elemental-ircd/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 */
	rb_strlcpy(passwd, __md5__magic, sizeof(passwd));
	strncat(passwd, sp, sl);
	rb_strlcat(passwd, "$", sizeof(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 */