425 - Enigmatic Encryption

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10153EN
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Posts: 148
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Location: Hong Kong
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Post by 10153EN » Mon Mar 25, 2002 5:59 pm

Any hints about this problem?

I can just think of brute force..
But seems may get time limit exceeded...
any other tricks??

Thx

10153EN
Experienced poster
Posts: 148
Joined: Sun Jan 06, 2002 2:00 am
Location: Hong Kong
Contact:

Post by 10153EN » Mon Mar 25, 2002 5:59 pm

Any hints about this problem?

I can just think of brute force..
But seems may get time limit exceeded...
any other tricks??

Thx

LittleJohn
Learning poster
Posts: 83
Joined: Wed Feb 27, 2002 2:00 am
Location: Taiwan

Post by LittleJohn » Mon Mar 25, 2002 6:19 pm

Removing the duplicate words will help you!

roticv
Learning poster
Posts: 63
Joined: Sat Dec 11, 2004 9:28 am

425 - Enigmatic Encryption

Post by roticv » Sun Aug 28, 2005 9:19 am

Hello,

I am really getting crazy over this question. I know I am supposed to use trie, and that's what I did. However, I am still getting WA. Here's my code

Code: Select all

#include <stdio.h>
#include <string.h>

struct nodeT{
int end;
struct nodeT *next[26];
};

char delim[] = "`~1!2@3#4$5%6^7&8*9(0)-_=+[{]}\\|;:'\",<.>/? \n";
int i,j,k,np,len,total,flag,cnt;
struct nodeT root;
struct nodeT nodes[30000];
int len1[6000];
char str[100];
char table[6000][6];
char hash[20];
char salt[3];
char key[10];
char path[10];

char *crypt(char *pw, char *salt);

void tolower(char *c){
	int ii;
	for (ii=0;c[ii]!=0;ii++){
		c[ii] |= 0x20;
	}
	return;
}

void addWord(struct nodeT *p, char *word){
	int ii, id,len = strlen(word);
	struct nodeT *v;
	for (ii=0;ii<len;ii++){
		id = word[ii]-'a';
		if (p->next[id]==NULL){
			memset(&nodes[np],0x0,sizeof (struct nodeT));
			p->next[id] = &nodes[np];
			np++;
		}
		p = p->next[id];
		if (ii == len - 1)
			p->end = 1;
	}
	return;
}

void printtrie(struct nodeT *p, int depth){
	int ii,iszero;
	path[depth] = 0;
	if (p->end == 1){
		len1[cnt] = strlen(path);
		strcpy(table[cnt],path);
		cnt++;
	}
	for (ii=0,iszero=1;ii<26;ii++){
		if (p->next[ii] != 0){
			path[depth] = ii+'a';
			printtrie(p->next[ii],depth+1);
			iszero = 0;
		}
	}
	if (iszero != 0 && p->end == 0){
		len1[cnt] = strlen(path);
		strcpy(table[cnt],path);
		cnt++;
	}
	return;
}

int main(){
	char *pch;
	memset(&root,0x0,sizeof(struct nodeT));
	np = 0; cnt = 0;
	gets(hash);
	salt[0] = hash[0]; salt[1] = hash[1];
	while (gets(str)!=NULL){
		pch = strtok(str,delim);
		while (pch!=NULL){
			len = strlen(pch);
			if (len < 6 && len > 1){
				tolower(pch);
				addWord(&root,pch);
			}
			pch = strtok(0,delim);
		}
	}
	printtrie(&root,0);
	flag = 0;
	for (i=0;i<(cnt-1);i++){
		for (j=i+1;j<cnt;j++){
			total = len1[i] + len1[j] + 1;
			if (total >= 5 && total <= 8){
				for (k=0;k<10;k+=2){
					if (k==6)
						continue;
					sprintf(key,"%s%d%s",table[i],k,table[j]);
					if (strcmp(crypt(key,salt),hash)==0){
						flag = 1;
						break;
					}
				}
			}
			if (flag == 1)
				break;
		}
		if (flag == 1)
			break;
	}
	printf("%s\n",key);
	return 0;
}



x140l31
Learning poster
Posts: 69
Joined: Tue Jan 30, 2007 12:51 am

Re: 425

Post by x140l31 » Tue Apr 08, 2008 1:45 am

One question, the original password at LEAST have a non-alphabetic character? or HAVE ONE non-alphabetic character {0, 2, 4 or 8}

can anyone help me with some inputs?

thanks!

