mbedtls/library/aesce.c
Yanray Wang b67b47425e Rename MBEDTLS_CIPHER_ENCRYPT_ONLY as MBEDTLS_BLOCK_CIPHER_NO_DECRYPT
Signed-off-by: Yanray Wang <yanray.wang@arm.com>
2023-10-31 17:22:06 +08:00

524 lines
17 KiB
C

/*
* Armv8-A Cryptographic Extension support functions for Aarch64
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#if defined(__aarch64__) && !defined(__ARM_FEATURE_CRYPTO) && \
defined(__clang__) && __clang_major__ >= 4
/* TODO: Re-consider above after https://reviews.llvm.org/D131064 merged.
*
* The intrinsic declaration are guarded by predefined ACLE macros in clang:
* these are normally only enabled by the -march option on the command line.
* By defining the macros ourselves we gain access to those declarations without
* requiring -march on the command line.
*
* `arm_neon.h` could be included by any header file, so we put these defines
* at the top of this file, before any includes.
*/
#define __ARM_FEATURE_CRYPTO 1
/* See: https://arm-software.github.io/acle/main/acle.html#cryptographic-extensions
*
* `__ARM_FEATURE_CRYPTO` is deprecated, but we need to continue to specify it
* for older compilers.
*/
#define __ARM_FEATURE_AES 1
#define MBEDTLS_ENABLE_ARM_CRYPTO_EXTENSIONS_COMPILER_FLAG
#endif
#include <string.h>
#include "common.h"
#if defined(MBEDTLS_AESCE_C)
#include "aesce.h"
#if defined(MBEDTLS_ARCH_IS_ARM64)
/* Compiler version checks. */
#if defined(__clang__)
# if __clang_major__ < 4
# error "Minimum version of Clang for MBEDTLS_AESCE_C is 4.0."
# endif
#elif defined(__GNUC__)
# if __GNUC__ < 6
# error "Minimum version of GCC for MBEDTLS_AESCE_C is 6.0."
# endif
#elif defined(_MSC_VER)
/* TODO: We haven't verified MSVC from 1920 to 1928. If someone verified that,
* please update this and document of `MBEDTLS_AESCE_C` in
* `mbedtls_config.h`. */
# if _MSC_VER < 1929
# error "Minimum version of MSVC for MBEDTLS_AESCE_C is 2019 version 16.11.2."
# endif
#endif
#ifdef __ARM_NEON
#include <arm_neon.h>
#else
#error "Target does not support NEON instructions"
#endif
#if !(defined(__ARM_FEATURE_CRYPTO) || defined(__ARM_FEATURE_AES)) || \
defined(MBEDTLS_ENABLE_ARM_CRYPTO_EXTENSIONS_COMPILER_FLAG)
# if defined(__ARMCOMPILER_VERSION)
# if __ARMCOMPILER_VERSION <= 6090000
# error "Must use minimum -march=armv8-a+crypto for MBEDTLS_AESCE_C"
# else
# pragma clang attribute push (__attribute__((target("aes"))), apply_to=function)
# define MBEDTLS_POP_TARGET_PRAGMA
# endif
# elif defined(__clang__)
# pragma clang attribute push (__attribute__((target("aes"))), apply_to=function)
# define MBEDTLS_POP_TARGET_PRAGMA
# elif defined(__GNUC__)
# pragma GCC push_options
# pragma GCC target ("+crypto")
# define MBEDTLS_POP_TARGET_PRAGMA
# elif defined(_MSC_VER)
# error "Required feature(__ARM_FEATURE_AES) is not enabled."
# endif
#endif /* !(__ARM_FEATURE_CRYPTO || __ARM_FEATURE_AES) ||
MBEDTLS_ENABLE_ARM_CRYPTO_EXTENSIONS_COMPILER_FLAG */
#if defined(__linux__) && !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
#include <asm/hwcap.h>
#include <sys/auxv.h>
signed char mbedtls_aesce_has_support_result = -1;
#if !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
/*
* AES instruction support detection routine
*/
int mbedtls_aesce_has_support_impl(void)
{
/* To avoid many calls to getauxval, cache the result. This is
* thread-safe, because we store the result in a char so cannot
* be vulnerable to non-atomic updates.
