Copied libratbox and related stuff from shadowircd upstream.

[irc/rqf/shadowircd.git] / libratbox / src / crypt.c

/*
 * crypt.c: Implements unix style crypt() for platforms that don't have it
 *          This version has both an md5 and des crypt.
 *          This was pretty much catted together from uclibc.
 */

/*
 * crypt() for uClibc
 *
 * Copyright (C) 2000 by Lineo, inc. and Erik Andersen
 * Copyright (C) 2000,2001 by Erik Andersen <andersen@uclibc.org>
 * Written by Erik Andersen <andersen@uclibc.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Library General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <libratbox_config.h>
#include <ratbox_lib.h>


#ifndef NEED_CRYPT
extern char *crypt(const char *key, const char *salt);

char *
rb_crypt(const char *key, const char *salt)
{
        return (crypt(key, salt));
}
#else

static char *__md5_crypt(const char *pw, const char *salt);
static char *__des_crypt(const char *pw, const char *salt);

char *
rb_crypt(const char *key, const char *salt)
{
        /* First, check if we are supposed to be using the MD5 replacement
         * instead of DES...  */
        if(salt[0] == '$' && salt[1] == '1' && salt[2] == '$')
                return __md5_crypt(key, salt);
        else
                return __des_crypt(key, salt);
}

/* Here is the des crypt() stuff */

/*
 * FreeSec: libcrypt for NetBSD
 *
 * Copyright (c) 1994 David Burren
 * All rights reserved.
 *
 * Adapted for FreeBSD-2.0 by Geoffrey M. Rehmet
 *      this file should now *only* export crypt(), in order to make
 *      binaries of libcrypt exportable from the USA
 *
 * Adapted for FreeBSD-4.0 by Mark R V Murray
 *      this file should now *only* export crypt_des(), in order to make
 *      a module that can be optionally included in libcrypt.
 *
 * 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. Neither the name of the author nor the names of other contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR 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.
 *
 * This is an original implementation of the DES and the crypt(3) interfaces
 * by David Burren <davidb@werj.com.au>.
 *
 * An excellent reference on the underlying algorithm (and related
 * algorithms) is:
 *
 *      B. Schneier, Applied Cryptography: protocols, algorithms,
 *      and source code in C, John Wiley & Sons, 1994.
 *
 * Note that in that book's description of DES the lookups for the initial,
 * pbox, and final permutations are inverted (this has been brought to the
 * attention of the author).  A list of errata for this book has been
 * posted to the sci.crypt newsgroup by the author and is available for FTP.
 *
 * ARCHITECTURE ASSUMPTIONS:
 *      It is assumed that the 8-byte arrays passed by reference can be
 *      addressed as arrays of uint32_t's (ie. the CPU is not picky about
 *      alignment).
 */


/* Re-entrantify me -- all this junk needs to be in 
 * struct crypt_data to make this really reentrant... */
static uint8_t inv_key_perm[64];
static uint8_t inv_comp_perm[56];
static uint8_t u_sbox[8][64];
static uint8_t un_pbox[32];
static uint32_t en_keysl[16], en_keysr[16];
static uint32_t de_keysl[16], de_keysr[16];
static uint32_t ip_maskl[8][256], ip_maskr[8][256];
static uint32_t fp_maskl[8][256], fp_maskr[8][256];
static uint32_t key_perm_maskl[8][128], key_perm_maskr[8][128];
static uint32_t comp_maskl[8][128], comp_maskr[8][128];
static uint32_t saltbits;
static uint32_t old_salt;
static uint32_t old_rawkey0, old_rawkey1;


/* Static stuff that stays resident and doesn't change after 
 * being initialized, and therefore doesn't need to be made 
 * reentrant. */
static uint8_t init_perm[64], final_perm[64];
static uint8_t m_sbox[4][4096];
static uint32_t psbox[4][256];




/* A pile of data */
static const uint8_t ascii64[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

static const uint8_t IP[64] = {
        58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4,
        62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8,
        57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
        61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7
};

static const uint8_t key_perm[56] = {
        57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18,
        10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36,
        63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22,
        14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4
};

static const uint8_t key_shifts[16] = {
        1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};

static const uint8_t comp_perm[48] = {
        14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10,
        23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2,
        41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48,
        44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32
};

/*
 *      No E box is used, as it's replaced by some ANDs, shifts, and ORs.
 */

static const uint8_t sbox[8][64] = {
        {
         14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
         0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
         4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
         15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13},
        {
         15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
         3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
         0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
         13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9},
        {
         10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
         13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
         13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
         1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12},
        {
         7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
         13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
         10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
         3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14},
        {
         2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
         14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
         4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
         11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3},
        {
         12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
         10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
         9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
         4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13},
        {
         4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
         13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
         1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
         6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12},
        {
         13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
         1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
         7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
         2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11}
};

static const uint8_t pbox[32] = {
        16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10,
        2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25
};

static const uint32_t bits32[32] = {
        0x80000000, 0x40000000, 0x20000000, 0x10000000,
        0x08000000, 0x04000000, 0x02000000, 0x01000000,
        0x00800000, 0x00400000, 0x00200000, 0x00100000,
        0x00080000, 0x00040000, 0x00020000, 0x00010000,
        0x00008000, 0x00004000, 0x00002000, 0x00001000,
        0x00000800, 0x00000400, 0x00000200, 0x00000100,
        0x00000080, 0x00000040, 0x00000020, 0x00000010,
        0x00000008, 0x00000004, 0x00000002, 0x00000001
};

static const uint8_t bits8[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };

static const uint32_t *bits28, *bits24;


static int
ascii_to_bin(char ch)
{
        if(ch > 'z')
                return (0);
        if(ch >= 'a')
                return (ch - 'a' + 38);
        if(ch > 'Z')
                return (0);
        if(ch >= 'A')
                return (ch - 'A' + 12);
        if(ch > '9')
                return (0);
        if(ch >= '.')
                return (ch - '.');
        return (0);
}

static void
des_init(void)
{
        int i, j, b, k, inbit, obit;
        uint32_t *p, *il, *ir, *fl, *fr;
        static int des_initialised = 0;

        if(des_initialised == 1)
                return;

        old_rawkey0 = old_rawkey1 = 0L;
        saltbits = 0L;
        old_salt = 0L;
        bits24 = (bits28 = bits32 + 4) + 4;