DD
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Posts: 145
Joined: Thu Aug 14, 2003 8:42 am
Location: Mountain View, California
Contact:

Re: 425 - Enigmatic Encryption

Post by DD » Tue Nov 04, 2008 5:53 pm

To roticv:
roticv wrote:Hello,

I am really getting crazy over this question. I know I am supposed to use trie, and that's what I did. However, I am still getting WA. Here's my code

Code: Select all

#include <stdio.h>
#include <string.h>

struct nodeT{
int end;
struct nodeT *next[26];
};

char delim[] = "`~1!2@3#4$5%6^7&8*9(0)-_=+[{]}\\|;:'\",<.>/? \n";
int i,j,k,np,len,total,flag,cnt;
struct nodeT root;
struct nodeT nodes[30000];
int len1[6000];
char str[100];
char table[6000][6];
char hash[20];
char salt[3];
char key[10];
char path[10];

char *crypt(char *pw, char *salt);

void tolower(char *c){
int ii;
for (ii=0;c[ii]!=0;ii++){
c[ii] |= 0x20;
}
return;
}

void addWord(struct nodeT *p, char *word){
int ii, id,len = strlen(word);
struct nodeT *v;
for (ii=0;ii<len;ii++){
id = word[ii]-'a';
if (p->next[id]==NULL){
memset(&nodes[np],0x0,sizeof (struct nodeT));
p->next[id] = &nodes[np];
np++;
}
p = p->next[id];
if (ii == len - 1)
p->end = 1;
}
return;
}

void printtrie(struct nodeT *p, int depth){
int ii,iszero;
path[depth] = 0;
if (p->end == 1){
len1[cnt] = strlen(path);
strcpy(table[cnt],path);
cnt++;
}
for (ii=0,iszero=1;ii<26;ii++){
if (p->next[ii] != 0){
path[depth] = ii+'a';
printtrie(p->next[ii],depth+1);
iszero = 0;
}
}
if (iszero != 0 && p->end == 0){
len1[cnt] = strlen(path);
strcpy(table[cnt],path);
cnt++;
}
return;
}

int main(){
char *pch;
memset(&root,0x0,sizeof(struct nodeT));
np = 0; cnt = 0;
gets(hash);
salt[0] = hash[0]; salt[1] = hash[1];
while (gets(str)!=NULL){
pch = strtok(str,delim);
while (pch!=NULL){
len = strlen(pch);
if (len < 6 && len > 1){
tolower(pch);
addWord(&root,pch);
}
pch = strtok(0,delim);
}
}
printtrie(&root,0);
flag = 0;
for (i=0;i<(cnt-1);i++){
for (j=i+1;j<cnt;j++){
total = len1[i] + len1[j] + 1;
if (total >= 5 && total <= 8){
for (k=0;k<10;k+=2){
if (k==6)
continue;
sprintf(key,"%s%d%s",table[i],k,table[j]);
if (strcmp(crypt(key,salt),hash)==0){
flag = 1;
break;
}
}
}
if (flag == 1)
break;
}
if (flag == 1)
break;
}
printf("%s\n",key);
return 0;
}


Although I didn't see any problem in your code, but I strongly recommanded that you can use the pre-defined "crypt" function in C.

To x140l31:
x140l31 wrote:One question, the original password at LEAST have a non-alphabetic character? or HAVE ONE non-alphabetic character {0, 2, 4 or 8}

can anyone help me with some inputs?

thanks!
I think there is only one non-alphabetic character in the original password.
Have you ever...
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anacharsis
Learning poster
Posts: 69
Joined: Mon Feb 09, 2015 1:56 am

Re: 425 - Enigmatic Encryption

Post by anacharsis » Sat Oct 08, 2016 10:23 pm

If anyone wants to try this one in Java, there is a Java implementation of the crypt() function here :
https://cseweb.ucsd.edu/classes/wi14/cs ... Crypt.java

Just in case that link breaks, it's also below.
(Note that C/C++ users are allowed to link to the library with the crypt command, so this is not cheating)

Code: Select all

/****************************************************************************
 * Java-based implementation of the unix crypt(3) command
 *
 * Based upon C source code written by Eric Young, eay@psych.uq.oz.au
 * Java conversion by John F. Dumas, jdumas@zgs.com
 *
 * Found at http://locutus.kingwoodcable.com/jfd/crypt.html
 * Minor optimizations by Wes Biggs, wes@cacas.org
 *
 * Eric's original code is licensed under the BSD license.  As this is
 * derivative, the same license applies.
 *
 * Note: Crypt.class is much smaller when compiled with javac -O
 ****************************************************************************/

public class Crypt {
  private Crypt() {} // defined so class can't be instantiated.

