crypt_util.c

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      for(word_value = 64; word_value--;) {
	if(word_value & mask1)
	  efp[comes_from_word][word_value][o_long] |= mask2;
      }
    }

    
    /*
     * Create revfinal: an array to undo final
     * the effects of efp
     */
    clearmem((char*)revfinal, sizeof(revfinal));
    for(bit = 0; bit < 96; bit++) {
      int ibit = initial_perm[esel[bit % 48] - 1 + ((bit >= 48) ? 32 : 0)] - 1;
      mask1 = bytemask[ibit % 6 +  2];
      mask2 = BITMASK(bit % 24);
      for(j = 64; j--;) {
        if(j & mask1) {
          revfinal[ibit / 6][j][bit / 24] |= 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(k, saltbits)
  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(k, saltbits)
  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(s)
  char *s;
  { ufc_long i, j, saltbits;

    if(!initialized)
      init_des();

    if(s[0] == current_salt[0] && s[1] == current_salt[1])
      return;
    current_salt[0] = s[0]; current_salt[1] = s[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(s[i]);
#ifdef notdef
      /* 
       * Some applications do rely on illegal
       * salts. It seems that UFC-crypt behaves
       * identically to standard crypt 
       * implementations on illegal salts -- glad
       */
      if(c < 0 || c > 63)
	c = 0;
#endif
      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(key)
  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(l1, l2, r1, r2)
  ufc_long l1,l2,r1,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(v1, v2, salt)
  ufc_long v1, v2;
  char *salt;
  { static char outbuf[14];
    int i, s, shf;

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

    for(i = 0; i < 5; i++) {
      shf = (26 - 6 * i); /* to cope with MSC compiler bug */
      outbuf[i + 2] = bin_to_ascii((v1 >> shf) & 0x3f);
    }

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

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

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

    return outbuf;
  }

ufc_long *_ufc_doit();

/* 
 * UNIX crypt function
 */
   
char *crypt(key, salt)
  char *key, *salt;
  { ufc_long *s;
    char ktab[9];

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

    /*
     * Setup key schedule
     */
    clearmem(ktab, sizeof ktab);
    (void)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);
    /*
     * Do final permutations
     */
    s = _ufc_dofinalperm(s[0], s[1], s[2], s[3]);

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

/* 
 * To make fcrypt users happy.
 * They don't need to call init_des.
 */

char *fcrypt(key, salt)
  char *key;
  char *salt;
  { return crypt(key, salt);
  }

/* 
 * UNIX encrypt function. Takes a bitvector
 * represented by one byte per bit and
 * encrypt/decrypt according to edflag
 */

void encrypt(block, edflag)
  char *block;
  int edflag;
  { ufc_long l1, l2, r1, r2, *s;
    int i;

    /*
     * Undo any salt changes to E expansion
     */
    setup_salt("..");

    /*
     * Reverse key table if
     * changing operation (encrypt/decrypt)
     */
    if((edflag == 0) != (direction == 0)) {
      for(i = 0; i < 8; i++) {
#ifdef _UFC_32_
	long32 x;
	x = _ufc_keytab[15-i][0]; 
        _ufc_keytab[15-i][0] = _ufc_keytab[i][0]; 
        _ufc_keytab[i][0] = x;

	x = _ufc_keytab[15-i][1]; 
        _ufc_keytab[15-i][1] = _ufc_keytab[i][1]; 
        _ufc_keytab[i][1] = x;
#endif
#ifdef _UFC_64_
	long64 x;
	x = _ufc_keytab[15-i];
	_ufc_keytab[15-i] = _ufc_keytab[i];
	_ufc_keytab[i] = x;
#endif
      }
      direction = edflag;
    }

    /*
     * Do initial permutation + E expansion
     */
    i = 0;
    for(l1 = 0; i < 24; i++) {
      if(block[initial_perm[esel[i]-1]-1])
	l1 |= BITMASK(i);
    }
    for(l2 = 0; i < 48; i++) {
      if(block[initial_perm[esel[i]-1]-1])
	l2 |= BITMASK(i-24);
    }

    i = 0;
    for(r1 = 0; i < 24; i++) {
      if(block[initial_perm[esel[i]-1+32]-1])
	r1 |= BITMASK(i);
    }
    for(r2 = 0; i < 48; i++) {
      if(block[initial_perm[esel[i]-1+32]-1])
	r2 |= BITMASK(i-24);
    }