        /*
         * Invert the S-boxes, reordering the input bits.
         */
        for(i = 0; i < 8; i++)
                for(j = 0; j < 64; j++)
                {
                        b = (j & 0x20) | ((j & 1) << 4) | ((j >> 1) & 0xf);
                        u_sbox[i][j] = sbox[i][b];
                }

        /*
         * Convert the inverted S-boxes into 4 arrays of 8 bits.
         * Each will handle 12 bits of the S-box input.
         */
        for(b = 0; b < 4; b++)
                for(i = 0; i < 64; i++)
                        for(j = 0; j < 64; j++)
                                m_sbox[b][(i << 6) | j] =
                                        (uint8_t)((u_sbox[(b << 1)][i] << 4) |
                                                  u_sbox[(b << 1) + 1][j]);

        /*
         * Set up the initial & final permutations into a useful form, and
         * initialise the inverted key permutation.
         */
        for(i = 0; i < 64; i++)
        {
                init_perm[final_perm[i] = IP[i] - 1] = (uint8_t)i;
                inv_key_perm[i] = 255;
        }

        /*
         * Invert the key permutation and initialise the inverted key
         * compression permutation.
         */
        for(i = 0; i < 56; i++)
        {
                inv_key_perm[key_perm[i] - 1] = (uint8_t)i;
                inv_comp_perm[i] = 255;
        }

        /*
         * Invert the key compression permutation.
         */
        for(i = 0; i < 48; i++)
        {
                inv_comp_perm[comp_perm[i] - 1] = (uint8_t)i;
        }

        /*
         * Set up the OR-mask arrays for the initial and final permutations,
         * and for the key initial and compression permutations.
         */
        for(k = 0; k < 8; k++)
        {
                for(i = 0; i < 256; i++)
                {
                        *(il = &ip_maskl[k][i]) = 0L;
                        *(ir = &ip_maskr[k][i]) = 0L;
                        *(fl = &fp_maskl[k][i]) = 0L;
                        *(fr = &fp_maskr[k][i]) = 0L;
                        for(j = 0; j < 8; j++)
                        {
                                inbit = 8 * k + j;
                                if(i & bits8[j])
                                {
                                        if((obit = init_perm[inbit]) < 32)
                                                *il |= bits32[obit];
                                        else
                                                *ir |= bits32[obit - 32];
                                        if((obit = final_perm[inbit]) < 32)
                                                *fl |= bits32[obit];
                                        else
                                                *fr |= bits32[obit - 32];
                                }
                        }
                }
                for(i = 0; i < 128; i++)
                {
                        *(il = &key_perm_maskl[k][i]) = 0L;
                        *(ir = &key_perm_maskr[k][i]) = 0L;
                        for(j = 0; j < 7; j++)
                        {
                                inbit = 8 * k + j;
                                if(i & bits8[j + 1])
                                {
                                        if((obit = inv_key_perm[inbit]) == 255)
                                                continue;
                                        if(obit < 28)
                                                *il |= bits28[obit];
                                        else
                                                *ir |= bits28[obit - 28];
                                }
                        }
                        *(il = &comp_maskl[k][i]) = 0L;
                        *(ir = &comp_maskr[k][i]) = 0L;
                        for(j = 0; j < 7; j++)
                        {
                                inbit = 7 * k + j;
                                if(i & bits8[j + 1])
                                {
                                        if((obit = inv_comp_perm[inbit]) == 255)
                                                continue;
                                        if(obit < 24)
                                                *il |= bits24[obit];
                                        else
                                                *ir |= bits24[obit - 24];
                                }
                        }
                }
        }

        /*
         * Invert the P-box permutation, and convert into OR-masks for
         * handling the output of the S-box arrays setup above.
         */
        for(i = 0; i < 32; i++)
                un_pbox[pbox[i] - 1] = (uint8_t)i;

        for(b = 0; b < 4; b++)
                for(i = 0; i < 256; i++)
                {
                        *(p = &psbox[b][i]) = 0L;
                        for(j = 0; j < 8; j++)
                        {
                                if(i & bits8[j])
                                        *p |= bits32[un_pbox[8 * b + j]];
                        }
                }

        des_initialised = 1;
}


static void
setup_salt(long salt)
{
        uint32_t obit, saltbit;
        int i;

        if(salt == (long)old_salt)
                return;
        old_salt = salt;

        saltbits = 0L;
        saltbit = 1;
        obit = 0x800000;
        for(i = 0; i < 24; i++)
        {
                if(salt & saltbit)
                        saltbits |= obit;
                saltbit <<= 1;
                obit >>= 1;
        }
}


static int
des_setkey(const char *key)
{
        uint32_t k0, k1, rawkey0, rawkey1;
        int shifts, round;

        des_init();

        rawkey0 = ntohl(*(const uint32_t *)key);
        rawkey1 = ntohl(*(const uint32_t *)(key + 4));

        if((rawkey0 | rawkey1) && rawkey0 == old_rawkey0 && rawkey1 == old_rawkey1)
        {
                /*
                 * Already setup for this key.
                 * This optimisation fails on a zero key (which is weak and
                 * has bad parity anyway) in order to simplify the starting
                 * conditions.
                 */
                return (0);
        }
        old_rawkey0 = rawkey0;
        old_rawkey1 = rawkey1;