* It is possible that we could end up setting result more than
* once, but that is harmless.
*/
if (mbedtls_aesce_has_support_result == -1) {
unsigned long auxval = getauxval(AT_HWCAP);
if ((auxval & (HWCAP_ASIMD | HWCAP_AES)) ==
(HWCAP_ASIMD | HWCAP_AES)) {
mbedtls_aesce_has_support_result = 1;
} else {
mbedtls_aesce_has_support_result = 0;
}
}
return mbedtls_aesce_has_support_result;
}
#endif
#endif /* defined(__linux__) && !defined(MBEDTLS_AES_USE_HARDWARE_ONLY) */
/* Single round of AESCE encryption */
#define AESCE_ENCRYPT_ROUND \
block = vaeseq_u8(block, vld1q_u8(keys)); \
block = vaesmcq_u8(block); \
keys += 16
/* Two rounds of AESCE encryption */
#define AESCE_ENCRYPT_ROUND_X2 AESCE_ENCRYPT_ROUND; AESCE_ENCRYPT_ROUND
MBEDTLS_OPTIMIZE_FOR_PERFORMANCE
static uint8x16_t aesce_encrypt_block(uint8x16_t block,
unsigned char *keys,
int rounds)
{
/* 10, 12 or 14 rounds. Unroll loop. */
if (rounds == 10) {
goto rounds_10;
}
if (rounds == 12) {
goto rounds_12;
}
AESCE_ENCRYPT_ROUND_X2;
rounds_12:
AESCE_ENCRYPT_ROUND_X2;
rounds_10:
AESCE_ENCRYPT_ROUND_X2;
AESCE_ENCRYPT_ROUND_X2;
AESCE_ENCRYPT_ROUND_X2;
AESCE_ENCRYPT_ROUND_X2;
AESCE_ENCRYPT_ROUND;
/* AES AddRoundKey for the previous round.
* SubBytes, ShiftRows for the final round. */
block = vaeseq_u8(block, vld1q_u8(keys));
keys += 16;
/* Final round: no MixColumns */
/* Final AddRoundKey */
block = veorq_u8(block, vld1q_u8(keys));
return block;
}
/* Single round of AESCE decryption
*
* AES AddRoundKey, SubBytes, ShiftRows
*
* block = vaesdq_u8(block, vld1q_u8(keys));
*
* AES inverse MixColumns for the next round.
*
* This means that we switch the order of the inverse AddRoundKey and
* inverse MixColumns operations. We have to do this as AddRoundKey is
* done in an atomic instruction together with the inverses of SubBytes
* and ShiftRows.
*
* It works because MixColumns is a linear operation over GF(2^8) and
* AddRoundKey is an exclusive or, which is equivalent to addition over
* GF(2^8). (The inverse of MixColumns needs to be applied to the
* affected round keys separately which has been done when the
* decryption round keys were calculated.)
