Index: crypto/curve25519-donna.c |
diff --git a/crypto/curve25519-donna.c b/crypto/curve25519-donna.c |
deleted file mode 100644 |
index f141ac028b0f7bba419c218aad66275b507eb8c3..0000000000000000000000000000000000000000 |
--- a/crypto/curve25519-donna.c |
+++ /dev/null |
@@ -1,592 +0,0 @@ |
-// Copyright (c) 2013 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-/* |
- * curve25519-donna: Curve25519 elliptic curve, public key function |
- * |
- * http://code.google.com/p/curve25519-donna/ |
- * |
- * Adam Langley <agl@imperialviolet.org> |
- * |
- * Derived from public domain C code by Daniel J. Bernstein <djb@cr.yp.to> |
- * |
- * More information about curve25519 can be found here |
- * http://cr.yp.to/ecdh.html |
- * |
- * djb's sample implementation of curve25519 is written in a special assembly |
- * language called qhasm and uses the floating point registers. |
- * |
- * This is, almost, a clean room reimplementation from the curve25519 paper. It |
- * uses many of the tricks described therein. Only the crecip function is taken |
- * from the sample implementation. |
- */ |
- |
-#include <string.h> |
-#include <stdint.h> |
- |
-typedef uint8_t u8; |
-typedef int32_t s32; |
-typedef int64_t limb; |
- |
-/* Field element representation: |
- * |
- * Field elements are written as an array of signed, 64-bit limbs, least |
- * significant first. The value of the field element is: |
- * x[0] + 2^26·x[1] + x^51·x[2] + 2^102·x[3] + ... |
- * |
- * i.e. the limbs are 26, 25, 26, 25, ... bits wide. |
- */ |
- |
-/* Sum two numbers: output += in */ |
-static void fsum(limb *output, const limb *in) { |
- unsigned i; |
- for (i = 0; i < 10; i += 2) { |
- output[0+i] = (output[0+i] + in[0+i]); |
- output[1+i] = (output[1+i] + in[1+i]); |
- } |
-} |
- |
-/* Find the difference of two numbers: output = in - output |
- * (note the order of the arguments!) |
- */ |
-static void fdifference(limb *output, const limb *in) { |
- unsigned i; |
- for (i = 0; i < 10; ++i) { |
- output[i] = (in[i] - output[i]); |
- } |
-} |
- |
-/* Multiply a number my a scalar: output = in * scalar */ |
-static void fscalar_product(limb *output, const limb *in, const limb scalar) { |
- unsigned i; |
- for (i = 0; i < 10; ++i) { |
- output[i] = in[i] * scalar; |
- } |
-} |
- |
-/* Multiply two numbers: output = in2 * in |
- * |
- * output must be distinct to both inputs. The inputs are reduced coefficient |
- * form, the output is not. |
- */ |
-static void fproduct(limb *output, const limb *in2, const limb *in) { |
- output[0] = ((limb) ((s32) in2[0])) * ((s32) in[0]); |
- output[1] = ((limb) ((s32) in2[0])) * ((s32) in[1]) + |
- ((limb) ((s32) in2[1])) * ((s32) in[0]); |
- output[2] = 2 * ((limb) ((s32) in2[1])) * ((s32) in[1]) + |
- ((limb) ((s32) in2[0])) * ((s32) in[2]) + |
- ((limb) ((s32) in2[2])) * ((s32) in[0]); |
- output[3] = ((limb) ((s32) in2[1])) * ((s32) in[2]) + |
