/*
 * @(#)Crypt.java	1.7 03/12/19
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

/*	Copyright (c) 1988 AT&T	*/
/*	  All Rights Reserved  	*/

/*	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T	*/
/*	The copyright notice above does not evidence any   	*/
/*	actual or intended publication of such source code.	*/


/**
 * Implements the UNIX crypt(3) function, based on a direct port of the
 * libc crypt function.
 *
 * <p>
 * From the crypt man page:
 * <p>
 * crypt() is the password encryption routine, based on the NBS
 * Data  Encryption  Standard,  with variations intended (among
 * other things) to frustrate use of  hardware  implementations
 * of the DES for key search.
 * <p>
 * The first argument to crypt() is  normally  a  user's  typed
 * password.   The  second  is a 2-character string chosen from
 * the set [a-zA-Z0-9./].  the  salt string is used to perturb 
 * the DES algorithm in one
 * of 4096 different ways, after which the password is used  as
 * the  key  to  encrypt  repeatedly  a  constant  string.  The
 * returned value points to the encrypted password, in the same
 * alphabet as the salt.  The first two characters are the salt
 * itself.
 * 
 * @version 1.5, 01/11/00
 * @author Roland Schemers
 */

package com.sun.security.auth.module;

class Crypt {

/* EXPORT DELETE START */

    private static final byte[] IP = {
	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,
    };

    private static final byte[] FP = {
	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,
    };

    private static final byte[] PC1_C = {
	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,
    };

    private static final byte[] PC1_D = {
	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,
    };

    private static final byte[] shifts = { 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1, };

    private static final byte[] PC2_C = {
	14, 17, 11, 24, 1, 5,
	3, 28, 15, 6, 21, 10,
	23, 19, 12, 4, 26, 8,
	16, 7, 27, 20, 13, 2,
    };

    private static final byte[] PC2_D = {
	41,52,31,37,47,55,
	30,40,51,45,33,48,
	44,49,39,56,34,53,
	46,42,50,36,29,32,
    };

    private byte[] C = new byte[28];
    private byte[] D = new byte[28];

    private byte[] KS;

    private byte[] E = new byte[48];

    private static final byte[] e2 = {
	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,
    };

    private void setkey(byte[] key) {
	int i, j, k;
	byte t;

	if (KS == null) {
	    KS = new byte[16*48];
	}

	for (i = 0; i < 28; i++) {
		C[i] = key[PC1_C[i]-1];
		D[i] = key[PC1_D[i]-1];
	}
	for (i = 0; i < 16; i++) {
		for (k = 0; k < shifts[i]; k++) {
			t = C[0];
			for (j = 0; j < 28-1; j++)
				C[j] = C[j+1];
			C[27] = t;
			t = D[0];
			for (j = 0; j < 28-1; j++)
				D[j] = D[j+1];
			D[27] = t;
		}
		for (j = 0; j < 24; j++) {
			int index = i * 48;

			KS[index+j] = C[PC2_C[j]-1];
			KS[index+j+24] = D[PC2_D[j]-28-1];
		}
	}
	for (i = 0; i < 48; i++)
		E[i] = e2[i];
    }


    private static final byte[][] S = {
	{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},
    };


    private static final byte[] 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,
    };

    private byte[]  L = new byte[64];
    private byte[] tempL = new byte[32];
    private byte[] f = new byte[32];
    private byte[] preS = new byte[48];


    private void encrypt(byte[] block,int fake) {
	int	i;
	int t, j, k;
	int R = 32; // &L[32]

	if (KS == null) {
	    KS = new byte[16*48];
	}

	for(j=0; j < 64; j++) {
	    L[j] = block[IP[j]-1];
	}
	for(i=0; i < 16; i++) {
	    int index = i * 48;

