Fix warnings from crypt.c compile.

[postgresql] / src / port / crypt.c

/*      $NetBSD: crypt.c,v 1.18 2001/03/01 14:37:35 wiz Exp $   */

/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Tom Truscott.
 *
 * 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. All advertising materials mentioning features or use of this software
 *        must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *        may be used to endorse or promote products derived from this software
 *        without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)crypt.c     8.1.1.1 (Berkeley) 8/18/93";

#else
__RCSID("$NetBSD: crypt.c,v 1.18 2001/03/01 14:37:35 wiz Exp $");
#endif
#endif   /* not lint */

#include "c.h"

#include <stddef.h>
#include <sys/types.h>
#include <limits.h>
#include <stdlib.h>

#ifndef WIN32
#include <unistd.h>
#endif

static int      des_setkey(const char *key);
static int      des_cipher(const char *in, char *out, long salt, int num_iter);

/*
 * UNIX password, and DES, encryption.
 * By Tom Truscott, trt@rti.rti.org,
 * from algorithms by Robert W. Baldwin and James Gillogly.
 *
 * References:
 * "Mathematical Cryptology for Computer Scientists and Mathematicians,"
 * by Wayne Patterson, 1987, ISBN 0-8476-7438-X.
 *
 * "Password Security: A Case History," R. Morris and Ken Thompson,
 * Communications of the ACM, vol. 22, pp. 594-597, Nov. 1979.
 *
 * "DES will be Totally Insecure within Ten Years," M.E. Hellman,
 * IEEE Spectrum, vol. 16, pp. 32-39, July 1979.
 */

/* =====  Configuration ==================== */

/*
 * define "MUST_ALIGN" if your compiler cannot load/store
 * long integers at arbitrary (e.g. odd) memory locations.
 * (Either that or never pass unaligned addresses to des_cipher!)
 */
/* #define      MUST_ALIGN */

#ifdef CHAR_BITS
#if CHAR_BITS != 8
#error C_block structure assumes 8 bit characters
#endif
#endif

/*
 * define "B64" to be the declaration for a 64 bit integer.
 * XXX this feature is currently unused, see "endian" comment below.
 */
#define B64 __int64

/*
 * define "LARGEDATA" to get faster permutations, by using about 72 kilobytes
 * of lookup tables.  This speeds up des_setkey() and des_cipher(), but has
 * little effect on crypt().
 */
/* #define      LARGEDATA */

/* compile with "-DSTATIC=void" when profiling */
#ifndef STATIC
#define STATIC  static void
#endif

/*
 * Define the "int32_t" type for integral type with a width of at least
 * 32 bits.
 */
typedef int int32_t;

