/*

 * Copyright 2013-2022 The OpenSSL Project Authors. All Rights Reserved.

 * Copyright (c) 2012, Intel Corporation. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 *

 * Originally written by Shay Gueron (1, 2), and Vlad Krasnov (1)

 * (1) Intel Corporation, Israel Development Center, Haifa, Israel

 * (2) University of Haifa, Israel

 */

#include <openssl/opensslconf.h>

#include "rsaz_exp.h"

#ifndef RSAZ_ENABLED

NON_EMPTY_TRANSLATION_UNIT

#else

/*

 * See crypto/bn/asm/rsaz-avx2.pl for further details.

 */

void rsaz_1024_norm2red_avx2(void *red, const void *norm);

void rsaz_1024_mul_avx2(void *ret, const void *a, const void *b,

                        const void *n, BN_ULONG k);

void rsaz_1024_sqr_avx2(void *ret, const void *a, const void *n, BN_ULONG k,

                        int cnt);

void rsaz_1024_scatter5_avx2(void *tbl, const void *val, int i);

void rsaz_1024_gather5_avx2(void *val, const void *tbl, int i);

void rsaz_1024_red2norm_avx2(void *norm, const void *red);

#if defined(__GNUC__)

# define ALIGN64        __attribute__((aligned(64)))

#elif defined(_MSC_VER)

# define ALIGN64        __declspec(align(64))

#elif defined(__SUNPRO_C)

# define ALIGN64

# pragma align 64(one,two80)

#else

/* not fatal, might hurt performance a little */

# define ALIGN64

#endif

ALIGN64 static const BN_ULONG one[40] = {

    1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

};

ALIGN64 static const BN_ULONG two80[40] = {

    0, 0, 1 << 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

};

void RSAZ_1024_mod_exp_avx2(BN_ULONG result_norm[16],

                            const BN_ULONG base_norm[16],

                            const BN_ULONG exponent[16],

                            const BN_ULONG m_norm[16], const BN_ULONG RR[16],

                            BN_ULONG k0)

{

    unsigned char storage[320 * 3 + 32 * 9 * 16 + 64]; /* 5.5KB */

    unsigned char *p_str = storage + (64 - ((size_t)storage % 64));

    unsigned char *a_inv, *m, *result;

    unsigned char *table_s = p_str + 320 * 3;

    unsigned char *R2 = table_s; /* borrow */

    int index;

    int wvalue;

    BN_ULONG tmp[16];

    if ((((size_t)p_str & 4095) + 320) >> 12) {

        result = p_str;

        a_inv = p_str + 320;

        m = p_str + 320 * 2;    /* should not cross page */

    } else {

        m = p_str;              /* should not cross page */

        result = p_str + 320;

        a_inv = p_str + 320 * 2;

    }

    rsaz_1024_norm2red_avx2(m, m_norm);

    rsaz_1024_norm2red_avx2(a_inv, base_norm);

    rsaz_1024_norm2red_avx2(R2, RR);

    rsaz_1024_mul_avx2(R2, R2, R2, m, k0);

    rsaz_1024_mul_avx2(R2, R2, two80, m, k0);

    /* table[0] = 1 */

    rsaz_1024_mul_avx2(result, R2, one, m, k0);

    /* table[1] = a_inv^1 */

    rsaz_1024_mul_avx2(a_inv, a_inv, R2, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 0);

    rsaz_1024_scatter5_avx2(table_s, a_inv, 1);

    /* table[2] = a_inv^2 */

    rsaz_1024_sqr_avx2(result, a_inv, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 2);

#if 0

    /* this is almost 2x smaller and less than 1% slower */

    for (index = 3; index < 32; index++) {

        rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

        rsaz_1024_scatter5_avx2(table_s, result, index);

    }

#else

    /* table[4] = a_inv^4 */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 4);

    /* table[8] = a_inv^8 */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 8);

    /* table[16] = a_inv^16 */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 16);

    /* table[17] = a_inv^17 */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 17);

    /* table[3] */

    rsaz_1024_gather5_avx2(result, table_s, 2);

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 3);

    /* table[6] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 6);

    /* table[12] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 12);

    /* table[24] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 24);

    /* table[25] */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 25);

    /* table[5] */

    rsaz_1024_gather5_avx2(result, table_s, 4);

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 5);

    /* table[10] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 10);

    /* table[20] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 20);

    /* table[21] */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 21);

    /* table[7] */

    rsaz_1024_gather5_avx2(result, table_s, 6);

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 7);

    /* table[14] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 14);

    /* table[28] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 28);

    /* table[29] */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 29);

    /* table[9] */

    rsaz_1024_gather5_avx2(result, table_s, 8);

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 9);

    /* table[18] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 18);

    /* table[19] */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 19);

    /* table[11] */

    rsaz_1024_gather5_avx2(result, table_s, 10);

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 11);

    /* table[22] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 22);

    /* table[23] */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 23);

    /* table[13] */

    rsaz_1024_gather5_avx2(result, table_s, 12);

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 13);

    /* table[26] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 26);

    /* table[27] */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 27);

    /* table[15] */

    rsaz_1024_gather5_avx2(result, table_s, 14);

