/*      $NetBSD: aes_ssse3_subr.c,v 1.3 2020/07/25 22:31:04 riastradh Exp $     */

/*-
 * Copyright (c) 2020 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(1, "$NetBSD: aes_ssse3_subr.c,v 1.3 2020/07/25 22:31:04 riastradh Exp $");

#ifdef _KERNEL
#include <sys/systm.h>
#include <lib/libkern/libkern.h>
#else
#include <assert.h>
#include <inttypes.h>
#include <stdio.h>
#define KASSERT                 assert
#endif

#include "aes_ssse3_impl.h"

static inline __m128i
loadblock(const void *in)
{
        return _mm_loadu_epi8(in);
}

static inline void
storeblock(void *out, __m128i block)
{
        _mm_storeu_epi8(out, block);
}

void
aes_ssse3_enc(const struct aesenc *enc, const uint8_t in[static 16],
    uint8_t out[static 16], uint32_t nrounds)
{
        __m128i block;

        block = loadblock(in);
        block = aes_ssse3_enc1(enc, block, nrounds);
        storeblock(out, block);
}

void
aes_ssse3_dec(const struct aesdec *dec, const uint8_t in[static 16],
    uint8_t out[static 16], uint32_t nrounds)
{
        __m128i block;

        block = loadblock(in);
        block = aes_ssse3_dec1(dec, block, nrounds);
        storeblock(out, block);
}

void
aes_ssse3_cbc_enc(const struct aesenc *enc, const uint8_t in[static 16],
    uint8_t out[static 16], size_t nbytes, uint8_t iv[static 16],
    uint32_t nrounds)
{
        __m128i cv;

        KASSERT(nbytes);

        cv = loadblock(iv);
        for (; nbytes; nbytes -= 16, in += 16, out += 16) {
                cv ^= loadblock(in);
                cv = aes_ssse3_enc1(enc, cv, nrounds);
                storeblock(out, cv);
        }
        storeblock(iv, cv);
}

void
aes_ssse3_cbc_dec(const struct aesdec *dec, const uint8_t in[static 16],
    uint8_t out[static 16], size_t nbytes, uint8_t iv[static 16],
    uint32_t nrounds)
{
        __m128i iv0, cv, b;

        KASSERT(nbytes);
        KASSERT(nbytes % 16 == 0);

        iv0 = loadblock(iv);
        cv = loadblock(in + nbytes - 16);
        storeblock(iv, cv);

        for (;;) {
                b = aes_ssse3_dec1(dec, cv, nrounds);
                if ((nbytes -= 16) == 0)
                        break;
                cv = loadblock(in + nbytes - 16);
                storeblock(out + nbytes, b ^ cv);
        }
        storeblock(out, b ^ iv0);
}

static inline __m128i
aes_ssse3_xts_update(__m128i t)
{
        const __m128i one = _mm_set_epi64x(1, 1);
        __m128i s, m, c;

        s = _mm_srli_epi64(t, 63);      /* 1 if high bit set else 0 */
        m = _mm_sub_epi64(s, one);      /* 0 if high bit set else -1 */
        m = _mm_shuffle_epi32(m, 0x4e); /* swap halves */
        c = _mm_set_epi64x(1, 0x87);    /* carry */

        return _mm_slli_epi64(t, 1) ^ (c & ~m);
}

static int
aes_ssse3_xts_update_selftest(void)
{
        static const struct {
                uint32_t in[4], out[4];
        } cases[] = {
                [0] = { {1}, {2} },
                [1] = { {0x80000000U,0,0,0}, {0,1,0,0} },
                [2] = { {0,0x80000000U,0,0}, {0,0,1,0} },
                [3] = { {0,0,0x80000000U,0}, {0,0,0,1} },
                [4] = { {0,0,0,0x80000000U}, {0x87,0,0,0} },
                [5] = { {0,0x80000000U,0,0x80000000U}, {0x87,0,1,0} },
        };
        unsigned i;
        uint32_t t[4];
        int result = 0;

        for (i = 0; i < sizeof(cases)/sizeof(cases[0]); i++) {
                t[0] = cases[i].in[0];
                t[1] = cases[i].in[1];
                t[2] = cases[i].in[2];
                t[3] = cases[i].in[3];
                storeblock(t, aes_ssse3_xts_update(loadblock(t)));
                if (t[0] != cases[i].out[0] ||
                    t[1] != cases[i].out[1] ||
                    t[2] != cases[i].out[2] ||
                    t[3] != cases[i].out[3]) {
                        printf("%s %u:"
                            " %"PRIx32" %"PRIx32" %"PRIx32" %"PRIx32"\n",
                            __func__, i, t[0], t[1], t[2], t[3]);
                        result = -1;
                }
        }

        return result;
}

void
aes_ssse3_xts_enc(const struct aesenc *enc, const uint8_t in[static 16],
    uint8_t out[static 16], size_t nbytes, uint8_t tweak[static 16],
    uint32_t nrounds)
{
        __m128i t, b;

