/*

 * Copyright 2002-2024 The OpenSSL Project Authors. 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

 */

#include "bn_local.h"

#include "internal/cryptlib.h"

#define BN_NIST_192_TOP (192+BN_BITS2-1)/BN_BITS2

#define BN_NIST_224_TOP (224+BN_BITS2-1)/BN_BITS2

#define BN_NIST_256_TOP (256+BN_BITS2-1)/BN_BITS2

#define BN_NIST_384_TOP (384+BN_BITS2-1)/BN_BITS2

#define BN_NIST_521_TOP (521+BN_BITS2-1)/BN_BITS2

/* pre-computed tables are "carry-less" values of modulus*(i+1) */

#if BN_BITS2 == 64

static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {

    {0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFEULL, 0xFFFFFFFFFFFFFFFFULL},

    {0xFFFFFFFFFFFFFFFEULL, 0xFFFFFFFFFFFFFFFDULL, 0xFFFFFFFFFFFFFFFFULL},

    {0xFFFFFFFFFFFFFFFDULL, 0xFFFFFFFFFFFFFFFCULL, 0xFFFFFFFFFFFFFFFFULL}

};

static const BN_ULONG _nist_p_192_sqr[] = {

    0x0000000000000001ULL, 0x0000000000000002ULL, 0x0000000000000001ULL,

    0xFFFFFFFFFFFFFFFEULL, 0xFFFFFFFFFFFFFFFDULL, 0xFFFFFFFFFFFFFFFFULL

};

static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {

    {0x0000000000000001ULL, 0xFFFFFFFF00000000ULL,

     0xFFFFFFFFFFFFFFFFULL, 0x00000000FFFFFFFFULL},

    {0x0000000000000002ULL, 0xFFFFFFFE00000000ULL,

     0xFFFFFFFFFFFFFFFFULL, 0x00000001FFFFFFFFULL} /* this one is

                                                    * "carry-full" */

};

static const BN_ULONG _nist_p_224_sqr[] = {

    0x0000000000000001ULL, 0xFFFFFFFE00000000ULL,

    0xFFFFFFFFFFFFFFFFULL, 0x0000000200000000ULL,

    0x0000000000000000ULL, 0xFFFFFFFFFFFFFFFEULL,

    0xFFFFFFFFFFFFFFFFULL

};

static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {

    {0xFFFFFFFFFFFFFFFFULL, 0x00000000FFFFFFFFULL,

     0x0000000000000000ULL, 0xFFFFFFFF00000001ULL},

    {0xFFFFFFFFFFFFFFFEULL, 0x00000001FFFFFFFFULL,

     0x0000000000000000ULL, 0xFFFFFFFE00000002ULL},

    {0xFFFFFFFFFFFFFFFDULL, 0x00000002FFFFFFFFULL,

     0x0000000000000000ULL, 0xFFFFFFFD00000003ULL},

    {0xFFFFFFFFFFFFFFFCULL, 0x00000003FFFFFFFFULL,

     0x0000000000000000ULL, 0xFFFFFFFC00000004ULL},

    {0xFFFFFFFFFFFFFFFBULL, 0x00000004FFFFFFFFULL,

     0x0000000000000000ULL, 0xFFFFFFFB00000005ULL},

};

static const BN_ULONG _nist_p_256_sqr[] = {

    0x0000000000000001ULL, 0xFFFFFFFE00000000ULL,

    0xFFFFFFFFFFFFFFFFULL, 0x00000001FFFFFFFEULL,

    0x00000001FFFFFFFEULL, 0x00000001FFFFFFFEULL,

    0xFFFFFFFE00000001ULL, 0xFFFFFFFE00000002ULL

};

static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {

    {0x00000000FFFFFFFFULL, 0xFFFFFFFF00000000ULL, 0xFFFFFFFFFFFFFFFEULL,

     0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL},

    {0x00000001FFFFFFFEULL, 0xFFFFFFFE00000000ULL, 0xFFFFFFFFFFFFFFFDULL,

     0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL},

    {0x00000002FFFFFFFDULL, 0xFFFFFFFD00000000ULL, 0xFFFFFFFFFFFFFFFCULL,

     0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL},

    {0x00000003FFFFFFFCULL, 0xFFFFFFFC00000000ULL, 0xFFFFFFFFFFFFFFFBULL,

     0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL},

    {0x00000004FFFFFFFBULL, 0xFFFFFFFB00000000ULL, 0xFFFFFFFFFFFFFFFAULL,

     0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL},

};

