smbd: Remove a confusing comment

[Samba.git] / lib / replace / crypt.c

/*
   This bit of code was derived from the UFC-crypt package which
   carries the following copyright 
   
   Modified for use by Samba by Andrew Tridgell, October 1994

   Note that this routine is only faster on some machines. Under Linux 1.1.51 
   libc 4.5.26 I actually found this routine to be slightly slower.

   Under SunOS I found a huge speedup by using these routines 
   (a factor of 20 or so)

   Warning: I've had a report from Steve Kennedy <steve@gbnet.org>
   that this crypt routine may sometimes get the wrong answer. Only
   use UFC_CRYT if you really need it.

*/

#include "replace.h"

#ifndef HAVE_CRYPT

/*
 * UFC-crypt: ultra fast crypt(3) implementation
 *
 * Copyright (C) 1991-1998, Free Software Foundation, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This library 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 Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 *
 * @(#)crypt_util.c     2.31 02/08/92
 *
 * Support routines
 *
 */


#ifndef long32
#define long32 int32_t
#endif

#ifndef long64
#define long64 int64_t
#endif

#ifndef ufc_long
#define ufc_long unsigned
#endif

#ifndef _UFC_64_
#define _UFC_32_
#endif

/* 
 * Permutation done once on the 56 bit 
 *  key derived from the original 8 byte ASCII key.
 */
static int pc1[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
};

/*
 * How much to rotate each 28 bit half of the pc1 permutated
 *  56 bit key before using pc2 to give the i' key
 */
static int rots[16] = { 
  1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 
};

/* 
 * Permutation giving the key 
 * of the i' DES round 
 */
static int pc2[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
};

/*
 * The E expansion table which selects
 * bits from the 32 bit intermediate result.
 */
static int esel[48] = { 
  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 int e_inverse[64];

/* 
 * Permutation done on the 
 * result of sbox lookups 
 */
static int perm32[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
};

/* 
 * The sboxes
 */
static int sbox[8][4][16]= {
        { { 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 }
        }
};

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

/* 
 * The 16 DES keys in BITMASK format 
 */
#ifdef _UFC_32_
long32 _ufc_keytab[16][2];
#endif

#ifdef _UFC_64_
long64 _ufc_keytab[16];
#endif


#define ascii_to_bin(c) ((c)>='a'?(c-59):(c)>='A'?((c)-53):(c)-'.')
#define bin_to_ascii(c) ((c)>=38?((c)-38+'a'):(c)>=12?((c)-12+'A'):(c)+'.')

/* Macro to set a bit (0..23) */
#define BITMASK(i) ( (1<<(11-(i)%12+3)) << ((i)<12?16:0) )

/*
 * sb arrays:
 *
 * Workhorses of the inner loop of the DES implementation.
 * They do sbox lookup, shifting of this  value, 32 bit
 * permutation and E permutation for the next round.
 *
 * Kept in 'BITMASK' format.
 */

#ifdef _UFC_32_
long32 _ufc_sb0[8192], _ufc_sb1[8192], _ufc_sb2[8192], _ufc_sb3[8192];
static long32 *sb[4] = {_ufc_sb0, _ufc_sb1, _ufc_sb2, _ufc_sb3}; 
#endif

#ifdef _UFC_64_
long64 _ufc_sb0[4096], _ufc_sb1[4096], _ufc_sb2[4096], _ufc_sb3[4096];
static long64 *sb[4] = {_ufc_sb0, _ufc_sb1, _ufc_sb2, _ufc_sb3}; 
#endif

/* 
 * eperm32tab: do 32 bit permutation and E selection
 *
 * The first index is the byte number in the 32 bit value to be permuted
 *  -  second  -   is the value of this byte
 *  -  third   -   selects the two 32 bit values
 *
 * The table is used and generated internally in init_des to speed it up
 */
static ufc_long eperm32tab[4][256][2];

