/* ====================================================================

 * Copyright (c) 2008 The OpenSSL Project.  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.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@openssl.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED 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 OpenSSL PROJECT OR

 * ITS 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 <openssl/crypto.h>

#include "modes_lcl.h"

#include <string.h>

#ifndef MODES_DEBUG

# ifndef NDEBUG

#  define NDEBUG

# endif

#endif

#include <assert.h>

#if !defined(STRICT_ALIGNMENT) && !defined(PEDANTIC)

# define STRICT_ALIGNMENT 0

#endif

void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,

                           size_t len, const void *key,

                           unsigned char ivec[16], block128_f block)

{

    size_t n;

    const unsigned char *iv = ivec;

    assert(in && out && key && ivec);

#if !defined(OPENSSL_SMALL_FOOTPRINT)

    if (STRICT_ALIGNMENT &&

        ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {

        while (len >= 16) {

            for (n = 0; n < 16; ++n)

                out[n] = in[n] ^ iv[n];

            (*block) (out, out, key);

            iv = out;

            len -= 16;

            in += 16;

            out += 16;

        }

    } else {

        while (len >= 16) {

            for (n = 0; n < 16; n += sizeof(size_t))

                *(size_t *)(out + n) =

                    *(size_t *)(in + n) ^ *(size_t *)(iv + n);

            (*block) (out, out, key);

            iv = out;

            len -= 16;

            in += 16;

            out += 16;

        }

    }

#endif

    while (len) {

        for (n = 0; n < 16 && n < len; ++n)

            out[n] = in[n] ^ iv[n];

        for (; n < 16; ++n)

            out[n] = iv[n];

        (*block) (out, out, key);

        iv = out;

        if (len <= 16)

            break;

        len -= 16;

        in += 16;

        out += 16;

    }

    memcpy(ivec, iv, 16);

}

void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,

                           size_t len, const void *key,

                           unsigned char ivec[16], block128_f block)

{

    size_t n;

    union {

        size_t t[16 / sizeof(size_t)];

        unsigned char c[16];

    } tmp;

    assert(in && out && key && ivec);

#if !defined(OPENSSL_SMALL_FOOTPRINT)

    if (in != out) {

        const unsigned char *iv = ivec;

        if (STRICT_ALIGNMENT &&

            ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {

            while (len >= 16) {

                (*block) (in, out, key);

                for (n = 0; n < 16; ++n)

                    out[n] ^= iv[n];

                iv = in;

                len -= 16;

                in += 16;

                out += 16;

            }

        } else if (16 % sizeof(size_t) == 0) { /* always true */

            while (len >= 16) {

                size_t *out_t = (size_t *)out, *iv_t = (size_t *)iv;

                (*block) (in, out, key);

                for (n = 0; n < 16 / sizeof(size_t); n++)

                    out_t[n] ^= iv_t[n];

                iv = in;

                len -= 16;

                in += 16;

                out += 16;

            }

        }

        memcpy(ivec, iv, 16);

    } else {

        if (STRICT_ALIGNMENT &&

            ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {

            unsigned char c;

            while (len >= 16) {

                (*block) (in, tmp.c, key);

                for (n = 0; n < 16; ++n) {

                    c = in[n];

                    out[n] = tmp.c[n] ^ ivec[n];

                    ivec[n] = c;

                }

                len -= 16;

                in += 16;

                out += 16;

            }

        } else if (16 % sizeof(size_t) == 0) { /* always true */

            while (len >= 16) {

                size_t c, *out_t = (size_t *)out, *ivec_t = (size_t *)ivec;

                const size_t *in_t = (const size_t *)in;

                (*block) (in, tmp.c, key);

                for (n = 0; n < 16 / sizeof(size_t); n++) {

                    c = in_t[n];

                    out_t[n] = tmp.t[n] ^ ivec_t[n];

                    ivec_t[n] = c;

                }

                len -= 16;

                in += 16;

                out += 16;

            }

        }

    }

#endif

    while (len) {

        unsigned char c;

        (*block) (in, tmp.c, key);

        for (n = 0; n < 16 && n < len; ++n) {

            c = in[n];

            out[n] = tmp.c[n] ^ ivec[n];

            ivec[n] = c;

        }

        if (len <= 16) {

            for (; n < 16; ++n)

                ivec[n] = in[n];

            break;

        }

        len -= 16;

        in += 16;

        out += 16;

    }

}