static const BN_ULONG _nist_p_384_sqr[] = {

    0xFFFFFFFE00000001ULL, 0x0000000200000000ULL, 0xFFFFFFFE00000000ULL,

    0x0000000200000000ULL, 0x0000000000000001ULL, 0x0000000000000000ULL,

    0x00000001FFFFFFFEULL, 0xFFFFFFFE00000000ULL, 0xFFFFFFFFFFFFFFFDULL,

    0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL

};

static const BN_ULONG _nist_p_521[] = {

    0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL,

    0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL,

    0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL,

    0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL,

    0x00000000000001FFULL

};

static const BN_ULONG _nist_p_521_sqr[] = {

    0x0000000000000001ULL, 0x0000000000000000ULL, 0x0000000000000000ULL,

    0x0000000000000000ULL, 0x0000000000000000ULL, 0x0000000000000000ULL,

    0x0000000000000000ULL, 0x0000000000000000ULL, 0xFFFFFFFFFFFFFC00ULL,

    0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL,

    0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL,

    0xFFFFFFFFFFFFFFFFULL, 0x000000000003FFFFULL

};

#elif BN_BITS2 == 32

static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {

    {0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF},

    {0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF},

    {0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFC, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF}

};

static const BN_ULONG _nist_p_192_sqr[] = {

    0x00000001, 0x00000000, 0x00000002, 0x00000000, 0x00000001, 0x00000000,

    0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF

};

static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {

    {0x00000001, 0x00000000, 0x00000000, 0xFFFFFFFF,

     0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF},

    {0x00000002, 0x00000000, 0x00000000, 0xFFFFFFFE,

     0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF}

};

static const BN_ULONG _nist_p_224_sqr[] = {

    0x00000001, 0x00000000, 0x00000000, 0xFFFFFFFE,

    0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000002,

    0x00000000, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFF,

    0xFFFFFFFF, 0xFFFFFFFF

};

static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {

    {0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000,

     0x00000000, 0x00000000, 0x00000001, 0xFFFFFFFF},

    {0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000001,

     0x00000000, 0x00000000, 0x00000002, 0xFFFFFFFE},

    {0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000002,

     0x00000000, 0x00000000, 0x00000003, 0xFFFFFFFD},

    {0xFFFFFFFC, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000003,

     0x00000000, 0x00000000, 0x00000004, 0xFFFFFFFC},

    {0xFFFFFFFB, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000004,

     0x00000000, 0x00000000, 0x00000005, 0xFFFFFFFB},

};

static const BN_ULONG _nist_p_256_sqr[] = {

    0x00000001, 0x00000000, 0x00000000, 0xFFFFFFFE,

    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE, 0x00000001,

    0xFFFFFFFE, 0x00000001, 0xFFFFFFFE, 0x00000001,

    0x00000001, 0xFFFFFFFE, 0x00000002, 0xFFFFFFFE

};

static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {

    {0xFFFFFFFF, 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF,

     0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF},

    {0xFFFFFFFE, 0x00000001, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFD, 0xFFFFFFFF,

     0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF},

    {0xFFFFFFFD, 0x00000002, 0x00000000, 0xFFFFFFFD, 0xFFFFFFFC, 0xFFFFFFFF,

     0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF},

    {0xFFFFFFFC, 0x00000003, 0x00000000, 0xFFFFFFFC, 0xFFFFFFFB, 0xFFFFFFFF,

     0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF},

    {0xFFFFFFFB, 0x00000004, 0x00000000, 0xFFFFFFFB, 0xFFFFFFFA, 0xFFFFFFFF,

     0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF},

};

static const BN_ULONG _nist_p_384_sqr[] = {

    0x00000001, 0xFFFFFFFE, 0x00000000, 0x00000002, 0x00000000, 0xFFFFFFFE,

    0x00000000, 0x00000002, 0x00000001, 0x00000000, 0x00000000, 0x00000000,

    0xFFFFFFFE, 0x00000001, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFD, 0xFFFFFFFF,

    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF

};

static const BN_ULONG _nist_p_521[] = { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,

    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,

    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,

    0xFFFFFFFF, 0x000001FF

};

static const BN_ULONG _nist_p_521_sqr[] = {

    0x00000001, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,

    0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,

    0x00000000, 0x00000000, 0x00000000, 0x00000000, 0xFFFFFC00, 0xFFFFFFFF,

    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,

    0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF,

    0xFFFFFFFF, 0xFFFFFFFF, 0x0003FFFF

};