- ((limb) ((s32) in2[2])) * ((s32) in[1]) + |
- ((limb) ((s32) in2[0])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[3])) * ((s32) in[0]); |
- output[4] = ((limb) ((s32) in2[2])) * ((s32) in[2]) + |
- 2 * (((limb) ((s32) in2[1])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[3])) * ((s32) in[1])) + |
- ((limb) ((s32) in2[0])) * ((s32) in[4]) + |
- ((limb) ((s32) in2[4])) * ((s32) in[0]); |
- output[5] = ((limb) ((s32) in2[2])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[3])) * ((s32) in[2]) + |
- ((limb) ((s32) in2[1])) * ((s32) in[4]) + |
- ((limb) ((s32) in2[4])) * ((s32) in[1]) + |
- ((limb) ((s32) in2[0])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[5])) * ((s32) in[0]); |
- output[6] = 2 * (((limb) ((s32) in2[3])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[1])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[5])) * ((s32) in[1])) + |
- ((limb) ((s32) in2[2])) * ((s32) in[4]) + |
- ((limb) ((s32) in2[4])) * ((s32) in[2]) + |
- ((limb) ((s32) in2[0])) * ((s32) in[6]) + |
- ((limb) ((s32) in2[6])) * ((s32) in[0]); |
- output[7] = ((limb) ((s32) in2[3])) * ((s32) in[4]) + |
- ((limb) ((s32) in2[4])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[2])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[5])) * ((s32) in[2]) + |
- ((limb) ((s32) in2[1])) * ((s32) in[6]) + |
- ((limb) ((s32) in2[6])) * ((s32) in[1]) + |
- ((limb) ((s32) in2[0])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[7])) * ((s32) in[0]); |
- output[8] = ((limb) ((s32) in2[4])) * ((s32) in[4]) + |
- 2 * (((limb) ((s32) in2[3])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[5])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[1])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[7])) * ((s32) in[1])) + |
- ((limb) ((s32) in2[2])) * ((s32) in[6]) + |
- ((limb) ((s32) in2[6])) * ((s32) in[2]) + |
- ((limb) ((s32) in2[0])) * ((s32) in[8]) + |
- ((limb) ((s32) in2[8])) * ((s32) in[0]); |
- output[9] = ((limb) ((s32) in2[4])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[5])) * ((s32) in[4]) + |
- ((limb) ((s32) in2[3])) * ((s32) in[6]) + |
- ((limb) ((s32) in2[6])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[2])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[7])) * ((s32) in[2]) + |
- ((limb) ((s32) in2[1])) * ((s32) in[8]) + |
- ((limb) ((s32) in2[8])) * ((s32) in[1]) + |
- ((limb) ((s32) in2[0])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[0]); |
- output[10] = 2 * (((limb) ((s32) in2[5])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[3])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[7])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[1])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[1])) + |
- ((limb) ((s32) in2[4])) * ((s32) in[6]) + |
- ((limb) ((s32) in2[6])) * ((s32) in[4]) + |
- ((limb) ((s32) in2[2])) * ((s32) in[8]) + |
- ((limb) ((s32) in2[8])) * ((s32) in[2]); |