        /*
         *      Do key permutation and split into two 28-bit subkeys.
         */
        k0 = key_perm_maskl[0][rawkey0 >> 25]
                | key_perm_maskl[1][(rawkey0 >> 17) & 0x7f]
                | key_perm_maskl[2][(rawkey0 >> 9) & 0x7f]
                | key_perm_maskl[3][(rawkey0 >> 1) & 0x7f]
                | key_perm_maskl[4][rawkey1 >> 25]
                | key_perm_maskl[5][(rawkey1 >> 17) & 0x7f]
                | key_perm_maskl[6][(rawkey1 >> 9) & 0x7f]
                | key_perm_maskl[7][(rawkey1 >> 1) & 0x7f];
        k1 = key_perm_maskr[0][rawkey0 >> 25]
                | key_perm_maskr[1][(rawkey0 >> 17) & 0x7f]
                | key_perm_maskr[2][(rawkey0 >> 9) & 0x7f]
                | key_perm_maskr[3][(rawkey0 >> 1) & 0x7f]
                | key_perm_maskr[4][rawkey1 >> 25]
                | key_perm_maskr[5][(rawkey1 >> 17) & 0x7f]
                | key_perm_maskr[6][(rawkey1 >> 9) & 0x7f]
                | key_perm_maskr[7][(rawkey1 >> 1) & 0x7f];
        /*
         *      Rotate subkeys and do compression permutation.
         */
        shifts = 0;
        for(round = 0; round < 16; round++)
        {
                uint32_t t0, t1;

                shifts += key_shifts[round];

                t0 = (k0 << shifts) | (k0 >> (28 - shifts));
                t1 = (k1 << shifts) | (k1 >> (28 - shifts));

                de_keysl[15 - round] =
                        en_keysl[round] = comp_maskl[0][(t0 >> 21) & 0x7f]
                        | comp_maskl[1][(t0 >> 14) & 0x7f]
                        | comp_maskl[2][(t0 >> 7) & 0x7f]
                        | comp_maskl[3][t0 & 0x7f]
                        | comp_maskl[4][(t1 >> 21) & 0x7f]
                        | comp_maskl[5][(t1 >> 14) & 0x7f]
                        | comp_maskl[6][(t1 >> 7) & 0x7f] | comp_maskl[7][t1 & 0x7f];

                de_keysr[15 - round] =
                        en_keysr[round] = comp_maskr[0][(t0 >> 21) & 0x7f]
                        | comp_maskr[1][(t0 >> 14) & 0x7f]
                        | comp_maskr[2][(t0 >> 7) & 0x7f]
                        | comp_maskr[3][t0 & 0x7f]
                        | comp_maskr[4][(t1 >> 21) & 0x7f]
                        | comp_maskr[5][(t1 >> 14) & 0x7f]
                        | comp_maskr[6][(t1 >> 7) & 0x7f] | comp_maskr[7][t1 & 0x7f];
        }
        return (0);
}


static int
do_des(uint32_t l_in, uint32_t r_in, uint32_t *l_out, uint32_t *r_out, int count)
{
        /*
         *      l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format.
         */
        uint32_t l, r, *kl, *kr, *kl1, *kr1;
        uint32_t f, r48l, r48r;
        int round;

        if(count == 0)
        {
                return (1);
        }
        else if(count > 0)
        {
                /*
                 * Encrypting
                 */
                kl1 = en_keysl;
                kr1 = en_keysr;
        }
        else
        {
                /*
                 * Decrypting
                 */
                count = -count;
                kl1 = de_keysl;
                kr1 = de_keysr;
        }

        /*
         *      Do initial permutation (IP).
         */
        l = ip_maskl[0][l_in >> 24]
                | ip_maskl[1][(l_in >> 16) & 0xff]
                | ip_maskl[2][(l_in >> 8) & 0xff]
                | ip_maskl[3][l_in & 0xff]
                | ip_maskl[4][r_in >> 24]
                | ip_maskl[5][(r_in >> 16) & 0xff]
                | ip_maskl[6][(r_in >> 8) & 0xff] | ip_maskl[7][r_in & 0xff];
        r = ip_maskr[0][l_in >> 24]
                | ip_maskr[1][(l_in >> 16) & 0xff]
                | ip_maskr[2][(l_in >> 8) & 0xff]
                | ip_maskr[3][l_in & 0xff]
                | ip_maskr[4][r_in >> 24]
                | ip_maskr[5][(r_in >> 16) & 0xff]
                | ip_maskr[6][(r_in >> 8) & 0xff] | ip_maskr[7][r_in & 0xff];

        while(count--)
        {
                /*
                 * Do each round.
                 */
                kl = kl1;
                kr = kr1;
                round = 16;
                while(round--)
                {
                        /*
                         * Expand R to 48 bits (simulate the E-box).
                         */
                        r48l = ((r & 0x00000001) << 23)
                                | ((r & 0xf8000000) >> 9)
                                | ((r & 0x1f800000) >> 11)
                                | ((r & 0x01f80000) >> 13) | ((r & 0x001f8000) >> 15);