  private static final int ITERATIONS = 16;

  private static final boolean shifts2[] = {
    false, false, true, true, true, true, true, true,
    false, true,  true, true, true, true, true, false
  };

  private static final int skb[][] = {
    {
      /* for C bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
      0x00000000, 0x00000010, 0x20000000, 0x20000010, 
      0x00010000, 0x00010010, 0x20010000, 0x20010010, 
      0x00000800, 0x00000810, 0x20000800, 0x20000810, 
      0x00010800, 0x00010810, 0x20010800, 0x20010810, 
      0x00000020, 0x00000030, 0x20000020, 0x20000030, 
      0x00010020, 0x00010030, 0x20010020, 0x20010030, 
      0x00000820, 0x00000830, 0x20000820, 0x20000830, 
      0x00010820, 0x00010830, 0x20010820, 0x20010830, 
      0x00080000, 0x00080010, 0x20080000, 0x20080010, 
      0x00090000, 0x00090010, 0x20090000, 0x20090010, 
      0x00080800, 0x00080810, 0x20080800, 0x20080810, 
      0x00090800, 0x00090810, 0x20090800, 0x20090810, 
      0x00080020, 0x00080030, 0x20080020, 0x20080030, 
      0x00090020, 0x00090030, 0x20090020, 0x20090030, 
      0x00080820, 0x00080830, 0x20080820, 0x20080830, 
      0x00090820, 0x00090830, 0x20090820, 0x20090830, 
    },
    {
      /* for C bits (numbered as per FIPS 46) 7 8 10 11 12 13 */
      0x00000000, 0x02000000, 0x00002000, 0x02002000, 
      0x00200000, 0x02200000, 0x00202000, 0x02202000, 
      0x00000004, 0x02000004, 0x00002004, 0x02002004, 
      0x00200004, 0x02200004, 0x00202004, 0x02202004, 
      0x00000400, 0x02000400, 0x00002400, 0x02002400, 
      0x00200400, 0x02200400, 0x00202400, 0x02202400, 
      0x00000404, 0x02000404, 0x00002404, 0x02002404, 
      0x00200404, 0x02200404, 0x00202404, 0x02202404, 
      0x10000000, 0x12000000, 0x10002000, 0x12002000, 
      0x10200000, 0x12200000, 0x10202000, 0x12202000, 
      0x10000004, 0x12000004, 0x10002004, 0x12002004, 
      0x10200004, 0x12200004, 0x10202004, 0x12202004, 
      0x10000400, 0x12000400, 0x10002400, 0x12002400, 
      0x10200400, 0x12200400, 0x10202400, 0x12202400, 
      0x10000404, 0x12000404, 0x10002404, 0x12002404, 
      0x10200404, 0x12200404, 0x10202404, 0x12202404, 
    },
    {
      /* for C bits (numbered as per FIPS 46) 14 15 16 17 19 20 */
      0x00000000, 0x00000001, 0x00040000, 0x00040001, 
      0x01000000, 0x01000001, 0x01040000, 0x01040001, 
      0x00000002, 0x00000003, 0x00040002, 0x00040003, 
      0x01000002, 0x01000003, 0x01040002, 0x01040003, 
      0x00000200, 0x00000201, 0x00040200, 0x00040201, 
      0x01000200, 0x01000201, 0x01040200, 0x01040201, 
      0x00000202, 0x00000203, 0x00040202, 0x00040203, 
      0x01000202, 0x01000203, 0x01040202, 0x01040203, 
      0x08000000, 0x08000001, 0x08040000, 0x08040001, 
      0x09000000, 0x09000001, 0x09040000, 0x09040001, 
      0x08000002, 0x08000003, 0x08040002, 0x08040003, 
      0x09000002, 0x09000003, 0x09040002, 0x09040003, 
      0x08000200, 0x08000201, 0x08040200, 0x08040201, 
      0x09000200, 0x09000201, 0x09040200, 0x09040201, 
      0x08000202, 0x08000203, 0x08040202, 0x08040203, 
      0x09000202, 0x09000203, 0x09040202, 0x09040203, 
    },
    {
      /* for C bits (numbered as per FIPS 46) 21 23 24 26 27 28 */
      0x00000000, 0x00100000, 0x00000100, 0x00100100, 
      0x00000008, 0x00100008, 0x00000108, 0x00100108, 
      0x00001000, 0x00101000, 0x00001100, 0x00101100, 
      0x00001008, 0x00101008, 0x00001108, 0x00101108, 
      0x04000000, 0x04100000, 0x04000100, 0x04100100, 
      0x04000008, 0x04100008, 0x04000108, 0x04100108, 
      0x04001000, 0x04101000, 0x04001100, 0x04101100, 
      0x04001008, 0x04101008, 0x04001108, 0x04101108, 
      0x00020000, 0x00120000, 0x00020100, 0x00120100, 
      0x00020008, 0x00120008, 0x00020108, 0x00120108, 
      0x00021000, 0x00121000, 0x00021100, 0x00121100, 
      0x00021008, 0x00121008, 0x00021108, 0x00121108, 
      0x04020000, 0x04120000, 0x04020100, 0x04120100, 
      0x04020008, 0x04120008, 0x04020108, 0x04120108, 