- output[11] = ((limb) ((s32) in2[5])) * ((s32) in[6]) + |
- ((limb) ((s32) in2[6])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[4])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[7])) * ((s32) in[4]) + |
- ((limb) ((s32) in2[3])) * ((s32) in[8]) + |
- ((limb) ((s32) in2[8])) * ((s32) in[3]) + |
- ((limb) ((s32) in2[2])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[2]); |
- output[12] = ((limb) ((s32) in2[6])) * ((s32) in[6]) + |
- 2 * (((limb) ((s32) in2[5])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[7])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[3])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[3])) + |
- ((limb) ((s32) in2[4])) * ((s32) in[8]) + |
- ((limb) ((s32) in2[8])) * ((s32) in[4]); |
- output[13] = ((limb) ((s32) in2[6])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[7])) * ((s32) in[6]) + |
- ((limb) ((s32) in2[5])) * ((s32) in[8]) + |
- ((limb) ((s32) in2[8])) * ((s32) in[5]) + |
- ((limb) ((s32) in2[4])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[4]); |
- output[14] = 2 * (((limb) ((s32) in2[7])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[5])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[5])) + |
- ((limb) ((s32) in2[6])) * ((s32) in[8]) + |
- ((limb) ((s32) in2[8])) * ((s32) in[6]); |
- output[15] = ((limb) ((s32) in2[7])) * ((s32) in[8]) + |
- ((limb) ((s32) in2[8])) * ((s32) in[7]) + |
- ((limb) ((s32) in2[6])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[6]); |
- output[16] = ((limb) ((s32) in2[8])) * ((s32) in[8]) + |
- 2 * (((limb) ((s32) in2[7])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[7])); |
- output[17] = ((limb) ((s32) in2[8])) * ((s32) in[9]) + |
- ((limb) ((s32) in2[9])) * ((s32) in[8]); |
- output[18] = 2 * ((limb) ((s32) in2[9])) * ((s32) in[9]); |
-} |
- |
-/* Reduce a long form to a short form by taking the input mod 2^255 - 19. */ |
-static void freduce_degree(limb *output) { |
- /* Each of these shifts and adds ends up multiplying the value by 19. */ |
- output[8] += output[18] << 4; |
- output[8] += output[18] << 1; |
- output[8] += output[18]; |
- output[7] += output[17] << 4; |
- output[7] += output[17] << 1; |
- output[7] += output[17]; |
- output[6] += output[16] << 4; |
- output[6] += output[16] << 1; |
- output[6] += output[16]; |
- output[5] += output[15] << 4; |
- output[5] += output[15] << 1; |
- output[5] += output[15]; |
- output[4] += output[14] << 4; |
- output[4] += output[14] << 1; |
- output[4] += output[14]; |
- output[3] += output[13] << 4; |
- output[3] += output[13] << 1; |
- output[3] += output[13]; |
- output[2] += output[12] << 4; |
- output[2] += output[12] << 1; |
- output[2] += output[12]; |
- output[1] += output[11] << 4; |
- output[1] += output[11] << 1; |
- output[1] += output[11]; |
- output[0] += output[10] << 4; |
- output[0] += output[10] << 1; |
- output[0] += output[10]; |
-} |
- |
