现成的class实现crypt算法

package com.elong.application.encrypt; 
public class Crypt 
{     
    static int sub[] = new int[48]; 
 
// TABLES 
/* Expansion table (32 to 48) */ 
int E_p[] = { 
       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 
}; 
 
/* Permutation Choice 1 for subkey generation (64/56 to 56) */ 
int PC1_p[] = { 
       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 
}; 
 
/* Permutation Choice 2 for subkey generation (56 to 48) */ 
int PC2_p[] = { 
       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 
}; 
 
/* Number of rotations for the iteration of key scheduling */ 
/* The concept of a table here doesn't fit our behavioral model */ 
/* This will be logic in our final design */ 
int keyrots[] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1}; 
 
/* Selection blocks 
* There are 8 sblocks, each of which is referenced by a 2 bit value 
* which picks the row, and a 4 bit value which picks the column 
* This number is then the 4 bit output for that select block 
*/ 
int sblocks[][][] = { 
        { { 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 } 
        } 
      }; 
 
/* Permutation P for after sblocks */ 
int P_p[] = { 
       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 
}; 
 
/* Inverse permutation of IP for end 
* Temporary - the true behavior will be implemented in a shift out register 
* (Look at the pattern obvious in an 8x8 layout) 
*/ 
int IPinv_p[] = { 
    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 
}; 
 
// CODE 
private void pr_bits (int[] s, int amt) 
{ 
    amt /= 8; 
    for (int i=0; i<amt; i++) 
    { 
        int x=0; 
        for (int j=0; j<8; j++) 
             x |= s[i*8+j] << (7-j); 
        Integer integ = new Integer(x); 
        System.out.print(integ.toString(x,16)+" "); 
    } 
    System.out.println(); 
}; 
 
private void permute (int[] by, int amt, int[] in, int[] out) 
{ 
  for (; --amt>=0; ) 
    out[amt] = in[by[amt]-1]; 
}; 
 
private void do_sblocks (int[] in, int[] out) 
{ 
    for (int i=0; i<8; i++) 
    { 
      int val = sblocks[i] 
                       [in[i*6] << 1 | in[i*6+5]] 
                       [in[i*6+1] << 3 | 
                        in[i*6+2] << 2 | 
                        in[i*6+3] << 1 | 
                        in[i*6+4] << 0 ]; 
      out[i*4+0] = val >> 3 & 1; 
      out[i*4+1] = val >> 2 & 1; 
      out[i*4+2] = val >> 1 & 1; 
      out[i*4+3] = val >> 0 & 1; 
    } 
}; 
 
private int ascii_to_bin (char c) 
{ 
  if (c>='a') return(c-59); 
  if (c>='A') return(c-53); 
  return(c-'.'); 
}; 
 
private  char bin_to_ascii (int c) 
{ 
  if (c>=38) return (char)(c-38+'a'); 
  if (c>=12) return (char)(c-12+'A'); 
  return (char)(c+'.'); 
}; 
 
private void load_salt (int[] saltmask, char[] salt) 
{ 
    int tot = ascii_to_bin (salt[0]) | (ascii_to_bin (salt[1]) << 6); 
    for (int i=0; i < 12; i++) 
      saltmask[i] = tot >> i & 1; 
}; 
 
private void do_salt (int[] bits, int[] saltmask) 
{ 
    for (int i=0; i<12; i++) 
        if (saltmask[i]!=0) 
        { 
          int t = bits[i]; 
          bits[i] = bits[24+i]; 
          bits[24+i] = t; 
        } 
}; 
 
private void load_key (int[] ikey, char[] password) 
{ 
    int tmp[] = new int[64]; 
 
    for (int i=0; i<8; i++) 
      for (int j=0; j<8; j++) 
        tmp[i*8+j] = (password[i] >> (6-j)) & 1; 
    permute(PC1_p, 56, tmp, ikey); 
}; 
 
private void subkey (int[] ikey, int iter) 
{ 
    int rots=keyrots[iter]; 
 
