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Diffstat (limited to 'security/nss/lib/freebl/ecl/curve25519_64.c')
-rw-r--r--security/nss/lib/freebl/ecl/curve25519_64.c508
1 files changed, 4 insertions, 504 deletions
diff --git a/security/nss/lib/freebl/ecl/curve25519_64.c b/security/nss/lib/freebl/ecl/curve25519_64.c
index 65f6bd41b5..a2e4296bbf 100644
--- a/security/nss/lib/freebl/ecl/curve25519_64.c
+++ b/security/nss/lib/freebl/ecl/curve25519_64.c
@@ -2,513 +2,13 @@
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-/*
- * Derived from public domain C code by Adan Langley and Daniel J. Bernstein
- */
-
-#include "uint128.h"
-
#include "ecl-priv.h"
-#include "mpi.h"
-
-#include <stdint.h>
-#include <stdio.h>
-#include <string.h>
-
-typedef uint8_t u8;
-typedef uint64_t felem;
-
-/* Sum two numbers: output += in */
-static void
-fsum(felem *output, const felem *in)
-{
- unsigned i;
- for (i = 0; i < 5; ++i) {
- output[i] += in[i];
- }
-}
-
-/* Find the difference of two numbers: output = in - output
- * (note the order of the arguments!)
- */
-static void
-fdifference_backwards(felem *ioutput, const felem *iin)
-{
- static const int64_t twotothe51 = ((int64_t)1l << 51);
- const int64_t *in = (const int64_t *)iin;
- int64_t *out = (int64_t *)ioutput;
-
- out[0] = in[0] - out[0];
- out[1] = in[1] - out[1];
- out[2] = in[2] - out[2];
- out[3] = in[3] - out[3];
- out[4] = in[4] - out[4];
-
- // An arithmetic shift right of 63 places turns a positive number to 0 and a
- // negative number to all 1's. This gives us a bitmask that lets us avoid
- // side-channel prone branches.
- int64_t t;
-
-#define NEGCHAIN(a, b) \
- t = out[a] >> 63; \
- out[a] += twotothe51 & t; \
- out[b] -= 1 & t;
-
-#define NEGCHAIN19(a, b) \
- t = out[a] >> 63; \
- out[a] += twotothe51 & t; \
- out[b] -= 19 & t;
-
- NEGCHAIN(0, 1);
- NEGCHAIN(1, 2);
- NEGCHAIN(2, 3);
- NEGCHAIN(3, 4);
- NEGCHAIN19(4, 0);
- NEGCHAIN(0, 1);
- NEGCHAIN(1, 2);
- NEGCHAIN(2, 3);
- NEGCHAIN(3, 4);
-}
-
-/* Multiply a number by a scalar: output = in * scalar */
-static void
-fscalar_product(felem *output, const felem *in,
- const felem scalar)
-{
- uint128_t tmp, tmp2;
-
- tmp = mul6464(in[0], scalar);
- output[0] = mask51(tmp);
-
- tmp2 = mul6464(in[1], scalar);
- tmp = add128(tmp2, rshift128(tmp, 51));
- output[1] = mask51(tmp);
-
- tmp2 = mul6464(in[2], scalar);
- tmp = add128(tmp2, rshift128(tmp, 51));
- output[2] = mask51(tmp);
-
- tmp2 = mul6464(in[3], scalar);
- tmp = add128(tmp2, rshift128(tmp, 51));
- output[3] = mask51(tmp);
-
- tmp2 = mul6464(in[4], scalar);
- tmp = add128(tmp2, rshift128(tmp, 51));
- output[4] = mask51(tmp);
-
- output[0] += mask_lower(rshift128(tmp, 51)) * 19;
-}
-
-/* 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
-fmul(felem *output, const felem *in2, const felem *in)
-{
- uint128_t t0, t1, t2, t3, t4, t5, t6, t7, t8;
-
- t0 = mul6464(in[0], in2[0]);
- t1 = add128(mul6464(in[1], in2[0]), mul6464(in[0], in2[1]));
- t2 = add128(add128(mul6464(in[0], in2[2]),
- mul6464(in[2], in2[0])),
- mul6464(in[1], in2[1]));
- t3 = add128(add128(add128(mul6464(in[0], in2[3]),
- mul6464(in[3], in2[0])),
- mul6464(in[1], in2[2])),
- mul6464(in[2], in2[1]));
- t4 = add128(add128(add128(add128(mul6464(in[0], in2[4]),
