/*

 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (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 <openssl/blowfish.h>

#include "bf_locl.h"

/*

 * Blowfish as implemented from 'Blowfish: Springer-Verlag paper' (From

 * LECTURE NOTES IN COMPUTER SCIENCE 809, FAST SOFTWARE ENCRYPTION, CAMBRIDGE

 * SECURITY WORKSHOP, CAMBRIDGE, U.K., DECEMBER 9-11, 1993)

 */

#if (BF_ROUNDS != 16) && (BF_ROUNDS != 20)

# error If you set BF_ROUNDS to some value other than 16 or 20, you will have \

to modify the code.

#endif

void BF_encrypt(BF_LONG *data, const BF_KEY *key)

{

    register BF_LONG l, r;

    register const BF_LONG *p, *s;

    p = key->P;

    s = &(key->S[0]);

    l = data[0];

    r = data[1];

    l ^= p[0];

    BF_ENC(r, l, s, p[1]);

    BF_ENC(l, r, s, p[2]);

    BF_ENC(r, l, s, p[3]);

    BF_ENC(l, r, s, p[4]);

    BF_ENC(r, l, s, p[5]);

    BF_ENC(l, r, s, p[6]);

    BF_ENC(r, l, s, p[7]);

    BF_ENC(l, r, s, p[8]);

    BF_ENC(r, l, s, p[9]);

    BF_ENC(l, r, s, p[10]);

    BF_ENC(r, l, s, p[11]);

    BF_ENC(l, r, s, p[12]);

    BF_ENC(r, l, s, p[13]);

    BF_ENC(l, r, s, p[14]);

    BF_ENC(r, l, s, p[15]);

    BF_ENC(l, r, s, p[16]);

# if BF_ROUNDS == 20

    BF_ENC(r, l, s, p[17]);

    BF_ENC(l, r, s, p[18]);

    BF_ENC(r, l, s, p[19]);

    BF_ENC(l, r, s, p[20]);

# endif

    r ^= p[BF_ROUNDS + 1];

    data[1] = l & 0xffffffffU;

    data[0] = r & 0xffffffffU;

}

void BF_decrypt(BF_LONG *data, const BF_KEY *key)

{

    register BF_LONG l, r;

    register const BF_LONG *p, *s;

    p = key->P;

    s = &(key->S[0]);

    l = data[0];

    r = data[1];

    l ^= p[BF_ROUNDS + 1];

#  if BF_ROUNDS == 20

    BF_ENC(r, l, s, p[20]);

    BF_ENC(l, r, s, p[19]);

    BF_ENC(r, l, s, p[18]);

    BF_ENC(l, r, s, p[17]);

#  endif

    BF_ENC(r, l, s, p[16]);

    BF_ENC(l, r, s, p[15]);

    BF_ENC(r, l, s, p[14]);

    BF_ENC(l, r, s, p[13]);

    BF_ENC(r, l, s, p[12]);

    BF_ENC(l, r, s, p[11]);

    BF_ENC(r, l, s, p[10]);

    BF_ENC(l, r, s, p[9]);

    BF_ENC(r, l, s, p[8]);

    BF_ENC(l, r, s, p[7]);

    BF_ENC(r, l, s, p[6]);

    BF_ENC(l, r, s, p[5]);

    BF_ENC(r, l, s, p[4]);

    BF_ENC(l, r, s, p[3]);

    BF_ENC(r, l, s, p[2]);

    BF_ENC(l, r, s, p[1]);

    r ^= p[0];

    data[1] = l & 0xffffffffU;

    data[0] = r & 0xffffffffU;

}

void BF_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,

                    const BF_KEY *schedule, unsigned char *ivec, int encrypt)

{

    register BF_LONG tin0, tin1;

    register BF_LONG tout0, tout1, xor0, xor1;

    register long l = length;

    BF_LONG tin[2];

    if (encrypt) {

        n2l(ivec, tout0);

        n2l(ivec, tout1);

        ivec -= 8;

        for (l -= 8; l >= 0; l -= 8) {

            n2l(in, tin0);

            n2l(in, tin1);

            tin0 ^= tout0;

            tin1 ^= tout1;

            tin[0] = tin0;

            tin[1] = tin1;

            BF_encrypt(tin, schedule);

            tout0 = tin[0];

            tout1 = tin[1];

            l2n(tout0, out);

            l2n(tout1, out);

        }

        if (l != -8) {

            n2ln(in, tin0, tin1, l + 8);

            tin0 ^= tout0;

            tin1 ^= tout1;

            tin[0] = tin0;

            tin[1] = tin1;

            BF_encrypt(tin, schedule);

            tout0 = tin[0];

            tout1 = tin[1];

            l2n(tout0, out);

            l2n(tout1, out);

        }

        l2n(tout0, ivec);

        l2n(tout1, ivec);

    } else {

        n2l(ivec, xor0);

        n2l(ivec, xor1);

        ivec -= 8;

        for (l -= 8; l >= 0; l -= 8) {

            n2l(in, tin0);

            n2l(in, tin1);

            tin[0] = tin0;

            tin[1] = tin1;

            BF_decrypt(tin, schedule);

            tout0 = tin[0] ^ xor0;

            tout1 = tin[1] ^ xor1;

            l2n(tout0, out);

            l2n(tout1, out);

            xor0 = tin0;

            xor1 = tin1;

        }

        if (l != -8) {

            n2l(in, tin0);

            n2l(in, tin1);

            tin[0] = tin0;

            tin[1] = tin1;

            BF_decrypt(tin, schedule);

            tout0 = tin[0] ^ xor0;

            tout1 = tin[1] ^ xor1;

            l2nn(tout0, tout1, out, l + 8);

            xor0 = tin0;

            xor1 = tin1;

        }

        l2n(xor0, ivec);

        l2n(xor1, ivec);

    }

    tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;

    tin[0] = tin[1] = 0;

}