/* $NetBSD: aes_ct_enc.c,v 1.1 2020/06/29 23:27:52 riastradh Exp $ */
/*
* Copyright (c) 2016 Thomas Pornin <
[email protected]>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(1, "$NetBSD: aes_ct_enc.c,v 1.1 2020/06/29 23:27:52 riastradh Exp $");
#include <sys/types.h>
#include <crypto/aes/aes_bear.h>
static inline void
add_round_key(uint32_t *q, const uint32_t *sk)
{
q[0] ^= sk[0];
q[1] ^= sk[1];
q[2] ^= sk[2];
q[3] ^= sk[3];
q[4] ^= sk[4];
q[5] ^= sk[5];
q[6] ^= sk[6];
q[7] ^= sk[7];
}
static inline void
shift_rows(uint32_t *q)
{
int i;
for (i = 0; i < 8; i ++) {
uint32_t x;
x = q[i];
q[i] = (x & 0x000000FF)
| ((x & 0x0000FC00) >> 2) | ((x & 0x00000300) << 6)
| ((x & 0x00F00000) >> 4) | ((x & 0x000F0000) << 4)
| ((x & 0xC0000000) >> 6) | ((x & 0x3F000000) << 2);
}
}
static inline uint32_t
rotr16(uint32_t x)
{
return (x << 16) | (x >> 16);
}
static inline void
mix_columns(uint32_t *q)
{
uint32_t q0, q1, q2, q3, q4, q5, q6, q7;
uint32_t r0, r1, r2, r3, r4, r5, r6, r7;
q0 = q[0];
q1 = q[1];
q2 = q[2];
q3 = q[3];
q4 = q[4];
q5 = q[5];
q6 = q[6];
q7 = q[7];
r0 = (q0 >> 8) | (q0 << 24);
r1 = (q1 >> 8) | (q1 << 24);
r2 = (q2 >> 8) | (q2 << 24);
r3 = (q3 >> 8) | (q3 << 24);
r4 = (q4 >> 8) | (q4 << 24);
r5 = (q5 >> 8) | (q5 << 24);
r6 = (q6 >> 8) | (q6 << 24);
r7 = (q7 >> 8) | (q7 << 24);
q[0] = q7 ^ r7 ^ r0 ^ rotr16(q0 ^ r0);
q[1] = q0 ^ r0 ^ q7 ^ r7 ^ r1 ^ rotr16(q1 ^ r1);
q[2] = q1 ^ r1 ^ r2 ^ rotr16(q2 ^ r2);
q[3] = q2 ^ r2 ^ q7 ^ r7 ^ r3 ^ rotr16(q3 ^ r3);
q[4] = q3 ^ r3 ^ q7 ^ r7 ^ r4 ^ rotr16(q4 ^ r4);
q[5] = q4 ^ r4 ^ r5 ^ rotr16(q5 ^ r5);
q[6] = q5 ^ r5 ^ r6 ^ rotr16(q6 ^ r6);
q[7] = q6 ^ r6 ^ r7 ^ rotr16(q7 ^ r7);
}
/* see inner.h */
void
br_aes_ct_bitslice_encrypt(unsigned num_rounds,
const uint32_t *skey, uint32_t *q)
{
unsigned u;
add_round_key(q, skey);
for (u = 1; u < num_rounds; u ++) {
br_aes_ct_bitslice_Sbox(q);
shift_rows(q);
mix_columns(q);
add_round_key(q, skey + (u << 3));
}
br_aes_ct_bitslice_Sbox(q);
shift_rows(q);
add_round_key(q, skey + (num_rounds << 3));
}