/* ==================================== */

#define _PASSWORD_EFMT1 '_'             /* extended encryption format */

/*
 * Cipher-block representation (Bob Baldwin):
 *
 * DES operates on groups of 64 bits, numbered 1..64 (sigh).  One
 * representation is to store one bit per byte in an array of bytes.  Bit N of
 * the NBS spec is stored as the LSB of the Nth byte (index N-1) in the array.
 * Another representation stores the 64 bits in 8 bytes, with bits 1..8 in the
 * first byte, 9..16 in the second, and so on.  The DES spec apparently has
 * bit 1 in the MSB of the first byte, but that is particularly noxious so we
 * bit-reverse each byte so that bit 1 is the LSB of the first byte, bit 8 is
 * the MSB of the first byte.  Specifically, the 64-bit input data and key are
 * converted to LSB format, and the output 64-bit block is converted back into
 * MSB format.
 *
 * DES operates internally on groups of 32 bits which are expanded to 48 bits
 * by permutation E and shrunk back to 32 bits by the S boxes.  To speed up
 * the computation, the expansion is applied only once, the expanded
 * representation is maintained during the encryption, and a compression
 * permutation is applied only at the end.      To speed up the S-box lookups,
 * the 48 bits are maintained as eight 6 bit groups, one per byte, which
 * directly feed the eight S-boxes.  Within each byte, the 6 bits are the
 * most significant ones.  The low two bits of each byte are zero.      (Thus,
 * bit 1 of the 48 bit E expansion is stored as the "4"-valued bit of the
 * first byte in the eight byte representation, bit 2 of the 48 bit value is
 * the "8"-valued bit, and so on.)      In fact, a combined "SPE"-box lookup is
 * used, in which the output is the 64 bit result of an S-box lookup which
 * has been permuted by P and expanded by E, and is ready for use in the next
 * iteration.  Two 32-bit wide tables, SPE[0] and SPE[1], are used for this
 * lookup.      Since each byte in the 48 bit path is a multiple of four, indexed
 * lookup of SPE[0] and SPE[1] is simple and fast.      The key schedule and
 * "salt" are also converted to this 8*(6+2) format.  The SPE table size is
 * 8*64*8 = 4K bytes.
 *
 * To speed up bit-parallel operations (such as XOR), the 8 byte
 * representation is "union"ed with 32 bit values "i0" and "i1", and, on
 * machines which support it, a 64 bit value "b64".  This data structure,
 * "C_block", has two problems.  First, alignment restrictions must be
 * honored.  Second, the byte-order (e.g. little-endian or big-endian) of
 * the architecture becomes visible.
 *
 * The byte-order problem is unfortunate, since on the one hand it is good
 * to have a machine-independent C_block representation (bits 1..8 in the
 * first byte, etc.), and on the other hand it is good for the LSB of the
 * first byte to be the LSB of i0.      We cannot have both these things, so we
 * currently use the "little-endian" representation and avoid any multi-byte
 * operations that depend on byte order.  This largely precludes use of the
 * 64-bit datatype since the relative order of i0 and i1 are unknown.  It
 * also inhibits grouping the SPE table to look up 12 bits at a time.  (The
 * 12 bits can be stored in a 16-bit field with 3 low-order zeroes and 1
 * high-order zero, providing fast indexing into a 64-bit wide SPE.)  On the
 * other hand, 64-bit datatypes are currently rare, and a 12-bit SPE lookup
 * requires a 128 kilobyte table, so perhaps this is not a big loss.
 *
 * Permutation representation (Jim Gillogly):
 *
 * A transformation is defined by its effect on each of the 8 bytes of the
 * 64-bit input.  For each byte we give a 64-bit output that has the bits in
 * the input distributed appropriately.  The transformation is then the OR
 * of the 8 sets of 64-bits.  This uses 8*256*8 = 16K bytes of storage for
 * each transformation.  Unless LARGEDATA is defined, however, a more compact
 * table is used which looks up 16 4-bit "chunks" rather than 8 8-bit chunks.
 * The smaller table uses 16*16*8 = 2K bytes for each transformation.  This
 * is slower but tolerable, particularly for password encryption in which
 * the SPE transformation is iterated many times.  The small tables total 9K
 * bytes, the large tables total 72K bytes.
 *
 * The transformations used are:
 * IE3264: MSB->LSB conversion, initial permutation, and expansion.
 *      This is done by collecting the 32 even-numbered bits and applying
 *      a 32->64 bit transformation, and then collecting the 32 odd-numbered
 *      bits and applying the same transformation.      Since there are only
 *      32 input bits, the IE3264 transformation table is half the size of
 *      the usual table.
 * CF6464: Compression, final permutation, and LSB->MSB conversion.
 *      This is done by two trivial 48->32 bit compressions to obtain
 *      a 64-bit block (the bit numbering is given in the "CIFP" table)
 *      followed by a 64->64 bit "cleanup" transformation.      (It would
 *      be possible to group the bits in the 64-bit block so that 2
 *      identical 32->32 bit transformations could be used instead,
 *      saving a factor of 4 in space and possibly 2 in time, but
 *      byte-ordering and other complications rear their ugly head.
 *      Similar opportunities/problems arise in the key schedule
 *      transforms.)
 * PC1ROT: MSB->LSB, PC1 permutation, rotate, and PC2 permutation.
 *      This admittedly baroque 64->64 bit transformation is used to
 *      produce the first code (in 8*(6+2) format) of the key schedule.
 * PC2ROT[0]: Inverse PC2 permutation, rotate, and PC2 permutation.
 *      It would be possible to define 15 more transformations, each
 *      with a different rotation, to generate the entire key schedule.
 *      To save space, however, we instead permute each code into the
 *      next by using a transformation that "undoes" the PC2 permutation,
 *      rotates the code, and then applies PC2.  Unfortunately, PC2
 *      transforms 56 bits into 48 bits, dropping 8 bits, so PC2 is not
 *      invertible.  We get around that problem by using a modified PC2
 *      which retains the 8 otherwise-lost bits in the unused low-order
 *      bits of each byte.      The low-order bits are cleared when the
 *      codes are stored into the key schedule.
 * PC2ROT[1]: Same as PC2ROT[0], but with two rotations.
 *      This is faster than applying PC2ROT[0] twice,
 *
 * The Bell Labs "salt" (Bob Baldwin):
 *
 * The salting is a simple permutation applied to the 48-bit result of E.
 * Specifically, if bit i (1 <= i <= 24) of the salt is set then bits i and
 * i+24 of the result are swapped.      The salt is thus a 24 bit number, with
 * 16777216 possible values.  (The original salt was 12 bits and could not
 * swap bits 13..24 with 36..48.)
 *
 * It is possible, but ugly, to warp the SPE table to account for the salt
 * permutation.  Fortunately, the conditional bit swapping requires only
 * about four machine instructions and can be done on-the-fly with about an
 * 8% performance penalty.
 */