/* 
 * do_pc1: permform pc1 permutation in the key schedule generation.
 *
 * The first   index is the byte number in the 8 byte ASCII key
 *  -  second    -      -    the two 28 bits halfs of the result
 *  -  third     -   selects the 7 bits actually used of each byte
 *
 * The result is kept with 28 bit per 32 bit with the 4 most significant
 * bits zero.
 */
static ufc_long do_pc1[8][2][128];

/*
 * do_pc2: permform pc2 permutation in the key schedule generation.
 *
 * The first   index is the septet number in the two 28 bit intermediate values
 *  -  second    -    -  -  septet values
 *
 * Knowledge of the structure of the pc2 permutation is used.
 *
 * The result is kept with 28 bit per 32 bit with the 4 most significant
 * bits zero.
 */
static ufc_long do_pc2[8][128];

/*
 * efp: undo an extra e selection and do final
 *      permutation giving the DES result.
 * 
 *      Invoked 6 bit a time on two 48 bit values
 *      giving two 32 bit longs.
 */
static ufc_long efp[16][64][2];

static unsigned char bytemask[8]  = {
  0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01
};

static ufc_long longmask[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
};


/*
 * Silly rewrite of 'bzero'. I do so
 * because some machines don't have
 * bzero and some don't have memset.
 */

static void clearmem(char *start, int cnt)
  { while(cnt--)
      *start++ = '\0';
  }

static int initialized = 0;

/* lookup a 6 bit value in sbox */

#define s_lookup(i,s) sbox[(i)][(((s)>>4) & 0x2)|((s) & 0x1)][((s)>>1) & 0xf];

/*
 * Initialize unit - may be invoked directly
 * by fcrypt users.
 */

static void ufc_init_des(void)
  { int comes_from_bit;
    int bit, sg;
    ufc_long j;
    ufc_long mask1, mask2;

    /*
     * Create the do_pc1 table used
     * to affect pc1 permutation
     * when generating keys
     */
    for(bit = 0; bit < 56; bit++) {
      comes_from_bit  = pc1[bit] - 1;
      mask1 = bytemask[comes_from_bit % 8 + 1];
      mask2 = longmask[bit % 28 + 4];
      for(j = 0; j < 128; j++) {
        if(j & mask1) 
          do_pc1[comes_from_bit / 8][bit / 28][j] |= mask2;
      }
    }

    /*
     * Create the do_pc2 table used
     * to affect pc2 permutation when
     * generating keys
     */
    for(bit = 0; bit < 48; bit++) {
      comes_from_bit  = pc2[bit] - 1;
      mask1 = bytemask[comes_from_bit % 7 + 1];
      mask2 = BITMASK(bit % 24);
      for(j = 0; j < 128; j++) {
        if(j & mask1)
          do_pc2[comes_from_bit / 7][j] |= mask2;
      }
    }

    /* 
     * Now generate the table used to do combined
     * 32 bit permutation and e expansion
     *
     * We use it because we have to permute 16384 32 bit
     * longs into 48 bit in order to initialize sb.
     *
     * Looping 48 rounds per permutation becomes 
     * just too slow...
     *
     */

    clearmem((char*)eperm32tab, sizeof(eperm32tab));

    for(bit = 0; bit < 48; bit++) {
      ufc_long inner_mask1,comes_from;
        
      comes_from = perm32[esel[bit]-1]-1;
      inner_mask1      = bytemask[comes_from % 8];
        
      for(j = 256; j--;) {
        if(j & inner_mask1)
          eperm32tab[comes_from / 8][j][bit / 24] |= BITMASK(bit % 24);
      }
    }
    
    /* 
     * Create the sb tables:
     *
     * For each 12 bit segment of an 48 bit intermediate
     * result, the sb table precomputes the two 4 bit
     * values of the sbox lookups done with the two 6
     * bit halves, shifts them to their proper place,
     * sends them through perm32 and finally E expands
     * them so that they are ready for the next
     * DES round.
     *
     */
    for(sg = 0; sg < 4; sg++) {
      int j1, j2;
      int s1, s2;
    
      for(j1 = 0; j1 < 64; j1++) {
        s1 = s_lookup(2 * sg, j1);
        for(j2 = 0; j2 < 64; j2++) {
          ufc_long to_permute, inx;
    
          s2         = s_lookup(2 * sg + 1, j2);
          to_permute = ((s1 << 4)  | s2) << (24 - 8 * sg);