*
* block = vaesimcq_u8(block);
*/
#define AESCE_DECRYPT_ROUND \
block = vaesdq_u8(block, vld1q_u8(keys)); \
block = vaesimcq_u8(block); \
keys += 16
/* Two rounds of AESCE decryption */
#define AESCE_DECRYPT_ROUND_X2 AESCE_DECRYPT_ROUND; AESCE_DECRYPT_ROUND
#if !defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
static uint8x16_t aesce_decrypt_block(uint8x16_t block,
unsigned char *keys,
int rounds)
{
/* 10, 12 or 14 rounds. Unroll loop. */
if (rounds == 10) {
goto rounds_10;
}
if (rounds == 12) {
goto rounds_12;
}
AESCE_DECRYPT_ROUND_X2;
rounds_12:
AESCE_DECRYPT_ROUND_X2;
rounds_10:
AESCE_DECRYPT_ROUND_X2;
AESCE_DECRYPT_ROUND_X2;
AESCE_DECRYPT_ROUND_X2;
AESCE_DECRYPT_ROUND_X2;
AESCE_DECRYPT_ROUND;
/* The inverses of AES AddRoundKey, SubBytes, ShiftRows finishing up the
* last full round. */
block = vaesdq_u8(block, vld1q_u8(keys));
keys += 16;
/* Inverse AddRoundKey for inverting the initial round key addition. */
block = veorq_u8(block, vld1q_u8(keys));
return block;
}
#endif
/*
* AES-ECB block en(de)cryption
*/
int mbedtls_aesce_crypt_ecb(mbedtls_aes_context *ctx,
int mode,
const unsigned char input[16],
unsigned char output[16])
{
uint8x16_t block = vld1q_u8(&input[0]);
unsigned char *keys = (unsigned char *) (ctx->buf + ctx->rk_offset);
#if !defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
if (mode == MBEDTLS_AES_ENCRYPT) {
block = aesce_encrypt_block(block, keys, ctx->nr);
} else {
block = aesce_decrypt_block(block, keys, ctx->nr);
}
#else
(void) mode;
block = aesce_encrypt_block(block, keys, ctx->nr);
#endif /* !MBEDTLS_BLOCK_CIPHER_NO_DECRYPT */
vst1q_u8(&output[0], block);
return 0;
}
/*
* Compute decryption round keys from encryption round keys
*/
#if !defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
void mbedtls_aesce_inverse_key(unsigned char *invkey,
const unsigned char *fwdkey,
int nr)
{
int i, j;
j = nr;
vst1q_u8(invkey, vld1q_u8(fwdkey + j * 16));
for (i = 1, j--; j > 0; i++, j--) {
vst1q_u8(invkey + i * 16,
vaesimcq_u8(vld1q_u8(fwdkey + j * 16)));
}
vst1q_u8(invkey + i * 16, vld1q_u8(fwdkey + j * 16));
}
#endif
static inline uint32_t aes_rot_word(uint32_t word)
{
return (word << (32 - 8)) | (word >> 8);
}
static inline uint32_t aes_sub_word(uint32_t in)
{
uint8x16_t v = vreinterpretq_u8_u32(vdupq_n_u32(in));
uint8x16_t zero = vdupq_n_u8(0);
/* vaeseq_u8 does both SubBytes and ShiftRows. Taking the first row yields
* the correct result as ShiftRows doesn't change the first row. */
v = vaeseq_u8(zero, v);
return vgetq_lane_u32(vreinterpretq_u32_u8(v), 0);
}
/*
* Key expansion function
*/
static void aesce_setkey_enc(unsigned char *rk,
const unsigned char *key,
const size_t key_bit_length)
{
static uint8_t const rcon[] = { 0x01, 0x02, 0x04, 0x08, 0x10,
0x20, 0x40, 0x80, 0x1b, 0x36 };
/* See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.197.pdf
* - Section 5, Nr = Nk + 6
* - Section 5.2, the length of round keys is Nb*(Nr+1)
*/
const uint32_t key_len_in_words = key_bit_length / 32; /* Nk */
const size_t round_key_len_in_words = 4; /* Nb */
const size_t rounds_needed = key_len_in_words + 6; /* Nr */
const size_t round_keys_len_in_words =
