aes-encrypt-internal.c File Reference

#include <assert.h>
#include "aes-internal.h"
#include "macros.h"

Go to the source code of this file.

Functions
void	_nettle_aes_encrypt (unsigned rounds, const uint32_t *keys, const struct aes_table *T, size_t length, uint8_t *dst, const uint8_t *src)

Function Documentation

_nettle_aes_encrypt()

void _nettle_aes_encrypt	(	unsigned	rounds,
		const uint32_t *	keys,
		const struct aes_table *	T,
		size_t	length,
		uint8_t *	dst,
		const uint8_t *	src
	)

Definition at line 57 of file aes-encrypt-internal.c.

{
  FOR_BLOCKS(length, dst, src, AES_BLOCK_SIZE)
    {
      uint32_t w0, w1, w2, w3;      /* working ciphertext */
      uint32_t t0, t1, t2, t3;
      unsigned i;
      
      /* Get clear text, using little-endian byte order.
       * Also XOR with the first subkey. */
 
      w0 = LE_READ_UINT32(src)      ^ keys[0];
      w1 = LE_READ_UINT32(src + 4)  ^ keys[1];
      w2 = LE_READ_UINT32(src + 8)  ^ keys[2];
      w3 = LE_READ_UINT32(src + 12) ^ keys[3];
 
      for (i = 1; i < rounds; i++)
    {
      t0 = AES_ROUND(T, w0, w1, w2, w3, keys[4*i]);
      t1 = AES_ROUND(T, w1, w2, w3, w0, keys[4*i + 1]);
      t2 = AES_ROUND(T, w2, w3, w0, w1, keys[4*i + 2]);
      t3 = AES_ROUND(T, w3, w0, w1, w2, keys[4*i + 3]);
 
      /* We could unroll the loop twice, to avoid these
         assignments. If all eight variables fit in registers,
         that should give a slight speedup. */
      w0 = t0;
      w1 = t1;
      w2 = t2;
      w3 = t3;
    }
 
      /* Final round */
 
      t0 = AES_FINAL_ROUND(T, w0, w1, w2, w3, keys[4*i]);
      t1 = AES_FINAL_ROUND(T, w1, w2, w3, w0, keys[4*i + 1]);
      t2 = AES_FINAL_ROUND(T, w2, w3, w0, w1, keys[4*i + 2]);
      t3 = AES_FINAL_ROUND(T, w3, w0, w1, w2, keys[4*i + 3]);
 
      LE_WRITE_UINT32(dst, t0);
      LE_WRITE_UINT32(dst + 4, t1);
      LE_WRITE_UINT32(dst + 8, t2);
      LE_WRITE_UINT32(dst + 12, t3);
    }
}

References AES_BLOCK_SIZE, AES_FINAL_ROUND, AES_ROUND, dst, FOR_BLOCKS, i, keys, LE_READ_UINT32, LE_WRITE_UINT32, length, src, T, benchmark::t1, w0, w1, w2, and w3.

Referenced by nettle_aes128_encrypt(), nettle_aes192_encrypt(), and nettle_aes256_encrypt().