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Diffstat (limited to 'curve25519-amd64.c')
| -rw-r--r-- | curve25519-amd64.c | 234 |
1 files changed, 0 insertions, 234 deletions
diff --git a/curve25519-amd64.c b/curve25519-amd64.c deleted file mode 100644 index 095b0d2..0000000 --- a/curve25519-amd64.c +++ /dev/null @@ -1,234 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 - * - * Copyright (C) 2015 Google Inc. All Rights Reserved. - * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. - * - * Original author: Peter Schwabe <peter@cryptojedi.org> - */ - -#include <linux/kernel.h> -#include <linux/string.h> - -typedef struct { uint64_t v[5]; } fe25519; - -asmlinkage void x25519_x86_64_work_cswap(fe25519 *, uint64_t); -asmlinkage void x25519_x86_64_mul(fe25519 *out, const fe25519 *a, const fe25519 *b); -asmlinkage void x25519_x86_64_square(fe25519 *out, const fe25519 *a); -asmlinkage void x25519_x86_64_freeze(fe25519 *); -asmlinkage void x25519_x86_64_ladderstep(fe25519 *work); - -enum { CURVE25519_POINT_SIZE = 32 }; - -static __always_inline void normalize_secret(u8 secret[CURVE25519_POINT_SIZE]) -{ - secret[0] &= 248; - secret[31] &= 127; - secret[31] |= 64; -} - -static void fe25519_setint(fe25519 *r, unsigned v) -{ - r->v[0] = v; - r->v[1] = 0; - r->v[2] = 0; - r->v[3] = 0; - r->v[4] = 0; -} - -// Assumes input x being reduced below 2^255 -static void fe25519_pack(unsigned char r[32], const fe25519 *x) -{ - fe25519 t; - t = *x; - x25519_x86_64_freeze(&t); - - r[0] = (uint8_t)(t.v[0] & 0xff); - r[1] = (uint8_t)((t.v[0] >> 8) & 0xff); - r[2] = (uint8_t)((t.v[0] >> 16) & 0xff); - r[3] = (uint8_t)((t.v[0] >> 24) & 0xff); - r[4] = (uint8_t)((t.v[0] >> 32) & 0xff); - r[5] = (uint8_t)((t.v[0] >> 40) & 0xff); - r[6] = (uint8_t)((t.v[0] >> 48)); - - r[6] ^= (uint8_t)((t.v[1] << 3) & 0xf8); - r[7] = (uint8_t)((t.v[1] >> 5) & 0xff); - r[8] = (uint8_t)((t.v[1] >> 13) & 0xff); - r[9] = (uint8_t)((t.v[1] >> 21) & 0xff); - r[10] = (uint8_t)((t.v[1] >> 29) & 0xff); - r[11] = (uint8_t)((t.v[1] >> 37) & 0xff); - r[12] = (uint8_t)((t.v[1] >> 45)); - - r[12] ^= (uint8_t)((t.v[2] << 6) & 0xc0); - r[13] = (uint8_t)((t.v[2] >> 2) & 0xff); - r[14] = (uint8_t)((t.v[2] >> 10) & 0xff); - r[15] = (uint8_t)((t.v[2] >> 18) & 0xff); - r[16] = (uint8_t)((t.v[2] >> 26) & 0xff); - r[17] = (uint8_t)((t.v[2] >> 34) & 0xff); - r[18] = (uint8_t)((t.v[2] >> 42) & 0xff); - r[19] = (uint8_t)((t.v[2] >> 50)); - - r[19] ^= (uint8_t)((t.v[3] << 1) & 0xfe); - r[20] = (uint8_t)((t.v[3] >> 7) & 