linux-stable/crypto/aegis128-neon-inner.c
Ard Biesheuvel 97b70180b7 crypto: aegis128/neon - move final tag check to SIMD domain
Instead of calculating the tag and returning it to the caller on
decryption, use a SIMD compare and min across vector to perform
the comparison. This is slightly more efficient, and removes the
need on the caller's part to wipe the tag from memory if the
decryption failed.

While at it, switch to unsigned int when passing cryptlen and
assoclen - we don't support input sizes where it matters anyway.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-11-27 17:13:40 +11:00

344 lines
8.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
*/
#ifdef CONFIG_ARM64
#include <asm/neon-intrinsics.h>
#define AES_ROUND "aese %0.16b, %1.16b \n\t aesmc %0.16b, %0.16b"
#else
#include <arm_neon.h>
#define AES_ROUND "aese.8 %q0, %q1 \n\t aesmc.8 %q0, %q0"
#endif
#define AEGIS_BLOCK_SIZE 16
#include <stddef.h>
extern int aegis128_have_aes_insn;
void *memcpy(void *dest, const void *src, size_t n);
struct aegis128_state {
uint8x16_t v[5];
};
extern const uint8_t crypto_aes_sbox[];
static struct aegis128_state aegis128_load_state_neon(const void *state)
{
return (struct aegis128_state){ {
vld1q_u8(state),
vld1q_u8(state + 16),
vld1q_u8(state + 32),
vld1q_u8(state + 48),
vld1q_u8(state + 64)
} };
}
static void aegis128_save_state_neon(struct aegis128_state st, void *state)
{
vst1q_u8(state, st.v[0]);
vst1q_u8(state + 16, st.v[1]);
vst1q_u8(state + 32, st.v[2]);
vst1q_u8(state + 48, st.v[3]);
vst1q_u8(state + 64, st.v[4]);
}
static inline __attribute__((always_inline))
uint8x16_t aegis_aes_round(uint8x16_t w)
{
uint8x16_t z = {};
#ifdef CONFIG_ARM64
if (!__builtin_expect(aegis128_have_aes_insn, 1)) {
static const uint8_t shift_rows[] = {
0x0, 0x5, 0xa, 0xf, 0x4, 0x9, 0xe, 0x3,
0x8, 0xd, 0x2, 0x7, 0xc, 0x1, 0x6, 0xb,
};
static const uint8_t ror32by8[] = {
0x1, 0x2, 0x3, 0x0, 0x5, 0x6, 0x7, 0x4,
0x9, 0xa, 0xb, 0x8, 0xd, 0xe, 0xf, 0xc,
};
uint8x16_t v;
// shift rows
w = vqtbl1q_u8(w, vld1q_u8(shift_rows));
// sub bytes
#ifndef CONFIG_CC_IS_GCC
v = vqtbl4q_u8(vld1q_u8_x4(crypto_aes_sbox), w);
v = vqtbx4q_u8(v, vld1q_u8_x4(crypto_aes_sbox + 0x40), w - 0x40);
v = vqtbx4q_u8(v, vld1q_u8_x4(crypto_aes_sbox + 0x80), w - 0x80);
v = vqtbx4q_u8(v, vld1q_u8_x4(crypto_aes_sbox + 0xc0), w - 0xc0);
#else
asm("tbl %0.16b, {v16.16b-v19.16b}, %1.16b" : "=w"(v) : "w"(w));
w -= 0x40;
asm("tbx %0.16b, {v20.16b-v23.16b}, %1.16b" : "+w"(v) : "w"(w));
w -= 0x40;
asm("tbx %0.16b, {v24.16b-v27.16b}, %1.16b" : "+w"(v) : "w"(w));
w -= 0x40;
asm("tbx %0.16b, {v28.16b-v31.16b}, %1.16b" : "+w"(v) : "w"(w));
#endif
// mix columns
w = (v << 1) ^ (uint8x16_t)(((int8x16_t)v >> 7) & 0x1b);
w ^= (uint8x16_t)vrev32q_u16((uint16x8_t)v);
w ^= vqtbl1q_u8(v ^ w, vld1q_u8(ror32by8));
return w;
}
#endif
/*
* We use inline asm here instead of the vaeseq_u8/vaesmcq_u8 intrinsics
* to force the compiler to issue the aese/aesmc instructions in pairs.