#else

# error "unsupported BN_BITS2"

#endif

static const BIGNUM ossl_bignum_nist_p_192 = {

    (BN_ULONG *)_nist_p_192[0],

    BN_NIST_192_TOP,

    BN_NIST_192_TOP,

    0,

    BN_FLG_STATIC_DATA

};

static const BIGNUM ossl_bignum_nist_p_224 = {

    (BN_ULONG *)_nist_p_224[0],

    BN_NIST_224_TOP,

    BN_NIST_224_TOP,

    0,

    BN_FLG_STATIC_DATA

};

static const BIGNUM ossl_bignum_nist_p_256 = {

    (BN_ULONG *)_nist_p_256[0],

    BN_NIST_256_TOP,

    BN_NIST_256_TOP,

    0,

    BN_FLG_STATIC_DATA

};

static const BIGNUM ossl_bignum_nist_p_384 = {

    (BN_ULONG *)_nist_p_384[0],

    BN_NIST_384_TOP,

    BN_NIST_384_TOP,

    0,

    BN_FLG_STATIC_DATA

};

static const BIGNUM ossl_bignum_nist_p_521 = {

    (BN_ULONG *)_nist_p_521,

    BN_NIST_521_TOP,

    BN_NIST_521_TOP,

    0,

    BN_FLG_STATIC_DATA

};

const BIGNUM *BN_get0_nist_prime_192(void)

{

    return &ossl_bignum_nist_p_192;

}

const BIGNUM *BN_get0_nist_prime_224(void)

{

    return &ossl_bignum_nist_p_224;

}

const BIGNUM *BN_get0_nist_prime_256(void)

{

    return &ossl_bignum_nist_p_256;

}

const BIGNUM *BN_get0_nist_prime_384(void)

{

    return &ossl_bignum_nist_p_384;

}

const BIGNUM *BN_get0_nist_prime_521(void)

{

    return &ossl_bignum_nist_p_521;

}

/*

 * To avoid more recent compilers (specifically clang-14) from treating this

 * code as a violation of the strict aliasing conditions and omitting it, this

 * cannot be declared as a function.  Moreover, the dst parameter cannot be

 * cached in a local since this no longer references the union and again falls

 * foul of the strict aliasing criteria.  Refer to #18225 for the initial

 * diagnostics and llvm/llvm-project#55255 for the later discussions with the

 * LLVM developers.  The problem boils down to if an array in the union is

 * converted to a pointer or if it is used directly.

 *

 * This function was inlined regardless, so there is no space cost to be

 * paid for making it a macro.

 */

#define nist_cp_bn_0(dst, src_in, top, max) \

{                                           \

    int ii;                                 \

    const BN_ULONG *src = src_in;           \

                                            \

    for (ii = 0; ii < top; ii++)            \

        (dst)[ii] = src[ii];                \

    for (; ii < max; ii++)                  \

        (dst)[ii] = 0;                      \

}

static void nist_cp_bn(BN_ULONG *dst, const BN_ULONG *src, int top)

{

    int i;

    for (i = 0; i < top; i++)

        dst[i] = src[i];

}

#if BN_BITS2 == 64

# define bn_cp_64(to, n, from, m)        (to)[n] = (m>=0)?((from)[m]):0;

# define bn_64_set_0(to, n)              (to)[n] = (BN_ULONG)0;

/*

 * two following macros are implemented under assumption that they

 * are called in a sequence with *ascending* n, i.e. as they are...

 */

# define bn_cp_32_naked(to, n, from, m)  (((n)&1)?(to[(n)/2]|=((m)&1)?(from[(m)/2]&BN_MASK2h):(from[(m)/2]<<32))\

                                                :(to[(n)/2] =((m)&1)?(from[(m)/2]>>32):(from[(m)/2]&BN_MASK2l)))

# define bn_32_set_0(to, n)              (((n)&1)?(to[(n)/2]&=BN_MASK2l):(to[(n)/2]=0));

# define bn_cp_32(to,n,from,m)           ((m)>=0)?bn_cp_32_naked(to,n,from,m):bn_32_set_0(to,n)

# if defined(L_ENDIAN)

#  if defined(__arch64__)

#   define NIST_INT64 long

#  else

#   define NIST_INT64 long long

#  endif

# endif

#else

# define bn_cp_64(to, n, from, m) \

        { \

        bn_cp_32(to, (n)*2, from, (m)*2); \

        bn_cp_32(to, (n)*2+1, from, (m)*2+1); \

        }

# define bn_64_set_0(to, n) \

        { \

        bn_32_set_0(to, (n)*2); \

        bn_32_set_0(to, (n)*2+1); \

        }

# define bn_cp_32(to, n, from, m)        (to)[n] = (m>=0)?((from)[m]):0;

# define bn_32_set_0(to, n)              (to)[n] = (BN_ULONG)0;

# if defined(_WIN32) && !defined(__GNUC__)

#  define NIST_INT64 __int64

# elif defined(BN_LLONG)

#  define NIST_INT64 long long

# endif

#endif                          /* BN_BITS2 != 64 */

#ifdef NIST_INT64

/* Helpers to load/store a 32-bit word (uint32_t) from/into a memory

 * location and avoid potential aliasing issue.  */

static ossl_inline uint32_t load_u32(const void *ptr)