-/* Reduce all coefficients of the short form input so that |x| < 2^26. |
- * |
- * On entry: |output[i]| < 2^62 |
- */ |
-static void freduce_coefficients(limb *output) { |
- unsigned i; |
- do { |
- output[10] = 0; |
- |
- for (i = 0; i < 10; i += 2) { |
- limb over = output[i] / 0x4000000l; |
- output[i+1] += over; |
- output[i] -= over * 0x4000000l; |
- |
- over = output[i+1] / 0x2000000; |
- output[i+2] += over; |
- output[i+1] -= over * 0x2000000; |
- } |
- output[0] += 19 * output[10]; |
- } while (output[10]); |
-} |
- |
-/* A helpful wrapper around fproduct: output = in * in2. |
- * |
- * output must be distinct to both inputs. The output is reduced degree and |
- * reduced coefficient. |
- */ |
-static void |
-fmul(limb *output, const limb *in, const limb *in2) { |
- limb t[19]; |
- fproduct(t, in, in2); |
- freduce_degree(t); |
- freduce_coefficients(t); |
- memcpy(output, t, sizeof(limb) * 10); |
-} |
- |
-static void fsquare_inner(limb *output, const limb *in) { |
- output[0] = ((limb) ((s32) in[0])) * ((s32) in[0]); |
- output[1] = 2 * ((limb) ((s32) in[0])) * ((s32) in[1]); |
- output[2] = 2 * (((limb) ((s32) in[1])) * ((s32) in[1]) + |
- ((limb) ((s32) in[0])) * ((s32) in[2])); |
- output[3] = 2 * (((limb) ((s32) in[1])) * ((s32) in[2]) + |
- ((limb) ((s32) in[0])) * ((s32) in[3])); |
- output[4] = ((limb) ((s32) in[2])) * ((s32) in[2]) + |
- 4 * ((limb) ((s32) in[1])) * ((s32) in[3]) + |
- 2 * ((limb) ((s32) in[0])) * ((s32) in[4]); |
- output[5] = 2 * (((limb) ((s32) in[2])) * ((s32) in[3]) + |
- ((limb) ((s32) in[1])) * ((s32) in[4]) + |
- ((limb) ((s32) in[0])) * ((s32) in[5])); |
- output[6] = 2 * (((limb) ((s32) in[3])) * ((s32) in[3]) + |
- ((limb) ((s32) in[2])) * ((s32) in[4]) + |
- ((limb) ((s32) in[0])) * ((s32) in[6]) + |
- 2 * ((limb) ((s32) in[1])) * ((s32) in[5])); |
- output[7] = 2 * (((limb) ((s32) in[3])) * ((s32) in[4]) + |
- ((limb) ((s32) in[2])) * ((s32) in[5]) + |
- ((limb) ((s32) in[1])) * ((s32) in[6]) + |
- ((limb) ((s32) in[0])) * ((s32) in[7])); |
- output[8] = ((limb) ((s32) in[4])) * ((s32) in[4]) + |
- 2 * (((limb) ((s32) in[2])) * ((s32) in[6]) + |
- ((limb) ((s32) in[0])) * ((s32) in[8]) + |
- 2 * (((limb) ((s32) in[1])) * ((s32) in[7]) + |
- ((limb) ((s32) in[3])) * ((s32) in[5]))); |
- output[9] = 2 * (((limb) ((s32) in[4])) * ((s32) in[5]) + |
- ((limb) ((s32) in[3])) * ((s32) in[6]) + |
- ((limb) ((s32) in[2])) * ((s32) in[7]) + |
- ((limb) ((s32) in[1])) * ((s32) in[8]) + |
- ((limb) ((s32) in[0])) * ((s32) in[9])); |
- output[10] = 2 * (((limb) ((s32) in[5])) * ((s32) in[5]) + |
- ((limb) ((s32) in[4])) * ((s32) in[6]) + |
- ((limb) ((s32) in[2])) * ((s32) in[8]) + |
- 2 * (((limb) ((s32) in[3])) * ((s32) in[7]) + |
- ((limb) ((s32) in[1])) * ((s32) in[9]))); |
- output[11] = 2 * (((limb) ((s32) in[5])) * ((s32) in[6]) + |
- ((limb) ((s32) in[4])) * ((s32) in[7]) + |
- ((limb) ((s32) in[3])) * ((s32) in[8]) + |
