1, small3);
+ felem_reduce(ftmp, tmp);
+
+ /* s2 = tmp = y2 * z1**3 */
+ felem_small_mul(tmp, y2, ftmp);
+ felem_reduce(ftmp5, tmp);
+
+ /* r = ftmp5 = (s2 - s1)*2 */
+ felem_diff_zero107(ftmp5, ftmp6);
+ /* ftmp5[i] < 2^107 + 2^107 = 2^108 */
+ felem_scalar(ftmp5, 2);
+ /* ftmp5[i] < 2^109 */
+ felem_shrink(small1, ftmp5);
+ y_equal = smallfelem_is_zero(small1);
+
+ if (x_equal && y_equal && !z1_is_zero && !z2_is_zero) {
+ point_double(x3, y3, z3, x1, y1, z1);
+ return;
+ }
+
+ /* I = ftmp = (2h)**2 */
+ felem_assign(ftmp, ftmp4);
+ felem_scalar(ftmp, 2);
+ /* ftmp[i] < 2*2^108 = 2^109 */
+ felem_square(tmp, ftmp);
+ felem_reduce(ftmp, tmp);
+
+ /* J = ftmp2 = h * I */
+ felem_mul(tmp, ftmp4, ftmp);
+ felem_reduce(ftmp2, tmp);
+
+ /* V = ftmp4 = U1 * I */
+ felem_mul(tmp, ftmp3, ftmp);
+ felem_reduce(ftmp4, tmp);
+
+ /* x_out = r**2 - J - 2V */
+ smallfelem_square(tmp, small1);
+ felem_reduce(x_out, tmp);
+ felem_assign(ftmp3, ftmp4);
+ felem_scalar(ftmp4, 2);
+ felem_sum(ftmp4, ftmp2);
+ /* ftmp4[i] < 2*2^101 + 2^101 < 2^103 */
+ felem_diff(x_out, ftmp4);
+ /* x_out[i] < 2^105 + 2^101 */
+
+ /* y_out = r(V-x_out) - 2 * s1 * J */
+ felem_diff_zero107(ftmp3, x_out);
+ /* ftmp3[i] < 2^107 + 2^101 < 2^108 */
+ felem_small_mul(tmp, small1, ftmp3);
+ felem_mul(tmp2, ftmp6, ftmp2);
+ longfelem_scalar(tmp2, 2);
+ /* tmp2[i] < 2*2^67 = 2^68 */
+ longfelem_diff(tmp, tmp2);
+ /* tmp[i] < 2^67 + 2^70 + 2^40 < 2^71 */
+ felem_reduce_zero105(y_out, tmp);
+ /* y_out[i] < 2^106 */
+
+ copy_small_conditional(x_out, x2, z1_is_zero);
+ copy_conditional(x_out, x1, z2_is_zero);
+ copy_small_conditional(y_out, y2, z1_is_zero);
+ copy_conditional(y_out, y1, z2_is_zero);
+ copy_small_conditional(z_out, z2, z1_is_zero);
+ copy_conditional(z_out, z1, z2_is_zero);
+ felem_assign(x3, x_out);
+ felem_assign(y3, y_out);
+ felem_assign(z3, z_out);
+}
diff --git a/third_party/openssl-nistp256c64/ecp_nistp256.h b/third_party/openssl-nistp256c64/ecp_nistp256.h
new file mode 100644
index 000000000..190b81b61
--- /dev/null
+++ b/third_party/openssl-nistp256c64/ecp_nistp256.h
@@ -0,0 +1,55 @@
+#include <stdint.h>
+
+# if defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
+ /* 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 */
+typedef __int128_t int128_t;
+# else
+# error "Need GCC 3.1 or later to define type uint128_t"
+# endif
+
+typedef uint8_t u8;
+typedef uint32_t u32;
+typedef uint64_t u64;
+typedef int64_t s64;
+
+/*
+ * The representation of field elements.
+ * ------------------------------------
+ *
+ * We represent field elements with either four 128-bit values, eight 128-bit
+ * values, or four 64-bit values. The field element represented is:
+ * v[0]*2^0 + v[1]*2^64 + v[2]*2^128 + v[3]*2^192 (mod p)
+ * or:
+ * v[0]*2^0 + v[1]*2^64 + v[2]*2^128 + ... + v[8]*2^512 (mod p)
+ *
+ * 128-bit values are called 'limbs'. Since the limbs are spaced only 64 bits
+ * apart, but are 128-bits wide, the most significant bits of each limb overlap
+ * with the least significant bits of the next.
+ *
+ * A field element with four limbs is an 'felem'. One with eight limbs is a
+ * 'longfelem'
+ *
+ * A field element with four, 64-bit values is called a 'smallfelem'. Small
+ * values are used as intermediate values before multiplication.
+ */
+
+# define NLIMBS 4
+
+typedef uint128_t limb;
+typedef limb felem[NLIMBS];
+typedef limb longfelem[NLIMBS * 2];
+typedef u64 smallfelem[NLIMBS];
+
+/*
+ * The underlying field. P256 operates over GF(2^256-2^224+2^192+2^96-1). We
+ * can serialise an element of this field into 32 bytes. We call this an
+ * felem_bytearray.
+ */
+
+typedef u8 felem_bytearray[32];
+void point_add(felem x3, felem y3, felem z3,
+ const felem x1, const felem y1, const felem z1,
+ const int mixed, const smallfelem x2,
+ const smallfelem y2, const smallfelem z2);
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-13 18:14:02 +0000