round_key_len_in_words * (rounds_needed + 1); /* Nb*(Nr+1) */
const uint32_t *rko_end = (uint32_t *) rk + round_keys_len_in_words;
memcpy(rk, key, key_len_in_words * 4);
for (uint32_t *rki = (uint32_t *) rk;
rki + key_len_in_words < rko_end;
rki += key_len_in_words) {
size_t iteration = (rki - (uint32_t *) rk) / key_len_in_words;
uint32_t *rko;
rko = rki + key_len_in_words;
rko[0] = aes_rot_word(aes_sub_word(rki[key_len_in_words - 1]));
rko[0] ^= rcon[iteration] ^ rki[0];
rko[1] = rko[0] ^ rki[1];
rko[2] = rko[1] ^ rki[2];
rko[3] = rko[2] ^ rki[3];
if (rko + key_len_in_words > rko_end) {
/* Do not write overflow words.*/
continue;
}
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
switch (key_bit_length) {
case 128:
break;
case 192:
rko[4] = rko[3] ^ rki[4];
rko[5] = rko[4] ^ rki[5];
break;
case 256:
rko[4] = aes_sub_word(rko[3]) ^ rki[4];
rko[5] = rko[4] ^ rki[5];
rko[6] = rko[5] ^ rki[6];
rko[7] = rko[6] ^ rki[7];
break;
}
#endif /* !MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH */
}
}
/*
* Key expansion, wrapper
*/
int mbedtls_aesce_setkey_enc(unsigned char *rk,
const unsigned char *key,
size_t bits)
{
switch (bits) {
case 128:
case 192:
case 256:
aesce_setkey_enc(rk, key, bits);
break;
default:
return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
}
return 0;
}
#if defined(MBEDTLS_GCM_C)
#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ == 5
/* Some intrinsics are not available for GCC 5.X. */
#define vreinterpretq_p64_u8(a) ((poly64x2_t) a)
#define vreinterpretq_u8_p128(a) ((uint8x16_t) a)
static inline poly64_t vget_low_p64(poly64x2_t __a)
{
uint64x2_t tmp = (uint64x2_t) (__a);
uint64x1_t lo = vcreate_u64(vgetq_lane_u64(tmp, 0));
return (poly64_t) (lo);
}
#endif /* !__clang__ && __GNUC__ && __GNUC__ == 5*/
/* vmull_p64/vmull_high_p64 wrappers.
*
* Older compilers miss some intrinsic functions for `poly*_t`. We use
* uint8x16_t and uint8x16x3_t as input/output parameters.
*/
#if defined(__GNUC__) && !defined(__clang__)
/* GCC reports incompatible type error without cast. GCC think poly64_t and
* poly64x1_t are different, that is different with MSVC and Clang. */
#define MBEDTLS_VMULL_P64(a, b) vmull_p64((poly64_t) a, (poly64_t) b)
#else
/* MSVC reports `error C2440: 'type cast'` with cast. Clang does not report
* error with/without cast. And I think poly64_t and poly64x1_t are same, no
* cast for clang also. */
#define MBEDTLS_VMULL_P64(a, b) vmull_p64(a, b)
#endif
static inline uint8x16_t pmull_low(uint8x16_t a, uint8x16_t b)
{
return vreinterpretq_u8_p128(
MBEDTLS_VMULL_P64(
vget_low_p64(vreinterpretq_p64_u8(a)),
vget_low_p64(vreinterpretq_p64_u8(b))
));
}
static inline uint8x16_t pmull_high(uint8x16_t a, uint8x16_t b)
{
return vreinterpretq_u8_p128(
vmull_high_p64(vreinterpretq_p64_u8(a),
vreinterpretq_p64_u8(b)));
}
/* GHASH does 128b polynomial multiplication on block in GF(2^128) defined by
* `x^128 + x^7 + x^2 + x + 1`.
*
* Arm64 only has 64b->128b polynomial multipliers, we need to do 4 64b
* multiplies to generate a 128b.
*
* `poly_mult_128` executes polynomial multiplication and outputs 256b that
* represented by 3 128b due to code size optimization.