                        r48r = ((r & 0x0001f800) << 7)
                                | ((r & 0x00001f80) << 5)
                                | ((r & 0x000001f8) << 3)
                                | ((r & 0x0000001f) << 1) | ((r & 0x80000000) >> 31);
                        /*
                         * Do salting for crypt() and friends, and
                         * XOR with the permuted key.
                         */
                        f = (r48l ^ r48r) & saltbits;
                        r48l ^= f ^ *kl++;
                        r48r ^= f ^ *kr++;
                        /*
                         * Do sbox lookups (which shrink it back to 32 bits)
                         * and do the pbox permutation at the same time.
                         */
                        f = psbox[0][m_sbox[0][r48l >> 12]]
                                | psbox[1][m_sbox[1][r48l & 0xfff]]
                                | psbox[2][m_sbox[2][r48r >> 12]]
                                | psbox[3][m_sbox[3][r48r & 0xfff]];
                        /*
                         * Now that we've permuted things, complete f().
                         */
                        f ^= l;
                        l = r;
                        r = f;
                }
                r = l;
                l = f;
        }
        /*
         * Do final permutation (inverse of IP).
         */
        *l_out = fp_maskl[0][l >> 24]
                | fp_maskl[1][(l >> 16) & 0xff]
                | fp_maskl[2][(l >> 8) & 0xff]
                | fp_maskl[3][l & 0xff]
                | fp_maskl[4][r >> 24]
                | fp_maskl[5][(r >> 16) & 0xff]
                | fp_maskl[6][(r >> 8) & 0xff] | fp_maskl[7][r & 0xff];
        *r_out = fp_maskr[0][l >> 24]
                | fp_maskr[1][(l >> 16) & 0xff]
                | fp_maskr[2][(l >> 8) & 0xff]
                | fp_maskr[3][l & 0xff]
                | fp_maskr[4][r >> 24]
                | fp_maskr[5][(r >> 16) & 0xff]
                | fp_maskr[6][(r >> 8) & 0xff] | fp_maskr[7][r & 0xff];
        return (0);
}


#if 0
static int
des_cipher(const char *in, char *out, uint32_t salt, int count)
{
        uint32_t l_out, r_out, rawl, rawr;
        int retval;
        union
        {
                uint32_t *ui32;
                const char *c;
        } trans;

        des_init();

        setup_salt(salt);

        trans.c = in;
        rawl = ntohl(*trans.ui32++);
        rawr = ntohl(*trans.ui32);

        retval = do_des(rawl, rawr, &l_out, &r_out, count);

        trans.c = out;
        *trans.ui32++ = htonl(l_out);
        *trans.ui32 = htonl(r_out);
        return (retval);
}
#endif

#if 0
void
setkey(const char *key)
{
        int i, j;
        uint32_t packed_keys[2];
        uint8_t *p;

        p = (uint8_t *)packed_keys;

        for(i = 0; i < 8; i++)
        {
                p[i] = 0;
                for(j = 0; j < 8; j++)
                        if(*key++ & 1)
                                p[i] |= bits8[j];
        }
        des_setkey((char *)p);
}


void
encrypt(char *block, int flag)
{
        uint32_t io[2];
        uint8_t *p;
        int i, j;

        des_init();

        setup_salt(0L);
        p = (uint8_t *)block;
        for(i = 0; i < 2; i++)
        {
                io[i] = 0L;
                for(j = 0; j < 32; j++)
                        if(*p++ & 1)
                                io[i] |= bits32[j];
        }
        do_des(io[0], io[1], io, io + 1, flag ? -1 : 1);
        for(i = 0; i < 2; i++)
                for(j = 0; j < 32; j++)
                        block[(i << 5) | j] = (io[i] & bits32[j]) ? 1 : 0;
}
#endif

static char *
__des_crypt(const char *key, const char *setting)
{
        uint32_t count, salt, l, r0, r1, keybuf[2];
        uint8_t *p, *q;
        static char output[21];

        des_init();

        /*
         * Copy the key, shifting each character up by one bit
         * and padding with zeros.
         */
        q = (uint8_t *)keybuf;
        while(q - (uint8_t *)keybuf - 8)
        {
                *q++ = *key << 1;
                if(*(q - 1))
                        key++;
        }
        if(des_setkey((char *)keybuf))
                return (NULL);

#if 0
        if(*setting == _PASSWORD_EFMT1)
        {
                int i;
                /*
                 * "new"-style:
                 *      setting - underscore, 4 bytes of count, 4 bytes of salt
                 *      key - unlimited characters
                 */
                for(i = 1, count = 0L; i < 5; i++)
                        count |= ascii_to_bin(setting[i]) << ((i - 1) * 6);

                for(i = 5, salt = 0L; i < 9; i++)
                        salt |= ascii_to_bin(setting[i]) << ((i - 5) * 6);

                while(*key)
                {
                        /*
                         * Encrypt the key with itself.
                         */
                        if(des_cipher((char *)keybuf, (char *)keybuf, 0L, 1))
                                return (NULL);
                        /*
                         * And XOR with the next 8 characters of the key.
                         */
                        q = (uint8_t *)keybuf;
                        while(q - (uint8_t *)keybuf - 8 && *key)
                                *q++ ^= *key++ << 1;

                        if(des_setkey((char *)keybuf))
                                return (NULL);
                }
                strncpy(output, setting, 9);

