/*

 * Copyright 2005-2016 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

 */

/**

 * The Whirlpool hashing function.

 *

 * See

 *      P.S.L.M. Barreto, V. Rijmen,

 *      ``The Whirlpool hashing function,''

 *      NESSIE submission, 2000 (tweaked version, 2001),

 *      <https://www.cosic.esat.kuleuven.ac.be/nessie/workshop/submissions/whirlpool.zip>

 *

 * Based on "@version 3.0 (2003.03.12)" by Paulo S.L.M. Barreto and

 * Vincent Rijmen. Lookup "reference implementations" on

 * <http://planeta.terra.com.br/informatica/paulobarreto/>

 *

 * =============================================================================

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ''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 AUTHORS 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.

 *

 */

/*

 * OpenSSL-specific implementation notes.

 *

 * WHIRLPOOL_Update as well as one-stroke WHIRLPOOL both expect

 * number of *bytes* as input length argument. Bit-oriented routine

 * as specified by authors is called WHIRLPOOL_BitUpdate[!] and

 * does not have one-stroke counterpart.

 *

 * WHIRLPOOL_BitUpdate implements byte-oriented loop, essentially

 * to serve WHIRLPOOL_Update. This is done for performance.

 *

 * Unlike authors' reference implementation, block processing

 * routine whirlpool_block is designed to operate on multi-block

 * input. This is done for performance.

 */

#include <openssl/crypto.h>

#include "wp_locl.h"

#include <string.h>

int WHIRLPOOL_Init(WHIRLPOOL_CTX *c)

{

    memset(c, 0, sizeof(*c));

    return 1;

}

int WHIRLPOOL_Update(WHIRLPOOL_CTX *c, const void *_inp, size_t bytes)

{

    /*

     * Well, largest suitable chunk size actually is

     * (1<<(sizeof(size_t)*8-3))-64, but below number is large enough for not

     * to care about excessive calls to WHIRLPOOL_BitUpdate...

     */

    size_t chunk = ((size_t)1) << (sizeof(size_t) * 8 - 4);

    const unsigned char *inp = _inp;

    while (bytes >= chunk) {

        WHIRLPOOL_BitUpdate(c, inp, chunk * 8);

        bytes -= chunk;

        inp += chunk;

    }

    if (bytes)

        WHIRLPOOL_BitUpdate(c, inp, bytes * 8);

    return 1;

}

void WHIRLPOOL_BitUpdate(WHIRLPOOL_CTX *c, const void *_inp, size_t bits)

{

    size_t n;

    unsigned int bitoff = c->bitoff,

        bitrem = bitoff % 8, inpgap = (8 - (unsigned int)bits % 8) & 7;

    const unsigned char *inp = _inp;

    /*

     * This 256-bit increment procedure relies on the size_t being natural

     * size of CPU register, so that we don't have to mask the value in order

     * to detect overflows.

     */

    c->bitlen[0] += bits;

    if (c->bitlen[0] < bits) {  /* overflow */

        n = 1;

        do {

            c->bitlen[n]++;

        } while (c->bitlen[n] == 0

                 && ++n < (WHIRLPOOL_COUNTER / sizeof(size_t)));

    }

#ifndef OPENSSL_SMALL_FOOTPRINT

 reconsider:

    if (inpgap == 0 && bitrem == 0) { /* byte-oriented loop */

        while (bits) {

            if (bitoff == 0 && (n = bits / WHIRLPOOL_BBLOCK)) {

                whirlpool_block(c, inp, n);

                inp += n * WHIRLPOOL_BBLOCK / 8;

                bits %= WHIRLPOOL_BBLOCK;

            } else {

                unsigned int byteoff = bitoff / 8;

                bitrem = WHIRLPOOL_BBLOCK - bitoff; /* re-use bitrem */

                if (bits >= bitrem) {

                    bits -= bitrem;

                    bitrem /= 8;

                    memcpy(c->data + byteoff, inp, bitrem);

                    inp += bitrem;

                    whirlpool_block(c, c->data, 1);

                    bitoff = 0;

                } else {

                    memcpy(c->data + byteoff, inp, bits / 8);

                    bitoff += (unsigned int)bits;

                    bits = 0;

                }

                c->bitoff = bitoff;