- ((limb) ((s32) in[2])) * ((s32) in[9])); |
- output[12] = ((limb) ((s32) in[6])) * ((s32) in[6]) + |
- 2 * (((limb) ((s32) in[4])) * ((s32) in[8]) + |
- 2 * (((limb) ((s32) in[5])) * ((s32) in[7]) + |
- ((limb) ((s32) in[3])) * ((s32) in[9]))); |
- output[13] = 2 * (((limb) ((s32) in[6])) * ((s32) in[7]) + |
- ((limb) ((s32) in[5])) * ((s32) in[8]) + |
- ((limb) ((s32) in[4])) * ((s32) in[9])); |
- output[14] = 2 * (((limb) ((s32) in[7])) * ((s32) in[7]) + |
- ((limb) ((s32) in[6])) * ((s32) in[8]) + |
- 2 * ((limb) ((s32) in[5])) * ((s32) in[9])); |
- output[15] = 2 * (((limb) ((s32) in[7])) * ((s32) in[8]) + |
- ((limb) ((s32) in[6])) * ((s32) in[9])); |
- output[16] = ((limb) ((s32) in[8])) * ((s32) in[8]) + |
- 4 * ((limb) ((s32) in[7])) * ((s32) in[9]); |
- output[17] = 2 * ((limb) ((s32) in[8])) * ((s32) in[9]); |
- output[18] = 2 * ((limb) ((s32) in[9])) * ((s32) in[9]); |
-} |
- |
-static void |
-fsquare(limb *output, const limb *in) { |
- limb t[19]; |
- fsquare_inner(t, in); |
- freduce_degree(t); |
- freduce_coefficients(t); |
- memcpy(output, t, sizeof(limb) * 10); |
-} |
- |
-/* Take a little-endian, 32-byte number and expand it into polynomial form */ |
-static void |
-fexpand(limb *output, const u8 *input) { |
-#define F(n,start,shift,mask) \ |
- output[n] = ((((limb) input[start + 0]) | \ |
- ((limb) input[start + 1]) << 8 | \ |
- ((limb) input[start + 2]) << 16 | \ |
- ((limb) input[start + 3]) << 24) >> shift) & mask; |
- F(0, 0, 0, 0x3ffffff); |
- F(1, 3, 2, 0x1ffffff); |
- F(2, 6, 3, 0x3ffffff); |
- F(3, 9, 5, 0x1ffffff); |
- F(4, 12, 6, 0x3ffffff); |
- F(5, 16, 0, 0x1ffffff); |
- F(6, 19, 1, 0x3ffffff); |
- F(7, 22, 3, 0x1ffffff); |
- F(8, 25, 4, 0x3ffffff); |
- F(9, 28, 6, 0x1ffffff); |
-#undef F |
-} |
- |
-/* Take a fully reduced polynomial form number and contract it into a |
- * little-endian, 32-byte array |
- */ |
-static void |
-fcontract(u8 *output, limb *input) { |
- int i; |
- |
- do { |
- for (i = 0; i < 9; ++i) { |
- if ((i & 1) == 1) { |
- while (input[i] < 0) { |
- input[i] += 0x2000000; |
- input[i + 1]--; |
- } |
- } else { |
- while (input[i] < 0) { |
- input[i] += 0x4000000; |
- input[i + 1]--; |
- } |
- } |
- } |
- while (input[9] < 0) { |
- input[9] += 0x2000000; |
- input[0] -= 19; |
- } |
- } while (input[0] < 0); |
- |
- input[1] <<= 2; |
- input[2] <<= 3; |
- input[3] <<= 5; |
- input[4] <<= 6; |
- input[6] <<= 1; |
- input[7] <<= 3; |
- input[8] <<= 4; |
- input[9] <<= 6; |
-#define F(i, s) \ |
- output[s+0] |= input[i] & 0xff; \ |
- output[s+1] = (input[i] >> 8) & 0xff; \ |
- output[s+2] = (input[i] >> 16) & 0xff; \ |
- output[s+3] = (input[i] >> 24) & 0xff; |
- output[0] = 0; |
- output[16] = 0; |
- F(0,0); |
- F(1,3); |
- F(2,6); |
- F(3,9); |
- F(4,12); |
- F(5,16); |
- F(6,19); |
- F(7,22); |
- F(8,25); |
- F(9,28); |
-#undef F |
-} |
- |
-/* Input: Q, Q', Q-Q' |
- * Output: 2Q, Q+Q' |
- * |
- * x2 z3: long form |
