I would like to accelerate my application by using AES-NI, by I am struggling to find any example that works with GCC or the assembler that comes with it. I am not interested in using SSL or any other library.
Thanks to Mr Glisse comment I could use some piece of code from Vincent Hanquez blog (the only info missing there is the need to include the magic header file and the magic command line arguments)
I reworked it a bit according to my taste:
#ifndef __AES_NI_H__
#define __AES_NI_H__
#include <stdint.h> //for int8_t
#include <string.h> //for memcmp
#include <wmmintrin.h> //for intrinsics for AES-NI
//compile using gcc and following arguments: -g;-O0;-Wall;-msse2;-msse;-march=native;-maes
//internal stuff
//macros
#define DO_ENC_BLOCK(m,k) \
do{\
m = _mm_xor_si128 (m, k[ 0]); \
m = _mm_aesenc_si128 (m, k[ 1]); \
m = _mm_aesenc_si128 (m, k[ 2]); \
m = _mm_aesenc_si128 (m, k[ 3]); \
m = _mm_aesenc_si128 (m, k[ 4]); \
m = _mm_aesenc_si128 (m, k[ 5]); \
m = _mm_aesenc_si128 (m, k[ 6]); \
m = _mm_aesenc_si128 (m, k[ 7]); \
m = _mm_aesenc_si128 (m, k[ 8]); \
m = _mm_aesenc_si128 (m, k[ 9]); \
m = _mm_aesenclast_si128(m, k[10]);\
}while(0)
#define DO_DEC_BLOCK(m,k) \
do{\
m = _mm_xor_si128 (m, k[10+0]); \
m = _mm_aesdec_si128 (m, k[10+1]); \
m = _mm_aesdec_si128 (m, k[10+2]); \
m = _mm_aesdec_si128 (m, k[10+3]); \
m = _mm_aesdec_si128 (m, k[10+4]); \
m = _mm_aesdec_si128 (m, k[10+5]); \
m = _mm_aesdec_si128 (m, k[10+6]); \
m = _mm_aesdec_si128 (m, k[10+7]); \
m = _mm_aesdec_si128 (m, k[10+8]); \
m = _mm_aesdec_si128 (m, k[10+9]); \
m = _mm_aesdeclast_si128(m, k[0]);\
}while(0)
#define AES_128_key_exp(k, rcon) aes_128_key_expansion(k, _mm_aeskeygenassist_si128(k, rcon))
static __m128i aes_128_key_expansion(__m128i key, __m128i keygened){
keygened = _mm_shuffle_epi32(keygened, _MM_SHUFFLE(3,3,3,3));
key = _mm_xor_si128(key, _mm_slli_si128(key, 4));
key = _mm_xor_si128(key, _mm_slli_si128(key, 4));
key = _mm_xor_si128(key, _mm_slli_si128(key, 4));
return _mm_xor_si128(key, keygened);
}
//public API
static void aes128_load_key_enc_only(uint8_t *enc_key, __m128i *key_schedule){
key_schedule[0] = _mm_loadu_si128((const __m128i*) enc_key);
key_schedule[1] = AES_128_key_exp(key_schedule[0], 0x01);
key_schedule[2] = AES_128_key_exp(key_schedule[1], 0x02);
key_schedule[3] = AES_128_key_exp(key_schedule[2], 0x04);
key_schedule[4] = AES_128_key_exp(key_schedule[3], 0x08);
key_schedule[5] = AES_128_key_exp(key_schedule[4], 0x10);
key_schedule[6] = AES_128_key_exp(key_schedule[5], 0x20);
key_schedule[7] = AES_128_key_exp(key_schedule[6], 0x40);
key_schedule[8] = AES_128_key_exp(key_schedule[7], 0x80);
key_schedule[9] = AES_128_key_exp(key_schedule[8], 0x1B);
key_schedule[10] = AES_128_key_exp(key_schedule[9], 0x36);
}
static void aes128_load_key(uint8_t *enc_key, __m128i *key_schedule){
aes128_load_key_enc_only(enc_key, key_schedule);
// generate decryption keys in reverse order.
// k[10] is shared by last encryption and first decryption rounds
// k[0] is shared by first encryption round and last decryption round (and is the original user key)
// For some implementation reasons, decryption key schedule is NOT the encryption key schedule in reverse order
key_schedule[11] = _mm_aesimc_si128(key_schedule[9]);
key_schedule[12] = _mm_aesimc_si128(key_schedule[8]);
key_schedule[13] = _mm_aesimc_si128(key_schedule[7]);
key_schedule[14] = _mm_aesimc_si128(key_schedule[6]);
key_schedule[15] = _mm_aesimc_si128(key_schedule[5]);
key_schedule[16] = _mm_aesimc_si128(key_schedule[4]);
key_schedule[17] = _mm_aesimc_si128(key_schedule[3]);
key_schedule[18] = _mm_aesimc_si128(key_schedule[2]);
key_schedule[19] = _mm_aesimc_si128(key_schedule[1]);
}
static void aes128_enc(__m128i *key_schedule, uint8_t *plainText,uint8_t *cipherText){
__m128i m = _mm_loadu_si128((__m128i *) plainText);
DO_ENC_BLOCK(m,key_schedule);
_mm_storeu_si128((__m128i *) cipherText, m);
}
static void aes128_dec(__m128i *key_schedule, uint8_t *cipherText,uint8_t *plainText){
__m128i m = _mm_loadu_si128((__m128i *) cipherText);
DO_DEC_BLOCK(m,key_schedule);
_mm_storeu_si128((__m128i *) plainText, m);
}
//return 0 if no error
//1 if encryption failed
//2 if decryption failed
//3 if both failed
static int aes128_self_test(void){
uint8_t plain[] = {0x32, 0x43, 0xf6, 0xa8, 0x88, 0x5a, 0x30, 0x8d, 0x31, 0x31, 0x98, 0xa2, 0xe0, 0x37, 0x07, 0x34};
uint8_t enc_key[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
uint8_t cipher[] = {0x39, 0x25, 0x84, 0x1d, 0x02, 0xdc, 0x09, 0xfb, 0xdc, 0x11, 0x85, 0x97, 0x19, 0x6a, 0x0b, 0x32};
uint8_t computed_cipher[16];
uint8_t computed_plain[16];
int out=0;
__m128i key_schedule[20];
aes128_load_key(enc_key,key_schedule);
aes128_enc(key_schedule,plain,computed_cipher);
aes128_dec(key_schedule,cipher,computed_plain);
if(memcmp(cipher,computed_cipher,sizeof(cipher))) out=1;
if(memcmp(plain,computed_plain,sizeof(plain))) out|=2;
return out;
}
#endif
That code is maintained here and can be seen to compile here