typedef union
{
        unsigned char b[8];
        struct
        {
                int32_t         i0;
                int32_t         i1;
        }                       b32;
#if defined(B64)
        B64                     b64;
#endif
}       C_block;

/*
 * Convert twenty-four-bit long in host-order
 * to six bits (and 2 low-order zeroes) per char little-endian format.
 */
#define TO_SIX_BIT(rslt, src) {                         \
                C_block cvt;                            \
                cvt.b[0] = src; src >>= 6;              \
                cvt.b[1] = src; src >>= 6;              \
                cvt.b[2] = src; src >>= 6;              \
                cvt.b[3] = src;                         \
                rslt = (cvt.b32.i0 & 0x3f3f3f3fL) << 2; \
        }

/*
 * These macros may someday permit efficient use of 64-bit integers.
 */
#define ZERO(d,d0,d1)                   d0 = 0, d1 = 0
#define LOAD(d,d0,d1,bl)                d0 = (bl).b32.i0, d1 = (bl).b32.i1
#define LOADREG(d,d0,d1,s,s0,s1)        d0 = s0, d1 = s1
#define OR(d,d0,d1,bl)                  d0 |= (bl).b32.i0, d1 |= (bl).b32.i1
#define STORE(s,s0,s1,bl)               (bl).b32.i0 = s0, (bl).b32.i1 = s1
#define DCL_BLOCK(d,d0,d1)              int32_t d0, d1

#if defined(LARGEDATA)
 /* Waste memory like crazy.  Also, do permutations in line */
#define LGCHUNKBITS 3
#define CHUNKBITS       (1<<LGCHUNKBITS)
#define PERM6464(d,d0,d1,cpp,p)                         \
        LOAD(d,d0,d1,(p)[(0<<CHUNKBITS)+(cpp)[0]]);             \
        OR (d,d0,d1,(p)[(1<<CHUNKBITS)+(cpp)[1]]);              \
        OR (d,d0,d1,(p)[(2<<CHUNKBITS)+(cpp)[2]]);              \
        OR (d,d0,d1,(p)[(3<<CHUNKBITS)+(cpp)[3]]);              \
        OR (d,d0,d1,(p)[(4<<CHUNKBITS)+(cpp)[4]]);              \
        OR (d,d0,d1,(p)[(5<<CHUNKBITS)+(cpp)[5]]);              \
        OR (d,d0,d1,(p)[(6<<CHUNKBITS)+(cpp)[6]]);              \
        OR (d,d0,d1,(p)[(7<<CHUNKBITS)+(cpp)[7]]);
#define PERM3264(d,d0,d1,cpp,p)                         \
        LOAD(d,d0,d1,(p)[(0<<CHUNKBITS)+(cpp)[0]]);             \
        OR (d,d0,d1,(p)[(1<<CHUNKBITS)+(cpp)[1]]);              \
        OR (d,d0,d1,(p)[(2<<CHUNKBITS)+(cpp)[2]]);              \
        OR (d,d0,d1,(p)[(3<<CHUNKBITS)+(cpp)[3]]);
#else
 /* "small data" */
#define LGCHUNKBITS 2
#define CHUNKBITS       (1<<LGCHUNKBITS)
#define PERM6464(d,d0,d1,cpp,p)                         \
        { C_block tblk; permute(cpp,&tblk,p,8); LOAD (d,d0,d1,tblk); }
#define PERM3264(d,d0,d1,cpp,p)                         \
        { C_block tblk; permute(cpp,&tblk,p,4); LOAD (d,d0,d1,tblk); }
#endif   /* LARGEDATA */

STATIC          init_des(void);
STATIC          init_perm(C_block[64 / CHUNKBITS][1 << CHUNKBITS], unsigned char[64], int, int);