- * x3 z3: long form |
- * x z: short form, destroyed |
- * xprime zprime: short form, destroyed |
- * qmqp: short form, preserved |
- */ |
-static void fmonty(limb *x2, limb *z2, /* output 2Q */ |
- limb *x3, limb *z3, /* output Q + Q' */ |
- limb *x, limb *z, /* input Q */ |
- limb *xprime, limb *zprime, /* input Q' */ |
- const limb *qmqp /* input Q - Q' */) { |
- limb origx[10], origxprime[10], zzz[19], xx[19], zz[19], xxprime[19], |
- zzprime[19], zzzprime[19], xxxprime[19]; |
- |
- memcpy(origx, x, 10 * sizeof(limb)); |
- fsum(x, z); |
- fdifference(z, origx); // does x - z |
- |
- memcpy(origxprime, xprime, sizeof(limb) * 10); |
- fsum(xprime, zprime); |
- fdifference(zprime, origxprime); |
- fproduct(xxprime, xprime, z); |
- fproduct(zzprime, x, zprime); |
- freduce_degree(xxprime); |
- freduce_coefficients(xxprime); |
- freduce_degree(zzprime); |
- freduce_coefficients(zzprime); |
- memcpy(origxprime, xxprime, sizeof(limb) * 10); |
- fsum(xxprime, zzprime); |
- fdifference(zzprime, origxprime); |
- fsquare(xxxprime, xxprime); |
- fsquare(zzzprime, zzprime); |
- fproduct(zzprime, zzzprime, qmqp); |
- freduce_degree(zzprime); |
- freduce_coefficients(zzprime); |
- memcpy(x3, xxxprime, sizeof(limb) * 10); |
- memcpy(z3, zzprime, sizeof(limb) * 10); |
- |
- fsquare(xx, x); |
- fsquare(zz, z); |
- fproduct(x2, xx, zz); |
- freduce_degree(x2); |
- freduce_coefficients(x2); |
- fdifference(zz, xx); // does zz = xx - zz |
- memset(zzz + 10, 0, sizeof(limb) * 9); |
- fscalar_product(zzz, zz, 121665); |
- freduce_degree(zzz); |
- freduce_coefficients(zzz); |
- fsum(zzz, xx); |
- fproduct(z2, zz, zzz); |
- freduce_degree(z2); |
- freduce_coefficients(z2); |
-} |
- |
-/* Calculates nQ where Q is the x-coordinate of a point on the curve |
- * |
- * resultx/resultz: the x coordinate of the resulting curve point (short form) |
- * n: a little endian, 32-byte number |
- * q: a point of the curve (short form) |
- */ |
-static void |
-cmult(limb *resultx, limb *resultz, const u8 *n, const limb *q) { |
- limb a[19] = {0}, b[19] = {1}, c[19] = {1}, d[19] = {0}; |
- limb *nqpqx = a, *nqpqz = b, *nqx = c, *nqz = d, *t; |
- limb e[19] = {0}, f[19] = {1}, g[19] = {0}, h[19] = {1}; |
- limb *nqpqx2 = e, *nqpqz2 = f, *nqx2 = g, *nqz2 = h; |
- |
- unsigned i, j; |
- |
- memcpy(nqpqx, q, sizeof(limb) * 10); |
- |
- for (i = 0; i < 32; ++i) { |
- u8 byte = n[31 - i]; |
- for (j = 0; j < 8; ++j) { |
- if (byte & 0x80) { |
- fmonty(nqpqx2, nqpqz2, |
- nqx2, nqz2, |
- nqpqx, nqpqz, |
- nqx, nqz, |
- q); |
- } else { |
- fmonty(nqx2, nqz2, |
- nqpqx2, nqpqz2, |
- nqx, nqz, |
- nqpqx, nqpqz, |
- q); |
- } |
- |
- t = nqx; |
- nqx = nqx2; |
- nqx2 = t; |
- t = nqz; |
- nqz = nqz2; |
- nqz2 = t; |
- t = nqpqx; |
- nqpqx = nqpqx2; |
- nqpqx2 = t; |
- t = nqpqz; |
- nqpqz = nqpqz2; |
- nqpqz2 = t; |
- |
- byte <<= 1; |
- } |
- } |
- |
- memcpy(resultx, nqx, sizeof(limb) * 10); |
