crypto: Add aesdec_ISB_ISR_AK

Add a primitive for InvSubBytes + InvShiftRows + AddRoundKey.

Reviewed-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 00:57:02 -07:00
parent 6b0a96ce3a
commit 192fa84986
3 changed files with 70 additions and 0 deletions

View file

@ -1261,6 +1261,51 @@ void aesenc_SB_SR_AK_genrev(AESState *r, const AESState *s, const AESState *k)
aesenc_SB_SR_AK_swap(r, s, k, true);
}
/*
* Perform InvSubBytes + InvShiftRows + AddRoundKey.
*/
static inline void
aesdec_ISB_ISR_AK_swap(AESState *ret, const AESState *st,
const AESState *rk, bool swap)
{
const int swap_b = swap ? 15 : 0;
AESState t;
t.b[swap_b ^ 0x0] = AES_isbox[st->b[swap_b ^ AES_ISH(0x0)]];
t.b[swap_b ^ 0x1] = AES_isbox[st->b[swap_b ^ AES_ISH(0x1)]];
t.b[swap_b ^ 0x2] = AES_isbox[st->b[swap_b ^ AES_ISH(0x2)]];
t.b[swap_b ^ 0x3] = AES_isbox[st->b[swap_b ^ AES_ISH(0x3)]];
t.b[swap_b ^ 0x4] = AES_isbox[st->b[swap_b ^ AES_ISH(0x4)]];
t.b[swap_b ^ 0x5] = AES_isbox[st->b[swap_b ^ AES_ISH(0x5)]];
t.b[swap_b ^ 0x6] = AES_isbox[st->b[swap_b ^ AES_ISH(0x6)]];
t.b[swap_b ^ 0x7] = AES_isbox[st->b[swap_b ^ AES_ISH(0x7)]];
t.b[swap_b ^ 0x8] = AES_isbox[st->b[swap_b ^ AES_ISH(0x8)]];
t.b[swap_b ^ 0x9] = AES_isbox[st->b[swap_b ^ AES_ISH(0x9)]];
t.b[swap_b ^ 0xa] = AES_isbox[st->b[swap_b ^ AES_ISH(0xA)]];
t.b[swap_b ^ 0xb] = AES_isbox[st->b[swap_b ^ AES_ISH(0xB)]];
t.b[swap_b ^ 0xc] = AES_isbox[st->b[swap_b ^ AES_ISH(0xC)]];
t.b[swap_b ^ 0xd] = AES_isbox[st->b[swap_b ^ AES_ISH(0xD)]];
t.b[swap_b ^ 0xe] = AES_isbox[st->b[swap_b ^ AES_ISH(0xE)]];
t.b[swap_b ^ 0xf] = AES_isbox[st->b[swap_b ^ AES_ISH(0xF)]];
/*
* Perform the AddRoundKey with generic vectors.
* This may be expanded to either host integer or host vector code.
* The key and output endianness match, so no bswap required.
*/
ret->v = t.v ^ rk->v;
}
void aesdec_ISB_ISR_AK_gen(AESState *r, const AESState *s, const AESState *k)
{
aesdec_ISB_ISR_AK_swap(r, s, k, false);
}
void aesdec_ISB_ISR_AK_genrev(AESState *r, const AESState *s, const AESState *k)
{
aesdec_ISB_ISR_AK_swap(r, s, k, true);
}
/**
* Expand the cipher key into the encryption key schedule.
*/