#ifndef LARGEDATA
STATIC          permute(unsigned char *, C_block *, C_block *, int);
#endif
#ifdef DEBUG
STATIC          prtab(char *, unsigned char *, int);
#endif


#ifndef LARGEDATA
STATIC
permute(cp, out, p, chars_in)
unsigned char *cp;
C_block    *out;
C_block    *p;
int                     chars_in;
{
        DCL_BLOCK(D, D0, D1);
        C_block    *tp;
        int                     t;

        ZERO(D, D0, D1);
        do
        {
                t = *cp++;
                tp = &p[t & 0xf];
                OR(D, D0, D1, *tp);
                p += (1 << CHUNKBITS);
                tp = &p[t >> 4];
                OR(D, D0, D1, *tp);
                p += (1 << CHUNKBITS);
        } while (--chars_in > 0);
        STORE(D, D0, D1, *out);
}
#endif   /* LARGEDATA */


/* =====  (mostly) Standard DES Tables ==================== */

static unsigned char IP[] = {   /* initial permutation */
        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,
};

/* The final permutation is the inverse of IP - no table is necessary */

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

static unsigned char PC1[] = {  /* permuted choice table 1 */
        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 unsigned char Rotates[] = {              /* PC1 rotation schedule */
        1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1,
};

/* note: each "row" of PC2 is left-padded with bits that make it invertible */
static unsigned char PC2[] = {  /* permuted choice table 2 */
        9, 18, 14, 17, 11, 24, 1, 5,
        22, 25, 3, 28, 15, 6, 21, 10,
        35, 38, 23, 19, 12, 4, 26, 8,
        43, 54, 16, 7, 27, 20, 13, 2,

        0, 0, 41, 52, 31, 37, 47, 55,
        0, 0, 30, 40, 51, 45, 33, 48,
        0, 0, 44, 49, 39, 56, 34, 53,
        0, 0, 46, 42, 50, 36, 29, 32,
};

static unsigned char S[8][64] = {               /* 48->32 bit substitution tables */
        /* S[1]                 */
        {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},
        /* S[2]                 */
        {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},
        /* S[3]                 */
        {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},
        /* S[4]                 */
        {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},
        /* S[5]                 */
        {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},
        /* S[6]                 */
        {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},
        /* S[7]                 */
        {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},
        /* S[8]                 */
        {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 unsigned char P32Tr[] = {        /* 32-bit permutation function */
        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 unsigned char CIFP[] = { /* compressed/interleaved permutation */
        1, 2, 3, 4, 17, 18, 19, 20,
        5, 6, 7, 8, 21, 22, 23, 24,
        9, 10, 11, 12, 25, 26, 27, 28,
        13, 14, 15, 16, 29, 30, 31, 32,

        33, 34, 35, 36, 49, 50, 51, 52,
        37, 38, 39, 40, 53, 54, 55, 56,
        41, 42, 43, 44, 57, 58, 59, 60,
        45, 46, 47, 48, 61, 62, 63, 64,
};

static unsigned char itoa64[] = /* 0..63 => ascii-64 */
"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";


/* =====  Tables that are initialized at run time  ==================== */


static unsigned char a64toi[128];               /* ascii-64 => 0..63 */

/* Initial key schedule permutation */
static C_block PC1ROT[64 / CHUNKBITS][1 << CHUNKBITS];

/* Subsequent key schedule rotation permutations */
static C_block PC2ROT[2][64 / CHUNKBITS][1 << CHUNKBITS];

/* Initial permutation/expansion table */
static C_block IE3264[32 / CHUNKBITS][1 << CHUNKBITS];

/* Table that combines the S, P, and E operations.      */
static int32_t SPE[2][8][64];

/* compressed/interleaved => final permutation table */
static C_block CF6464[64 / CHUNKBITS][1 << CHUNKBITS];


/* ==================================== */


static C_block constdatablock;  /* encryption constant */
static char cryptresult[1 + 4 + 4 + 11 + 1];    /* encrypted result */

extern char *__md5crypt(const char *, const char *);    /* XXX */
extern char *__bcrypt(const char *, const char *);              /* XXX */


/*
 * Return a pointer to static data consisting of the "setting"
 * followed by an encryption produced by the "key" and "setting".
 */
char *
crypt(key, setting)
const char *key;
const char *setting;
{
        char       *encp;
        int32_t         i;
        int                     t;
        int32_t         salt;
        int                     num_iter,
                                salt_size;
        C_block         keyblock,
                                rsltblock;