0xff); - r[21] = (uint8_t)((t.v[3] >> 15) & 0xff); - r[22] = (uint8_t)((t.v[3] >> 23) & 0xff); - r[23] = (uint8_t)((t.v[3] >> 31) & 0xff); - r[24] = (uint8_t)((t.v[3] >> 39) & 0xff); - r[25] = (uint8_t)((t.v[3] >> 47)); - - r[25] ^= (uint8_t)((t.v[4] << 4) & 0xf0); - r[26] = (uint8_t)((t.v[4] >> 4) & 0xff); - r[27] = (uint8_t)((t.v[4] >> 12) & 0xff); - r[28] = (uint8_t)((t.v[4] >> 20) & 0xff); - r[29] = (uint8_t)((t.v[4] >> 28) & 0xff); - r[30] = (uint8_t)((t.v[4] >> 36) & 0xff); - r[31] = (uint8_t)((t.v[4] >> 44)); -} - -static void fe25519_unpack(fe25519 *r, const uint8_t x[32]) -{ - r->v[0] = x[0]; - r->v[0] += (uint64_t)x[1] << 8; - r->v[0] += (uint64_t)x[2] << 16; - r->v[0] += (uint64_t)x[3] << 24; - r->v[0] += (uint64_t)x[4] << 32; - r->v[0] += (uint64_t)x[5] << 40; - r->v[0] += ((uint64_t)x[6] & 7) << 48; - - r->v[1] = x[6] >> 3; - r->v[1] += (uint64_t)x[7] << 5; - r->v[1] += (uint64_t)x[8] << 13; - r->v[1] += (uint64_t)x[9] << 21; - r->v[1] += (uint64_t)x[10] << 29; - r->v[1] += (uint64_t)x[11] << 37; - r->v[1] += ((uint64_t)x[12] & 63) << 45; - - r->v[2] = x[12] >> 6; - r->v[2] += (uint64_t)x[13] << 2; - r->v[2] += (uint64_t)x[14] << 10; - r->v[2] += (uint64_t)x[15] << 18; - r->v[2] += (uint64_t)x[16] << 26; - r->v[2] += (uint64_t)x[17] << 34; - r->v[2] += (uint64_t)x[18] << 42; - r->v[2] += ((uint64_t)x[19] & 1) << 50; - - r->v[3] = x[19] >> 1; - r->v[3] += (uint64_t)x[20] << 7; - r->v[3] += (uint64_t)x[21] << 15; - r->v[3] += (uint64_t)x[22] << 23; - r->v[3] += (uint64_t)x[23] << 31; - r->v[3] += (uint64_t)x[24] << 39; - r->v[3] += ((uint64_t)x[25] & 15) << 47; - - r->v[4] = x[25] >> 4; - r->v[4] += (uint64_t)x[26] << 4; - r->v[4] += (uint64_t)x[27] << 12; - r->v[4] += (uint64_t)x[28] << 20; - r->v[4] += (uint64_t)x[29] << 28; - r->v[4] += (uint64_t)x[30] << 36; - r->v[4] += ((uint64_t)x[31] & 127) << 44; -} - -static void fe25519_invert(fe25519 *r, const fe25519 *x) -{ - fe25519 z2; - fe25519 z9; - fe25519 z11; - fe25519 z2_5_0; - fe25519 z2_10_0; - fe25519 z2_20_0; - fe25519 z2_50_0; - fe25519 z2_100_0; - fe25519 t; - int i; - - /* 2 */ x25519_x86_64_square(&z2, x); - /* 4 */ x25519_x86_64_square(&t, &z2); - /* 8 */ x25519_x86_64_square(&t, &t); - /* 9 */ x25519_x86_64_mul(&z9, &t, x); - /* 11 */ x25519_x86_64_mul(&z11, &z9, &z2); - /* 22 */ x25519_x86_64_square(&t, &z11); - /* 2^5 - 2^0 = 31 */ x25519_x86_64_mul(&z2_5_0, &t, &z9); - - /* 2^6 - 2^1 */ x25519_x86_64_square(&t, &z2_5_0); - /* 2^20 - 2^10 */ for (i = 1; i < 5; i++) { x25519_x86_64_square(&t, &t); } - /* 