cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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poly1305-donna64.c (3898B)

      1// SPDX-License-Identifier: GPL-2.0 OR MIT
      2/*
      3 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
      4 *
      5 * This is based in part on Andrew Moon's poly1305-donna, which is in the
      6 * public domain.
      7 */
      8
      9#include <linux/kernel.h>
     10#include <asm/unaligned.h>
     11#include <crypto/internal/poly1305.h>
     12
     13typedef __uint128_t u128;
     14
     15void poly1305_core_setkey(struct poly1305_core_key *key,
     16			  const u8 raw_key[POLY1305_BLOCK_SIZE])
     17{
     18	u64 t0, t1;
     19
     20	/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
     21	t0 = get_unaligned_le64(&raw_key[0]);
     22	t1 = get_unaligned_le64(&raw_key[8]);
     23
     24	key->key.r64[0] = t0 & 0xffc0fffffffULL;
     25	key->key.r64[1] = ((t0 >> 44) | (t1 << 20)) & 0xfffffc0ffffULL;
     26	key->key.r64[2] = ((t1 >> 24)) & 0x00ffffffc0fULL;
     27
     28	/* s = 20*r */
     29	key->precomputed_s.r64[0] = key->key.r64[1] * 20;
     30	key->precomputed_s.r64[1] = key->key.r64[2] * 20;
     31}
     32EXPORT_SYMBOL(poly1305_core_setkey);
     33
     34void poly1305_core_blocks(struct poly1305_state *state,
     35			  const struct poly1305_core_key *key, const void *src,
     36			  unsigned int nblocks, u32 hibit)
     37{
     38	const u8 *input = src;
     39	u64 hibit64;
     40	u64 r0, r1, r2;
     41	u64 s1, s2;
     42	u64 h0, h1, h2;
     43	u64 c;
     44	u128 d0, d1, d2, d;
     45
     46	if (!nblocks)
     47		return;
     48
     49	hibit64 = ((u64)hibit) << 40;
     50
     51	r0 = key->key.r64[0];
     52	r1 = key->key.r64[1];
     53	r2 = key->key.r64[2];
     54
     55	h0 = state->h64[0];
     56	h1 = state->h64[1];
     57	h2 = state->h64[2];
     58
     59	s1 = key->precomputed_s.r64[0];
     60	s2 = key->precomputed_s.r64[1];
     61
     62	do {
     63		u64 t0, t1;
     64
     65		/* h += m[i] */
     66		t0 = get_unaligned_le64(&input[0]);
     67		t1 = get_unaligned_le64(&input[8]);
     68
     69		h0 += t0 & 0xfffffffffffULL;
     70		h1 += ((t0 >> 44) | (t1 << 20)) & 0xfffffffffffULL;
     71		h2 += (((t1 >> 24)) & 0x3ffffffffffULL) | hibit64;
     72
     73		/* h *= r */
     74		d0 = (u128)h0 * r0;
     75		d = (u128)h1 * s2;
     76		d0 += d;
     77		d = (u128)h2 * s1;
     78		d0 += d;
     79		d1 = (u128)h0 * r1;
     80		d = (u128)h1 * r0;
     81		d1 += d;
     82		d = (u128)h2 * s2;
     83		d1 += d;
     84		d2 = (u128)h0 * r2;
     85		d = (u128)h1 * r1;
     86		d2 += d;
     87		d = (u128)h2 * r0;
     88		d2 += d;
     89
     90		/* (partial) h %= p */
     91		c = (u64)(d0 >> 44);
     92		h0 = (u64)d0 & 0xfffffffffffULL;
     93		d1 += c;
     94		c = (u64)(d1 >> 44);
     95		h1 = (u64)d1 & 0xfffffffffffULL;
     96		d2 += c;
     97		c = (u64)(d2 >> 42);
     98		h2 = (u64)d2 & 0x3ffffffffffULL;
     99		h0 += c * 5;
    100		c = h0 >> 44;
    101		h0 = h0 & 0xfffffffffffULL;
    102		h1 += c;
    103
    104		input += POLY1305_BLOCK_SIZE;
    105	} while (--nblocks);
    106
    107	state->h64[0] = h0;
    108	state->h64[1] = h1;
    109	state->h64[2] = h2;
    110}
    111EXPORT_SYMBOL(poly1305_core_blocks);
    112
    113void poly1305_core_emit(const struct poly1305_state *state, const u32 nonce[4],
    114			void *dst)
    115{
    116	u8 *mac = dst;
    117	u64 h0, h1, h2, c;
    118	u64 g0, g1, g2;
    119	u64 t0, t1;
    120
    121	/* fully carry h */
    122	h0 = state->h64[0];
    123	h1 = state->h64[1];
    124	h2 = state->h64[2];
    125
    126	c = h1 >> 44;
    127	h1 &= 0xfffffffffffULL;
    128	h2 += c;
    129	c = h2 >> 42;
    130	h2 &= 0x3ffffffffffULL;
    131	h0 += c * 5;
    132	c = h0 >> 44;
    133	h0 &= 0xfffffffffffULL;
    134	h1 += c;
    135	c = h1 >> 44;
    136	h1 &= 0xfffffffffffULL;
    137	h2 += c;
    138	c = h2 >> 42;
    139	h2 &= 0x3ffffffffffULL;
    140	h0 += c * 5;
    141	c = h0 >> 44;
    142	h0 &= 0xfffffffffffULL;
    143	h1 += c;
    144
    145	/* compute h + -p */
    146	g0 = h0 + 5;
    147	c  = g0 >> 44;
    148	g0 &= 0xfffffffffffULL;
    149	g1 = h1 + c;
    150	c  = g1 >> 44;
    151	g1 &= 0xfffffffffffULL;
    152	g2 = h2 + c - (1ULL << 42);
    153
    154	/* select h if h < p, or h + -p if h >= p */
    155	c = (g2 >> ((sizeof(u64) * 8) - 1)) - 1;
    156	g0 &= c;
    157	g1 &= c;
    158	g2 &= c;
    159	c  = ~c;
    160	h0 = (h0 & c) | g0;
    161	h1 = (h1 & c) | g1;
    162	h2 = (h2 & c) | g2;
    163
    164	if (likely(nonce)) {
    165		/* h = (h + nonce) */
    166		t0 = ((u64)nonce[1] << 32) | nonce[0];
    167		t1 = ((u64)nonce[3] << 32) | nonce[2];
    168
    169		h0 += t0 & 0xfffffffffffULL;
    170		c = h0 >> 44;
    171		h0 &= 0xfffffffffffULL;
    172		h1 += (((t0 >> 44) | (t1 << 20)) & 0xfffffffffffULL) + c;
    173		c = h1 >> 44;
    174		h1 &= 0xfffffffffffULL;
    175		h2 += (((t1 >> 24)) & 0x3ffffffffffULL) + c;
    176		h2 &= 0x3ffffffffffULL;
    177	}
    178
    179	/* mac = h % (2^128) */
    180	h0 = h0 | (h1 << 44);
    181	h1 = (h1 >> 20) | (h2 << 24);
    182
    183	put_unaligned_le64(h0, &mac[0]);
    184	put_unaligned_le64(h1, &mac[8]);
    185}
    186EXPORT_SYMBOL(poly1305_core_emit);