- mul6464(in[4], in2[0])),
- mul6464(in[3], in2[1])),
- mul6464(in[1], in2[3])),
- mul6464(in[2], in2[2]));
- t5 = add128(add128(add128(mul6464(in[4], in2[1]),
- mul6464(in[1], in2[4])),
- mul6464(in[2], in2[3])),
- mul6464(in[3], in2[2]));
- t6 = add128(add128(mul6464(in[4], in2[2]),
- mul6464(in[2], in2[4])),
- mul6464(in[3], in2[3]));
- t7 = add128(mul6464(in[3], in2[4]), mul6464(in[4], in2[3]));
- t8 = mul6464(in[4], in2[4]);
-
- t0 = add128(t0, mul12819(t5));
- t1 = add128(t1, mul12819(t6));
- t2 = add128(t2, mul12819(t7));
- t3 = add128(t3, mul12819(t8));
-
- t1 = add128(t1, rshift128(t0, 51));
- t0 = mask51full(t0);
- t2 = add128(t2, rshift128(t1, 51));
- t1 = mask51full(t1);
- t3 = add128(t3, rshift128(t2, 51));
- t4 = add128(t4, rshift128(t3, 51));
- t0 = add128(t0, mul12819(rshift128(t4, 51)));
- t1 = add128(t1, rshift128(t0, 51));
- t2 = mask51full(t2);
- t2 = add128(t2, rshift128(t1, 51));
-
- output[0] = mask51(t0);
- output[1] = mask51(t1);
- output[2] = mask_lower(t2);
- output[3] = mask51(t3);
- output[4] = mask51(t4);
-}
-
-static void
-fsquare(felem *output, const felem *in)
-{
- uint128_t t0, t1, t2, t3, t4, t5, t6, t7, t8;
-
- t0 = mul6464(in[0], in[0]);
- t1 = lshift128(mul6464(in[0], in[1]), 1);
- t2 = add128(lshift128(mul6464(in[0], in[2]), 1),
- mul6464(in[1], in[1]));
- t3 = add128(lshift128(mul6464(in[0], in[3]), 1),
- lshift128(mul6464(in[1], in[2]), 1));
- t4 = add128(add128(lshift128(mul6464(in[0], in[4]), 1),
- lshift128(mul6464(in[3], in[1]), 1)),
- mul6464(in[2], in[2]));
- t5 = add128(lshift128(mul6464(in[4], in[1]), 1),
- lshift128(mul6464(in[2], in[3]), 1));
- t6 = add128(lshift128(mul6464(in[4], in[2]), 1),
- mul6464(in[3], in[3]));
- t7 = lshift128(mul6464(in[3], in[4]), 1);
- t8 = mul6464(in[4], in[4]);
-
- t0 = add128(t0, mul12819(t5));
- t1 = add128(t1, mul12819(t6));
- t2 = add128(t2, mul12819(t7));
- t3 = add128(t3, mul12819(t8));
-
- t1 = add128(t1, rshift128(t0, 51));
- t0 = mask51full(t0);
- t2 = add128(t2, rshift128(t1, 51));
- t1 = mask51full(t1);
- t3 = add128(t3, rshift128(t2, 51));
- t4 = add128(t4, rshift128(t3, 51));
- t0 = add128(t0, mul12819(rshift128(t4, 51)));
- t1 = add128(t1, rshift128(t0, 51));
-
- output[0] = mask51(t0);
- output[1] = mask_lower(t1);
- output[2] = mask51(t2);
- output[3] = mask51(t3);
- output[4] = mask51(t4);
-}
-
-/* Take a 32-byte number and expand it into polynomial form */
-static void NO_SANITIZE_ALIGNMENT
-fexpand(felem *output, const u8 *in)
-{
- output[0] = *((const uint64_t *)(in)) & MASK51;
- output[1] = (*((const uint64_t *)(in + 6)) >> 3) & MASK51;
- output[2] = (*((const uint64_t *)(in + 12)) >> 6) & MASK51;
- output[3] = (*((const uint64_t *)(in + 19)) >> 1) & MASK51;
- output[4] = (*((const uint64_t *)(in + 24)) >> 12) & MASK51;
-}
-
-/* Take a fully reduced polynomial form number and contract it into a
- * 32-byte array
- */
-static void
-fcontract(u8 *output, const felem *input)
-{
- uint128_t t0 = init128x(input[0]);
- uint128_t t1 = init128x(input[1]);
- uint128_t t2 = init128x(input[2]);
- uint128_t t3 = init128x(input[3]);
- uint128_t t4 = init128x(input[4]);
- uint128_t tmp = init128x(19);
-
- t1 = add128(t1, rshift128(t0, 51));
