cmd/crypt/crypt.c

	crypt.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"
/*
 *  A one-rotor machine designed along the lines of Enigma
 *  but considerably trivialized.
 */

/* EXPORT DELETE START */
#define ECHO 010
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <crypt.h>
#include <errno.h>

#define ROTORSZ 256
#define MASK 0377
char    t1[ROTORSZ];
char    t2[ROTORSZ];
char    t3[ROTORSZ];

static void
setup(pw)
char *pw;
{
    int ic, i, k, temp;
    unsigned random;
    char buf[13];
    long seed;
    char *ret;
    int err;

    (void) strncpy(buf, pw, 8);
    buf[8] = buf[0];
    buf[9] = buf[1];
    errno = 0;
    ret = des_crypt(buf, &buf[8]);
    if (ret == NULL) {
        err = errno;
        (void) fprintf(stderr, "crypt: setup failed, unable to"
            " initialize rotors: %s\n", strerror(err));
        exit(1);
    }
    (void) strncpy(buf, ret, 13);
    seed = 123;
    for (i = 0; i < 13; i++)
        seed = seed*buf[i] + i;
    for (i = 0; i < ROTORSZ; i++) {
        t1[i] = i;
        t3[i] = 0;
    }
    for (i = 0; i < ROTORSZ; i++) {
        seed = 5*seed + buf[i%13];
        random = seed % 65521;
        k = ROTORSZ-1 - i;
        ic = (random&MASK)%(k+1);
        random >>= 8;
        temp = t1[k];
        t1[k] = t1[ic];
        t1[ic] = temp;
        if (t3[k] != 0) continue;
        ic = (random&MASK) % k;
        while (t3[ic] != 0) ic = (ic+1) % k;
        t3[k] = ic;
        t3[ic] = k;
    }
    for (i = 0; i < ROTORSZ; i++)
        t2[t1[i]&MASK] = i;
}
/* EXPORT DELETE END */

int
main(int argc, char **argv)
{
/* EXPORT DELETE START */
    extern int optind;
    char *p1;
    int i, n1, n2, nchar;
    int c;
    struct {
        long offset;
        unsigned int count;
    } header;
    int pflag = 0;
    int kflag = 0;
    char *buf;
    char key[8];
    char *keyvar = "CrYpTkEy=XXXXXXXX";
    char *s;

    if (argc < 2) {
        if ((buf = (char *)getpass("Enter key:")) == NULL) {
            (void) fprintf(stderr, "Cannot open /dev/tty\n");
            exit(1);
        }
        setup(buf);
    } else {
        while ((c = getopt(argc, argv, "pk")) != EOF)
            switch (c) {
            case 'p':
            /* notify editor that exec has succeeded */
                if (write(1, "y", 1) != 1)
                    exit(1);
                if (read(0, key, 8) != 8)
                    exit(1);
                setup(key);
                pflag = 1;
                break;
            case 'k':
                if ((s = getenv("CrYpTkEy")) == (char *)NULL) {
                    (void) fprintf(stderr,
                        "CrYpTkEy not set.\n");
                    exit(1);
                }
                (void) strncpy(key, s, 8);
                setup(key);
                kflag = 1;
                break;
            case '?':
                (void) fprintf(stderr,
                    "usage: crypt [ -k ] [ key]\n");
                exit(2);
            }
        if (pflag == 0 && kflag == 0) {
            (void) strncpy(keyvar+9, argv[optind], 8);
            (void) putenv(keyvar);
            (void) execlp("crypt", "crypt", "-k", 0);
        }
    }
    if (pflag)
        for (;;) {
            if ((nchar = read(0, (char *)&header, sizeof (header)))
                != sizeof (header))
                exit(nchar);
            n1 = (int)(header.offset&MASK);
            n2 = (int)((header.offset >> 8) &MASK);
            nchar = header.count;
            buf = (char *)malloc(nchar);
            p1 = buf;
            if (read(0, buf, nchar) != nchar)
                exit(1);
            while (nchar--) {
                *p1 = t2[(t3[(t1[(*p1 + n1)&MASK]+
                    n2)&MASK] - n2)&MASK] - n1;
                n1++;
                if (n1 == ROTORSZ) {
                    n1 = 0;
                    n2++;
                    if (n2 == ROTORSZ) n2 = 0;
                }
                p1++;
            }
            nchar = header.count;
            if (write(1, buf, nchar) != nchar)
                exit(1);
            free(buf);
        }

    n1 = 0;
    n2 = 0;

    while ((i = getchar()) >= 0) {
        i = t2[(t3[(t1[(i+n1)&MASK]+n2)&MASK]-n2)&MASK]-n1;
        (void) putchar(i);
        n1++;
        if (n1 == ROTORSZ) {
            n1 = 0;
            n2++;
            if (n2 == ROTORSZ) n2 = 0;
        }
    }
    return (0);
/* EXPORT DELETE END */
}