* This is much faster on many cores, where the instruction pair can
* execute in a single cycle.
*/
asm(AES_ROUND : "+w"(w) : "w"(z));
return w;
}
static inline __attribute__((always_inline))
struct aegis128_state aegis128_update_neon(struct aegis128_state st,
uint8x16_t m)
{
m ^= aegis_aes_round(st.v[4]);
st.v[4] ^= aegis_aes_round(st.v[3]);
st.v[3] ^= aegis_aes_round(st.v[2]);
st.v[2] ^= aegis_aes_round(st.v[1]);
st.v[1] ^= aegis_aes_round(st.v[0]);
st.v[0] ^= m;
return st;
}
static inline __attribute__((always_inline))
void preload_sbox(void)
{
if (!IS_ENABLED(CONFIG_ARM64) ||
!IS_ENABLED(CONFIG_CC_IS_GCC) ||
__builtin_expect(aegis128_have_aes_insn, 1))
return;
asm("ld1 {v16.16b-v19.16b}, [%0], #64 \n\t"
"ld1 {v20.16b-v23.16b}, [%0], #64 \n\t"
"ld1 {v24.16b-v27.16b}, [%0], #64 \n\t"
"ld1 {v28.16b-v31.16b}, [%0] \n\t"
:: "r"(crypto_aes_sbox));
}
void crypto_aegis128_init_neon(void *state, const void *key, const void *iv)
{
static const uint8_t const0[] = {
0x00, 0x01, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d,
0x15, 0x22, 0x37, 0x59, 0x90, 0xe9, 0x79, 0x62,
};
static const uint8_t const1[] = {
0xdb, 0x3d, 0x18, 0x55, 0x6d, 0xc2, 0x2f, 0xf1,
0x20, 0x11, 0x31, 0x42, 0x73, 0xb5, 0x28, 0xdd,
};
uint8x16_t k = vld1q_u8(key);
uint8x16_t kiv = k ^ vld1q_u8(iv);
struct aegis128_state st = {{
kiv,
vld1q_u8(const1),
vld1q_u8(const0),
k ^ vld1q_u8(const0),
k ^ vld1q_u8(const1),
}};
int i;
preload_sbox();
for (i = 0; i < 5; i++) {
st = aegis128_update_neon(st, k);
st = aegis128_update_neon(st, kiv);
}
aegis128_save_state_neon(st, state);
}
void crypto_aegis128_update_neon(void *state, const void *msg)
{
struct aegis128_state st = aegis128_load_state_neon(state);
preload_sbox();
st = aegis128_update_neon(st, vld1q_u8(msg));
aegis128_save_state_neon(st, state);
}
#ifdef CONFIG_ARM
/*
* AArch32 does not provide these intrinsics natively because it does not
* implement the underlying instructions. AArch32 only provides 64-bit
* wide vtbl.8/vtbx.8 instruction, so use those instead.
*/
static uint8x16_t vqtbl1q_u8(uint8x16_t a, uint8x16_t b)
{
union {
uint8x16_t val;
uint8x8x2_t pair;
} __a = { a };
return vcombine_u8(vtbl2_u8(__a.pair, vget_low_u8(b)),
vtbl2_u8(__a.pair, vget_high_u8(b)));
}
static uint8x16_t vqtbx1q_u8(uint8x16_t v, uint8x16_t a, uint8x16_t b)
{
union {
uint8x16_t val;
uint8x8x2_t pair;
} __a = { a };
return vcombine_u8(vtbx2_u8(vget_low_u8(v), __a.pair, vget_low_u8(b)),
vtbx2_u8(vget_high_u8(v), __a.pair, vget_high_u8(b)));
}
static int8_t vminvq_s8(int8x16_t v)
{
int8x8_t s = vpmin_s8(vget_low_s8(v), vget_high_s8(v));
s = vpmin_s8(s, s);
s = vpmin_s8(s, s);
s = vpmin_s8(s, s);
return vget_lane_s8(s, 0);
}
#endif
static const uint8_t permute[] __aligned(64) = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