#ifdef _UFC_32_
          inx = ((j1 << 6)  | j2) << 1;
          sb[sg][inx  ]  = eperm32tab[0][(to_permute >> 24) & 0xff][0];
          sb[sg][inx+1]  = eperm32tab[0][(to_permute >> 24) & 0xff][1];
          sb[sg][inx  ] |= eperm32tab[1][(to_permute >> 16) & 0xff][0];
          sb[sg][inx+1] |= eperm32tab[1][(to_permute >> 16) & 0xff][1];
          sb[sg][inx  ] |= eperm32tab[2][(to_permute >>  8) & 0xff][0];
          sb[sg][inx+1] |= eperm32tab[2][(to_permute >>  8) & 0xff][1];
          sb[sg][inx  ] |= eperm32tab[3][(to_permute)       & 0xff][0];
          sb[sg][inx+1] |= eperm32tab[3][(to_permute)       & 0xff][1];
#endif
#ifdef _UFC_64_
          inx = ((j1 << 6)  | j2);
          sb[sg][inx]  = 
            ((long64)eperm32tab[0][(to_permute >> 24) & 0xff][0] << 32) |
             (long64)eperm32tab[0][(to_permute >> 24) & 0xff][1];
          sb[sg][inx] |=
            ((long64)eperm32tab[1][(to_permute >> 16) & 0xff][0] << 32) |
             (long64)eperm32tab[1][(to_permute >> 16) & 0xff][1];
          sb[sg][inx] |= 
            ((long64)eperm32tab[2][(to_permute >>  8) & 0xff][0] << 32) |
             (long64)eperm32tab[2][(to_permute >>  8) & 0xff][1];
          sb[sg][inx] |=
            ((long64)eperm32tab[3][(to_permute)       & 0xff][0] << 32) |
             (long64)eperm32tab[3][(to_permute)       & 0xff][1];
#endif
        }
      }
    }  

    /* 
     * Create an inverse matrix for esel telling
     * where to plug out bits if undoing it
     */
    for(bit=48; bit--;) {
      e_inverse[esel[bit] - 1     ] = bit;
      e_inverse[esel[bit] - 1 + 32] = bit + 48;
    }

    /* 
     * create efp: the matrix used to
     * undo the E expansion and effect final permutation
     */
    clearmem((char*)efp, sizeof efp);
    for(bit = 0; bit < 64; bit++) {
      int o_bit, o_long;
      ufc_long word_value, inner_mask1, inner_mask2;
      int comes_from_f_bit, comes_from_e_bit;
      int comes_from_word, bit_within_word;

      /* See where bit i belongs in the two 32 bit long's */
      o_long = bit / 32; /* 0..1  */
      o_bit  = bit % 32; /* 0..31 */

      /* 
       * And find a bit in the e permutated value setting this bit.
       *
       * Note: the e selection may have selected the same bit several
       * times. By the initialization of e_inverse, we only look
       * for one specific instance.
       */
      comes_from_f_bit = final_perm[bit] - 1;         /* 0..63 */
      comes_from_e_bit = e_inverse[comes_from_f_bit]; /* 0..95 */
      comes_from_word  = comes_from_e_bit / 6;        /* 0..15 */
      bit_within_word  = comes_from_e_bit % 6;        /* 0..5  */

      inner_mask1 = longmask[bit_within_word + 26];
      inner_mask2 = longmask[o_bit];

      for(word_value = 64; word_value--;) {
        if(word_value & inner_mask1)
          efp[comes_from_word][word_value][o_long] |= inner_mask2;
      }
    }
    initialized++;
  }

/* 
 * Process the elements of the sb table permuting the
 * bits swapped in the expansion by the current salt.
 */

#ifdef _UFC_32_
static void shuffle_sb(long32 *k, ufc_long saltbits)
  { ufc_long j;
    long32 x;
    for(j=4096; j--;) {
      x = (k[0] ^ k[1]) & (long32)saltbits;
      *k++ ^= x;
      *k++ ^= x;
    }
  }
#endif