- t0 = mask51full(t0);
- t2 = add128(t2, rshift128(t1, 51));
- t1 = mask51full(t1);
- t3 = add128(t3, rshift128(t2, 51));
- t2 = mask51full(t2);
- t4 = add128(t4, rshift128(t3, 51));
- t3 = mask51full(t3);
- t0 = add128(t0, mul12819(rshift128(t4, 51)));
- t4 = mask51full(t4);
-
- t1 = add128(t1, rshift128(t0, 51));
- t0 = mask51full(t0);
- t2 = add128(t2, rshift128(t1, 51));
- t1 = mask51full(t1);
- t3 = add128(t3, rshift128(t2, 51));
- t2 = mask51full(t2);
- t4 = add128(t4, rshift128(t3, 51));
- t3 = mask51full(t3);
- t0 = add128(t0, mul12819(rshift128(t4, 51)));
- t4 = mask51full(t4);
-
- /* now t is between 0 and 2^255-1, properly carried. */
- /* case 1: between 0 and 2^255-20. case 2: between 2^255-19 and 2^255-1. */
-
- t0 = add128(t0, tmp);
-
- t1 = add128(t1, rshift128(t0, 51));
- t0 = mask51full(t0);
- t2 = add128(t2, rshift128(t1, 51));
- t1 = mask51full(t1);
- t3 = add128(t3, rshift128(t2, 51));
- t2 = mask51full(t2);
- t4 = add128(t4, rshift128(t3, 51));
- t3 = mask51full(t3);
- t0 = add128(t0, mul12819(rshift128(t4, 51)));
- t4 = mask51full(t4);
-
- /* now between 19 and 2^255-1 in both cases, and offset by 19. */
-
- t0 = add128(t0, init128x(0x8000000000000 - 19));
- tmp = init128x(0x8000000000000 - 1);
- t1 = add128(t1, tmp);
- t2 = add128(t2, tmp);
- t3 = add128(t3, tmp);
- t4 = add128(t4, tmp);
-
- /* now between 2^255 and 2^256-20, and offset by 2^255. */
-
- t1 = add128(t1, rshift128(t0, 51));
- t0 = mask51full(t0);
- t2 = add128(t2, rshift128(t1, 51));
- t1 = mask51full(t1);
- t3 = add128(t3, rshift128(t2, 51));
- t2 = mask51full(t2);
- t4 = add128(t4, rshift128(t3, 51));
- t3 = mask51full(t3);
- t4 = mask51full(t4);
-
- *((uint64_t *)(output)) = mask_lower(t0) | mask_lower(t1) << 51;
- *((uint64_t *)(output + 8)) = (mask_lower(t1) >> 13) | (mask_lower(t2) << 38);
- *((uint64_t *)(output + 16)) = (mask_lower(t2) >> 26) | (mask_lower(t3) << 25);
- *((uint64_t *)(output + 24)) = (mask_lower(t3) >> 39) | (mask_lower(t4) << 12);
-}
-
-/* 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(felem *x2, felem *z2, /* output 2Q */
- felem *x3, felem *z3, /* output Q + Q' */
- felem *x, felem *z, /* input Q */
- felem *xprime, felem *zprime, /* input Q' */
- const felem *qmqp /* input Q - Q' */)
-{
- felem origx[5], origxprime[5], zzz[5], xx[5], zz[5], xxprime[5], zzprime[5],
- zzzprime[5];
-
- memcpy(origx, x, 5 * sizeof(felem));
- fsum(x, z);
- fdifference_backwards(z, origx); // does x - z
-
- memcpy(origxprime, xprime, sizeof(felem) * 5);
- fsum(xprime, zprime);
- fdifference_backwards(zprime, origxprime);
- fmul(xxprime, xprime, z);
- fmul(zzprime, x, zprime);
- memcpy(origxprime, xxprime, sizeof(felem) * 5);
- fsum(xxprime, zzprime);
- fdifference_backwards(zzprime, origxprime);
- fsquare(x3, xxprime);
- fsquare(zzzprime, zzprime);
- fmul(z3, zzzprime, qmqp);
-
- fsquare(xx, x);
- fsquare(zz, z);
- fmul(x2, xx, zz);
- fdifference_backwards(zz, xx); // does zz = xx - zz
- fscalar_product(zzz, zz, 121665);
- fsum(zzz, xx);
- fmul(z2, zz, zzz);
-}
-
-// -----------------------------------------------------------------------------
-// Maybe swap the contents of two felem arrays (@a and @b), each @len elements
-// long. Perform the swap iff @swap is non-zero.