	    for(j=0; j < 32; j++) {
		tempL[j] = L[R+j];
	    }
	    for(j=0; j < 48; j++) {
		preS[j] = (byte) (L[R+E[j]-1] ^ KS[index+j]);
	    }
	    for(j=0; j < 8; j++) {
		t = 6*j;
		k = S[j][(preS[t+0]<<5)+
			 (preS[t+1]<<3)+
			 (preS[t+2]<<2)+
			 (preS[t+3]<<1)+
			 (preS[t+4]<<0)+
			 (preS[t+5]<<4)];
		t = 4*j;
		f[t+0] = (byte) ((k>>3)&01);
		f[t+1] = (byte) ((k>>2)&01);
		f[t+2] = (byte) ((k>>1)&01);
		f[t+3] = (byte) ((k>>0)&01);
	    }
	    for(j=0; j < 32; j++) {
			L[R+j] = (byte) (L[j] ^ f[P[j]-1]);
	    }
	    for(j=0; j < 32; j++) {
			L[j] = tempL[j];
	    }
	}
	for(j=0; j < 32; j++) {
	    t = L[j];
	    L[j] = L[R+j];
	    L[R+j] = (byte)t;
	}
	for(j=0; j < 64; j++) {
		block[j] = L[FP[j]-1];
	}
    }
/* EXPORT DELETE END */

    /**
     * Creates a new Crypt object for use with the crypt method.
     *
     */

    public Crypt() 
    {
	// does nothing at this time
	super();
    }

    /**
     * Implements the libc crypt(3) function. 
     *
     * @param pw the password to "encrypt".
     *
     * @param salt the salt to use.
     *
     * @return A new byte[13] array that contains the encrypted
     * password. The first two characters are the salt.
     *
     */

    public synchronized byte[] crypt(byte[] pw, byte[] salt) {
	int c, i, j, pwi;
 	byte temp;
	byte[] block = new byte[66];
	byte[] iobuf = new byte[13];

/* EXPORT DELETE START */

 	pwi = 0;

 	for(i=0; pwi < pw.length && i < 64; pwi++) {
	    c = pw[pwi];
	    for(j=0; j < 7; j++, i++) {
		block[i] = (byte) ((c>>(6-j)) & 01);
	    }
	    i++;
 	}

 	setkey(block);

 	for(i=0; i < 66; i++) {
	    block[i] = 0;
	}

 	for(i=0; i < 2; i++) {
	    c = salt[i];
	    iobuf[i] = (byte)c;
	    if(c > 'Z')
		c -= 6;
	    if(c > '9')
		c -= 7;
	    c -= '.';
	    for(j=0; j < 6; j++) {
		if( ((c>>j) & 01) != 0) {
		    temp = E[6*i+j];
		    E[6*i+j] = E[6*i+j+24];
		    E[6*i+j+24] = temp;
		}
	    }
 	}

 	for(i=0; i < 25; i++) {
 		encrypt(block,0);
	}

 	for(i=0; i < 11; i++) {
	    c = 0;
	    for(j=0; j < 6; j++) {
		c <<= 1;
		c |= block[6*i+j];
	    }
	    c += '.';
	    if(c > '9') {
		c += 7;
	    }
	    if(c > 'Z') {
		c += 6;
	    }
	    iobuf[i+2] = (byte)c;
 	}
 	//iobuf[i+2] = 0;
 	if(iobuf[1] == 0) {
	    iobuf[1] = iobuf[0];
	}
/* EXPORT DELETE END */
 	return(iobuf);
    }

    /**
     * program to test the crypt routine.
     *
     * The first parameter is the cleartext password, the second is
     * the salt to use. The salt should be two characters from the 
     * set [a-zA-Z0-9./]. Outputs the crypt result.
     *
     * @param arg command line arguments.
     *
     */
      
    public static void main(String arg[]) {

	if (arg.length!=2) {
	    System.err.println("usage: Crypt password salt");
	    System.exit(1);
	}

	Crypt c = new Crypt();
	try {
	    byte result[] = c.crypt
	        (arg[0].getBytes("ISO-8859-1"), arg[1].getBytes("ISO-8859-1"));
	    for (int i=0; i<result.length; i++) {
	        System.out.println(" "+i+" "+(char)result[i]);
	    }
	} catch (java.io.UnsupportedEncodingException uee) {
	    // cannot happen
	}
    }
}