*
* Output layout:
* | | | |
* |------------|-------------|-------------|
* | ret.val[0] | h3:h2:00:00 | high 128b |
* | ret.val[1] | :m2:m1:00 | middle 128b |
* | ret.val[2] | : :l1:l0 | low 128b |
*/
static inline uint8x16x3_t poly_mult_128(uint8x16_t a, uint8x16_t b)
{
uint8x16x3_t ret;
uint8x16_t h, m, l; /* retval high/middle/low */
uint8x16_t c, d, e;
h = pmull_high(a, b); /* h3:h2:00:00 = a1*b1 */
l = pmull_low(a, b); /* : :l1:l0 = a0*b0 */
c = vextq_u8(b, b, 8); /* :c1:c0 = b0:b1 */
d = pmull_high(a, c); /* :d2:d1:00 = a1*b0 */
e = pmull_low(a, c); /* :e2:e1:00 = a0*b1 */
m = veorq_u8(d, e); /* :m2:m1:00 = d + e */
ret.val[0] = h;
ret.val[1] = m;
ret.val[2] = l;
return ret;
}
/*
* Modulo reduction.
*
* See: https://www.researchgate.net/publication/285612706_Implementing_GCM_on_ARMv8
*
* Section 4.3
*
* Modular reduction is slightly more complex. Write the GCM modulus as f(z) =
* z^128 +r(z), where r(z) = z^7+z^2+z+ 1. The well known approach is to
* consider that z^128 ≡r(z) (mod z^128 +r(z)), allowing us to write the 256-bit
* operand to be reduced as a(z) = h(z)z^128 +l(z)≡h(z)r(z) + l(z). That is, we
* simply multiply the higher part of the operand by r(z) and add it to l(z). If
* the result is still larger than 128 bits, we reduce again.
*/
static inline uint8x16_t poly_mult_reduce(uint8x16x3_t input)
{
uint8x16_t const ZERO = vdupq_n_u8(0);
uint64x2_t r = vreinterpretq_u64_u8(vdupq_n_u8(0x87));
#if defined(__GNUC__)
/* use 'asm' as an optimisation barrier to prevent loading MODULO from
* memory. It is for GNUC compatible compilers.
*/
asm ("" : "+w" (r));
#endif
uint8x16_t const MODULO = vreinterpretq_u8_u64(vshrq_n_u64(r, 64 - 8));
uint8x16_t h, m, l; /* input high/middle/low 128b */
uint8x16_t c, d, e, f, g, n, o;
h = input.val[0]; /* h3:h2:00:00 */
m = input.val[1]; /* :m2:m1:00 */
l = input.val[2]; /* : :l1:l0 */
c = pmull_high(h, MODULO); /* :c2:c1:00 = reduction of h3 */
d = pmull_low(h, MODULO); /* : :d1:d0 = reduction of h2 */
e = veorq_u8(c, m); /* :e2:e1:00 = m2:m1:00 + c2:c1:00 */
f = pmull_high(e, MODULO); /* : :f1:f0 = reduction of e2 */
g = vextq_u8(ZERO, e, 8); /* : :g1:00 = e1:00 */
n = veorq_u8(d, l); /* : :n1:n0 = d1:d0 + l1:l0 */
o = veorq_u8(n, f); /* o1:o0 = f1:f0 + n1:n0 */
return veorq_u8(o, g); /* = o1:o0 + g1:00 */
}
/*
* GCM multiplication: c = a times b in GF(2^128)
*/
void mbedtls_aesce_gcm_mult(unsigned char c[16],
const unsigned char a[16],
const unsigned char b[16])
{
uint8x16_t va, vb, vc;
va = vrbitq_u8(vld1q_u8(&a[0]));
vb = vrbitq_u8(vld1q_u8(&b[0]));
vc = vrbitq_u8(poly_mult_reduce(poly_mult_128(va, vb)));
vst1q_u8(&c[0], vc);
}
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_POP_TARGET_PRAGMA)
#if defined(__clang__)
#pragma clang attribute pop
#elif defined(__GNUC__)
#pragma GCC pop_options
#endif
#undef MBEDTLS_POP_TARGET_PRAGMA
#endif
#endif /* MBEDTLS_ARCH_IS_ARM64 */
#endif /* MBEDTLS_AESCE_C */