{

    uint32_t tmp;

    memcpy(&tmp, ptr, sizeof(tmp));

    return tmp;

}

static ossl_inline void store_lo32(void *ptr, NIST_INT64 val)

{

    /* A cast is needed for big-endian system: on a 32-bit BE system

     * NIST_INT64 may be defined as well if the compiler supports 64-bit

     * long long.  */

    uint32_t tmp = (uint32_t)val;

    memcpy(ptr, &tmp, sizeof(tmp));

}

#endif /* NIST_INT64 */

#define nist_set_192(to, from, a1, a2, a3) \

        { \

        bn_cp_64(to, 0, from, (a3) - 3) \

        bn_cp_64(to, 1, from, (a2) - 3) \

        bn_cp_64(to, 2, from, (a1) - 3) \

        }

int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,

                    BN_CTX *ctx)

{

    int top = a->top, i;

    int carry;

    register BN_ULONG *r_d, *a_d = a->d;

    union {

        BN_ULONG bn[BN_NIST_192_TOP];

        unsigned int ui[BN_NIST_192_TOP * sizeof(BN_ULONG) /

                        sizeof(unsigned int)];

    } buf;

    BN_ULONG c_d[BN_NIST_192_TOP], *res;

    static const BIGNUM ossl_bignum_nist_p_192_sqr = {

        (BN_ULONG *)_nist_p_192_sqr,

        OSSL_NELEM(_nist_p_192_sqr),

        OSSL_NELEM(_nist_p_192_sqr),

        0, BN_FLG_STATIC_DATA

    };

    field = &ossl_bignum_nist_p_192; /* just to make sure */

    if (BN_is_negative(a) || BN_ucmp(a, &ossl_bignum_nist_p_192_sqr) >= 0)

        return BN_nnmod(r, a, field, ctx);

    i = BN_ucmp(field, a);

    if (i == 0) {

        BN_zero(r);

        return 1;

    } else if (i > 0)

        return (r == a) ? 1 : (BN_copy(r, a) != NULL);

    if (r != a) {

        if (!bn_wexpand(r, BN_NIST_192_TOP))

            return 0;

        r_d = r->d;

        nist_cp_bn(r_d, a_d, BN_NIST_192_TOP);

    } else

        r_d = a_d;

    nist_cp_bn_0(buf.bn, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP,

                 BN_NIST_192_TOP);

#if defined(NIST_INT64)

    {

        NIST_INT64 acc;         /* accumulator */

        unsigned int *rp = (unsigned int *)r_d;

        const unsigned int *bp = (const unsigned int *)buf.ui;

        acc = load_u32(&rp[0]);

        acc += bp[3 * 2 - 6];

        acc += bp[5 * 2 - 6];

        store_lo32(&rp[0], acc);

        acc >>= 32;

        acc += load_u32(&rp[1]);

        acc += bp[3 * 2 - 5];

        acc += bp[5 * 2 - 5];

        store_lo32(&rp[1], acc);

        acc >>= 32;

        acc += load_u32(&rp[2]);

        acc += bp[3 * 2 - 6];

        acc += bp[4 * 2 - 6];

        acc += bp[5 * 2 - 6];

        store_lo32(&rp[2], acc);

        acc >>= 32;

        acc += load_u32(&rp[3]);

        acc += bp[3 * 2 - 5];

        acc += bp[4 * 2 - 5];

        acc += bp[5 * 2 - 5];

        store_lo32(&rp[3], acc);

        acc >>= 32;

        acc += load_u32(&rp[4]);

        acc += bp[4 * 2 - 6];

        acc += bp[5 * 2 - 6];

        store_lo32(&rp[4], acc);

        acc >>= 32;

        acc += load_u32(&rp[5]);

        acc += bp[4 * 2 - 5];

        acc += bp[5 * 2 - 5];

        store_lo32(&rp[5], acc);

        carry = (int)(acc >> 32);

    }

#else

    {

        BN_ULONG t_d[BN_NIST_192_TOP];

        nist_set_192(t_d, buf.bn, 0, 3, 3);

        carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);

        nist_set_192(t_d, buf.bn, 4, 4, 0);

        carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);

        nist_set_192(t_d, buf.bn, 5, 5, 5)

            carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);

    }

#endif

    if (carry > 0)

        carry =

            (int)bn_sub_words(r_d, r_d, _nist_p_192[carry - 1],

                              BN_NIST_192_TOP);

    else

        carry = 1;

    /*

     * we need 'if (carry==0 || result>=modulus) result-=modulus;'

     * as comparison implies subtraction, we can write

     * 'tmp=result-modulus; if (!carry || !borrow) result=tmp;'

     * this is what happens below, but without explicit if:-) a.