void crypto_aegis128_encrypt_chunk_neon(void *state, void *dst, const void *src,
unsigned int size)
{
struct aegis128_state st = aegis128_load_state_neon(state);
const int short_input = size < AEGIS_BLOCK_SIZE;
uint8x16_t msg;
preload_sbox();
while (size >= AEGIS_BLOCK_SIZE) {
uint8x16_t s = st.v[1] ^ (st.v[2] & st.v[3]) ^ st.v[4];
msg = vld1q_u8(src);
st = aegis128_update_neon(st, msg);
msg ^= s;
vst1q_u8(dst, msg);
size -= AEGIS_BLOCK_SIZE;
src += AEGIS_BLOCK_SIZE;
dst += AEGIS_BLOCK_SIZE;
}
if (size > 0) {
uint8x16_t s = st.v[1] ^ (st.v[2] & st.v[3]) ^ st.v[4];
uint8_t buf[AEGIS_BLOCK_SIZE];
const void *in = src;
void *out = dst;
uint8x16_t m;
if (__builtin_expect(short_input, 0))
in = out = memcpy(buf + AEGIS_BLOCK_SIZE - size, src, size);
m = vqtbl1q_u8(vld1q_u8(in + size - AEGIS_BLOCK_SIZE),
vld1q_u8(permute + 32 - size));
st = aegis128_update_neon(st, m);
vst1q_u8(out + size - AEGIS_BLOCK_SIZE,
vqtbl1q_u8(m ^ s, vld1q_u8(permute + size)));
if (__builtin_expect(short_input, 0))
memcpy(dst, out, size);
else
vst1q_u8(out - AEGIS_BLOCK_SIZE, msg);
}
aegis128_save_state_neon(st, state);
}
void crypto_aegis128_decrypt_chunk_neon(void *state, void *dst, const void *src,
unsigned int size)
{
struct aegis128_state st = aegis128_load_state_neon(state);
const int short_input = size < AEGIS_BLOCK_SIZE;
uint8x16_t msg;
preload_sbox();
while (size >= AEGIS_BLOCK_SIZE) {
msg = vld1q_u8(src) ^ st.v[1] ^ (st.v[2] & st.v[3]) ^ st.v[4];
st = aegis128_update_neon(st, msg);
vst1q_u8(dst, msg);
size -= AEGIS_BLOCK_SIZE;
src += AEGIS_BLOCK_SIZE;
dst += AEGIS_BLOCK_SIZE;
}
if (size > 0) {
uint8x16_t s = st.v[1] ^ (st.v[2] & st.v[3]) ^ st.v[4];
uint8_t buf[AEGIS_BLOCK_SIZE];
const void *in = src;
void *out = dst;
uint8x16_t m;
if (__builtin_expect(short_input, 0))
in = out = memcpy(buf + AEGIS_BLOCK_SIZE - size, src, size);
m = s ^ vqtbx1q_u8(s, vld1q_u8(in + size - AEGIS_BLOCK_SIZE),
vld1q_u8(permute + 32 - size));
st = aegis128_update_neon(st, m);
vst1q_u8(out + size - AEGIS_BLOCK_SIZE,
vqtbl1q_u8(m, vld1q_u8(permute + size)));
if (__builtin_expect(short_input, 0))
memcpy(dst, out, size);
else
vst1q_u8(out - AEGIS_BLOCK_SIZE, msg);
}
aegis128_save_state_neon(st, state);
}
int crypto_aegis128_final_neon(void *state, void *tag_xor,
unsigned int assoclen,
unsigned int cryptlen,
unsigned int authsize)
{
struct aegis128_state st = aegis128_load_state_neon(state);
uint8x16_t v;
int i;
preload_sbox();
v = st.v[3] ^ (uint8x16_t)vcombine_u64(vmov_n_u64(8ULL * assoclen),
vmov_n_u64(8ULL * cryptlen));
for (i = 0; i < 7; i++)
st = aegis128_update_neon(st, v);
v = st.v[0] ^ st.v[1] ^ st.v[2] ^ st.v[3] ^ st.v[4];
if (authsize > 0) {
v = vqtbl1q_u8(~vceqq_u8(v, vld1q_u8(tag_xor)),
vld1q_u8(permute + authsize));
return vminvq_s8((int8x16_t)v);
}
vst1q_u8(tag_xor, v);
return 0;
}