      0x04021000, 0x04121000, 0x04021100, 0x04121100, 
      0x04021008, 0x04121008, 0x04021108, 0x04121108, 
    },
    {
      /* for D bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
      0x00000000, 0x10000000, 0x00010000, 0x10010000, 
      0x00000004, 0x10000004, 0x00010004, 0x10010004, 
      0x20000000, 0x30000000, 0x20010000, 0x30010000, 
      0x20000004, 0x30000004, 0x20010004, 0x30010004, 
      0x00100000, 0x10100000, 0x00110000, 0x10110000, 
      0x00100004, 0x10100004, 0x00110004, 0x10110004, 
      0x20100000, 0x30100000, 0x20110000, 0x30110000, 
      0x20100004, 0x30100004, 0x20110004, 0x30110004, 
      0x00001000, 0x10001000, 0x00011000, 0x10011000, 
      0x00001004, 0x10001004, 0x00011004, 0x10011004, 
      0x20001000, 0x30001000, 0x20011000, 0x30011000, 
      0x20001004, 0x30001004, 0x20011004, 0x30011004, 
      0x00101000, 0x10101000, 0x00111000, 0x10111000, 
      0x00101004, 0x10101004, 0x00111004, 0x10111004, 
      0x20101000, 0x30101000, 0x20111000, 0x30111000, 
      0x20101004, 0x30101004, 0x20111004, 0x30111004, 
    },
    {
      /* for D bits (numbered as per FIPS 46) 8 9 11 12 13 14 */
      0x00000000, 0x08000000, 0x00000008, 0x08000008, 
      0x00000400, 0x08000400, 0x00000408, 0x08000408, 
      0x00020000, 0x08020000, 0x00020008, 0x08020008, 
      0x00020400, 0x08020400, 0x00020408, 0x08020408, 
      0x00000001, 0x08000001, 0x00000009, 0x08000009, 
      0x00000401, 0x08000401, 0x00000409, 0x08000409, 
      0x00020001, 0x08020001, 0x00020009, 0x08020009, 
      0x00020401, 0x08020401, 0x00020409, 0x08020409, 
      0x02000000, 0x0A000000, 0x02000008, 0x0A000008, 
      0x02000400, 0x0A000400, 0x02000408, 0x0A000408, 
      0x02020000, 0x0A020000, 0x02020008, 0x0A020008, 
      0x02020400, 0x0A020400, 0x02020408, 0x0A020408, 
      0x02000001, 0x0A000001, 0x02000009, 0x0A000009, 
      0x02000401, 0x0A000401, 0x02000409, 0x0A000409, 
      0x02020001, 0x0A020001, 0x02020009, 0x0A020009, 
      0x02020401, 0x0A020401, 0x02020409, 0x0A020409, 
    },
    {
      /* for D bits (numbered as per FIPS 46) 16 17 18 19 20 21 */
      0x00000000, 0x00000100, 0x00080000, 0x00080100, 
      0x01000000, 0x01000100, 0x01080000, 0x01080100, 
      0x00000010, 0x00000110, 0x00080010, 0x00080110, 
      0x01000010, 0x01000110, 0x01080010, 0x01080110, 
      0x00200000, 0x00200100, 0x00280000, 0x00280100, 
      0x01200000, 0x01200100, 0x01280000, 0x01280100, 
      0x00200010, 0x00200110, 0x00280010, 0x00280110, 
      0x01200010, 0x01200110, 0x01280010, 0x01280110, 
      0x00000200, 0x00000300, 0x00080200, 0x00080300, 
      0x01000200, 0x01000300, 0x01080200, 0x01080300, 
      0x00000210, 0x00000310, 0x00080210, 0x00080310, 
      0x01000210, 0x01000310, 0x01080210, 0x01080310, 
      0x00200200, 0x00200300, 0x00280200, 0x00280300, 
      0x01200200, 0x01200300, 0x01280200, 0x01280300, 
      0x00200210, 0x00200310, 0x00280210, 0x00280310, 
      0x01200210, 0x01200310, 0x01280210, 0x01280310, 
    },
    {
      /* for D bits (numbered as per FIPS 46) 22 23 24 25 27 28 */
      0x00000000, 0x04000000, 0x00040000, 0x04040000, 
      0x00000002, 0x04000002, 0x00040002, 0x04040002, 
      0x00002000, 0x04002000, 0x00042000, 0x04042000, 
      0x00002002, 0x04002002, 0x00042002, 0x04042002, 
      0x00000020, 0x04000020, 0x00040020, 0x04040020, 
      0x00000022, 0x04000022, 0x00040022, 0x04040022, 
      0x00002020, 0x04002020, 0x00042020, 0x04042020, 
      0x00002022, 0x04002022, 0x00042022, 0x04042022, 
      0x00000800, 0x04000800, 0x00040800, 0x04040800, 
      0x00000802, 0x04000802, 0x00040802, 0x04040802, 
      0x00002800, 0x04002800, 0x00042800, 0x04042800, 
      0x00002802, 0x04002802, 0x00042802, 0x04042802, 
      0x00000820, 0x04000820, 0x00040820, 0x04040820, 
      0x00000822, 0x04000822, 0x00040822, 0x04040822, 
      0x00002820, 0x04002820, 0x00042820, 0x04042820, 
      0x00002822, 0x04002822, 0x00042822, 0x04042822, 
    }
  };
  
