在ARM处理器上实现AES加密可以采用硬件加速的方式。例如,使用ARMv8指令集中的AES指令进行加密操作,这样可以获得更高的加密效率。以下为使用ARMv8指令集中AES指令进行加密的示例代码:
#include
void AES_encrypt(const uint8_t *in, uint8_t *out, const AES_KEY *key)
{
uint8x16_t in_block, out_block;
uint8x16_t round_key[15];
/* load round keys */
round_key[0] = vld1q_u8(key->rd_key);
round_key[1] = vld1q_u8(key->rd_key + 16);
round_key[2] = vld1q_u8(key->rd_key + 32);
round_key[3] = vld1q_u8(key->rd_key + 48);
round_key[4] = vld1q_u8(key->rd_key + 64);
round_key[5] = vld1q_u8(key->rd_key + 80);
round_key[6] = vld1q_u8(key->rd_key + 96);
round_key[7] = vld1q_u8(key->rd_key + 112);
round_key[8] = vld1q_u8(key->rd_key + 128);
round_key[9] = vld1q_u8(key->rd_key + 144);
round_key[10] = vld1q_u8(key->rd_key + 160);
round_key[11] = vld1q_u8(key->rd_key + 176);
round_key[12] = vld1q_u8(key->rd_key + 192);
round_key[13] = vld1q_u8(key->rd_key + 208);
round_key[14] = vld1q_u8(key->rd_key + 224);
/* load input block */
in_block = vld1q_u8(in);
/* first round */
out_block = vaesmcq_u8(vaeseq_u8(in_block, round_key[0]));
/* next 13 rounds */
out_block = vaesmcq_u8(vaeseq_u8(out_block, round_key[1]));
out_block = vaesmcq_u8(vaeseq_u8(out_block, round_key[2]));
out_block = vaesmcq_u8(vaeseq_u8(out_block, round_key[3]));
out