#if 0
        /* Non-DES encryption schemes hook in here. */
        if (setting[0] == _PASSWORD_NONDES)
        {
                switch (setting[1])
                {
                        case '2':
                                return (__bcrypt(key, setting));
                        case '1':
                        default:
                                return (__md5crypt(key, setting));
                }
        }
#endif

        for (i = 0; i < 8; i++)
        {
                if ((t = 2 * (unsigned char) (*key)) != 0)
                        key++;
                keyblock.b[i] = t;
        }
        if (des_setkey((char *) keyblock.b))            /* also initializes
                                                                                                 * "a64toi" */
                return (NULL);

        encp = &cryptresult[0];
        switch (*setting)
        {
                case _PASSWORD_EFMT1:

                        /*
                         * Involve the rest of the password 8 characters at a time.
                         */
                        while (*key)
                        {
                                if (des_cipher((char *) (void *) &keyblock,
                                                           (char *) (void *) &keyblock, 0L, 1))
                                        return (NULL);
                                for (i = 0; i < 8; i++)
                                {
                                        if ((t = 2 * (unsigned char) (*key)) != 0)
                                                key++;
                                        keyblock.b[i] ^= t;
                                }
                                if (des_setkey((char *) keyblock.b))
                                        return (NULL);
                        }

                        *encp++ = *setting++;

                        /* get iteration count */
                        num_iter = 0;
                        for (i = 4; --i >= 0;)
                        {
                                if ((t = (unsigned char) setting[i]) == '\0')
                                        t = '.';
                                encp[i] = t;
                                num_iter = (num_iter << 6) | a64toi[t];
                        }
                        setting += 4;
                        encp += 4;
                        salt_size = 4;
                        break;
                default:
                        num_iter = 25;
                        salt_size = 2;
        }

        salt = 0;
        for (i = salt_size; --i >= 0;)
        {
                if ((t = (unsigned char) setting[i]) == '\0')
                        t = '.';
                encp[i] = t;
                salt = (salt << 6) | a64toi[t];
        }
        encp += salt_size;
        if (des_cipher((char *) (void *) &constdatablock,
                                   (char *) (void *) &rsltblock, salt, num_iter))
                return (NULL);

        /*
         * Encode the 64 cipher bits as 11 ascii characters.
         */
        i = ((int32_t) ((rsltblock.b[0] << 8) | rsltblock.b[1]) << 8) |
                rsltblock.b[2];
        encp[3] = itoa64[i & 0x3f];
        i >>= 6;
        encp[2] = itoa64[i & 0x3f];
        i >>= 6;
        encp[1] = itoa64[i & 0x3f];
        i >>= 6;
        encp[0] = itoa64[i];
        encp += 4;
        i = ((int32_t) ((rsltblock.b[3] << 8) | rsltblock.b[4]) << 8) |
                rsltblock.b[5];
        encp[3] = itoa64[i & 0x3f];
        i >>= 6;
        encp[2] = itoa64[i & 0x3f];
        i >>= 6;
        encp[1] = itoa64[i & 0x3f];
        i >>= 6;
        encp[0] = itoa64[i];
        encp += 4;
        i = ((int32_t) ((rsltblock.b[6]) << 8) | rsltblock.b[7]) << 2;
        encp[2] = itoa64[i & 0x3f];
        i >>= 6;
        encp[1] = itoa64[i & 0x3f];
        i >>= 6;
        encp[0] = itoa64[i];

        encp[3] = 0;

        return (cryptresult);
}


/*
 * The Key Schedule, filled in by des_setkey() or setkey().
 */
#define KS_SIZE 16
static C_block KS[KS_SIZE];

static volatile int des_ready = 0;

/*
 * Set up the key schedule from the key.
 */
static int
des_setkey(key)
const char *key;
{
        DCL_BLOCK(K, K0, K1);
        C_block    *ptabp;
        int                     i;

        if (!des_ready)
                init_des();

        PERM6464(K, K0, K1, (unsigned char *) key, (C_block *) PC1ROT);
        key = (char *) &KS[0];
        STORE(K & ~0x03030303L, K0 & ~0x03030303L, K1, *(C_block *) key);
        for (i = 1; i < 16; i++)
        {
                key += sizeof(C_block);
                STORE(K, K0, K1, *(C_block *) key);
                ptabp = (C_block *) PC2ROT[Rotates[i] - 1];
                PERM6464(K, K0, K1, (unsigned char *) key, ptabp);
                STORE(K & ~0x03030303L, K0 & ~0x03030303L, K1, *(C_block *) key);
        }
        return (0);
}