  private static final int SPtrans[][] = {
    {
      /* nibble 0 */
      0x00820200, 0x00020000, 0x80800000, 0x80820200,
      0x00800000, 0x80020200, 0x80020000, 0x80800000,
      0x80020200, 0x00820200, 0x00820000, 0x80000200,
      0x80800200, 0x00800000, 0x00000000, 0x80020000,
      0x00020000, 0x80000000, 0x00800200, 0x00020200,
      0x80820200, 0x00820000, 0x80000200, 0x00800200,
      0x80000000, 0x00000200, 0x00020200, 0x80820000,
      0x00000200, 0x80800200, 0x80820000, 0x00000000,
      0x00000000, 0x80820200, 0x00800200, 0x80020000,
      0x00820200, 0x00020000, 0x80000200, 0x00800200,
      0x80820000, 0x00000200, 0x00020200, 0x80800000,
      0x80020200, 0x80000000, 0x80800000, 0x00820000,
      0x80820200, 0x00020200, 0x00820000, 0x80800200,
      0x00800000, 0x80000200, 0x80020000, 0x00000000,
      0x00020000, 0x00800000, 0x80800200, 0x00820200,
      0x80000000, 0x80820000, 0x00000200, 0x80020200,
    },
    {
      /* nibble 1 */
      0x10042004, 0x00000000, 0x00042000, 0x10040000,
      0x10000004, 0x00002004, 0x10002000, 0x00042000,
      0x00002000, 0x10040004, 0x00000004, 0x10002000,
      0x00040004, 0x10042000, 0x10040000, 0x00000004,
      0x00040000, 0x10002004, 0x10040004, 0x00002000,
      0x00042004, 0x10000000, 0x00000000, 0x00040004,
      0x10002004, 0x00042004, 0x10042000, 0x10000004,
      0x10000000, 0x00040000, 0x00002004, 0x10042004,
      0x00040004, 0x10042000, 0x10002000, 0x00042004,
      0x10042004, 0x00040004, 0x10000004, 0x00000000,
      0x10000000, 0x00002004, 0x00040000, 0x10040004,
      0x00002000, 0x10000000, 0x00042004, 0x10002004,
      0x10042000, 0x00002000, 0x00000000, 0x10000004,
      0x00000004, 0x10042004, 0x00042000, 0x10040000,
      0x10040004, 0x00040000, 0x00002004, 0x10002000,
      0x10002004, 0x00000004, 0x10040000, 0x00042000,
    },
    {
      /* nibble 2 */
      0x41000000, 0x01010040, 0x00000040, 0x41000040,
      0x40010000, 0x01000000, 0x41000040, 0x00010040,
      0x01000040, 0x00010000, 0x01010000, 0x40000000,
      0x41010040, 0x40000040, 0x40000000, 0x41010000,
      0x00000000, 0x40010000, 0x01010040, 0x00000040,
      0x40000040, 0x41010040, 0x00010000, 0x41000000,
      0x41010000, 0x01000040, 0x40010040, 0x01010000,
      0x00010040, 0x00000000, 0x01000000, 0x40010040,
      0x01010040, 0x00000040, 0x40000000, 0x00010000,
      0x40000040, 0x40010000, 0x01010000, 0x41000040,
      0x00000000, 0x01010040, 0x00010040, 0x41010000,
      0x40010000, 0x01000000, 0x41010040, 0x40000000,
      0x40010040, 0x41000000, 0x01000000, 0x41010040,
      0x00010000, 0x01000040, 0x41000040, 0x00010040,
      0x01000040, 0x00000000, 0x41010000, 0x40000040,
      0x41000000, 0x40010040, 0x00000040, 0x01010000,
    },
    {
      /* nibble 3 */
      0x00100402, 0x04000400, 0x00000002, 0x04100402,
      0x00000000, 0x04100000, 0x04000402, 0x00100002,
      0x04100400, 0x04000002, 0x04000000, 0x00000402,
      0x04000002, 0x00100402, 0x00100000, 0x04000000,
      0x04100002, 0x00100400, 0x00000400, 0x00000002,
      0x00100400, 0x04000402, 0x04100000, 0x00000400,
      0x00000402, 0x00000000, 0x00100002, 0x04100400,
      0x04000400, 0x04100002, 0x04100402, 0x00100000,
      0x04100002, 0x00000402, 0x00100000, 0x04000002,
      0x00100400, 0x04000400, 0x00000002, 0x04100000,
      0x04000402, 0x00000000, 0x00000400, 0x00100002,
      0x00000000, 0x04100002, 0x04100400, 0x00000400,
      0x04000000, 0x04100402, 0x00100402, 0x00100000,
      0x04100402, 0x00000002, 0x04000400, 0x00100402,
      0x00100002, 0x00100400, 0x04100000, 0x04000402,
      0x00000402, 0x04000000, 0x04000002, 0x04100400,