                /*
                 * Double check that we weren't given a short setting.
                 * If we were, the above code will probably have created
                 * wierd values for count and salt, but we don't really care.
                 * Just make sure the output string doesn't have an extra
                 * NUL in it.
                 */
                output[9] = '\0';
                p = (uint8_t *)output + strlen(output);
        }
        else
#endif
        {
                /*
                 * "old"-style:
                 *      setting - 2 bytes of salt
                 *      key - up to 8 characters
                 */
                count = 25;

                salt = (ascii_to_bin(setting[1]) << 6) | ascii_to_bin(setting[0]);

                output[0] = setting[0];
                /*
                 * If the encrypted password that the salt was extracted from
                 * is only 1 character long, the salt will be corrupted.  We
                 * need to ensure that the output string doesn't have an extra
                 * NUL in it!
                 */
                output[1] = setting[1] ? setting[1] : output[0];

                p = (uint8_t *)output + 2;
        }
        setup_salt(salt);
        /*
         * Do it.
         */
        if(do_des(0L, 0L, &r0, &r1, (int)count))
                return (NULL);
        /*
         * Now encode the result...
         */
        l = (r0 >> 8);
        *p++ = ascii64[(l >> 18) & 0x3f];
        *p++ = ascii64[(l >> 12) & 0x3f];
        *p++ = ascii64[(l >> 6) & 0x3f];
        *p++ = ascii64[l & 0x3f];

        l = (r0 << 16) | ((r1 >> 16) & 0xffff);
        *p++ = ascii64[(l >> 18) & 0x3f];
        *p++ = ascii64[(l >> 12) & 0x3f];
        *p++ = ascii64[(l >> 6) & 0x3f];
        *p++ = ascii64[l & 0x3f];

        l = r1 << 2;
        *p++ = ascii64[(l >> 12) & 0x3f];
        *p++ = ascii64[(l >> 6) & 0x3f];
        *p++ = ascii64[l & 0x3f];
        *p = 0;

        return (output);
}

/* Now md5 crypt */

/*
 * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
 *
 * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
 * rights reserved.
 *
 * License to copy and use this software is granted provided that it
 * is identified as the "RSA Data Security, Inc. MD5 Message-Digest
 * Algorithm" in all material mentioning or referencing this software
 * or this function.
 *
 * License is also granted to make and use derivative works provided
 * that such works are identified as "derived from the RSA Data
 * Security, Inc. MD5 Message-Digest Algorithm" in all material
 * mentioning or referencing the derived work.
 *
 * RSA Data Security, Inc. makes no representations concerning either
 * the merchantability of this software or the suitability of this
 * software for any particular purpose. It is provided "as is"
 * without express or implied warranty of any kind.
 *
 * These notices must be retained in any copies of any part of this
 * documentation and/or software.
 *
 * $FreeBSD: src/lib/libmd/md5c.c,v 1.9.2.1 1999/08/29 14:57:12 peter Exp $
 *
 * This code is the same as the code published by RSA Inc.  It has been
 * edited for clarity and style only.
 *
 * ----------------------------------------------------------------------------
 * The md5_crypt() function was taken from freeBSD's libcrypt and contains 
 * this license: 
 *    "THE BEER-WARE LICENSE" (Revision 42):
 *     <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
 *     can do whatever you want with this stuff. If we meet some day, and you think
 *     this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 *
 * $FreeBSD: src/lib/libcrypt/crypt.c,v 1.7.2.1 1999/08/29 14:56:33 peter Exp $
 *
 * ----------------------------------------------------------------------------
 * On April 19th, 2001 md5_crypt() was modified to make it reentrant 
 * by Erik Andersen <andersen@uclibc.org>
 *
 *
 * June 28, 2001             Manuel Novoa III
 *
 * "Un-inlined" code using loops and static const tables in order to
 * reduce generated code size (on i386 from approx 4k to approx 2.5k).
 *
 * June 29, 2001             Manuel Novoa III
 *
 * Completely removed static PADDING array.
 *
 * Reintroduced the loop unrolling in MD5_Transform and added the
 * MD5_SIZE_OVER_SPEED option for configurability.  Define below as:
 *       0    fully unrolled loops
 *       1    partially unrolled (4 ops per loop)
 *       2    no unrolling -- introduces the need to swap 4 variables (slow)
 *       3    no unrolling and all 4 loops merged into one with switch
 *               in each loop (glacial)
 * On i386, sizes are roughly (-Os -fno-builtin):
 *     0: 3k     1: 2.5k     2: 2.2k     3: 2k
 *
 *
 * Since SuSv3 does not require crypt_r, modified again August 7, 2002
 * by Erik Andersen to remove reentrance stuff...
 */

/*
 * Valid values are  1 (fastest/largest) to 3 (smallest/slowest).
 */
#define MD5_SIZE_OVER_SPEED 1

/**********************************************************************/

/* MD5 context. */
struct MD5Context
{
        uint32_t state[4];      /* state (ABCD) */
        uint32_t count[2];      /* number of bits, modulo 2^64 (lsb first) */
        unsigned char buffer[64];       /* input buffer */
};

static void __md5_Init(struct MD5Context *);
static void __md5_Update(struct MD5Context *, const char *, unsigned int);
static void __md5_Pad(struct MD5Context *);
static void __md5_Final(char[16], struct MD5Context *);
static void __md5_Transform(uint32_t[4], const unsigned char[64]);


static const char __md5__magic[] = "$1$";       /* This string is magic for this algorithm.  Having 
                                                   it this way, we can get better later on */
static const unsigned char __md5_itoa64[] =     /* 0 ... 63 => ascii - 64 */
        "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";



#ifdef i386
#define __md5_Encode memcpy
#define __md5_Decode memcpy
#else /* i386 */

/*
 * __md5_Encodes input (uint32_t) into output (unsigned char). Assumes len is
 * a multiple of 4.
 */

static void
__md5_Encode(unsigned char *output, uint32_t *input, unsigned int len)
{
        unsigned int i, j;

        for(i = 0, j = 0; j < len; i++, j += 4)
        {
                output[j] = (unsigned char)(input[i] & 0xff);
                output[j + 1] = (unsigned char)((input[i] >> 8) & 0xff);
                output[j + 2] = (unsigned char)((input[i] >> 16) & 0xff);
                output[j + 3] = (unsigned char)((input[i] >> 24) & 0xff);
        }
}