            }

        }

    } else                      /* bit-oriented loop */

#endif

    {

        /*-

                   inp

                   |

                   +-------+-------+-------

                      |||||||||||||||||||||

                   +-------+-------+-------

        +-------+-------+-------+-------+-------

        ||||||||||||||                          c->data

        +-------+-------+-------+-------+-------

                |

                c->bitoff/8

        */

        while (bits) {

            unsigned int byteoff = bitoff / 8;

            unsigned char b;

#ifndef OPENSSL_SMALL_FOOTPRINT

            if (bitrem == inpgap) {

                c->data[byteoff++] |= inp[0] & (0xff >> inpgap);

                inpgap = 8 - inpgap;

                bitoff += inpgap;

                bitrem = 0;     /* bitoff%8 */

                bits -= inpgap;

                inpgap = 0;     /* bits%8 */

                inp++;

                if (bitoff == WHIRLPOOL_BBLOCK) {

                    whirlpool_block(c, c->data, 1);

                    bitoff = 0;

                }

                c->bitoff = bitoff;

                goto reconsider;

            } else

#endif

            if (bits > 8) {

                b = ((inp[0] << inpgap) | (inp[1] >> (8 - inpgap)));

                b &= 0xff;

                if (bitrem)

                    c->data[byteoff++] |= b >> bitrem;

                else

                    c->data[byteoff++] = b;

                bitoff += 8;

                bits -= 8;

                inp++;

                if (bitoff >= WHIRLPOOL_BBLOCK) {

                    whirlpool_block(c, c->data, 1);

                    byteoff = 0;

                    bitoff %= WHIRLPOOL_BBLOCK;

                }

                if (bitrem)

                    c->data[byteoff] = b << (8 - bitrem);

            } else {            /* remaining less than or equal to 8 bits */

                b = (inp[0] << inpgap) & 0xff;

                if (bitrem)

                    c->data[byteoff++] |= b >> bitrem;

                else

                    c->data[byteoff++] = b;

                bitoff += (unsigned int)bits;

                if (bitoff == WHIRLPOOL_BBLOCK) {

                    whirlpool_block(c, c->data, 1);

                    byteoff = 0;

                    bitoff %= WHIRLPOOL_BBLOCK;

                }

                if (bitrem)

                    c->data[byteoff] = b << (8 - bitrem);

                bits = 0;

            }

            c->bitoff = bitoff;

        }

    }

}

int WHIRLPOOL_Final(unsigned char *md, WHIRLPOOL_CTX *c)

{

    unsigned int bitoff = c->bitoff, byteoff = bitoff / 8;

    size_t i, j, v;

    unsigned char *p;

    bitoff %= 8;

    if (bitoff)

        c->data[byteoff] |= 0x80 >> bitoff;

    else

        c->data[byteoff] = 0x80;

    byteoff++;

    /* pad with zeros */

    if (byteoff > (WHIRLPOOL_BBLOCK / 8 - WHIRLPOOL_COUNTER)) {

        if (byteoff < WHIRLPOOL_BBLOCK / 8)

            memset(&c->data[byteoff], 0, WHIRLPOOL_BBLOCK / 8 - byteoff);

        whirlpool_block(c, c->data, 1);

        byteoff = 0;

    }

    if (byteoff < (WHIRLPOOL_BBLOCK / 8 - WHIRLPOOL_COUNTER))

        memset(&c->data[byteoff], 0,

               (WHIRLPOOL_BBLOCK / 8 - WHIRLPOOL_COUNTER) - byteoff);

    /* smash 256-bit c->bitlen in big-endian order */

    p = &c->data[WHIRLPOOL_BBLOCK / 8 - 1]; /* last byte in c->data */

    for (i = 0; i < WHIRLPOOL_COUNTER / sizeof(size_t); i++)

        for (v = c->bitlen[i], j = 0; j < sizeof(size_t); j++, v >>= 8)

            *p-- = (unsigned char)(v & 0xff);

    whirlpool_block(c, c->data, 1);

    if (md) {

        memcpy(md, c->H.c, WHIRLPOOL_DIGEST_LENGTH);

        OPENSSL_cleanse(c, sizeof(*c));

        return 1;

    }

    return 0;

}

unsigned char *WHIRLPOOL(const void *inp, size_t bytes, unsigned char *md)

{

    WHIRLPOOL_CTX ctx;

    static unsigned char m[WHIRLPOOL_DIGEST_LENGTH];

    if (md == NULL)

        md = m;

    WHIRLPOOL_Init(&ctx);

    WHIRLPOOL_Update(&ctx, inp, bytes);

    WHIRLPOOL_Final(md, &ctx);

    return md;

}