#ifdef _UFC_64_
static void shuffle_sb(long64 *k, ufc_long saltbits)
  { ufc_long j;
    long64 x;
    for(j=4096; j--;) {
      x = ((*k >> 32) ^ *k) & (long64)saltbits;
      *k++ ^= (x << 32) | x;
    }
  }
#endif

/* 
 * Setup the unit for a new salt
 * Hopefully we'll not see a new salt in each crypt call.
 */

static unsigned char current_salt[3] = "&&"; /* invalid value */
static ufc_long current_saltbits = 0;
static int direction = 0;

static void setup_salt(const char *s1)
  { ufc_long i, j, saltbits;
    const unsigned char *s2 = (const unsigned char *)s1;

    if(!initialized)
      ufc_init_des();

    if(s2[0] == current_salt[0] && s2[1] == current_salt[1])
      return;
    current_salt[0] = s2[0]; current_salt[1] = s2[1];

    /* 
     * This is the only crypt change to DES:
     * entries are swapped in the expansion table
     * according to the bits set in the salt.
     */
    saltbits = 0;
    for(i = 0; i < 2; i++) {
      long c=ascii_to_bin(s2[i]);
      if(c < 0 || c > 63)
        c = 0;
      for(j = 0; j < 6; j++) {
        if((c >> j) & 0x1)
          saltbits |= BITMASK(6 * i + j);
      }
    }

    /*
     * Permute the sb table values
     * to reflect the changed e
     * selection table
     */
    shuffle_sb(_ufc_sb0, current_saltbits ^ saltbits); 
    shuffle_sb(_ufc_sb1, current_saltbits ^ saltbits);
    shuffle_sb(_ufc_sb2, current_saltbits ^ saltbits);
    shuffle_sb(_ufc_sb3, current_saltbits ^ saltbits);

    current_saltbits = saltbits;
  }

static void ufc_mk_keytab(char *key)
  { ufc_long v1, v2, *k1;
    int i;
#ifdef _UFC_32_
    long32 v, *k2 = &_ufc_keytab[0][0];
#endif
#ifdef _UFC_64_
    long64 v, *k2 = &_ufc_keytab[0];
#endif

    v1 = v2 = 0; k1 = &do_pc1[0][0][0];
    for(i = 8; i--;) {
      v1 |= k1[*key   & 0x7f]; k1 += 128;
      v2 |= k1[*key++ & 0x7f]; k1 += 128;
    }

    for(i = 0; i < 16; i++) {
      k1 = &do_pc2[0][0];

      v1 = (v1 << rots[i]) | (v1 >> (28 - rots[i]));
      v  = k1[(v1 >> 21) & 0x7f]; k1 += 128;
      v |= k1[(v1 >> 14) & 0x7f]; k1 += 128;
      v |= k1[(v1 >>  7) & 0x7f]; k1 += 128;
      v |= k1[(v1      ) & 0x7f]; k1 += 128;

#ifdef _UFC_32_
      *k2++ = v;
      v = 0;
#endif
#ifdef _UFC_64_
      v <<= 32;
#endif

      v2 = (v2 << rots[i]) | (v2 >> (28 - rots[i]));
      v |= k1[(v2 >> 21) & 0x7f]; k1 += 128;
      v |= k1[(v2 >> 14) & 0x7f]; k1 += 128;
      v |= k1[(v2 >>  7) & 0x7f]; k1 += 128;
      v |= k1[(v2      ) & 0x7f];