     */

    res = (bn_sub_words(c_d, r_d, _nist_p_192[0], BN_NIST_192_TOP) && carry)

        ? r_d

        : c_d;

    nist_cp_bn(r_d, res, BN_NIST_192_TOP);

    r->top = BN_NIST_192_TOP;

    bn_correct_top(r);

    return 1;

}

typedef BN_ULONG (*bn_addsub_f) (BN_ULONG *, const BN_ULONG *,

                                 const BN_ULONG *, int);

#define nist_set_224(to, from, a1, a2, a3, a4, a5, a6, a7) \

        { \

        bn_cp_32(to, 0, from, (a7) - 7) \

        bn_cp_32(to, 1, from, (a6) - 7) \

        bn_cp_32(to, 2, from, (a5) - 7) \

        bn_cp_32(to, 3, from, (a4) - 7) \

        bn_cp_32(to, 4, from, (a3) - 7) \

        bn_cp_32(to, 5, from, (a2) - 7) \

        bn_cp_32(to, 6, from, (a1) - 7) \

        }

int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,

                    BN_CTX *ctx)

{

    int top = a->top, i;

    int carry;

    BN_ULONG *r_d, *a_d = a->d;

    union {

        BN_ULONG bn[BN_NIST_224_TOP];

        unsigned int ui[BN_NIST_224_TOP * sizeof(BN_ULONG) /

                        sizeof(unsigned int)];

    } buf;

    BN_ULONG c_d[BN_NIST_224_TOP], *res;

    bn_addsub_f adjust;

    static const BIGNUM ossl_bignum_nist_p_224_sqr = {

        (BN_ULONG *)_nist_p_224_sqr,

        OSSL_NELEM(_nist_p_224_sqr),

        OSSL_NELEM(_nist_p_224_sqr),

        0, BN_FLG_STATIC_DATA

    };

    field = &ossl_bignum_nist_p_224; /* just to make sure */

    if (BN_is_negative(a) || BN_ucmp(a, &ossl_bignum_nist_p_224_sqr) >= 0)

        return BN_nnmod(r, a, field, ctx);

    i = BN_ucmp(field, a);

    if (i == 0) {

        BN_zero(r);

        return 1;

    } else if (i > 0)

        return (r == a) ? 1 : (BN_copy(r, a) != NULL);

    if (r != a) {

        if (!bn_wexpand(r, BN_NIST_224_TOP))

            return 0;

        r_d = r->d;

        nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);

    } else

        r_d = a_d;

#if BN_BITS2==64

    /* copy upper 256 bits of 448 bit number ... */

    nist_cp_bn_0(c_d, a_d + (BN_NIST_224_TOP - 1),

                 top - (BN_NIST_224_TOP - 1), BN_NIST_224_TOP);

    /* ... and right shift by 32 to obtain upper 224 bits */

    nist_set_224(buf.bn, c_d, 14, 13, 12, 11, 10, 9, 8);

    /* truncate lower part to 224 bits too */

    r_d[BN_NIST_224_TOP - 1] &= BN_MASK2l;

#else

    nist_cp_bn_0(buf.bn, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP,

                 BN_NIST_224_TOP);

#endif

#if defined(NIST_INT64) && BN_BITS2!=64

    {

        NIST_INT64 acc;         /* accumulator */

        unsigned int *rp = (unsigned int *)r_d;

        const unsigned int *bp = (const unsigned int *)buf.ui;

        acc = rp[0];

        acc -= bp[7 - 7];

        acc -= bp[11 - 7];

        rp[0] = (unsigned int)acc;

        acc >>= 32;

        acc += rp[1];

        acc -= bp[8 - 7];

        acc -= bp[12 - 7];

        rp[1] = (unsigned int)acc;

        acc >>= 32;

        acc += rp[2];

        acc -= bp[9 - 7];

        acc -= bp[13 - 7];

        rp[2] = (unsigned int)acc;

        acc >>= 32;

        acc += rp[3];

        acc += bp[7 - 7];

        acc += bp[11 - 7];

        acc -= bp[10 - 7];

        rp[3] = (unsigned int)acc;

        acc >>= 32;

        acc += rp[4];

        acc += bp[8 - 7];

        acc += bp[12 - 7];

        acc -= bp[11 - 7];

        rp[4] = (unsigned int)acc;

        acc >>= 32;

        acc += rp[5];

        acc += bp[9 - 7];

        acc += bp[13 - 7];

        acc -= bp[12 - 7];

        rp[5] = (unsigned int)acc;

        acc >>= 32;

        acc += rp[6];

        acc += bp[10 - 7];

        acc -= bp[13 - 7];

        rp[6] = (unsigned int)acc;

        carry = (int)(acc >> 32);