/*
 * Encrypt (or decrypt if num_iter < 0) the 8 chars at "in" with abs(num_iter)
 * iterations of DES, using the given 24-bit salt and the pre-computed key
 * schedule, and store the resulting 8 chars at "out" (in == out is permitted).
 *
 * NOTE: the performance of this routine is critically dependent on your
 * compiler and machine architecture.
 */
static int
des_cipher(in, out, salt, num_iter)
const char *in;
char       *out;
long            salt;
int                     num_iter;
{
        /* variables that we want in registers, most important first */
#if defined(pdp11)
        int                     j;
#endif
        int32_t         L0,
                                L1,
                                R0,
                                R1,
                                k;
        C_block    *kp;
        int                     ks_inc,
                                loop_count;
        C_block         B;

        L0 = salt;
        TO_SIX_BIT(salt, L0);           /* convert to 4*(6+2) format */

#if defined(__vax__) || defined(pdp11)
        salt = ~salt;                           /* "x &~ y" is faster than "x & y". */
#define SALT (~salt)
#else
#define SALT salt
#endif

#if defined(MUST_ALIGN)
        B.b[0] = in[0];
        B.b[1] = in[1];
        B.b[2] = in[2];
        B.b[3] = in[3];
        B.b[4] = in[4];
        B.b[5] = in[5];
        B.b[6] = in[6];
        B.b[7] = in[7];
        LOAD(L, L0, L1, B);
#else
        LOAD(L, L0, L1, *(C_block *) in);
#endif
        LOADREG(R, R0, R1, L, L0, L1);
        L0 &= 0x55555555L;
        L1 &= 0x55555555L;
        L0 = (L0 << 1) | L1;            /* L0 is the even-numbered input bits */
        R0 &= 0xaaaaaaaaL;
        R1 = (R1 >> 1) & 0x55555555L;
        L1 = R0 | R1;                           /* L1 is the odd-numbered input bits */
        STORE(L, L0, L1, B);
        PERM3264(L, L0, L1, B.b, (C_block *) IE3264);           /* even bits */
        PERM3264(R, R0, R1, B.b + 4, (C_block *) IE3264);       /* odd bits */

        if (num_iter >= 0)
        {                                                       /* encryption */
                kp = &KS[0];
                ks_inc = sizeof(*kp);
        }
        else
        {                                                       /* decryption */
                num_iter = -num_iter;
                kp = &KS[KS_SIZE - 1];
                ks_inc = -(long) sizeof(*kp);
        }

        while (--num_iter >= 0)
        {
                loop_count = 8;
                do
                {

#define SPTAB(t, i) \
                (*(int32_t *)((unsigned char *)t + i*(sizeof(int32_t)/4)))
#if defined(gould)
                        /* use this if B.b[i] is evaluated just once ... */
#define DOXOR(x,y,i)    x^=SPTAB(SPE[0][i],B.b[i]); y^=SPTAB(SPE[1][i],B.b[i]);
#else
#if defined(pdp11)
                        /* use this if your "long" int indexing is slow */
#define DOXOR(x,y,i)    j=B.b[i]; x^=SPTAB(SPE[0][i],j); y^=SPTAB(SPE[1][i],j);
#else
                        /* use this if "k" is allocated to a register ... */
#define DOXOR(x,y,i)    k=B.b[i]; x^=SPTAB(SPE[0][i],k); y^=SPTAB(SPE[1][i],k);
#endif
#endif

#define CRUNCH(p0, p1, q0, q1)  \
                        k = (q0 ^ q1) & SALT;   \
                        B.b32.i0 = k ^ q0 ^ kp->b32.i0;         \
                        B.b32.i1 = k ^ q1 ^ kp->b32.i1;         \
                        kp = (C_block *)((char *)kp+ks_inc);    \
                                                        \
                        DOXOR(p0, p1, 0);               \
                        DOXOR(p0, p1, 1);               \
                        DOXOR(p0, p1, 2);               \
                        DOXOR(p0, p1, 3);               \
                        DOXOR(p0, p1, 4);               \
                        DOXOR(p0, p1, 5);               \
                        DOXOR(p0, p1, 6);               \
                        DOXOR(p0, p1, 7);