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 15);

    /* table[30] */

    rsaz_1024_sqr_avx2(result, result, m, k0, 1);

    rsaz_1024_scatter5_avx2(table_s, result, 30);

    /* table[31] */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    rsaz_1024_scatter5_avx2(table_s, result, 31);

#endif

    /* load first window */

    p_str = (unsigned char *)exponent;

    wvalue = p_str[127] >> 3;

    rsaz_1024_gather5_avx2(result, table_s, wvalue);

    index = 1014;

    while (index > -1) {        /* loop for the remaining 127 windows */

        rsaz_1024_sqr_avx2(result, result, m, k0, 5);

        wvalue = (p_str[(index / 8) + 1] << 8) | p_str[index / 8];

        wvalue = (wvalue >> (index % 8)) & 31;

        index -= 5;

        rsaz_1024_gather5_avx2(a_inv, table_s, wvalue); /* borrow a_inv */

        rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    }

    /* square four times */

    rsaz_1024_sqr_avx2(result, result, m, k0, 4);

    wvalue = p_str[0] & 15;

    rsaz_1024_gather5_avx2(a_inv, table_s, wvalue); /* borrow a_inv */

    rsaz_1024_mul_avx2(result, result, a_inv, m, k0);

    /* from Montgomery */

    rsaz_1024_mul_avx2(result, result, one, m, k0);

    rsaz_1024_red2norm_avx2(result_norm, result);

    bn_reduce_once_in_place(result_norm, /*carry=*/0, m_norm, tmp, 16);

    OPENSSL_cleanse(storage, sizeof(storage));

    OPENSSL_cleanse(tmp, sizeof(tmp));

}

/*

 * See crypto/bn/rsaz-x86_64.pl for further details.

 */

void rsaz_512_mul(void *ret, const void *a, const void *b, const void *n,

                  BN_ULONG k);

void rsaz_512_mul_scatter4(void *ret, const void *a, const void *n,

                           BN_ULONG k, const void *tbl, unsigned int power);

void rsaz_512_mul_gather4(void *ret, const void *a, const void *tbl,

                          const void *n, BN_ULONG k, unsigned int power);

void rsaz_512_mul_by_one(void *ret, const void *a, const void *n, BN_ULONG k);

void rsaz_512_sqr(void *ret, const void *a, const void *n, BN_ULONG k,

                  int cnt);

void rsaz_512_scatter4(void *tbl, const BN_ULONG *val, int power);

void rsaz_512_gather4(BN_ULONG *val, const void *tbl, int power);

void RSAZ_512_mod_exp(BN_ULONG result[8],

                      const BN_ULONG base[8], const BN_ULONG exponent[8],

                      const BN_ULONG m[8], BN_ULONG k0, const BN_ULONG RR[8])

{

    unsigned char storage[16 * 8 * 8 + 64 * 2 + 64]; /* 1.2KB */

    unsigned char *table = storage + (64 - ((size_t)storage % 64));

    BN_ULONG *a_inv = (BN_ULONG *)(table + 16 * 8 * 8);

    BN_ULONG *temp = (BN_ULONG *)(table + 16 * 8 * 8 + 8 * 8);

    unsigned char *p_str = (unsigned char *)exponent;

    int index;

    unsigned int wvalue;

    BN_ULONG tmp[8];

    /* table[0] = 1_inv */

    temp[0] = 0 - m[0];

    temp[1] = ~m[1];

    temp[2] = ~m[2];

    temp[3] = ~m[3];

    temp[4] = ~m[4];

    temp[5] = ~m[5];

    temp[6] = ~m[6];

    temp[7] = ~m[7];

    rsaz_512_scatter4(table, temp, 0);

    /* table [1] = a_inv^1 */

    rsaz_512_mul(a_inv, base, RR, m, k0);

    rsaz_512_scatter4(table, a_inv, 1);

    /* table [2] = a_inv^2 */

    rsaz_512_sqr(temp, a_inv, m, k0, 1);

    rsaz_512_scatter4(table, temp, 2);

    for (index = 3; index < 16; index++)

        rsaz_512_mul_scatter4(temp, a_inv, m, k0, table, index);

    /* load first window */

    wvalue = p_str[63];

    rsaz_512_gather4(temp, table, wvalue >> 4);

    rsaz_512_sqr(temp, temp, m, k0, 4);

    rsaz_512_mul_gather4(temp, temp, table, m, k0, wvalue & 0xf);

    for (index = 62; index >= 0; index--) {

        wvalue = p_str[index];

        rsaz_512_sqr(temp, temp, m, k0, 4);

        rsaz_512_mul_gather4(temp, temp, table, m, k0, wvalue >> 4);

        rsaz_512_sqr(temp, temp, m, k0, 4);

        rsaz_512_mul_gather4(temp, temp, table, m, k0, wvalue & 0x0f);

    }

    /* from Montgomery */

    rsaz_512_mul_by_one(result, temp, m, k0);

    bn_reduce_once_in_place(result, /*carry=*/0, m, tmp, 8);

    OPENSSL_cleanse(storage, sizeof(storage));

    OPENSSL_cleanse(tmp, sizeof(tmp));

}

#endif