# if BN_BITS2==64

        rp[7] = carry;

# endif

    }

#else

    {

        BN_ULONG t_d[BN_NIST_224_TOP];

        nist_set_224(t_d, buf.bn, 10, 9, 8, 7, 0, 0, 0);

        carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);

        nist_set_224(t_d, buf.bn, 0, 13, 12, 11, 0, 0, 0);

        carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);

        nist_set_224(t_d, buf.bn, 13, 12, 11, 10, 9, 8, 7);

        carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);

        nist_set_224(t_d, buf.bn, 0, 0, 0, 0, 13, 12, 11);

        carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);

# if BN_BITS2==64

        carry = (int)(r_d[BN_NIST_224_TOP - 1] >> 32);

# endif

    }

#endif

    adjust = bn_sub_words;

    if (carry > 0) {

        carry =

            (int)bn_sub_words(r_d, r_d, _nist_p_224[carry - 1],

                              BN_NIST_224_TOP);

#if BN_BITS2==64

        carry = (int)(~(r_d[BN_NIST_224_TOP - 1] >> 32)) & 1;

#endif

    } else if (carry < 0) {

        /*

         * it's a bit more complicated logic in this case. if bn_add_words

         * yields no carry, then result has to be adjusted by unconditionally

         * *adding* the modulus. but if it does, then result has to be

         * compared to the modulus and conditionally adjusted by

         * *subtracting* the latter.

         */

        carry =

            (int)bn_add_words(r_d, r_d, _nist_p_224[-carry - 1],

                              BN_NIST_224_TOP);

        adjust = carry ? bn_sub_words : bn_add_words;

    } else

        carry = 1;

    /* otherwise it's effectively same as in BN_nist_mod_192... */

    res = ((*adjust) (c_d, r_d, _nist_p_224[0], BN_NIST_224_TOP) && carry)

        ? r_d

        : c_d;

    nist_cp_bn(r_d, res, BN_NIST_224_TOP);

    r->top = BN_NIST_224_TOP;

    bn_correct_top(r);

    return 1;

}

#define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \

        { \

        bn_cp_32(to, 0, from, (a8) - 8) \

        bn_cp_32(to, 1, from, (a7) - 8) \

        bn_cp_32(to, 2, from, (a6) - 8) \

        bn_cp_32(to, 3, from, (a5) - 8) \

        bn_cp_32(to, 4, from, (a4) - 8) \

        bn_cp_32(to, 5, from, (a3) - 8) \

        bn_cp_32(to, 6, from, (a2) - 8) \

        bn_cp_32(to, 7, from, (a1) - 8) \

        }

int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,

                    BN_CTX *ctx)

{

    int i, top = a->top;

    int carry = 0;

    register BN_ULONG *a_d = a->d, *r_d;

    union {

        BN_ULONG bn[BN_NIST_256_TOP];

        unsigned int ui[BN_NIST_256_TOP * sizeof(BN_ULONG) /

                        sizeof(unsigned int)];

    } buf;

    BN_ULONG c_d[BN_NIST_256_TOP], *res;

    bn_addsub_f adjust;

    static const BIGNUM ossl_bignum_nist_p_256_sqr = {

        (BN_ULONG *)_nist_p_256_sqr,

        OSSL_NELEM(_nist_p_256_sqr),

        OSSL_NELEM(_nist_p_256_sqr),

        0, BN_FLG_STATIC_DATA

    };

    field = &ossl_bignum_nist_p_256; /* just to make sure */

    if (BN_is_negative(a) || BN_ucmp(a, &ossl_bignum_nist_p_256_sqr) >= 0)

        return BN_nnmod(r, a, field, ctx);

    i = BN_ucmp(field, a);

    if (i == 0) {

        BN_zero(r);

        return 1;

    } else if (i > 0)

        return (r == a) ? 1 : (BN_copy(r, a) != NULL);

    if (r != a) {

        if (!bn_wexpand(r, BN_NIST_256_TOP))

            return 0;

        r_d = r->d;

        nist_cp_bn(r_d, a_d, BN_NIST_256_TOP);