                        CRUNCH(L0, L1, R0, R1);
                        CRUNCH(R0, R1, L0, L1);
                } while (--loop_count != 0);
                kp = (C_block *) ((char *) kp - (ks_inc * KS_SIZE));


                /* swap L and R */
                L0 ^= R0;
                L1 ^= R1;
                R0 ^= L0;
                R1 ^= L1;
                L0 ^= R0;
                L1 ^= R1;
        }

        /* store the encrypted (or decrypted) result */
        L0 = ((L0 >> 3) & 0x0f0f0f0fL) | ((L1 << 1) & 0xf0f0f0f0L);
        L1 = ((R0 >> 3) & 0x0f0f0f0fL) | ((R1 << 1) & 0xf0f0f0f0L);
        STORE(L, L0, L1, B);
        PERM6464(L, L0, L1, B.b, (C_block *) CF6464);
#if defined(MUST_ALIGN)
        STORE(L, L0, L1, B);
        out[0] = B.b[0];
        out[1] = B.b[1];
        out[2] = B.b[2];
        out[3] = B.b[3];
        out[4] = B.b[4];
        out[5] = B.b[5];
        out[6] = B.b[6];
        out[7] = B.b[7];
#else
        STORE(L, L0, L1, *(C_block *) out);
#endif
        return (0);
}


/*
 * Initialize various tables.  This need only be done once.  It could even be
 * done at compile time, if the compiler were capable of that sort of thing.
 */
STATIC
init_des()
{
        int                     i,
                                j;
        int32_t         k;
        int                     tableno;
        static unsigned char perm[64],
                                tmp32[32];              /* "static" for speed */
/*      static volatile long init_start = 0; not used */

        /*
         * table that converts chars "./0-9A-Za-z"to integers 0-63.
         */
        for (i = 0; i < 64; i++)
                a64toi[itoa64[i]] = i;

        /*
         * PC1ROT - bit reverse, then PC1, then Rotate, then PC2.
         */
        for (i = 0; i < 64; i++)
                perm[i] = 0;
        for (i = 0; i < 64; i++)
        {
                if ((k = PC2[i]) == 0)
                        continue;
                k += Rotates[0] - 1;
                if ((k % 28) < Rotates[0])
                        k -= 28;
                k = PC1[k];
                if (k > 0)
                {
                        k--;
                        k = (k | 07) - (k & 07);
                        k++;
                }
                perm[i] = k;
        }
#ifdef DEBUG
        prtab("pc1tab", perm, 8);
#endif
        init_perm(PC1ROT, perm, 8, 8);

        /*
         * PC2ROT - PC2 inverse, then Rotate (once or twice), then PC2.
         */
        for (j = 0; j < 2; j++)
        {
                unsigned char pc2inv[64];

                for (i = 0; i < 64; i++)
                        perm[i] = pc2inv[i] = 0;
                for (i = 0; i < 64; i++)
                {
                        if ((k = PC2[i]) == 0)
                                continue;
                        pc2inv[k - 1] = i + 1;
                }
                for (i = 0; i < 64; i++)
                {
                        if ((k = PC2[i]) == 0)
                                continue;
                        k += j;
                        if ((k % 28) <= j)
                                k -= 28;
                        perm[i] = pc2inv[k];
                }
#ifdef DEBUG
                prtab("pc2tab", perm, 8);
#endif
                init_perm(PC2ROT[j], perm, 8, 8);
        }

        /*
         * Bit reverse, then initial permutation, then expansion.
         */
        for (i = 0; i < 8; i++)
        {
                for (j = 0; j < 8; j++)
                {
                        k = (j < 2) ? 0 : IP[ExpandTr[i * 6 + j - 2] - 1];
                        if (k > 32)
                                k -= 32;
                        else if (k > 0)
                                k--;
                        if (k > 0)
                        {
                                k--;
                                k = (k | 07) - (k & 07);
                                k++;
                        }
                        perm[i * 8 + j] = k;
                }
        }
#ifdef DEBUG
        prtab("ietab", perm, 8);
#endif
        init_perm(IE3264, perm, 4, 8);

        /*
         * Compression, then final permutation, then bit reverse.
         */
        for (i = 0; i < 64; i++)
        {
                k = IP[CIFP[i] - 1];
                if (k > 0)
                {
                        k--;
                        k = (k | 07) - (k & 07);
                        k++;
                }
                perm[k - 1] = i + 1;
        }
#ifdef DEBUG
        prtab("cftab", perm, 8);
#endif
        init_perm(CF6464, perm, 8, 8);