    },
    {
      /* nibble 4 */
      0x02000000, 0x00004000, 0x00000100, 0x02004108,
      0x02004008, 0x02000100, 0x00004108, 0x02004000,
      0x00004000, 0x00000008, 0x02000008, 0x00004100,
      0x02000108, 0x02004008, 0x02004100, 0x00000000,
      0x00004100, 0x02000000, 0x00004008, 0x00000108,
      0x02000100, 0x00004108, 0x00000000, 0x02000008,
      0x00000008, 0x02000108, 0x02004108, 0x00004008,
      0x02004000, 0x00000100, 0x00000108, 0x02004100,
      0x02004100, 0x02000108, 0x00004008, 0x02004000,
      0x00004000, 0x00000008, 0x02000008, 0x02000100,
      0x02000000, 0x00004100, 0x02004108, 0x00000000,
      0x00004108, 0x02000000, 0x00000100, 0x00004008,
      0x02000108, 0x00000100, 0x00000000, 0x02004108,
      0x02004008, 0x02004100, 0x00000108, 0x00004000,
      0x00004100, 0x02004008, 0x02000100, 0x00000108,
      0x00000008, 0x00004108, 0x02004000, 0x02000008,
    },
    {
      /* nibble 5 */
      0x20000010, 0x00080010, 0x00000000, 0x20080800,
      0x00080010, 0x00000800, 0x20000810, 0x00080000,
      0x00000810, 0x20080810, 0x00080800, 0x20000000,
      0x20000800, 0x20000010, 0x20080000, 0x00080810,
      0x00080000, 0x20000810, 0x20080010, 0x00000000,
      0x00000800, 0x00000010, 0x20080800, 0x20080010,
      0x20080810, 0x20080000, 0x20000000, 0x00000810,
      0x00000010, 0x00080800, 0x00080810, 0x20000800,
      0x00000810, 0x20000000, 0x20000800, 0x00080810,
      0x20080800, 0x00080010, 0x00000000, 0x20000800,
      0x20000000, 0x00000800, 0x20080010, 0x00080000,
      0x00080010, 0x20080810, 0x00080800, 0x00000010,
      0x20080810, 0x00080800, 0x00080000, 0x20000810,
      0x20000010, 0x20080000, 0x00080810, 0x00000000,
      0x00000800, 0x20000010, 0x20000810, 0x20080800,
      0x20080000, 0x00000810, 0x00000010, 0x20080010,
    },
    {
      /* nibble 6 */
      0x00001000, 0x00000080, 0x00400080, 0x00400001,
      0x00401081, 0x00001001, 0x00001080, 0x00000000,
      0x00400000, 0x00400081, 0x00000081, 0x00401000,
      0x00000001, 0x00401080, 0x00401000, 0x00000081,
      0x00400081, 0x00001000, 0x00001001, 0x00401081,
      0x00000000, 0x00400080, 0x00400001, 0x00001080,
      0x00401001, 0x00001081, 0x00401080, 0x00000001,
      0x00001081, 0x00401001, 0x00000080, 0x00400000,
      0x00001081, 0x00401000, 0x00401001, 0x00000081,
      0x00001000, 0x00000080, 0x00400000, 0x00401001,
      0x00400081, 0x00001081, 0x00001080, 0x00000000,
      0x00000080, 0x00400001, 0x00000001, 0x00400080,
      0x00000000, 0x00400081, 0x00400080, 0x00001080,
      0x00000081, 0x00001000, 0x00401081, 0x00400000,
      0x00401080, 0x00000001, 0x00001001, 0x00401081,
      0x00400001, 0x00401080, 0x00401000, 0x00001001,
    },
    {
      /* nibble 7 */
      0x08200020, 0x08208000, 0x00008020, 0x00000000,
      0x08008000, 0x00200020, 0x08200000, 0x08208020,
      0x00000020, 0x08000000, 0x00208000, 0x00008020,
      0x00208020, 0x08008020, 0x08000020, 0x08200000,
      0x00008000, 0x00208020, 0x00200020, 0x08008000,
      0x08208020, 0x08000020, 0x00000000, 0x00208000,
      0x08000000, 0x00200000, 0x08008020, 0x08200020,
      0x00200000, 0x00008000, 0x08208000, 0x00000020,
      0x00200000, 0x00008000, 0x08000020, 0x08208020,
      0x00008020, 0x08000000, 0x00000000, 0x00208000,
      0x08200020, 0x08008020, 0x08008000, 0x00200020,
      0x08208000, 0x00000020, 0x00200020, 0x08008000,
      0x08208020, 0x00200000, 0x08200000, 0x08000020,
      0x00208000, 0x00008020, 0x08008020, 0x08200000,
      0x00000020, 0x08208000, 0x00208020, 0x00000000,
      0x08000000, 0x08200020, 0x00008000, 0x00208020
    }
  };
  
