Source Code 1992 March/Source_Code_CD-ROM_Walnut_Creek_March_1992.iso/usenet/altsrcs/2/2082/chpasswd.c

C/C++ Source or Header | 1990-12-28 | 4.8 KB | 219 lines

/*
 * Copyright 1990, John F. Haugh II
 * All rights reserved.
 *
 * Use, duplication, and disclosure prohibited without
 * the express written permission of the author.
 *
 * chpass - update passwords in batch
 *
 *    chpass reads standard input for a list of colon separated
 *    user names and new passwords.  the appropriate password
 *    files are updated to reflect the changes.  because the
 *    changes are made in a batch fashion, the user must run
 *    the mkpasswd command after this command terminates since
 *    no password updates occur until the very end.
 */

#include <stdio.h>
#include <pwd.h>
#include <fcntl.h>
#include <string.h>
#include "config.h"
#ifdef    SHADOWPWD
#include "shadow.h"
#endif

#ifndef    lint
static    char    sccsid[] = "@(#)chpasswd.c    3.1 01:18:53 11/14/90";
#endif

char    *Prog;

extern    char    *pw_encrypt();

/*
 * If it weren't for the different structures and differences in how
 * certain fields were manipulated, I could just use macros to replace
 * the function calls for the different file formats.  So I make the
 * best of things and just use macros to replace a few of the calls.
 */

#ifdef    SHADOWPWD
#define    pw_lock        spw_lock
#define    pw_open        spw_open
#define    pw_close    spw_close
#define    pw_unlock    spw_unlock
#endif

/*
 * usage - display usage message and exit
 */

usage ()
{
    fprintf (stderr, "usage: %s\n", Prog);
    exit (1);
}

main (argc, argv)
int    argc;
char    **argv;
{
    char    buf[BUFSIZ];
    char    *name;
    char    *newpwd;
    char    *cp;
#ifdef    SHADOWPWD
    struct    spwd    *sp;
    struct    spwd    newsp;
    struct    spwd    *spw_locate();
#else
    struct    passwd    *pw;
    struct    passwd    newpw;
    struct    passwd    *pw_locate();
    char    newage[5];
#endif
    int    errors = 0;
    int    line = 0;
    long    now = time ((long *) 0) / (24L*3600L);

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

    if (argc != 1)
        usage ();

    /*
     * Lock the password file and open it for reading.  This will
     * bring all of the entries into memory where they may be
     * updated.
     */

    if (! pw_lock ()) {
        fprintf (stderr, "%s: can't lock password file\n", Prog);
        exit (1);
    }
    if (! pw_open (O_RDWR)) {
        fprintf (stderr, "%s: can't open password file\n", Prog);
        exit (1);
    }

    /*
     * Read each line, separating the user name from the password.
     * The password entry for each user will be looked up in the
     * appropriate file (shadow or passwd) and the password changed.
     * For shadow files the last change date is set directly, for
     * passwd files the last change date is set in the age only if
     * aging information is present.
     */

    while (fgets (buf, sizeof buf, stdin) != (char *) 0) {
        line++;
        if (cp = strrchr (buf, '\n')) {
            *cp = '\0';
        } else {
            fprintf (stderr, "%s: line %d: line too long\n",
                Prog, line);
            errors++;
            continue;
        }

        /*
         * The username is the first field.  It is separated
         * from the password with a ":" character which is
         * replaced with a NUL to give the new password.  The
         * new password will then be encrypted in the normal
         * fashion with a new salt generated.
         */

        name = buf;
        if (cp = strchr (name, ':')) {
            *cp++ = '\0';
        } else {
            fprintf (stderr, "%s: line %d: missing new password\n",
                Prog, line);
            errors++;
            continue;
        }
        newpwd = cp;
        cp = pw_encrypt (newpwd, (char *) 0);

        /*
         * Get the password file entry for this user.  The user
         * must already exist.
         */

#ifdef    SHADOWPWD
        if (! (sp = spw_locate (name)))
#else
        if (! (pw = pw_locate (name)))
#endif
        {
            fprintf (stderr, "%s: line %d: unknown user %s\n",
                Prog, line, name);
            errors++;
            continue;
        }

        /*
         * The freshly encrypted new password is merged into
         * the user's password file entry and the last password
         * change date is set to the current date.
         */

#ifdef    SHADOWPWD
        newsp = *sp;
        newsp.sp_pwdp = cp;
        newsp.sp_lstchg = now;
#else
        newpw = *pw;
        newpw.pw_passwd = cp;
        if (newpw.pw_age[0]) {
            strcpy (newage, newpw.pw_age);
            strcpy (newage + 2, l64a (now / 7));
            newpw.pw_age = newage;
        }
#endif

        /*
         * The updated password file entry is then put back
         * and will be written to the password file later, after
         * all the other entries have been updated as well.
         */

#ifdef    SHADOWPWD
        if (! spw_update (&newsp))
#else
        if (! pw_update (&newpw))
#endif
        {
            fprintf (stderr, "%s: line %d: cannot update password entry\n",
                Prog, line);
            errors++;
            continue;
        }
    }

    /*
     * Any detected errors will cause the entire set of changes
     * to be aborted.  Unlocking the password file will cause
     * all of the changes to be ignored.  Otherwise the file is
     * closed, causing the changes to be written out all at
     * once, and then unlocked afterwards.
     */

    if (errors) {
        fprintf ("%s: error detected, changes ignored\n", Prog);
        pw_unlock ();
        exit (1);
    }
    if (! pw_close ()) {
        fprintf ("%s: error updating password file\n", Prog);
        exit (1);
    }
    (void) pw_unlock ();
}