crypto: Add aesenc_MC

Add a primitive for MixColumns.

Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2023-06-02 01:49:21 -07:00
parent 192fa84986
commit 04e1f30eed
3 changed files with 81 additions and 0 deletions

View file

@ -28,6 +28,8 @@
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "qemu/osdep.h"
#include "qemu/bswap.h"
#include "qemu/bitops.h"
#include "crypto/aes.h"
#include "crypto/aes-round.h"
@ -1216,6 +1218,65 @@ static const u32 rcon[] = {
0x1B000000, 0x36000000, /* for 128-bit blocks, Rijndael never uses more than 10 rcon values */
};
/*
* Perform MixColumns.
*/
static inline void
aesenc_MC_swap(AESState *r, const AESState *st, bool swap)
{
int swap_b = swap * 0xf;
int swap_w = swap * 0x3;
bool be = HOST_BIG_ENDIAN ^ swap;
uint32_t t;
/* Note that AES_mc_rot is encoded for little-endian. */
t = ( AES_mc_rot[st->b[swap_b ^ 0x0]] ^
rol32(AES_mc_rot[st->b[swap_b ^ 0x1]], 8) ^
rol32(AES_mc_rot[st->b[swap_b ^ 0x2]], 16) ^
rol32(AES_mc_rot[st->b[swap_b ^ 0x3]], 24));
if (be) {
t = bswap32(t);
}
r->w[swap_w ^ 0] = t;
t = ( AES_mc_rot[st->b[swap_b ^ 0x4]] ^
rol32(AES_mc_rot[st->b[swap_b ^ 0x5]], 8) ^
rol32(AES_mc_rot[st->b[swap_b ^ 0x6]], 16) ^
rol32(AES_mc_rot[st->b[swap_b ^ 0x7]], 24));
if (be) {
t = bswap32(t);
}
r->w[swap_w ^ 1] = t;
t = ( AES_mc_rot[st->b[swap_b ^ 0x8]] ^
rol32(AES_mc_rot[st->b[swap_b ^ 0x9]], 8) ^
rol32(AES_mc_rot[st->b[swap_b ^ 0xA]], 16) ^
rol32(AES_mc_rot[st->b[swap_b ^ 0xB]], 24));
if (be) {
t = bswap32(t);
}
r->w[swap_w ^ 2] = t;
t = ( AES_mc_rot[st->b[swap_b ^ 0xC]] ^
rol32(AES_mc_rot[st->b[swap_b ^ 0xD]], 8) ^
rol32(AES_mc_rot[st->b[swap_b ^ 0xE]], 16) ^
rol32(AES_mc_rot[st->b[swap_b ^ 0xF]], 24));
if (be) {
t = bswap32(t);
}
r->w[swap_w ^ 3] = t;
}
void aesenc_MC_gen(AESState *r, const AESState *st)
{
aesenc_MC_swap(r, st, false);
}
void aesenc_MC_genrev(AESState *r, const AESState *st)
{
aesenc_MC_swap(r, st, true);
}
/*
* Perform SubBytes + ShiftRows + AddRoundKey.
*/