        /*
         * SPE table
         */
        for (i = 0; i < 48; i++)
                perm[i] = P32Tr[ExpandTr[i] - 1];
        for (tableno = 0; tableno < 8; tableno++)
        {
                for (j = 0; j < 64; j++)
                {
                        k = (((j >> 0) & 01) << 5) |
                                (((j >> 1) & 01) << 3) |
                                (((j >> 2) & 01) << 2) |
                                (((j >> 3) & 01) << 1) |
                                (((j >> 4) & 01) << 0) |
                                (((j >> 5) & 01) << 4);
                        k = S[tableno][k];
                        k = (((k >> 3) & 01) << 0) |
                                (((k >> 2) & 01) << 1) |
                                (((k >> 1) & 01) << 2) |
                                (((k >> 0) & 01) << 3);
                        for (i = 0; i < 32; i++)
                                tmp32[i] = 0;
                        for (i = 0; i < 4; i++)
                                tmp32[4 * tableno + i] = (k >> i) & 01;
                        k = 0;
                        for (i = 24; --i >= 0;)
                                k = (k << 1) | tmp32[perm[i] - 1];
                        TO_SIX_BIT(SPE[0][tableno][j], k);
                        k = 0;
                        for (i = 24; --i >= 0;)
                                k = (k << 1) | tmp32[perm[i + 24] - 1];
                        TO_SIX_BIT(SPE[1][tableno][j], k);
                }
        }

        des_ready = 1;
}

/*
 * Initialize "perm" to represent transformation "p", which rearranges
 * (perhaps with expansion and/or contraction) one packed array of bits
 * (of size "chars_in" characters) into another array (of size "chars_out"
 * characters).
 *
 * "perm" must be all-zeroes on entry to this routine.
 */
STATIC
init_perm(perm, p, chars_in, chars_out)
C_block         perm[64 / CHUNKBITS][1 << CHUNKBITS];
unsigned char p[64];
int                     chars_in,
                        chars_out;
{
        int                     i,
                                j,
                                k,
                                l;

        for (k = 0; k < chars_out * 8; k++)
        {                                                       /* each output bit position */
                l = p[k] - 1;                   /* where this bit comes from */
                if (l < 0)
                        continue;                       /* output bit is always 0 */
                i = l >> LGCHUNKBITS;   /* which chunk this bit comes from */
                l = 1 << (l & (CHUNKBITS - 1)); /* mask for this bit */
                for (j = 0; j < (1 << CHUNKBITS); j++)
                {                                               /* each chunk value */
                        if ((j & l) != 0)
                                perm[i][j].b[k >> 3] |= 1 << (k & 07);
                }
        }
}

/*
 * "setkey" routine (for backwards compatibility)
 */
#ifdef NOT_USED
int
setkey(key)
const char *key;
{
        int                     i,
                                j,
                                k;
        C_block         keyblock;

        for (i = 0; i < 8; i++)
        {
                k = 0;
                for (j = 0; j < 8; j++)
                {
                        k <<= 1;
                        k |= (unsigned char) *key++;
                }
                keyblock.b[i] = k;
        }
        return (des_setkey((char *) keyblock.b));
}

/*
 * "encrypt" routine (for backwards compatibility)
 */
static int
encrypt(block, flag)
char       *block;
int                     flag;
{
        int                     i,
                                j,
                                k;
        C_block         cblock;

        for (i = 0; i < 8; i++)
        {
                k = 0;
                for (j = 0; j < 8; j++)
                {
                        k <<= 1;
                        k |= (unsigned char) *block++;
                }
                cblock.b[i] = k;
        }
        if (des_cipher((char *) &cblock, (char *) &cblock, 0L, (flag ? -1 : 1)))
                return (1);
        for (i = 7; i >= 0; i--)
        {
                k = cblock.b[i];
                for (j = 7; j >= 0; j--)
                {
                        *--block = k & 01;
                        k >>= 1;
                }
        }
        return (0);
}
#endif

#ifdef DEBUG
STATIC
prtab(s, t, num_rows)
char       *s;
unsigned char *t;
int                     num_rows;
{
        int                     i,
                                j;

        (void) printf("%s:\n", s);
        for (i = 0; i < num_rows; i++)
        {
                for (j = 0; j < 8; j++)
                        (void) printf("%3d", t[i * 8 + j]);
                (void) printf("\n");
        }
        (void) printf("\n");
}

#endif