/*

 * Copyright 1995-2020 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

 */

/*

 * MD2 low level APIs are deprecated for public use, but still ok for

 * internal use.

 */

#include "internal/deprecated.h"

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <openssl/crypto.h>

#include <openssl/des.h>

#include <openssl/mdc2.h>

#include "internal/common.h"

static void mdc2_body(MDC2_CTX *c, const unsigned char *in, size_t len);

int MDC2_Init(MDC2_CTX *c)

{

    c->num = 0;

    c->pad_type = 1;

    memset(&(c->h[0]), 0x52, MDC2_BLOCK);

    memset(&(c->hh[0]), 0x25, MDC2_BLOCK);

    return 1;

}

int MDC2_Update(MDC2_CTX *c, const unsigned char *in, size_t len)

{

    size_t i, j;

    i = c->num;

    if (i != 0) {

        if (len < MDC2_BLOCK - i) {

            /* partial block */

            memcpy(&(c->data[i]), in, len);

            c->num += (int)len;

            return 1;

        } else {

            /* filled one */

            j = MDC2_BLOCK - i;

            memcpy(&(c->data[i]), in, j);

            len -= j;

            in += j;

            c->num = 0;

            mdc2_body(c, &(c->data[0]), MDC2_BLOCK);

        }

    }

    i = len & ~((size_t)MDC2_BLOCK - 1);

    if (i > 0)

        mdc2_body(c, in, i);

    j = len - i;

    if (j > 0) {

        memcpy(&(c->data[0]), &(in[i]), j);

        c->num = (int)j;

    }

    return 1;

}

static void mdc2_body(MDC2_CTX *c, const unsigned char *in, size_t len)

{

    register DES_LONG tin0, tin1;

    register DES_LONG ttin0, ttin1;

    DES_LONG d[2], dd[2];

    DES_key_schedule k;

    unsigned char *p;

    size_t i;

    for (i = 0; i < len; i += 8) {

        c2l(in, tin0);

        d[0] = dd[0] = tin0;

        c2l(in, tin1);

        d[1] = dd[1] = tin1;

        c->h[0] = (c->h[0] & 0x9f) | 0x40;

        c->hh[0] = (c->hh[0] & 0x9f) | 0x20;

        DES_set_odd_parity(&c->h);

        DES_set_key_unchecked(&c->h, &k);

        DES_encrypt1(d, &k, 1);

        DES_set_odd_parity(&c->hh);

        DES_set_key_unchecked(&c->hh, &k);

        DES_encrypt1(dd, &k, 1);

        ttin0 = tin0 ^ dd[0];

        ttin1 = tin1 ^ dd[1];

        tin0 ^= d[0];

        tin1 ^= d[1];

        p = c->h;

        l2c(tin0, p);

        l2c(ttin1, p);

        p = c->hh;

        l2c(ttin0, p);

        l2c(tin1, p);

    }

}

int MDC2_Final(unsigned char *md, MDC2_CTX *c)

{

    unsigned int i;

    int j;

    i = c->num;

    j = c->pad_type;

    if ((i > 0) || (j == 2)) {

        if (j == 2)

            c->data[i++] = 0x80;

        memset(&(c->data[i]), 0, MDC2_BLOCK - i);

        mdc2_body(c, c->data, MDC2_BLOCK);

    }

    memcpy(md, (char *)c->h, MDC2_BLOCK);

    memcpy(&(md[MDC2_BLOCK]), (char *)c->hh, MDC2_BLOCK);

    return 1;

}