  private static final int byteToUnsigned(byte b) {
    int value = (int) b;
    return (value >= 0) ? value : value + 256;
  }

  private static int fourBytesToInt(byte b[], int offset) {
    return byteToUnsigned(b[offset++]) 
      | (byteToUnsigned(b[offset++]) <<  8) 
      | (byteToUnsigned(b[offset++]) << 16) 
      | (byteToUnsigned(b[offset]) << 24);
  }

  private static final void intToFourBytes(int iValue, byte b[], int offset) {
    b[offset++] = (byte)((iValue)        & 0xff);
    b[offset++] = (byte)((iValue >>> 8 ) & 0xff);
    b[offset++] = (byte)((iValue >>> 16) & 0xff);
    b[offset] = (byte)((iValue >>> 24) & 0xff);
  }
  
  private static final void PERM_OP(int a, int b, int n, int m, int results[]) {
    int t;

    t = ((a >>> n) ^ b) & m;
    a ^= t << n;
    b ^= t;

    results[0] = a;
    results[1] = b;
  }

  private static final int HPERM_OP(int a, int n, int m) {
    int t;
    
    t = ((a << (16 - n)) ^ a) & m;
    a = a ^ t ^ (t >>> (16 - n));
    
    return a;
  }

  private static int [] des_set_key(byte key[]) {
    int schedule[] = new int [ITERATIONS * 2];
    
    int c = fourBytesToInt(key, 0);
    int d = fourBytesToInt(key, 4);
    
    int results[] = new int[2];

    PERM_OP(d, c, 4, 0x0f0f0f0f, results);
    d = results[0]; c = results[1];
    
    c = HPERM_OP(c, -2, 0xcccc0000);
    d = HPERM_OP(d, -2, 0xcccc0000);
    
    PERM_OP(d, c, 1, 0x55555555, results);
    d = results[0]; c = results[1];
    
    PERM_OP(c, d, 8, 0x00ff00ff, results);
    c = results[0]; d = results[1];
    
    PERM_OP(d, c, 1, 0x55555555, results);
    d = results[0]; c = results[1];
    
    d = (((d & 0x000000ff) <<  16) |  (d & 0x0000ff00)     |
	 ((d & 0x00ff0000) >>> 16) | ((c & 0xf0000000) >>> 4));
    c &= 0x0fffffff;
    
    int s, t;
    int j = 0;
    
    for(int i = 0; i < ITERATIONS; i ++) {
      if(shifts2[i]) {
	c = (c >>> 2) | (c << 26);
	d = (d >>> 2) | (d << 26);
      } else {
	c = (c >>> 1) | (c << 27);
	d = (d >>> 1) | (d << 27);
      }
      
      c &= 0x0fffffff;
      d &= 0x0fffffff;
      
      s = skb[0][ (c       ) & 0x3f                       ]|
	skb[1][((c >>>  6) & 0x03) | ((c >>>  7) & 0x3c)]|
	skb[2][((c >>> 13) & 0x0f) | ((c >>> 14) & 0x30)]|
	skb[3][((c >>> 20) & 0x01) | ((c >>> 21) & 0x06) |
				   ((c >>> 22) & 0x38)];

