InfoMagic Internet Tools 1993 July/Internet Tools.iso/RockRidge/security/shadow-3.1.4/dpmain.c

C/C++ Source or Header | 1991-11-26 | 4.2 KB | 228 lines

/*
 * Copyright 1990, 1991 John F. Haugh II
 * All rights reserved.
 *
 * Permission is granted to copy and create derivative works for any
 * non-commercial purpose, provided this copyright notice is preserved
 * in all copies of source code, or included in human readable form
 * and conspicuously displayed on all copies of object code or
 * distribution media.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <fcntl.h>
#ifdef    BSD
#include <strings.h>
#else
#include <string.h>
#endif
#include "dialup.h"

#ifndef    lint
static    char    sccsid[] = "@(#)dpmain.c    3.4    17:31:55    8/4/91";
#endif

#ifdef    USG
#define    bzero(p,l)    memset(p, 0, l)
#endif

#define    DTMP    "/etc/d_passwd.tmp"

/*
 * Prompts and messages go here.
 */

#define    PASS1    "Shell password:"
#define    PASS2    "re-enter Shell password:"
#define    NOMATCH    "%s: Passwords do not match, try again.\n"
#define    NOFOUND    "%s: Shell %s not found.\n"

int    aflg;
int    dflg;
char    *Prog;

extern    char    *pw_encrypt();
extern    char    *getpass();

usage ()
{
    fprintf (stderr, "Usage: %s [ -(a|d) ] shell\n", Prog);
    exit (1);
}

main (argc, argv)
int    argc;
char    **argv;
{
    struct    dialup    *dial;
    struct    dialup    dent;
    struct    stat    sb;
    FILE    *fp;
    char    *shell;
    char    *cp;
    char    pass[BUFSIZ];
    int    fd;
    int    found = 0;
    int    opt;
    extern    int    optind;
    extern    char    *optarg;

    if (Prog = strrchr (argv[0], '/'))
        Prog++;
    else
        Prog = argv[0];

    while ((opt = getopt (argc, argv, "a:d:")) != EOF) {
        switch (opt) {
            case 'a':
                aflg++;
                shell = optarg;
                break;
            case 'd':
                dflg++;
                shell = optarg;
                break;
            default:
                usage ();
        }
    }
    if (! aflg && ! dflg)
        aflg++;

    if (! shell) {
        if (optind >= argc)
            usage ();
        else
            shell = argv[optind];
    }
    if (aflg + dflg != 1)
        usage ();

    /*
     * Add a new shell to the password file, or update an existing
     * entry.  Begin by getting an encrypted password for this
     * shell.
     */

    if (aflg) {
        int    tries = 3;

        dent.du_shell = shell;
        dent.du_passwd = "";

again:
        if (! (cp = getpass (PASS1)))
            exit (1);

        strcpy (pass, cp);
        bzero (cp, strlen (cp));

        if (! (cp = getpass (PASS2)))
            exit (1);

        if (strcmp (pass, cp)) {
            bzero (pass, strlen (pass));
            bzero (cp, strlen (cp));
            fprintf (stderr, NOMATCH, Prog);

            if (--tries)
                goto again;

            exit (1);
        }
        bzero (cp, strlen (cp));
        dent.du_passwd = pw_encrypt (pass, (char *) 0);
        bzero (pass, strlen (pass));
    }

    /*
     * Create the temporary file for the updated dialup password
     * information to be placed into.  Turn it into a (FILE *)
     * for use by putduent().
     */

    if ((fd = open (DTMP, O_CREAT|O_EXCL|O_RDWR, 0600)) < 0) {
        sprintf (pass, "%s: can't create %s", Prog, DTMP);
        perror (pass);
        exit (1);
    }
    if (! (fp = fdopen (fd, "r+"))) {
        sprintf (pass, "%s: can't open %s", Prog, DTMP);
        perror (pass);
        exit (1);
    }

    /*
     * Scan the dialup password file for the named entry,
     * copying out other entries along the way.  Copying
     * stops when a match is found or the file runs out.
     */

    while (dial = getduent ()) {
        if (strcmp (dial->du_shell, shell) == 0) {
            found = 1;
            break;
        }
        if (putduent (dial, fp))
            goto failure;
    }

    /*
     * To delete the entry, just don't copy it.  To update
     * the entry, output the modified version - works with
     * new entries as well.
     */

    if (dflg && ! found) {
        fprintf (stderr, NOMATCH, Prog, shell);
        exit (1);
    }
    if (aflg)
        if (putduent (&dent, fp))
            goto failure;

    /*
     * Now copy out the remaining entries.  Flush and close the
     * new file before doing anything nasty to the existing
     * file.
     */


    while (dial = getduent ())
        if (putduent (dial, fp))
            goto failure;

    if (fflush (fp))
        goto failure;

    fclose (fp);

    /*
     * If the original file did not exist, we must create a new
     * file with owner "root" and mode 400.  Otherwise we copy
     * the modes from the existing file to the new file.
     *
     * After this is done the new file will replace the old file.
     */

    if (! stat (DIALPWD, &sb)) {
        chown (DTMP, sb.st_uid, sb.st_gid);
        chmod (DTMP, sb.st_mode);
        unlink (DIALPWD);
    } else {
        chown (DTMP, 0, 0);
        chmod (DTMP, 0400);
    }
    link (DTMP, DIALPWD);
    unlink (DTMP);

    sync ();
    exit (0);

failure:
    unlink (DTMP);
    exit (1);
}