-//
-// This function performs the swap without leaking any side-channel
-// information.
-// -----------------------------------------------------------------------------
-static void
-swap_conditional(felem *a, felem *b, unsigned len, felem iswap)
-{
- unsigned i;
- const felem swap = 1 + ~iswap;
-
- for (i = 0; i < len; ++i) {
- const felem x = swap & (a[i] ^ b[i]);
- a[i] ^= x;
- b[i] ^= x;
- }
-}
-
-/* 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 32-byte number
- * q: a point of the curve (short form)
- */
-static void
-cmult(felem *resultx, felem *resultz, const u8 *n, const felem *q)
-{
- felem a[5] = { 0 }, b[5] = { 1 }, c[5] = { 1 }, d[5] = { 0 };
- felem *nqpqx = a, *nqpqz = b, *nqx = c, *nqz = d, *t;
- felem e[5] = { 0 }, f[5] = { 1 }, g[5] = { 0 }, h[5] = { 1 };
- felem *nqpqx2 = e, *nqpqz2 = f, *nqx2 = g, *nqz2 = h;
-
- unsigned i, j;
-
- memcpy(nqpqx, q, sizeof(felem) * 5);
-
- for (i = 0; i < 32; ++i) {
- u8 byte = n[31 - i];
- for (j = 0; j < 8; ++j) {
- const felem bit = byte >> 7;
-
- swap_conditional(nqx, nqpqx, 5, bit);
- swap_conditional(nqz, nqpqz, 5, bit);
- fmonty(nqx2, nqz2, nqpqx2, nqpqz2, nqx, nqz, nqpqx, nqpqz, q);
- swap_conditional(nqx2, nqpqx2, 5, bit);
- swap_conditional(nqz2, nqpqz2, 5, bit);
-
- 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(felem) * 5);
- memcpy(resultz, nqz, sizeof(felem) * 5);
-}
-
-// -----------------------------------------------------------------------------
-// Shamelessly copied from djb's code
-// -----------------------------------------------------------------------------
-static void
-crecip(felem *out, const felem *z)
-{
- felem z2[5];
- felem z9[5];
- felem z11[5];
- felem z2_5_0[5];
- felem z2_10_0[5];
- felem z2_20_0[5];
- felem z2_50_0[5];
- felem z2_100_0[5];
- felem t0[5];
- felem t1[5];
- 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);
-}
+#include "../verified/Hacl_Curve25519.h"
SECStatus
-ec_Curve25519_mul(uint8_t *mypublic, const uint8_t *secret,
- const uint8_t *basepoint)
+ec_Curve25519_mul(uint8_t *mypublic, const uint8_t *secret, const uint8_t *basepoint)
{
- felem bp[5], x[5], z[5], zmone[5];
- 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);
-
+ // Note: this cast is safe because HaCl* state has a post-condition that only "mypublic" changed.
+ Hacl_Curve25519_crypto_scalarmult(mypublic, (uint8_t *)secret, (uint8_t *)basepoint);
return 0;
}
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