/*
 * __md5_Decodes input (unsigned char) into output (uint32_t). Assumes len is
 * a multiple of 4.
 */

static void
__md5_Decode(uint32_t *output, const unsigned char *input, unsigned int len)
{
        unsigned int i, j;

        for(i = 0, j = 0; j < len; i++, j += 4)
                output[i] = ((uint32_t)input[j]) | (((uint32_t)input[j + 1]) << 8) |
                        (((uint32_t)input[j + 2]) << 16) | (((uint32_t)input[j + 3]) << 24);
}
#endif /* i386 */

/* F, G, H and I are basic MD5 functions. */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/*
 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
 * Rotation is separate from addition to prevent recomputation.
 */
#define FF(a, b, c, d, x, s, ac) { \
        (a) += F ((b), (c), (d)) + (x) + (uint32_t)(ac); \
        (a) = ROTATE_LEFT ((a), (s)); \
        (a) += (b); \
        }
#define GG(a, b, c, d, x, s, ac) { \
        (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
        (a) = ROTATE_LEFT ((a), (s)); \
        (a) += (b); \
        }
#define HH(a, b, c, d, x, s, ac) { \
        (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
        (a) = ROTATE_LEFT ((a), (s)); \
        (a) += (b); \
        }
#define II(a, b, c, d, x, s, ac) { \
        (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \
        (a) = ROTATE_LEFT ((a), (s)); \
        (a) += (b); \
        }

/* MD5 initialization. Begins an MD5 operation, writing a new context. */

static void
__md5_Init(struct MD5Context *context)
{
        context->count[0] = context->count[1] = 0;

        /* Load magic initialization constants.  */
        context->state[0] = 0x67452301;
        context->state[1] = 0xefcdab89;
        context->state[2] = 0x98badcfe;
        context->state[3] = 0x10325476;
}

/* 
 * MD5 block update operation. Continues an MD5 message-digest
 * operation, processing another message block, and updating the
 * context.
 */

static void
__md5_Update(struct MD5Context *context, const char *xinput, unsigned int inputLen)
{
        unsigned int i, lindex, partLen;
        const unsigned char *input = (const unsigned char *)xinput;     /* i hate gcc */
        /* Compute number of bytes mod 64 */
        lindex = (unsigned int)((context->count[0] >> 3) & 0x3F);

        /* Update number of bits */
        if((context->count[0] += ((uint32_t)inputLen << 3)) < ((uint32_t)inputLen << 3))
                context->count[1]++;
        context->count[1] += ((uint32_t)inputLen >> 29);

        partLen = 64 - lindex;

        /* Transform as many times as possible. */
        if(inputLen >= partLen)
        {
                memcpy(&context->buffer[lindex], input, partLen);
                __md5_Transform(context->state, context->buffer);

                for(i = partLen; i + 63 < inputLen; i += 64)
                        __md5_Transform(context->state, &input[i]);

                lindex = 0;
        }
        else
                i = 0;

        /* Buffer remaining input */
        memcpy(&context->buffer[lindex], &input[i], inputLen - i);
}

/*
 * MD5 padding. Adds padding followed by original length.
 */

static void
__md5_Pad(struct MD5Context *context)
{
        char bits[8];
        unsigned int lindex, padLen;
        char PADDING[64];

        memset(PADDING, 0, sizeof(PADDING));
        PADDING[0] = 0x80;

        /* Save number of bits */
        __md5_Encode(bits, context->count, 8);

        /* Pad out to 56 mod 64. */
        lindex = (unsigned int)((context->count[0] >> 3) & 0x3f);
        padLen = (lindex < 56) ? (56 - lindex) : (120 - lindex);
        __md5_Update(context, PADDING, padLen);

        /* Append length (before padding) */
        __md5_Update(context, bits, 8);
}

/*
 * MD5 finalization. Ends an MD5 message-digest operation, writing the
 * the message digest and zeroizing the context.
 */

static void
__md5_Final(char xdigest[16], struct MD5Context *context)
{
        unsigned char *digest = (unsigned char *)xdigest;
        /* Do padding. */
        __md5_Pad(context);

        /* Store state in digest */
        __md5_Encode(digest, context->state, 16);

        /* Zeroize sensitive information. */
        memset(context, 0, sizeof(*context));
}

/* MD5 basic transformation. Transforms state based on block. */

static void
__md5_Transform(state, block)
     uint32_t state[4];
     const unsigned char block[64];
{
        uint32_t a, b, c, d, x[16];

#if MD5_SIZE_OVER_SPEED > 1
        uint32_t temp;
        const char *ps;

        static const char S[] = {
                7, 12, 17, 22,
                5, 9, 14, 20,
                4, 11, 16, 23,
                6, 10, 15, 21
        };
#endif /* MD5_SIZE_OVER_SPEED > 1 */

#if MD5_SIZE_OVER_SPEED > 0
        const uint32_t *pc;
        const char *pp;
        int i;

        static const uint32_t C[] = {
                /* round 1 */
                0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
                0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
                0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
                0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
                /* round 2 */
                0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
                0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8,
                0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
                0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
                /* round 3 */
                0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
                0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
                0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
                0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
                /* round 4 */
                0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
                0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
                0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
                0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
        };

        static const char P[] = {
                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,   /* 1 */
                1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12,   /* 2 */
                5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2,   /* 3 */
                0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9    /* 4 */
        };

#endif /* MD5_SIZE_OVER_SPEED > 0 */

        __md5_Decode(x, block, 64);

        a = state[0];
        b = state[1];
        c = state[2];
        d = state[3];

