/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
// This implementation was taken from the public domain, neon2 version in
// SUPERCOP by D. J. Bernstein and Peter Schwabe.
#include <openssl_grpc/poly1305.h>
#include <string.h>
#include "../internal.h"
#include "internal.h"
#if defined(OPENSSL_POLY1305_NEON)
typedef struct {
uint32_t v[12]; // for alignment; only using 10
} fe1305x2;
#define addmulmod openssl_poly1305_neon2_addmulmod
#define blocks openssl_poly1305_neon2_blocks
extern void addmulmod(fe1305x2 *r, const fe1305x2 *x, const fe1305x2 *y,
const fe1305x2 *c);
extern int blocks(fe1305x2 *h, const fe1305x2 *precomp, const uint8_t *in,
size_t inlen);
static void freeze(fe1305x2 *r) {
int i;
uint32_t x0 = r->v[0];
uint32_t x1 = r->v[2];
uint32_t x2 = r->v[4];
uint32_t x3 = r->v[6];
uint32_t x4 = r->v[8];
uint32_t y0;
uint32_t y1;
uint32_t y2;
uint32_t y3;
uint32_t y4;
uint32_t swap;
for (i = 0; i < 3; ++i) {
x1 += x0 >> 26;
x0 &= 0x3ffffff;
x2 += x1 >> 26;
x1 &= 0x3ffffff;
x3 += x2 >> 26;
x2 &= 0x3ffffff;
x4 += x3 >> 26;
x3 &= 0x3ffffff;
x0 += 5 * (x4 >> 26);
x4 &= 0x3ffffff;
}
y0 = x0 + 5;
y1 = x1 + (y0 >> 26);
y0 &= 0x3ffffff;
y2 = x2 + (y1 >> 26);
y1 &= 0x3ffffff;
y3 = x3 + (y2 >> 26);
y2 &= 0x3ffffff;
y4 = x4 + (y3 >> 26);
y3 &= 0x3ffffff;
swap = -(y4 >> 26);
y4 &= 0x3ffffff;
y0 ^= x0;
y1 ^= x1;
y2 ^= x2;
y3 ^= x3;
y4 ^= x4;
y0 &= swap;
y1 &= swap;
y2 &= swap;
y3 &= swap;
y4 &= swap;
y0 ^= x0;
y1 ^= x1;
y2 ^= x2;
y3 ^= x3;
y4 ^= x4;
r->v[0] = y0;
r->v[2] = y1;
r->v[4] = y2;
r->v[6] = y3;
r->v[8] = y4;
}
static void store32(uint8_t out[4], uint32_t v) { OPENSSL_memcpy(out, &v, 4); }
// load32 exists to avoid breaking strict aliasing rules in
// fe1305x2_frombytearray.
static uint32_t load32(const uint8_t t[4]) {
uint32_t tmp;
OPENSSL_memcpy(&tmp, t, sizeof(tmp));
return tmp;
}
static void fe1305x2_tobytearray(uint8_t r[16], fe1305x2 *x) {
uint32_t x0 = x->v[0];
uint32_t x1 = x->v[2];
uint32_t x2 = x->v[4];
uint32_t x3 = x->v[6];
uint32_t x4 = x->v[8];
x1 += x0 >> 26;
x0 &= 0x3ffffff;
x2 += x1 >> 26;
x1 &= 0x3ffffff;
x3 += x2 >> 26;
x2 &= 0x3ffffff;
x4 += x3 >> 26;
x3 &= 0x3ffffff;
store32(r, x0 + (x1 << 26));
store32(r + 4, (x1 >> 6) + (x2 << 20));
store32(r + 8, (x2 >> 12) + (x3 << 14));
store32(r + 12, (x3 >> 18) + (x4 << 8));
}
static void fe1305x2_frombytearray(fe1305x2 *r, const uint8_t *x, size_t xlen) {
size_t i;
uint8_t t[17];
for (i = 0; (i < 16) && (i < xlen); i++) {
t[i] = x[i];
}
xlen -= i;
x += i;
t[i++] = 1;
for (; i < 17; i++) {
t[i] = 0;
}
r->v[0] = 0x3ffffff & load32(t);
r->v[2] = 0x3ffffff & (load32(t + 3) >> 2);
r->v[4] = 0x3ffffff & (load32(t + 6) >> 4);
r->v[6] = 0x3ffffff & (load32(t + 9) >> 6);
r->v[8] = load32(t + 13);
if (xlen) {
for (i = 0; (i < 16) && (i < xlen); i++) {
t[i] = x[i];
}
t[i++] = 1;
for (; i < 17; i++) {
t[i] = 0;
}
r->v[1] = 0x3ffffff & load32(t);
r->v[3] = 0x3ffffff & (load32(t + 3) >> 2);
r->v[5] = 0x3ffffff & (load32(t + 6) >> 4);
r->v[7] = 0x3ffffff & (load32(t + 9) >> 6);
r->v[9] = load32(t + 13);
} else {
r->v[1] = r->v[3] = r->v[5] = r->v[7] = r->v[9] = 0;
}
}
static const alignas(16) fe1305x2 zero;
struct poly1305_state_st {