- memcpy(resultz, nqz, sizeof(limb) * 10); |
-} |
- |
-// ----------------------------------------------------------------------------- |
-// Shamelessly copied from djb's code |
-// ----------------------------------------------------------------------------- |
-static void |
-crecip(limb *out, const limb *z) { |
- limb z2[10]; |
- limb z9[10]; |
- limb z11[10]; |
- limb z2_5_0[10]; |
- limb z2_10_0[10]; |
- limb z2_20_0[10]; |
- limb z2_50_0[10]; |
- limb z2_100_0[10]; |
- limb t0[10]; |
- limb t1[10]; |
- int i; |
- |
- /* 2 */ fsquare(z2,z); |
- /* 4 */ fsquare(t1,z2); |
- /* 8 */ fsquare(t0,t1); |
- /* 9 */ fmul(z9,t0,z); |
- /* 11 */ fmul(z11,z9,z2); |
- /* 22 */ fsquare(t0,z11); |
- /* 2^5 - 2^0 = 31 */ fmul(z2_5_0,t0,z9); |
- |
- /* 2^6 - 2^1 */ fsquare(t0,z2_5_0); |
- /* 2^7 - 2^2 */ fsquare(t1,t0); |
- /* 2^8 - 2^3 */ fsquare(t0,t1); |
- /* 2^9 - 2^4 */ fsquare(t1,t0); |
- /* 2^10 - 2^5 */ fsquare(t0,t1); |
- /* 2^10 - 2^0 */ fmul(z2_10_0,t0,z2_5_0); |
- |
- /* 2^11 - 2^1 */ fsquare(t0,z2_10_0); |
- /* 2^12 - 2^2 */ fsquare(t1,t0); |
- /* 2^20 - 2^10 */ |
- for (i = 2;i < 10;i += 2) { fsquare(t0,t1); fsquare(t1,t0); } |
- /* 2^20 - 2^0 */ fmul(z2_20_0,t1,z2_10_0); |
- |
- /* 2^21 - 2^1 */ fsquare(t0,z2_20_0); |
- /* 2^22 - 2^2 */ fsquare(t1,t0); |
- /* 2^40 - 2^20 */ |
- for (i = 2;i < 20;i += 2) { fsquare(t0,t1); fsquare(t1,t0); } |
- /* 2^40 - 2^0 */ fmul(t0,t1,z2_20_0); |
- |
- /* 2^41 - 2^1 */ fsquare(t1,t0); |
- /* 2^42 - 2^2 */ fsquare(t0,t1); |
- /* 2^50 - 2^10 */ |
- for (i = 2;i < 10;i += 2) { fsquare(t1,t0); fsquare(t0,t1); } |
- /* 2^50 - 2^0 */ fmul(z2_50_0,t0,z2_10_0); |
- |
- /* 2^51 - 2^1 */ fsquare(t0,z2_50_0); |
- /* 2^52 - 2^2 */ fsquare(t1,t0); |
- /* 2^100 - 2^50 */ |
- for (i = 2;i < 50;i += 2) { fsquare(t0,t1); fsquare(t1,t0); } |
- /* 2^100 - 2^0 */ fmul(z2_100_0,t1,z2_50_0); |
- |
- /* 2^101 - 2^1 */ fsquare(t1,z2_100_0); |
- /* 2^102 - 2^2 */ fsquare(t0,t1); |
- /* 2^200 - 2^100 */ |
- for (i = 2;i < 100;i += 2) { fsquare(t1,t0); fsquare(t0,t1); } |
- /* 2^200 - 2^0 */ fmul(t1,t0,z2_100_0); |
- |
- /* 2^201 - 2^1 */ fsquare(t0,t1); |
- /* 2^202 - 2^2 */ fsquare(t1,t0); |
- /* 2^250 - 2^50 */ |
- for (i = 2;i < 50;i += 2) { fsquare(t0,t1); fsquare(t1,t0); } |
- /* 2^250 - 2^0 */ fmul(t0,t1,z2_50_0); |
- |
- /* 2^251 - 2^1 */ fsquare(t1,t0); |
- /* 2^252 - 2^2 */ fsquare(t0,t1); |
- /* 2^253 - 2^3 */ fsquare(t1,t0); |
- /* 2^254 - 2^4 */ fsquare(t0,t1); |
- /* 2^255 - 2^5 */ fsquare(t1,t0); |
- /* 2^255 - 21 */ fmul(out,t1,z11); |
-} |
- |
-int |
-curve25519_donna(u8 *mypublic, const u8 *secret, const u8 *basepoint) { |
- limb bp[10], x[10], z[10], zmone[10]; |
- uint8_t e[32]; |
- int i; |
- |
- for (i = 0; i < 32; ++i) e[i] = secret[i]; |
- e[0] &= 248; |
- e[31] &= 127; |
- e[31] |= 64; |
- |
- fexpand(bp, basepoint); |
- cmult(x, z, e, bp); |
- crecip(zmone, z); |
- fmul(z, x, zmone); |
- fcontract(mypublic, z); |
- return 0; |
-} |