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ternfs-XTXMarkets/cpp/core/Crypto.cpp
2025-09-17 18:20:23 +01:00

113 lines
3.5 KiB
C++

// Copyright 2016 Intel Corporation
// Copyright 2025 XTX Markets Technologies Limited
//
// SPDX-License-Identifier: Apache-2.0
#include <emmintrin.h>
#include <wmmintrin.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include "Crypto.hpp"
#include "Exception.hpp"
void generateSecretKey(std::array<uint8_t, 16>& key) {
int ret = getentropy(key.data(), 16);
if (ret != 0) {
throw SYSCALL_EXCEPTION("getentropy");
}
}
// adapted from the Intel Cryptography Primitives Library
static inline __m128i aes128_assist(__m128i temp1, __m128i temp2) {
__m128i temp3;
temp2 = _mm_shuffle_epi32(temp2 ,0xff);
temp3 = _mm_slli_si128(temp1, 0x4);
temp1 = _mm_xor_si128(temp1, temp3);
temp3 = _mm_slli_si128(temp3, 0x4);
temp1 = _mm_xor_si128(temp1, temp3);
temp3 = _mm_slli_si128(temp3, 0x4);
temp1 = _mm_xor_si128(temp1, temp3);
temp1 = _mm_xor_si128(temp1, temp2);
return temp1;
}
// adapted from the Intel Cryptography Primitives Library
void expandKey(const std::array<uint8_t, 16>& userKey, AES128Key& key) {
__m128i temp1, temp2;
__m128i *k = (__m128i*)key.key;
temp1 = _mm_loadu_si128((__m128i*)userKey.data());
k[0] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x1);
temp1 = aes128_assist(temp1, temp2);
k[1] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x2);
temp1 = aes128_assist(temp1, temp2);
k[2] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x4);
temp1 = aes128_assist(temp1, temp2);
k[3] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x8);
temp1 = aes128_assist(temp1, temp2);
k[4] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x10);
temp1 = aes128_assist(temp1, temp2);
k[5] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x20);
temp1 = aes128_assist(temp1, temp2);
k[6] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x40);
temp1 = aes128_assist(temp1, temp2);
k[7] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x80);
temp1 = aes128_assist(temp1, temp2);
k[8] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x1b);
temp1 = aes128_assist(temp1, temp2);
k[9] = temp1;
temp2 = _mm_aeskeygenassist_si128(temp1, 0x36);
temp1 = aes128_assist(temp1, temp2);
k[10] = temp1;
}
std::array<uint8_t, 8> cbcmac(const AES128Key& key, const uint8_t* data, size_t len) {
// load key
__m128i xmmKey[11];
for (int i = 0; i < 11; i++) {
xmmKey[i] = _mm_load_si128((__m128i*)(&key) + i);
}
// CBC MAC step
__m128i block = _mm_setzero_si128();
__m128i dataBlock;
auto step = [&xmmKey, &block, &dataBlock]() {
// CBC xor
block = _mm_xor_si128(block, dataBlock);
// encrypt
block = _mm_xor_si128(block, xmmKey[0]); // Whitening step (Round 0)
for (int i = 1; i < 10; i++) {
block = _mm_aesenc_si128(block, xmmKey[i]); // Round i
}
block = _mm_aesenclast_si128(block, xmmKey[10]); // Round 10
};
// unpadded load
size_t i = 0;
for (; len-i >= 16; i += 16) {
dataBlock = _mm_loadu_si128((__m128i*)(data+i));
step();
}
// zero-padded load
ALIGNED(16) uint8_t scratch[16];
if (len-i > 0) {
memset(scratch, 0, 16);
memcpy(scratch, data+i, len-i);
dataBlock = _mm_load_si128((__m128i*)scratch);
step();
}
// extract MAC
_mm_store_si128((__m128i*)scratch, block);
std::array<uint8_t, 8> mac;
memcpy(mac.data(), scratch, 8);
return mac;
}