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/* $OpenBSD: crypt2.c,v 1.5 2014/05/17 13:27:55 tedu Exp $ */
/*
* FreeSec: libcrypt
*
* Copyright (c) 1994 David Burren
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. 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.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <pwd.h>
#include <unistd.h>
#include <string.h>
#ifdef DEBUG
# include <stdio.h>
#endif
extern const u_char _des_bits8[8];
extern const u_int32_t _des_bits32[32];
extern int _des_initialised;
void _des_init(void);
u_int32_t _des_setup_salt(int32_t salt);
int _des_do_des(u_int32_t , u_int32_t , u_int32_t *, u_int32_t *, int, u_int32_t);
int
setkey(const char *key)
{
int i, j;
u_int32_t packed_keys[2];
u_char *p;
p = (u_char *) packed_keys;
for (i = 0; i < 8; i++) {
p[i] = 0;
for (j = 0; j < 8; j++)
if (*key++ & 1)
p[i] |= _des_bits8[j];
}
return(des_setkey((char *)p));
}
int
encrypt(char *block, int flag)
{
u_int32_t saltbits, io[2];
u_char *p;
int i, j, retval;
if (!_des_initialised)
_des_init();
saltbits = _des_setup_salt(0);
p = (u_char *)block;
for (i = 0; i < 2; i++) {
io[i] = 0L;
for (j = 0; j < 32; j++)
if (*p++ & 1)
io[i] |= _des_bits32[j];
}
retval = _des_do_des(io[0], io[1], io, io + 1, flag ? -1 : 1, saltbits);
for (i = 0; i < 2; i++)
for (j = 0; j < 32; j++)
block[(i << 5) | j] = (io[i] & _des_bits32[j]) ? 1 : 0;
return(retval);
}
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