        KASSERT(nbytes);
        KASSERT(nbytes % 16 == 0);

        t = loadblock(tweak);
        for (; nbytes; nbytes -= 16, in += 16, out += 16) {
                b = t ^ loadblock(in);
                b = aes_ssse3_enc1(enc, b, nrounds);
                storeblock(out, t ^ b);
                t = aes_ssse3_xts_update(t);
        }
        storeblock(tweak, t);
}

void
aes_ssse3_xts_dec(const struct aesdec *dec, const uint8_t in[static 16],
    uint8_t out[static 16], size_t nbytes, uint8_t tweak[static 16],
    uint32_t nrounds)
{
        __m128i t, b;

        KASSERT(nbytes);
        KASSERT(nbytes % 16 == 0);

        t = loadblock(tweak);
        for (; nbytes; nbytes -= 16, in += 16, out += 16) {
                b = t ^ loadblock(in);
                b = aes_ssse3_dec1(dec, b, nrounds);
                storeblock(out, t ^ b);
                t = aes_ssse3_xts_update(t);
        }
        storeblock(tweak, t);
}

void
aes_ssse3_cbcmac_update1(const struct aesenc *enc, const uint8_t in[static 16],
    size_t nbytes, uint8_t auth0[static 16], uint32_t nrounds)
{
        __m128i auth;

        KASSERT(nbytes);
        KASSERT(nbytes % 16 == 0);

        auth = loadblock(auth0);
        for (; nbytes; nbytes -= 16, in += 16)
                auth = aes_ssse3_enc1(enc, auth ^ loadblock(in), nrounds);
        storeblock(auth0, auth);
}

void
aes_ssse3_ccm_enc1(const struct aesenc *enc, const uint8_t in[static 16],
    uint8_t out[static 16], size_t nbytes, uint8_t authctr[static 32],
    uint32_t nrounds)
{
        const __m128i ctr32_inc = _mm_set_epi32(1, 0, 0, 0);
        const __m128i bs32 =
            _mm_set_epi32(0x0c0d0e0f, 0x08090a0b, 0x04050607, 0x00010203);
        __m128i auth, ctr_be, ctr, ptxt;

        KASSERT(nbytes);
        KASSERT(nbytes % 16 == 0);

        auth = loadblock(authctr);
        ctr_be = loadblock(authctr + 16);
        ctr = _mm_shuffle_epi8(ctr_be, bs32);
        for (; nbytes; nbytes -= 16, in += 16, out += 16) {
                ptxt = loadblock(in);
                auth = aes_ssse3_enc1(enc, auth ^ ptxt, nrounds);
                ctr = _mm_add_epi32(ctr, ctr32_inc);
                ctr_be = _mm_shuffle_epi8(ctr, bs32);
                storeblock(out, ptxt ^ aes_ssse3_enc1(enc, ctr_be, nrounds));
        }
        storeblock(authctr, auth);
        storeblock(authctr + 16, ctr_be);
}

void
aes_ssse3_ccm_dec1(const struct aesenc *enc, const uint8_t in[static 16],
    uint8_t out[static 16], size_t nbytes, uint8_t authctr[static 32],
    uint32_t nrounds)
{
        const __m128i ctr32_inc = _mm_set_epi32(1, 0, 0, 0);
        const __m128i bs32 =
            _mm_set_epi32(0x0c0d0e0f, 0x08090a0b, 0x04050607, 0x00010203);
        __m128i auth, ctr_be, ctr, ptxt;

        KASSERT(nbytes);
        KASSERT(nbytes % 16 == 0);

        auth = loadblock(authctr);
        ctr_be = loadblock(authctr + 16);
        ctr = _mm_shuffle_epi8(ctr_be, bs32);
        for (; nbytes; nbytes -= 16, in += 16, out += 16) {
                ctr = _mm_add_epi32(ctr, ctr32_inc);
                ctr_be = _mm_shuffle_epi8(ctr, bs32);
                ptxt = loadblock(in) ^ aes_ssse3_enc1(enc, ctr_be, nrounds);
                storeblock(out, ptxt);
                auth = aes_ssse3_enc1(enc, auth ^ ptxt, nrounds);
        }
        storeblock(authctr, auth);
        storeblock(authctr + 16, ctr_be);
}

int
aes_ssse3_selftest(void)
{

        if (aes_ssse3_xts_update_selftest())
                return -1;

        return 0;
}