    } else

        r_d = a_d;

    nist_cp_bn_0(buf.bn, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP,

                 BN_NIST_256_TOP);

#if defined(NIST_INT64)

    {

        NIST_INT64 acc;         /* accumulator */

        unsigned int *rp = (unsigned int *)r_d;

        const unsigned int *bp = (const unsigned int *)buf.ui;

        acc = load_u32(&rp[0]);

        acc += bp[8 - 8];

        acc += bp[9 - 8];

        acc -= bp[11 - 8];

        acc -= bp[12 - 8];

        acc -= bp[13 - 8];

        acc -= bp[14 - 8];

        store_lo32(&rp[0], acc);

        acc >>= 32;

        acc += load_u32(&rp[1]);

        acc += bp[9 - 8];

        acc += bp[10 - 8];

        acc -= bp[12 - 8];

        acc -= bp[13 - 8];

        acc -= bp[14 - 8];

        acc -= bp[15 - 8];

        store_lo32(&rp[1], acc);

        acc >>= 32;

        acc += load_u32(&rp[2]);

        acc += bp[10 - 8];

        acc += bp[11 - 8];

        acc -= bp[13 - 8];

        acc -= bp[14 - 8];

        acc -= bp[15 - 8];

        store_lo32(&rp[2], acc);

        acc >>= 32;

        acc += load_u32(&rp[3]);

        acc += bp[11 - 8];

        acc += bp[11 - 8];

        acc += bp[12 - 8];

        acc += bp[12 - 8];

        acc += bp[13 - 8];

        acc -= bp[15 - 8];

        acc -= bp[8 - 8];

        acc -= bp[9 - 8];

        store_lo32(&rp[3], acc);

        acc >>= 32;

        acc += load_u32(&rp[4]);

        acc += bp[12 - 8];

        acc += bp[12 - 8];

        acc += bp[13 - 8];

        acc += bp[13 - 8];

        acc += bp[14 - 8];

        acc -= bp[9 - 8];

        acc -= bp[10 - 8];

        store_lo32(&rp[4], acc);

        acc >>= 32;

        acc += load_u32(&rp[5]);

        acc += bp[13 - 8];

        acc += bp[13 - 8];

        acc += bp[14 - 8];

        acc += bp[14 - 8];

        acc += bp[15 - 8];

        acc -= bp[10 - 8];

        acc -= bp[11 - 8];

        store_lo32(&rp[5], acc);

        acc >>= 32;

        acc += load_u32(&rp[6]);

        acc += bp[14 - 8];

        acc += bp[14 - 8];

        acc += bp[15 - 8];

        acc += bp[15 - 8];

        acc += bp[14 - 8];

        acc += bp[13 - 8];

        acc -= bp[8 - 8];

        acc -= bp[9 - 8];

        store_lo32(&rp[6], acc);

        acc >>= 32;

        acc += load_u32(&rp[7]);

        acc += bp[15 - 8];

        acc += bp[15 - 8];

        acc += bp[15 - 8];

        acc += bp[8 - 8];

        acc -= bp[10 - 8];

        acc -= bp[11 - 8];

        acc -= bp[12 - 8];

        acc -= bp[13 - 8];

        store_lo32(&rp[7], acc);

        carry = (int)(acc >> 32);

    }

#else

    {

        BN_ULONG t_d[BN_NIST_256_TOP];

        /*

         * S1

         */

        nist_set_256(t_d, buf.bn, 15, 14, 13, 12, 11, 0, 0, 0);

        /*

         * S2

         */

        nist_set_256(c_d, buf.bn, 0, 15, 14, 13, 12, 0, 0, 0);

        carry = (int)bn_add_words(t_d, t_d, c_d, BN_NIST_256_TOP);

        /* left shift */

        {

            register BN_ULONG *ap, t, c;

            ap = t_d;

            c = 0;

            for (i = BN_NIST_256_TOP; i != 0; --i) {

                t = *ap;

                *(ap++) = ((t << 1) | c) & BN_MASK2;

                c = (t & BN_TBIT) ? 1 : 0;

            }

            carry <<= 1;

            carry |= c;

        }

        carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);

        /*

         * S3

         */

        nist_set_256(t_d, buf.bn, 15, 14, 0, 0, 0, 10, 9, 8);

        carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);

        /*

         * S4

         */

        nist_set_256(t_d, buf.bn, 8, 13, 15, 14, 13, 11, 10, 9);

        carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);

        /*

         * D1

         */

        nist_set_256(t_d, buf.bn, 10, 8, 0, 0, 0, 13, 12, 11);

        carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);