      *k2++ = v;
    }

    direction = 0;
  }

/* 
 * Undo an extra E selection and do final permutations
 */

ufc_long *_ufc_dofinalperm(ufc_long l1, ufc_long l2, ufc_long r1, ufc_long r2)
  { ufc_long v1, v2, x;
    static ufc_long ary[2];

    x = (l1 ^ l2) & current_saltbits; l1 ^= x; l2 ^= x;
    x = (r1 ^ r2) & current_saltbits; r1 ^= x; r2 ^= x;

    v1=v2=0; l1 >>= 3; l2 >>= 3; r1 >>= 3; r2 >>= 3;

    v1 |= efp[15][ r2         & 0x3f][0]; v2 |= efp[15][ r2 & 0x3f][1];
    v1 |= efp[14][(r2 >>= 6)  & 0x3f][0]; v2 |= efp[14][ r2 & 0x3f][1];
    v1 |= efp[13][(r2 >>= 10) & 0x3f][0]; v2 |= efp[13][ r2 & 0x3f][1];
    v1 |= efp[12][(r2 >>= 6)  & 0x3f][0]; v2 |= efp[12][ r2 & 0x3f][1];

    v1 |= efp[11][ r1         & 0x3f][0]; v2 |= efp[11][ r1 & 0x3f][1];
    v1 |= efp[10][(r1 >>= 6)  & 0x3f][0]; v2 |= efp[10][ r1 & 0x3f][1];
    v1 |= efp[ 9][(r1 >>= 10) & 0x3f][0]; v2 |= efp[ 9][ r1 & 0x3f][1];
    v1 |= efp[ 8][(r1 >>= 6)  & 0x3f][0]; v2 |= efp[ 8][ r1 & 0x3f][1];

    v1 |= efp[ 7][ l2         & 0x3f][0]; v2 |= efp[ 7][ l2 & 0x3f][1];
    v1 |= efp[ 6][(l2 >>= 6)  & 0x3f][0]; v2 |= efp[ 6][ l2 & 0x3f][1];
    v1 |= efp[ 5][(l2 >>= 10) & 0x3f][0]; v2 |= efp[ 5][ l2 & 0x3f][1];
    v1 |= efp[ 4][(l2 >>= 6)  & 0x3f][0]; v2 |= efp[ 4][ l2 & 0x3f][1];

    v1 |= efp[ 3][ l1         & 0x3f][0]; v2 |= efp[ 3][ l1 & 0x3f][1];
    v1 |= efp[ 2][(l1 >>= 6)  & 0x3f][0]; v2 |= efp[ 2][ l1 & 0x3f][1];
    v1 |= efp[ 1][(l1 >>= 10) & 0x3f][0]; v2 |= efp[ 1][ l1 & 0x3f][1];
    v1 |= efp[ 0][(l1 >>= 6)  & 0x3f][0]; v2 |= efp[ 0][ l1 & 0x3f][1];

    ary[0] = v1; ary[1] = v2;
    return ary;
  }

/* 
 * crypt only: convert from 64 bit to 11 bit ASCII 
 * prefixing with the salt
 */

static char *output_conversion(ufc_long v1, ufc_long v2, const char *salt)
  { static char outbuf[14];
    int i, s;

    outbuf[0] = salt[0];
    outbuf[1] = salt[1] ? salt[1] : salt[0];

    for(i = 0; i < 5; i++)
      outbuf[i + 2] = bin_to_ascii((v1 >> (26 - 6 * i)) & 0x3f);

    s  = (v2 & 0xf) << 2;
    v2 = (v2 >> 2) | ((v1 & 0x3) << 30);

    for(i = 5; i < 10; i++)
      outbuf[i + 2] = bin_to_ascii((v2 >> (56 - 6 * i)) & 0x3f);

    outbuf[12] = bin_to_ascii(s);
    outbuf[13] = 0;

    return outbuf;
  }

/* 
 * UNIX crypt function
 */

static ufc_long *_ufc_doit(ufc_long , ufc_long, ufc_long, ufc_long, ufc_long);
   
char *ufc_crypt(const char *key,const char *salt)
  { ufc_long *s;
    char ktab[9];

    /*
     * Hack DES tables according to salt
     */
    setup_salt(salt);

    /*
     * Setup key schedule
     */
    clearmem(ktab, sizeof ktab);
    strncpy(ktab, key, 8);
    ufc_mk_keytab(ktab);

    /*
     * Go for the 25 DES encryptions
     */
    s = _ufc_doit((ufc_long)0, (ufc_long)0, 
                  (ufc_long)0, (ufc_long)0, (ufc_long)25);

