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Subject: [9fans] encryption routines for il
To: 9fans@cse.psu.edu
Date: Wed, 22 Apr 1998 18:14:48 +0100 (BST)
From: Digby Tarvin <digbyt@acm.org>
Reply-To: digbyt@acm.org (Digby Tarvin)
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I am looking at installing Pace Willisson's Unix based Authentication
server on my BSDI box (thanks to Russ Cox for letting me know about
it).

If anyone outside the US has implemented compatible versions of the
missing encryption routines, please let me know.

Thanks,
DigbyT
-- 
Digby R. S. Tarvin                                              digbyt@acm.org
http://www.cthulhu.dircon.co.uk




X-Authentication-Warning: claven.cse.psu.edu: majordom set sender to owner-9fans using -f
Date: Wed, 22 Apr 1998 14:26:51 -0400
To: 9fans@cse.psu.edu
From: "Russ Cox" <rsc@plan9.bell-labs.com>
Subject: re: [9fans] encryption routines for il
Sender: owner-9fans@cse.psu.edu
Reply-To: 9fans@cse.psu.edu

Take Pace's il.tar.gz, make des.c a null file, and then
use the following encrypt.c:

(The inspiration and almost all of the code for this came from Kenji Arisawa.)

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#define DESKEYLEN 7
#define NAMELEN 22
typedef unsigned char uchar;

uchar a[8] = { 128, 64, 32, 16, 8, 4, 2, 1 };

/*  get bit status at the bit position n of string s
    char s[8]
    int n: 0 .. 63
*/
int strbit(char *s, int n)
{   int q,m;
    q = n / 8;
    m = n % 8;
    return (s[q] & a[m]?1:0);
}

/*  uchar s[8]
    uchar x[1]
    */
uchar s2b(uchar *s)
{   int i;
    uchar x;
    x = 0;
    for(i = 0; i < 8; i++) if(s[i]) x |= a[i];
    return x;
}

/*  uchar s[8]
    uchar x[1]
    */
void b2s(uchar x, uchar *s)
{   int i;
    for(i = 0; i < 8; i++) s[i] = 0;
    for(i = 0; i < 8; i++) if(x & a[i]) s[i] = 1;
}

/* uchar s[64], x[8] */
void blk2str(uchar *x, uchar *s)
{   int i;
    for(i = 0; i < 8; i++) b2s(x[i],&s[8*i]);
}

/* uchar s[64], x[8] */
void str2blk(uchar *s, uchar *x)
{   int i;
    for(i = 0; i < 8; i++) x[i] = s2b(&s[8*i]);
}

/* Plan9 encrypt
   uchar key[7]    --- deskey
   uchar t[8]     --- target(des cypher block)
 */
void des(uchar *key, uchar *t)
{   int i,j;
    char s[64],u[64];
    for(j = 0; j < 8; j++){
        for(i = 0; i < 7; i++) s[8*j + i] = strbit(key, 7*j + i);
        s[8*j + 7] = 0;
    }
    setkey(s);
    blk2str(t,u);
    encrypt(u,0); /* encrypt */
    str2blk(u,t);
}

void
plan9_encrypt(uchar *key, uchar *t, int len)
{
	des(key, t);
}

This doesn't work under Linux.  Don't complain to me.

Russ