| /* |
| * 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_HAVE_ARM64) |
| |
| #if !defined(__ARM_FEATURE_AES) || defined(MBEDTLS_ENABLE_ARM_CRYPTO_EXTENSIONS_COMPILER_FLAG) |
| # if defined(__clang__) |
| # if __clang_major__ < 4 |
| # error "A more recent Clang is required for MBEDTLS_AESCE_C" |
| # endif |
| # pragma clang attribute push (__attribute__((target("crypto"))), apply_to=function) |
| # define MBEDTLS_POP_TARGET_PRAGMA |
| # elif defined(__GNUC__) |
| # if __GNUC__ < 6 |
| # error "A more recent GCC is required for MBEDTLS_AESCE_C" |
| # endif |
| # pragma GCC push_options |
| # pragma GCC target ("arch=armv8-a+crypto") |
| # define MBEDTLS_POP_TARGET_PRAGMA |
| # else |
| # error "Only GCC and Clang supported for MBEDTLS_AESCE_C" |
| # endif |
| #endif /* !__ARM_FEATURE_AES || MBEDTLS_ENABLE_ARM_CRYPTO_EXTENSIONS_COMPILER_FLAG */ |
| |
| #include <arm_neon.h> |
| |
| #if defined(__linux__) |
| #include <asm/hwcap.h> |
| #include <sys/auxv.h> |
| #endif |
| |
| /* |
| * AES instruction support detection routine |
| */ |
| int mbedtls_aesce_has_support(void) |
| { |
| #if defined(__linux__) |
| unsigned long auxval = getauxval(AT_HWCAP); |
| return (auxval & (HWCAP_ASIMD | HWCAP_AES)) == |
| (HWCAP_ASIMD | HWCAP_AES); |
| #else |
| /* Assume AES instructions are supported. */ |
| return 1; |
| #endif |
| } |
| |
| static uint8x16_t aesce_encrypt_block(uint8x16_t block, |
| unsigned char *keys, |
| int rounds) |
| { |
| for (int i = 0; i < rounds - 1; i++) { |
| /* AES AddRoundKey, SubBytes, ShiftRows (in this order). |
| * AddRoundKey adds the round key for the previous round. */ |
| block = vaeseq_u8(block, vld1q_u8(keys + i * 16)); |
| /* AES mix columns */ |
| block = vaesmcq_u8(block); |
| } |
| |
| /* AES AddRoundKey for the previous round. |
| * SubBytes, ShiftRows for the final round. */ |
| block = vaeseq_u8(block, vld1q_u8(keys + (rounds -1) * 16)); |
| |
| /* Final round: no MixColumns */ |
| |
| /* Final AddRoundKey */ |
| block = veorq_u8(block, vld1q_u8(keys + rounds * 16)); |
| |
| return block; |
| } |
| |
| static uint8x16_t aesce_decrypt_block(uint8x16_t block, |
| unsigned char *keys, |
| int rounds) |
| { |
| |
| for (int i = 0; i < rounds - 1; i++) { |
| /* AES AddRoundKey, SubBytes, ShiftRows */ |
| block = vaesdq_u8(block, vld1q_u8(keys + i * 16)); |
| /* 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); |
| } |
| |
| /* The inverses of AES AddRoundKey, SubBytes, ShiftRows finishing up the |
| * last full round. */ |
| block = vaesdq_u8(block, vld1q_u8(keys + (rounds - 1) * 16)); |
| |
| /* Inverse AddRoundKey for inverting the initial round key addition. */ |
| block = veorq_u8(block, vld1q_u8(keys + rounds * 16)); |
| |
| return block; |
| } |
| |
| /* |
| * 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 (mode == MBEDTLS_AES_ENCRYPT) { |
| block = aesce_encrypt_block(block, keys, ctx->nr); |
| } else { |
| block = aesce_decrypt_block(block, keys, ctx->nr); |
| } |
| vst1q_u8(&output[0], block); |
| |
| return 0; |
| } |
| |
| /* |
| * Compute decryption round keys from encryption round keys |
| */ |
| 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)); |
| |
| } |
| |
| 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; |
| } |
| 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; |
| } |
| } |
| } |
| |
| /* |
| * 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. |
| */ |
| static inline uint8x16_t pmull_low(uint8x16_t a, uint8x16_t b) |
| { |
| return vreinterpretq_u8_p128( |
| vmull_p64( |
| (poly64_t) vget_low_p64(vreinterpretq_p64_u8(a)), |
| (poly64_t) 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); |
| /* use 'asm' as an optimisation barrier to prevent loading MODULO from memory */ |
| uint64x2_t r = vreinterpretq_u64_u8(vdupq_n_u8(0x87)); |
| asm ("" : "+w" (r)); |
| 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_HAVE_ARM64 */ |
| |
| #endif /* MBEDTLS_AESCE_C */ |