uint8_t data[sizeof(fe1305x2[5]) + 128];
uint8_t buf[32];
size_t buf_used;
uint8_t key[16];
};
OPENSSL_STATIC_ASSERT(
sizeof(struct poly1305_state_st) + 63 <= sizeof(poly1305_state),
"poly1305_state isn't large enough to hold aligned poly1305_state_st.");
void CRYPTO_poly1305_init_neon(poly1305_state *state, const uint8_t key[32]) {
struct poly1305_state_st *st = (struct poly1305_state_st *)(state);
fe1305x2 *const r = (fe1305x2 *)(st->data + (15 & (-(int)st->data)));
fe1305x2 *const h = r + 1;
fe1305x2 *const c = h + 1;
fe1305x2 *const precomp = c + 1;
r->v[1] = r->v[0] = 0x3ffffff & load32(key);
r->v[3] = r->v[2] = 0x3ffff03 & (load32(key + 3) >> 2);
r->v[5] = r->v[4] = 0x3ffc0ff & (load32(key + 6) >> 4);
r->v[7] = r->v[6] = 0x3f03fff & (load32(key + 9) >> 6);
r->v[9] = r->v[8] = 0x00fffff & (load32(key + 12) >> 8);
for (size_t j = 0; j < 10; j++) {
h->v[j] = 0; // XXX: should fast-forward a bit
}
addmulmod(precomp, r, r, &zero); // precompute r^2
addmulmod(precomp + 1, precomp, precomp, &zero); // precompute r^4
OPENSSL_memcpy(st->key, key + 16, 16);
st->buf_used = 0;
}
void CRYPTO_poly1305_update_neon(poly1305_state *state, const uint8_t *in,
size_t in_len) {
struct poly1305_state_st *st = (struct poly1305_state_st *)(state);
fe1305x2 *const r = (fe1305x2 *)(st->data + (15 & (-(int)st->data)));
fe1305x2 *const h = r + 1;
fe1305x2 *const c = h + 1;
fe1305x2 *const precomp = c + 1;
if (st->buf_used) {
size_t todo = 32 - st->buf_used;
if (todo > in_len) {
todo = in_len;
}
for (size_t i = 0; i < todo; i++) {
st->buf[st->buf_used + i] = in[i];
}
st->buf_used += todo;
in_len -= todo;
in += todo;
if (st->buf_used == sizeof(st->buf) && in_len) {
addmulmod(h, h, precomp, &zero);
fe1305x2_frombytearray(c, st->buf, sizeof(st->buf));
for (size_t i = 0; i < 10; i++) {
h->v[i] += c->v[i];
}
st->buf_used = 0;
}
}
while (in_len > 32) {
size_t tlen = 1048576;
if (in_len < tlen) {
tlen = in_len;
}
tlen -= blocks(h, precomp, in, tlen);
in_len -= tlen;
in += tlen;
}
if (in_len) {
for (size_t i = 0; i < in_len; i++) {
st->buf[i] = in[i];
}
st->buf_used = in_len;
}
}
void CRYPTO_poly1305_finish_neon(poly1305_state *state, uint8_t mac[16]) {
struct poly1305_state_st *st = (struct poly1305_state_st *)(state);
fe1305x2 *const r = (fe1305x2 *)(st->data + (15 & (-(int)st->data)));
fe1305x2 *const h = r + 1;
fe1305x2 *const c = h + 1;
fe1305x2 *const precomp = c + 1;
addmulmod(h, h, precomp, &zero);
if (st->buf_used > 16) {
fe1305x2_frombytearray(c, st->buf, st->buf_used);
precomp->v[1] = r->v[1];
precomp->v[3] = r->v[3];
precomp->v[5] = r->v[5];
precomp->v[7] = r->v[7];
precomp->v[9] = r->v[9];
addmulmod(h, h, precomp, c);
} else if (st->buf_used > 0) {
fe1305x2_frombytearray(c, st->buf, st->buf_used);
r->v[1] = 1;
r->v[3] = 0;
r->v[5] = 0;
r->v[7] = 0;
r->v[9] = 0;
addmulmod(h, h, r, c);
}
h->v[0] += h->v[1];
h->v[2] += h->v[3];
h->v[4] += h->v[5];
h->v[6] += h->v[7];
h->v[8] += h->v[9];
freeze(h);
fe1305x2_frombytearray(c, st->key, 16);
c->v[8] ^= (1 << 24);
h->v[0] += c->v[0];
h->v[2] += c->v[2];
h->v[4] += c->v[4];
h->v[6] += c->v[6];
h->v[8] += c->v[8];
fe1305x2_tobytearray(mac, h);
}
#endif // OPENSSL_POLY1305_NEON