/*      $NetBSD: aes_sse2_4x32.c,v 1.1 2025/11/23 22:48:26 riastradh Exp $      */

/*
 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
 *
 * 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_sse2_4x32.c,v 1.1 2025/11/23 22:48:26 riastradh Exp $");

#include <sys/types.h>

#ifdef _KERNEL
#include <lib/libkern/libkern.h>
#else
#include <string.h>
#endif

#include "aes_sse2_4x32_impl.h"

/* see inner.h */
void
aes_sse2_4x32_bitslice_Sbox(__m128i q[static 8])
{
        /*
         * This S-box implementation is a straightforward translation of
         * the circuit described by Boyar and Peralta in "A new
         * combinational logic minimization technique with applications
         * to cryptology" (https://eprint.iacr.org/2009/191.pdf).
         *
         * Note that variables x* (input) and s* (output) are numbered
         * in "reverse" order (x0 is the high bit, x7 is the low bit).
         */

        __m128i x0, x1, x2, x3, x4, x5, x6, x7;
        __m128i y1, y2, y3, y4, y5, y6, y7, y8, y9;
        __m128i y10, y11, y12, y13, y14, y15, y16, y17, y18, y19;
        __m128i y20, y21;
        __m128i z0, z1, z2, z3, z4, z5, z6, z7, z8, z9;
        __m128i z10, z11, z12, z13, z14, z15, z16, z17;
        __m128i t0, t1, t2, t3, t4, t5, t6, t7, t8, t9;
        __m128i t10, t11, t12, t13, t14, t15, t16, t17, t18, t19;
        __m128i t20, t21, t22, t23, t24, t25, t26, t27, t28, t29;
        __m128i t30, t31, t32, t33, t34, t35, t36, t37, t38, t39;
        __m128i t40, t41, t42, t43, t44, t45, t46, t47, t48, t49;
        __m128i t50, t51, t52, t53, t54, t55, t56, t57, t58, t59;
        __m128i t60, t61, t62, t63, t64, t65, t66, t67;
        __m128i s0, s1, s2, s3, s4, s5, s6, s7;

        x0 = q[7];
        x1 = q[6];
        x2 = q[5];
        x3 = q[4];
        x4 = q[3];
        x5 = q[2];
        x6 = q[1];
        x7 = q[0];

        /*
         * Top linear transformation.
         */
        y14 = x3 ^ x5;
        y13 = x0 ^ x6;
        y9 = x0 ^ x3;
        y8 = x0 ^ x5;
        t0 = x1 ^ x2;
        y1 = t0 ^ x7;
        y4 = y1 ^ x3;
        y12 = y13 ^ y14;
        y2 = y1 ^ x0;
        y5 = y1 ^ x6;
        y3 = y5 ^ y8;
        t1 = x4 ^ y12;
        y15 = t1 ^ x5;
        y20 = t1 ^ x1;
        y6 = y15 ^ x7;
        y10 = y15 ^ t0;
        y11 = y20 ^ y9;
        y7 = x7 ^ y11;
        y17 = y10 ^ y11;
        y19 = y10 ^ y8;
        y16 = t0 ^ y11;
        y21 = y13 ^ y16;
        y18 = x0 ^ y16;

        /*
         * Non-linear section.
         */
        t2 = y12 & y15;
        t3 = y3 & y6;
        t4 = t3 ^ t2;
        t5 = y4 & x7;
        t6 = t5 ^ t2;
        t7 = y13 & y16;
        t8 = y5 & y1;
        t9 = t8 ^ t7;
        t10 = y2 & y7;
        t11 = t10 ^ t7;
        t12 = y9 & y11;
        t13 = y14 & y17;
        t14 = t13 ^ t12;
        t15 = y8 & y10;
        t16 = t15 ^ t12;
        t17 = t4 ^ t14;
        t18 = t6 ^ t16;
        t19 = t9 ^ t14;
        t20 = t11 ^ t16;
        t21 = t17 ^ y20;
        t22 = t18 ^ y19;
        t23 = t19 ^ y21;
        t24 = t20 ^ y18;

        t25 = t21 ^ t22;
        t26 = t21 & t23;
        t27 = t24 ^ t26;
        t28 = t25 & t27;
        t29 = t28 ^ t22;
        t30 = t23 ^ t24;
        t31 = t22 ^ t26;
        t32 = t31 & t30;
        t33 = t32 ^ t24;
        t34 = t23 ^ t33;
        t35 = t27 ^ t33;
        t36 = t24 & t35;
        t37 = t36 ^ t34;
        t38 = t27 ^ t36;
        t39 = t29 & t38;
        t40 = t25 ^ t39;

        t41 = t40 ^ t37;
        t42 = t29 ^ t33;
        t43 = t29 ^ t40;
        t44 = t33 ^ t37;
        t45 = t42 ^ t41;
        z0 = t44 & y15;
        z1 = t37 & y6;
        z2 = t33 & x7;
        z3 = t43 & y16;
        z4 = t40 & y1;
        z5 = t29 & y7;
        z6 = t42 & y11;
        z7 = t45 & y17;
        z8 = t41 & y10;
        z9 = t44 & y12;
        z10 = t37 & y3;
        z11 = t33 & y4;
        z12 = t43 & y13;
        z13 = t40 & y5;
        z14 = t29 & y2;
        z15 = t42 & y9;
        z16 = t45 & y14;
        z17 = t41 & y8;