        /*

         * D2

         */

        nist_set_256(t_d, buf.bn, 11, 9, 0, 0, 15, 14, 13, 12);

        carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);

        /*

         * D3

         */

        nist_set_256(t_d, buf.bn, 12, 0, 10, 9, 8, 15, 14, 13);

        carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);

        /*

         * D4

         */

        nist_set_256(t_d, buf.bn, 13, 0, 11, 10, 9, 0, 15, 14);

        carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);

    }

#endif

    /* see BN_nist_mod_224 for explanation */

    adjust = bn_sub_words;

    if (carry > 0)

        carry =

            (int)bn_sub_words(r_d, r_d, _nist_p_256[carry - 1],

                              BN_NIST_256_TOP);

    else if (carry < 0) {

        carry =

            (int)bn_add_words(r_d, r_d, _nist_p_256[-carry - 1],

                              BN_NIST_256_TOP);

        adjust = carry ? bn_sub_words : bn_add_words;

    } else

        carry = 1;

    res = ((*adjust) (c_d, r_d, _nist_p_256[0], BN_NIST_256_TOP) && carry)

        ? r_d

        : c_d;

    nist_cp_bn(r_d, res, BN_NIST_256_TOP);

    r->top = BN_NIST_256_TOP;

    bn_correct_top(r);

    return 1;

}

#define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \

        { \

        bn_cp_32(to, 0, from,  (a12) - 12) \

        bn_cp_32(to, 1, from,  (a11) - 12) \

        bn_cp_32(to, 2, from,  (a10) - 12) \

        bn_cp_32(to, 3, from,  (a9) - 12)  \

        bn_cp_32(to, 4, from,  (a8) - 12)  \

        bn_cp_32(to, 5, from,  (a7) - 12)  \

        bn_cp_32(to, 6, from,  (a6) - 12)  \

        bn_cp_32(to, 7, from,  (a5) - 12)  \

        bn_cp_32(to, 8, from,  (a4) - 12)  \

        bn_cp_32(to, 9, from,  (a3) - 12)  \

        bn_cp_32(to, 10, from, (a2) - 12)  \

        bn_cp_32(to, 11, from, (a1) - 12)  \

        }

int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,

                    BN_CTX *ctx)

{

    int i, top = a->top;

    int carry = 0;

    register BN_ULONG *r_d, *a_d = a->d;

    union {

        BN_ULONG bn[BN_NIST_384_TOP];

        unsigned int ui[BN_NIST_384_TOP * sizeof(BN_ULONG) /

                        sizeof(unsigned int)];

    } buf;

    BN_ULONG c_d[BN_NIST_384_TOP], *res;

    bn_addsub_f adjust;

    static const BIGNUM ossl_bignum_nist_p_384_sqr = {

        (BN_ULONG *)_nist_p_384_sqr,

        OSSL_NELEM(_nist_p_384_sqr),

        OSSL_NELEM(_nist_p_384_sqr),

        0, BN_FLG_STATIC_DATA

    };

    field = &ossl_bignum_nist_p_384; /* just to make sure */

    if (BN_is_negative(a) || BN_ucmp(a, &ossl_bignum_nist_p_384_sqr) >= 0)

        return BN_nnmod(r, a, field, ctx);

    i = BN_ucmp(field, a);

    if (i == 0) {

        BN_zero(r);

        return 1;

    } else if (i > 0)

        return (r == a) ? 1 : (BN_copy(r, a) != NULL);

    if (r != a) {

        if (!bn_wexpand(r, BN_NIST_384_TOP))

            return 0;

        r_d = r->d;

        nist_cp_bn(r_d, a_d, BN_NIST_384_TOP);

    } else

        r_d = a_d;

    nist_cp_bn_0(buf.bn, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP,

                 BN_NIST_384_TOP);

#if defined(NIST_INT64)

    {

        NIST_INT64 acc;         /* accumulator */

        unsigned int *rp = (unsigned int *)r_d;

        const unsigned int *bp = (const unsigned int *)buf.ui;

        acc = load_u32(&rp[0]);

        acc += bp[12 - 12];

        acc += bp[21 - 12];

        acc += bp[20 - 12];

        acc -= bp[23 - 12];

        store_lo32(&rp[0], acc);

        acc >>= 32;

        acc += load_u32(&rp[1]);

        acc += bp[13 - 12];

        acc += bp[22 - 12];

        acc += bp[23 - 12];

        acc -= bp[12 - 12];

        acc -= bp[20 - 12];

        store_lo32(&rp[1], acc);

        acc >>= 32;