    /*
     * Do DES inner loops + final conversion
     */
    s = _ufc_doit(l1, l2, r1, r2, (ufc_long)1);
    /*
     * Do final permutations
     */
    s = _ufc_dofinalperm(s[0], s[1], s[2], s[3]);

    /*
     * And convert to bit array
     */
    l1 = s[0]; r1 = s[1];
    for(i = 0; i < 32; i++) {
      *block++ = (l1 & longmask[i]) != 0;
    }
    for(i = 0; i < 32; i++) {
      *block++ = (r1 & longmask[i]) != 0;
    }
    
  }

/* 
 * UNIX setkey function. Take a 64 bit DES
 * key and setup the machinery.
 */

void setkey(key)
  char *key;
  { int i,j;
    unsigned char c;
    unsigned char ktab[8];

    setup_salt(".."); /* be sure we're initialized */

    for(i = 0; i < 8; i++) {
      for(j = 0, c = 0; j < 8; j++)
	c = c << 1 | *key++;
      ktab[i] = c >> 1;
    }
    
    ufc_mk_keytab(ktab);
  }

/* 
 * Ultrix crypt16 function, thanks to [e-mail] (Paul Leyland)
 */
   
char *crypt16(key, salt)
  char *key, *salt;
  { ufc_long *s, *t;
    char ktab[9], ttab[9];
    static char q[14], res[25];
    /*
     * Hack DES tables according to salt
     */
    setup_salt(salt);
    
    /*
     * Setup key schedule
     */
    clearmem(ktab, sizeof ktab);
    (void)strncpy(ktab, key, 8);
    ufc_mk_keytab(ktab);
    
    /*
     * Go for first 20 DES encryptions
     */
    s = _ufc_doit((ufc_long)0, (ufc_long)0, 
		  (ufc_long)0, (ufc_long)0, (ufc_long)20);
    
    /*
     * And convert back to 6 bit ASCII
     */
    strcpy (res, output_conversion(s[0], s[1], salt));
    
    clearmem(ttab, sizeof ttab);
    if (strlen (key) > 8) (void)strncpy(ttab, key+8, 8);
    ufc_mk_keytab(ttab);
    
    /*
     * Go for second 5 DES encryptions
     */
    t = _ufc_doit((ufc_long)0, (ufc_long)0, 
		  (ufc_long)0, (ufc_long)0, (ufc_long)5);
    /*
     * And convert back to 6 bit ASCII
     */
    strcpy (q, output_conversion(t[0], t[1], salt));
    strcpy (res+13, q+2);
    
    clearmem(ktab, sizeof ktab);
    (void)strncpy(ktab, key, 8);
    ufc_mk_keytab(ktab);
    
    return res;
  }

/*
 * Experimental -- not supported -- may choke your dog
 */

void ufc_setup_password(cookie, s)
  long *cookie;
  char *s;
  { char c;
    int i;
    ufc_long x;
    ufc_long dl1, dl2, dr1, dr2;

    setup_salt(s);
    dl1 = dl2 = dr1 = dr2 = 0;
    for(i = 0, s += 2; c = *s++; i++) {
      int x = ascii_to_bin(c);
      dl1 |= revfinal[i][x][0];
      dl2 |= revfinal[i][x][1];
      dr1 |= revfinal[i][x][2];
      dr2 |= revfinal[i][x][3];
    }
    x = (dl1 ^ dl2) & current_saltbits;
    x = (dr1 ^ dr2) & current_saltbits;
    cookie[0] = dl1 ^ x; cookie[1] = dl2 ^ x;
    cookie[2] = dr1 ^ x; cookie[3] = dr2 ^ x;
  }

void ufc_do_pw(cookie, guess)
  long *cookie;  
  char *guess;
  { char ktab[9];
    ufc_long *s;
    clearmem(ktab, sizeof ktab);
    (void)strncpy(ktab, guess, 8);
    ufc_mk_keytab(ktab);
    s = _ufc_doit((ufc_long)0, (ufc_long)0, 
		  (ufc_long)0, (ufc_long)0, (ufc_long)25);
    cookie[0] = s[0];    cookie[1] = s[1];
    cookie[2] = s[2];    cookie[3] = s[3];
  }