    int tmp0l=ikey[0]; 
    int tmp1l=ikey[1]; 
    int tmp0r=ikey[28]; 
    int tmp1r=ikey[29]; 
    for (int i=0; i<28-rots; i++) 
    { 
      ikey[i] = ikey[i+rots]; 
      ikey[28+i] = ikey[28+i+rots]; 
    } 
    if(rots==2) 
    { 
      ikey[26] = tmp0l; 
      ikey[27] = tmp1l; 
      ikey[54] = tmp0r; 
      ikey[55] = tmp1r; 
    } 
    else 
    { 
      ikey[27] = tmp0l; 
      ikey[55] = tmp0r; 
    } 
 
    permute (PC2_p,48,ikey,sub); 
}; 
 
private void xor(int[] src1, int[] src2, int index, int num) 
{ 
    for (int i=0; i<num; i++) 
      src1[i] = (src1[i] ^ src2[index+i]) & 1; 
}; 
 
private void print_bits(int[] s, int amt ) 
{ 
    for (int i=0; i<amt; i++) 
      System.out.print (""+s[i]); 
    System.out.println (""); 
}; 
 
private void do_f(int[] in,int index, int[] out, int iter, int[] ikey, int[] saltmask) 
{ 
  int tmp48[] = new int[48], tmp32[] = new int[32], skey[]; 
     
    for (int i=0; i<32; i++) 
      tmp32[i] = in[i+index]; 
    permute (E_p,48,tmp32, tmp48); 
    do_salt (tmp48, saltmask); 
 
    subkey (ikey,iter); 
    skey = sub; 
    xor (tmp48,skey,0,48);   // Goed 
    do_sblocks (tmp48, tmp32); 
    permute (P_p, 32, tmp32,out); 
}; 
 
private char[] mycrypt (char[] password, char[] salt) 
{ 
    int bits[] = new int[64]; 
    int outl[] = new int[32]; 
    int outr[] = new int[32]; 
    int done[] = new int[66]; // In c-code array-size was 64 !?! 
    int ikey[] = new int[56]; 
    int saltmask[]=new int[12]; 
    char[] answer= new char[14]; 
 
    for (int i=0; i<64; i++) 
      bits[i]=0; 
    load_key(ikey,password); 
    load_salt(saltmask,salt); 
 
    for (int dess=0; dess<25; dess++) 
    { 
        for (int iters=0; iters<16; iters+=2) 
        { 
            do_f(bits,32,outl,iters,ikey,saltmask); 
            xor(outl,bits,0,32); 
            do_f(outl,0,outr,iters+1,ikey,saltmask); 
            xor(outr,bits,32,32); 
 
            if (iters != 14) 
                for (int i=0; i<32; i++) 
                { 
                  bits[i] = outl[i]; 
                  bits[i+32] = outr[i]; 
                } 
            else 
                for (int i=0; i<32; i++) 
                { 
                  bits[i] = outr[i]; 
                  bits[i+32] = outl[i]; 
                } 
        } 
    } 
    permute(IPinv_p, 64, bits, done); 
 
    answer[0] = (char)salt[0]; 
    answer[1] = (char)salt[1]; 
    for (int i=0; i<11; i++) 
    { 
        char c=0; 
        for (int j=0; j<6; j++) 
          c |= done[6*i+j] << (5-j); 
        answer[i+2] = bin_to_ascii (c); 
    } 
    return answer; 
}; 
 
/** 
* This method decodes the given password 
* Encryption is based on the one way DES encryption 
* @return The encrypted password 
* @param passwd is the password to encrypt 
* @param s is salt 
*/ 
public String decode (String passwd, String s) 
{ 
    char[] password = new char[9]; 
    char[] salt = new char[3]; 
    String uitkomst; 
 
    passwd.getChars (0,passwd.length()>=8 ? 8 : passwd.length(),password,0);    
    s.getChars (0,2,salt,0); 
 
    uitkomst = new String ().valueOf (mycrypt (password,salt)); 
    return (uitkomst.substring (0,13)); 
} 
 
};

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