#if MD5_SIZE_OVER_SPEED > 2
        pc = C;
        pp = P;
        ps = S - 4;

        for(i = 0; i < 64; i++)
        {
                if((i & 0x0f) == 0)
                        ps += 4;
                temp = a;
                switch (i >> 4)
                {
                case 0:
                        temp += F(b, c, d);
                        break;
                case 1:
                        temp += G(b, c, d);
                        break;
                case 2:
                        temp += H(b, c, d);
                        break;
                case 3:
                        temp += I(b, c, d);
                        break;
                }
                temp += x[(int)(*pp++)] + *pc++;
                temp = ROTATE_LEFT(temp, ps[i & 3]);
                temp += b;
                a = d;
                d = c;
                c = b;
                b = temp;
        }
#elif MD5_SIZE_OVER_SPEED > 1
        pc = C;
        pp = P;
        ps = S;

        /* Round 1 */
        for(i = 0; i < 16; i++)
        {
                FF(a, b, c, d, x[(int)(*pp++)], ps[i & 0x3], *pc++);
                temp = d;
                d = c;
                c = b;
                b = a;
                a = temp;
        }

        /* Round 2 */
        ps += 4;
        for(; i < 32; i++)
        {
                GG(a, b, c, d, x[(int)(*pp++)], ps[i & 0x3], *pc++);
                temp = d;
                d = c;
                c = b;
                b = a;
                a = temp;
        }
        /* Round 3 */
        ps += 4;
        for(; i < 48; i++)
        {
                HH(a, b, c, d, x[(int)(*pp++)], ps[i & 0x3], *pc++);
                temp = d;
                d = c;
                c = b;
                b = a;
                a = temp;
        }

        /* Round 4 */
        ps += 4;
        for(; i < 64; i++)
        {
                II(a, b, c, d, x[(int)(*pp++)], ps[i & 0x3], *pc++);
                temp = d;
                d = c;
                c = b;
                b = a;
                a = temp;
        }
#elif MD5_SIZE_OVER_SPEED > 0
        pc = C;
        pp = P;

        /* Round 1 */
        for(i = 0; i < 4; i++)
        {
                FF(a, b, c, d, x[(int)(*pp++)], 7, *pc++);
                FF(d, a, b, c, x[(int)(*pp++)], 12, *pc++);
                FF(c, d, a, b, x[(int)(*pp++)], 17, *pc++);
                FF(b, c, d, a, x[(int)(*pp++)], 22, *pc++);
        }

        /* Round 2 */
        for(i = 0; i < 4; i++)
        {
                GG(a, b, c, d, x[(int)(*pp++)], 5, *pc++);
                GG(d, a, b, c, x[(int)(*pp++)], 9, *pc++);
                GG(c, d, a, b, x[(int)(*pp++)], 14, *pc++);
                GG(b, c, d, a, x[(int)(*pp++)], 20, *pc++);
        }
        /* Round 3 */
        for(i = 0; i < 4; i++)
        {
                HH(a, b, c, d, x[(int)(*pp++)], 4, *pc++);
                HH(d, a, b, c, x[(int)(*pp++)], 11, *pc++);
                HH(c, d, a, b, x[(int)(*pp++)], 16, *pc++);
                HH(b, c, d, a, x[(int)(*pp++)], 23, *pc++);
        }

        /* Round 4 */
        for(i = 0; i < 4; i++)
        {
                II(a, b, c, d, x[(int)(*pp++)], 6, *pc++);
                II(d, a, b, c, x[(int)(*pp++)], 10, *pc++);
                II(c, d, a, b, x[(int)(*pp++)], 15, *pc++);
                II(b, c, d, a, x[(int)(*pp++)], 21, *pc++);
        }
#else
        /* Round 1 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
        FF(a, b, c, d, x[0], S11, 0xd76aa478);  /* 1 */
        FF(d, a, b, c, x[1], S12, 0xe8c7b756);  /* 2 */
        FF(c, d, a, b, x[2], S13, 0x242070db);  /* 3 */
        FF(b, c, d, a, x[3], S14, 0xc1bdceee);  /* 4 */
        FF(a, b, c, d, x[4], S11, 0xf57c0faf);  /* 5 */
        FF(d, a, b, c, x[5], S12, 0x4787c62a);  /* 6 */
        FF(c, d, a, b, x[6], S13, 0xa8304613);  /* 7 */
        FF(b, c, d, a, x[7], S14, 0xfd469501);  /* 8 */
        FF(a, b, c, d, x[8], S11, 0x698098d8);  /* 9 */
        FF(d, a, b, c, x[9], S12, 0x8b44f7af);  /* 10 */
        FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
        FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
        FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
        FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
        FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
        FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

        /* Round 2 */
#define S21 5
#define S22 9
#define S23 14
#define S24 20
        GG(a, b, c, d, x[1], S21, 0xf61e2562);  /* 17 */
        GG(d, a, b, c, x[6], S22, 0xc040b340);  /* 18 */
        GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
        GG(b, c, d, a, x[0], S24, 0xe9b6c7aa);  /* 20 */
        GG(a, b, c, d, x[5], S21, 0xd62f105d);  /* 21 */
        GG(d, a, b, c, x[10], S22, 0x2441453);  /* 22 */
        GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
        GG(b, c, d, a, x[4], S24, 0xe7d3fbc8);  /* 24 */
        GG(a, b, c, d, x[9], S21, 0x21e1cde6);  /* 25 */
        GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
        GG(c, d, a, b, x[3], S23, 0xf4d50d87);  /* 27 */
        GG(b, c, d, a, x[8], S24, 0x455a14ed);  /* 28 */
        GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
        GG(d, a, b, c, x[2], S22, 0xfcefa3f8);  /* 30 */
        GG(c, d, a, b, x[7], S23, 0x676f02d9);  /* 31 */
        GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