    /*
     * And convert back to 6 bit ASCII
     */
    return output_conversion(s[0], s[1], salt);
  }


#ifdef _UFC_32_

/*
 * 32 bit version
 */

extern long32 _ufc_keytab[16][2];
extern long32 _ufc_sb0[], _ufc_sb1[], _ufc_sb2[], _ufc_sb3[];

#define SBA(sb, v) (*(long32*)((char*)(sb)+(v)))

static ufc_long *_ufc_doit(ufc_long l1, ufc_long l2, ufc_long r1, ufc_long r2, ufc_long itr)
  { int i;
    long32 s, *k;

    while(itr--) {
      k = &_ufc_keytab[0][0];
      for(i=8; i--; ) {
        s = *k++ ^ r1;
        l1 ^= SBA(_ufc_sb1, s & 0xffff); l2 ^= SBA(_ufc_sb1, (s & 0xffff)+4);  
        l1 ^= SBA(_ufc_sb0, s >>= 16);   l2 ^= SBA(_ufc_sb0, (s)         +4); 
        s = *k++ ^ r2; 
        l1 ^= SBA(_ufc_sb3, s & 0xffff); l2 ^= SBA(_ufc_sb3, (s & 0xffff)+4);
        l1 ^= SBA(_ufc_sb2, s >>= 16);   l2 ^= SBA(_ufc_sb2, (s)         +4);

        s = *k++ ^ l1; 
        r1 ^= SBA(_ufc_sb1, s & 0xffff); r2 ^= SBA(_ufc_sb1, (s & 0xffff)+4);  
        r1 ^= SBA(_ufc_sb0, s >>= 16);   r2 ^= SBA(_ufc_sb0, (s)         +4); 
        s = *k++ ^ l2; 
        r1 ^= SBA(_ufc_sb3, s & 0xffff); r2 ^= SBA(_ufc_sb3, (s & 0xffff)+4);  
        r1 ^= SBA(_ufc_sb2, s >>= 16);   r2 ^= SBA(_ufc_sb2, (s)         +4);
      } 
      s=l1; l1=r1; r1=s; s=l2; l2=r2; r2=s;
    }
    return _ufc_dofinalperm(l1, l2, r1, r2);
  }

#endif

#ifdef _UFC_64_

/*
 * 64 bit version
 */

extern long64 _ufc_keytab[16];
extern long64 _ufc_sb0[], _ufc_sb1[], _ufc_sb2[], _ufc_sb3[];

#define SBA(sb, v) (*(long64*)((char*)(sb)+(v)))

static ufc_long *_ufc_doit(ufc_long l1, ufc_long l2, ufc_long r1, ufc_long r2, ufc_long itr)
  { int i;
    long64 l, r, s, *k;

    l = (((long64)l1) << 32) | ((long64)l2);
    r = (((long64)r1) << 32) | ((long64)r2);

    while(itr--) {
      k = &_ufc_keytab[0];
      for(i=8; i--; ) {
        s = *k++ ^ r;
        l ^= SBA(_ufc_sb3, (s >>  0) & 0xffff);
        l ^= SBA(_ufc_sb2, (s >> 16) & 0xffff);
        l ^= SBA(_ufc_sb1, (s >> 32) & 0xffff);
        l ^= SBA(_ufc_sb0, (s >> 48) & 0xffff);

        s = *k++ ^ l;
        r ^= SBA(_ufc_sb3, (s >>  0) & 0xffff);
        r ^= SBA(_ufc_sb2, (s >> 16) & 0xffff);
        r ^= SBA(_ufc_sb1, (s >> 32) & 0xffff);
        r ^= SBA(_ufc_sb0, (s >> 48) & 0xffff);
      } 
      s=l; l=r; r=s;
    }

    l1 = l >> 32; l2 = l & 0xffffffff;
    r1 = r >> 32; r2 = r & 0xffffffff;
    return _ufc_dofinalperm(l1, l2, r1, r2);
  }

#endif


#else
 int ufc_dummy_procedure(void);
 int ufc_dummy_procedure(void) {return 0;}
#endif