      t = skb[4][ (d     )  & 0x3f                       ]|
	skb[5][((d >>> 7) & 0x03) | ((d >>>  8) & 0x3c)]|
	skb[6][ (d >>>15) & 0x3f                       ]|
	skb[7][((d >>>21) & 0x0f) | ((d >>> 22) & 0x30)];
      
      schedule[j++] = ((t <<  16) | (s & 0x0000ffff)) & 0xffffffff;
      s             = ((s >>> 16) | (t & 0xffff0000));
      
      s             = (s << 4) | (s >>> 28);
      schedule[j++] = s & 0xffffffff;
    }
    return schedule;
  }

  private static final int D_ENCRYPT(int L, int R, int S, int E0, int E1, int s[]) {
    int t, u, v;
    
    v = R ^ (R >>> 16);
    u = v & E0;
    v = v & E1;
    u = (u ^ (u << 16)) ^ R ^ s[S];
    t = (v ^ (v << 16)) ^ R ^ s[S + 1];
    t = (t >>> 4) | (t << 28);
    
    L ^= SPtrans[1][(t       ) & 0x3f] |
      SPtrans[3][(t >>>  8) & 0x3f] |
      SPtrans[5][(t >>> 16) & 0x3f] |
      SPtrans[7][(t >>> 24) & 0x3f] |
      SPtrans[0][(u       ) & 0x3f] |
      SPtrans[2][(u >>>  8) & 0x3f] |
      SPtrans[4][(u >>> 16) & 0x3f] |
      SPtrans[6][(u >>> 24) & 0x3f];

    return L;
  }
  
  private static final int [] body(int schedule[], int Eswap0, int Eswap1) {
    int left = 0;
    int right = 0;
    int t     = 0;

    for (int j = 0; j < 25; j ++) {
      for (int i = 0; i < ITERATIONS * 2; i += 4) {
	left  = D_ENCRYPT(left,  right, i,     Eswap0, Eswap1, schedule);
	right = D_ENCRYPT(right, left,  i + 2, Eswap0, Eswap1, schedule);
      }
      t     = left; 
      left  = right; 
      right = t;
    }
    
    t = right;

    right = (left >>> 1) | (left << 31);
    left  = (t    >>> 1) | (t    << 31);
    
    left  &= 0xffffffff;
    right &= 0xffffffff;

    int results[] = new int[2];

    PERM_OP(right, left, 1, 0x55555555, results); 
    right = results[0]; left = results[1];
    
    PERM_OP(left, right, 8, 0x00ff00ff, results); 
    left = results[0]; right = results[1];

    PERM_OP(right, left, 2, 0x33333333, results); 
    right = results[0]; left = results[1];
    
    PERM_OP(left, right, 16, 0x0000ffff, results);
    left = results[0]; right = results[1];
    
    PERM_OP(right, left, 4, 0x0f0f0f0f, results);
    right = results[0]; left = results[1];
    
    int out[] = new int[2];
    
    out[0] = left; 
    out[1] = right;
    
    return out;
  }

  public static final String alphabet = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

  public static final String crypt(String salt, String original) {
    // wwb -- Should do some sanity checks: salt needs to be 2 chars, in alpha.
    while(salt.length() < 2)
      salt += "A";

    char[] buffer = new char [13];

    char charZero = salt.charAt(0);
    char charOne  = salt.charAt(1);
    
    buffer[0] = charZero;
    buffer[1] = charOne;

    int Eswap0 = alphabet.indexOf(charZero);
    int Eswap1 = alphabet.indexOf(charOne) << 4;
    byte key[] = new byte[8];
    
    for(int i = 0; i < key.length; i ++)
      key[i] = (byte)0;
    
    for(int i = 0; i < key.length && i < original.length(); i ++)
      key[i] = (byte) (((int) original.charAt(i)) << 1);

    int schedule[] = des_set_key(key);
    int out[]      = body(schedule, Eswap0, Eswap1);
    
    byte b[] = new byte[9];
    
    intToFourBytes(out[0], b, 0);
    intToFourBytes(out[1], b, 4);
    b[8] = 0;

    for(int i = 2, y = 0, u = 0x80; i < 13; i ++) {
      for(int j = 0, c = 0; j < 6; j ++) {
	c <<= 1;

	if(((int)b[y] & u) != 0)
	  c |= 1;

	u >>>= 1;
	
	if (u == 0) {
	  y++;
	  u = 0x80;
	}
	buffer[i] = alphabet.charAt(c);
      }
    }
    return new String(buffer);
  }
}

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