2^10 - 2^0 */ x25519_x86_64_mul(&z2_10_0, &t, &z2_5_0); - - /* 2^11 - 2^1 */ x25519_x86_64_square(&t, &z2_10_0); - /* 2^20 - 2^10 */ for (i = 1; i < 10; i++) { x25519_x86_64_square(&t, &t); } - /* 2^20 - 2^0 */ x25519_x86_64_mul(&z2_20_0, &t, &z2_10_0); - - /* 2^21 - 2^1 */ x25519_x86_64_square(&t, &z2_20_0); - /* 2^40 - 2^20 */ for (i = 1; i < 20; i++) { x25519_x86_64_square(&t, &t); } - /* 2^40 - 2^0 */ x25519_x86_64_mul(&t, &t, &z2_20_0); - - /* 2^41 - 2^1 */ x25519_x86_64_square(&t, &t); - /* 2^50 - 2^10 */ for (i = 1; i < 10; i++) { x25519_x86_64_square(&t, &t); } - /* 2^50 - 2^0 */ x25519_x86_64_mul(&z2_50_0, &t, &z2_10_0); - - /* 2^51 - 2^1 */ x25519_x86_64_square(&t, &z2_50_0); - /* 2^100 - 2^50 */ for (i = 1; i < 50; i++) { x25519_x86_64_square(&t, &t); } - /* 2^100 - 2^0 */ x25519_x86_64_mul(&z2_100_0, &t, &z2_50_0); - - /* 2^101 - 2^1 */ x25519_x86_64_square(&t, &z2_100_0); - /* 2^200 - 2^100 */ for (i = 1; i < 100; i++) { - x25519_x86_64_square(&t, &t); - } - /* 2^200 - 2^0 */ x25519_x86_64_mul(&t, &t, &z2_100_0); - - /* 2^201 - 2^1 */ x25519_x86_64_square(&t, &t); - /* 2^250 - 2^50 */ for (i = 1; i < 50; i++) { x25519_x86_64_square(&t, &t); } - /* 2^250 - 2^0 */ x25519_x86_64_mul(&t, &t, &z2_50_0); - - /* 2^251 - 2^1 */ x25519_x86_64_square(&t, &t); - /* 2^252 - 2^2 */ x25519_x86_64_square(&t, &t); - /* 2^253 - 2^3 */ x25519_x86_64_square(&t, &t); - - /* 2^254 - 2^4 */ x25519_x86_64_square(&t, &t); - - /* 2^255 - 2^5 */ x25519_x86_64_square(&t, &t); - /* 2^255 - 21 */ x25519_x86_64_mul(r, &t, &z11); -} - -static void mladder(fe25519 *xr, fe25519 *zr, const uint8_t s[32]) -{ - int i, j; - uint8_t prevbit = 0; - fe25519 work[5]; - - work[0] = *xr; - fe25519_setint(work + 1, 1); - fe25519_setint(work + 2, 0); - work[3] = *xr; - fe25519_setint(work + 4, 1); - - j = 6; - for (i = 31; i >= 0; i--) { - while (j >= 0) { - const uint8_t bit = 1 & (s[i] >> j); - const uint64_t swap = bit ^ prevbit; - prevbit = bit; - x25519_x86_64_work_cswap(work + 1, swap); - x25519_x86_64_ladderstep(work); - j -= 1; - } - j = 7; - } - - *xr = work[1]; - *zr = work[2]; -} -bool curve25519_amd64(u8 out[CURVE25519_POINT_SIZE], const u8 scalar[CURVE25519_POINT_SIZE], const u8 point[CURVE25519_POINT_SIZE]) -{ - fe25519 t; - fe25519 z; - uint8_t e[32]; - memcpy(e, scalar, sizeof(e)); - normalize_secret(e); - - fe25519_unpack(&t, point); - mladder(&t, &z, e); - fe25519_invert(&z, &z); - x25519_x86_64_mul(&t, &t, &z); - fe25519_pack(out, &t); - return true; -} |