        /* Round 3 */
#define S31 4
#define S32 11
#define S33 16
#define S34 23
        HH(a, b, c, d, x[5], S31, 0xfffa3942);  /* 33 */
        HH(d, a, b, c, x[8], S32, 0x8771f681);  /* 34 */
        HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
        HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
        HH(a, b, c, d, x[1], S31, 0xa4beea44);  /* 37 */
        HH(d, a, b, c, x[4], S32, 0x4bdecfa9);  /* 38 */
        HH(c, d, a, b, x[7], S33, 0xf6bb4b60);  /* 39 */
        HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
        HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
        HH(d, a, b, c, x[0], S32, 0xeaa127fa);  /* 42 */
        HH(c, d, a, b, x[3], S33, 0xd4ef3085);  /* 43 */
        HH(b, c, d, a, x[6], S34, 0x4881d05);   /* 44 */
        HH(a, b, c, d, x[9], S31, 0xd9d4d039);  /* 45 */
        HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
        HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
        HH(b, c, d, a, x[2], S34, 0xc4ac5665);  /* 48 */

        /* Round 4 */
#define S41 6
#define S42 10
#define S43 15
#define S44 21
        II(a, b, c, d, x[0], S41, 0xf4292244);  /* 49 */
        II(d, a, b, c, x[7], S42, 0x432aff97);  /* 50 */
        II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
        II(b, c, d, a, x[5], S44, 0xfc93a039);  /* 52 */
        II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
        II(d, a, b, c, x[3], S42, 0x8f0ccc92);  /* 54 */
        II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
        II(b, c, d, a, x[1], S44, 0x85845dd1);  /* 56 */
        II(a, b, c, d, x[8], S41, 0x6fa87e4f);  /* 57 */
        II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
        II(c, d, a, b, x[6], S43, 0xa3014314);  /* 59 */
        II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
        II(a, b, c, d, x[4], S41, 0xf7537e82);  /* 61 */
        II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
        II(c, d, a, b, x[2], S43, 0x2ad7d2bb);  /* 63 */
        II(b, c, d, a, x[9], S44, 0xeb86d391);  /* 64 */
#endif

        state[0] += a;
        state[1] += b;
        state[2] += c;
        state[3] += d;

        /* Zeroize sensitive information. */
        memset(x, 0, sizeof(x));
}


static void
__md5_to64(char *s, unsigned long v, int n)
{
        while(--n >= 0)
        {
                *s++ = __md5_itoa64[v & 0x3f];
                v >>= 6;
        }
}

/*
 * UNIX password
 *
 * Use MD5 for what it is best at...
 */

static char *
__md5_crypt(const char *pw, const char *salt)
{
        /* Static stuff */
        static const char *sp, *ep;
        static char passwd[120], *p;

        char final[17];         /* final[16] exists only to aid in looping */
        int sl, pl, i, __md5__magic_len, pw_len;
        struct MD5Context ctx, ctx1;
        unsigned long l;

        /* Refine the Salt first */
        sp = salt;

        /* If it starts with the magic string, then skip that */
        __md5__magic_len = strlen(__md5__magic);
        if(!strncmp(sp, __md5__magic, __md5__magic_len))
                sp += __md5__magic_len;

        /* It stops at the first '$', max 8 chars */
        for(ep = sp; *ep && *ep != '$' && ep < (sp + 8); ep++)
                continue;

        /* get the length of the true salt */
        sl = ep - sp;

        __md5_Init(&ctx);

        /* The password first, since that is what is most unknown */
        pw_len = strlen(pw);
        __md5_Update(&ctx, pw, pw_len);

        /* Then our magic string */
        __md5_Update(&ctx, __md5__magic, __md5__magic_len);

        /* Then the raw salt */
        __md5_Update(&ctx, sp, sl);

        /* Then just as many characters of the MD5(pw,salt,pw) */
        __md5_Init(&ctx1);
        __md5_Update(&ctx1, pw, pw_len);
        __md5_Update(&ctx1, sp, sl);
        __md5_Update(&ctx1, pw, pw_len);
        __md5_Final(final, &ctx1);
        for(pl = pw_len; pl > 0; pl -= 16)
                __md5_Update(&ctx, final, pl > 16 ? 16 : pl);

        /* Don't leave anything around in vm they could use. */
        memset(final, 0, sizeof final);

        /* Then something really weird... */
        for(i = pw_len; i; i >>= 1)
        {
                __md5_Update(&ctx, ((i & 1) ? final : pw), 1);
        }

        /* Now make the output string */
        strcpy(passwd, __md5__magic);
        strncat(passwd, sp, sl);
        strcat(passwd, "$");

        __md5_Final(final, &ctx);

        /*
         * and now, just to make sure things don't run too fast
         * On a 60 Mhz Pentium this takes 34 msec, so you would
         * need 30 seconds to build a 1000 entry dictionary...
         */
        for(i = 0; i < 1000; i++)
        {
                __md5_Init(&ctx1);
                if(i & 1)
                        __md5_Update(&ctx1, pw, pw_len);
                else
                        __md5_Update(&ctx1, final, 16);

                if(i % 3)
                        __md5_Update(&ctx1, sp, sl);

                if(i % 7)
                        __md5_Update(&ctx1, pw, pw_len);

                if(i & 1)
                        __md5_Update(&ctx1, final, 16);
                else
                        __md5_Update(&ctx1, pw, pw_len);
                __md5_Final(final, &ctx1);
        }

        p = passwd + strlen(passwd);

        final[16] = final[5];
        for(i = 0; i < 5; i++)
        {
                l = (final[i] << 16) | (final[i + 6] << 8) | final[i + 12];
                __md5_to64(p, l, 4);
                p += 4;
        }
        l = final[11];
        __md5_to64(p, l, 2);
        p += 2;
        *p = '\0';

        /* Don't leave anything around in vm they could use. */
        memset(final, 0, sizeof final);

        return passwd;
}

#endif /* NEED_CRYPT */