        /*
         * Bottom linear transformation.
         */
        t46 = z15 ^ z16;
        t47 = z10 ^ z11;
        t48 = z5 ^ z13;
        t49 = z9 ^ z10;
        t50 = z2 ^ z12;
        t51 = z2 ^ z5;
        t52 = z7 ^ z8;
        t53 = z0 ^ z3;
        t54 = z6 ^ z7;
        t55 = z16 ^ z17;
        t56 = z12 ^ t48;
        t57 = t50 ^ t53;
        t58 = z4 ^ t46;
        t59 = z3 ^ t54;
        t60 = t46 ^ t57;
        t61 = z14 ^ t57;
        t62 = t52 ^ t58;
        t63 = t49 ^ t58;
        t64 = z4 ^ t59;
        t65 = t61 ^ t62;
        t66 = z1 ^ t63;
        s0 = t59 ^ t63;
        s6 = t56 ^ ~t62;
        s7 = t48 ^ ~t60;
        t67 = t64 ^ t65;
        s3 = t53 ^ t66;
        s4 = t51 ^ t66;
        s5 = t47 ^ t65;
        s1 = t64 ^ ~s3;
        s2 = t55 ^ ~t67;

        q[7] = s0;
        q[6] = s1;
        q[5] = s2;
        q[4] = s3;
        q[3] = s4;
        q[2] = s5;
        q[1] = s6;
        q[0] = s7;
}

/* see inner.h */
void
aes_sse2_4x32_ortho(__m128i q[static 8])
{
#define SWAPN(cl, ch, s, x, y)   do { \
                __m128i cl128 = _mm_set1_epi32(cl); \
                __m128i ch128 = _mm_set1_epi32(ch); \
                __m128i a, b; \
                a = _mm_load_si128(&(x)); \
                b = _mm_load_si128(&(y)); \
                _mm_store_si128(&(x), \
                    (a & cl128) | _mm_slli_epi32((b & cl128), (s))); \
                _mm_store_si128(&(y), \
                    _mm_srli_epi32((a & ch128), (s)) | (b & ch128)); \
        } while (0)

#define SWAP2(x, y)   SWAPN(0x55555555, 0xAAAAAAAA, 1, x, y)
#define SWAP4(x, y)   SWAPN(0x33333333, 0xCCCCCCCC, 2, x, y)
#define SWAP8(x, y)   SWAPN(0x0F0F0F0F, 0xF0F0F0F0, 4, x, y)

        SWAP2(q[0], q[1]);
        SWAP2(q[2], q[3]);
        SWAP2(q[4], q[5]);
        SWAP2(q[6], q[7]);

        SWAP4(q[0], q[2]);
        SWAP4(q[1], q[3]);
        SWAP4(q[4], q[6]);
        SWAP4(q[5], q[7]);

        SWAP8(q[0], q[4]);
        SWAP8(q[1], q[5]);
        SWAP8(q[2], q[6]);
        SWAP8(q[3], q[7]);
}

static const unsigned char Rcon[] = {
        0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36
};

static uint32_t
sub_word(uint32_t x)
{
        __m128i q[8];
        uint32_t y;

        memset(q, 0, sizeof(q));
        q[0] = _mm_loadu_si32(&x);
        aes_sse2_4x32_ortho(q);
        aes_sse2_4x32_bitslice_Sbox(q);
        aes_sse2_4x32_ortho(q);
        _mm_storeu_si32(&y, q[0]);
        return y;
}

/* see inner.h */
unsigned
aes_sse2_4x32_keysched(uint32_t comp_skey[static 60], const void *key,
    size_t key_len)
{
        unsigned num_rounds;
        int i, j, k, nk, nkf;
        uint32_t tmp;
        uint32_t skey[120];

        switch (key_len) {
        case 16:
                num_rounds = 10;
                break;
        case 24:
                num_rounds = 12;
                break;
        case 32:
                num_rounds = 14;
                break;
        default:
                /* abort(); */
                return 0;
        }
        nk = (int)(key_len >> 2);
        nkf = (int)((num_rounds + 1) << 2);
        tmp = 0;
        for (i = 0; i < nk; i ++) {
                tmp = br_dec32le((const unsigned char *)key + (i << 2));
                skey[(i << 1) + 0] = tmp;
                skey[(i << 1) + 1] = tmp;
        }
        for (i = nk, j = 0, k = 0; i < nkf; i ++) {
                if (j == 0) {
                        tmp = (tmp << 24) | (tmp >> 8);
                        tmp = sub_word(tmp) ^ Rcon[k];
                } else if (nk > 6 && j == 4) {
                        tmp = sub_word(tmp);
                }
                tmp ^= skey[(i - nk) << 1];
                skey[(i << 1) + 0] = tmp;
                skey[(i << 1) + 1] = tmp;
                if (++ j == nk) {
                        j = 0;
                        k ++;
                }
        }
        for (i = 0; i < nkf; i += 4) {
                __m128i q[8];

                for (j = 0; j < 8; j++)
                        q[j] = _mm_loadu_si32(&skey[(i << 1) + j]);
                aes_sse2_4x32_ortho(q);
                for (j = 0; j < 8; j++)
                        _mm_storeu_si32(&skey[(i << 1) + j], q[j]);
        }
        for (i = 0, j = 0; i < nkf; i ++, j += 2) {
                comp_skey[i] = (skey[j + 0] & 0x55555555)
                        | (skey[j + 1] & 0xAAAAAAAA);
        }
        return num_rounds;
}

/* see inner.h */
void
aes_sse2_4x32_skey_expand(uint32_t skey[static 120],
        unsigned num_rounds, const uint32_t comp_skey[static 60])
{
        unsigned u, v, n;

        n = (num_rounds + 1) << 2;
        for (u = 0, v = 0; u < n; u ++, v += 2) {
                uint32_t x, y;

                x = y = comp_skey[u];
                x &= 0x55555555;
                skey[v + 0] = x | (x << 1);
                y &= 0xAAAAAAAA;
                skey[v + 1] = y | (y >> 1);
        }
}