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-rw-r--r--login-utils/chfn.c480
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diff --git a/login-utils/chfn.c b/login-utils/chfn.c
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+/*
+ * chfn.c -- change your finger information
+ * (c) 1994 by salvatore valente <svalente@athena.mit.edu>
+ * (c) 2012 by Cody Maloney <cmaloney@theoreticalchaos.com>
+ *
+ * this program is free software. you can redistribute it and
+ * modify it under the terms of the gnu general public license.
+ * there is no warranty.
+ *
+ * $Author: aebr $
+ * $Revision: 1.18 $
+ * $Date: 1998/06/11 22:30:11 $
+ *
+ * Updated Thu Oct 12 09:19:26 1995 by faith@cs.unc.edu with security
+ * patches from Zefram <A.Main@dcs.warwick.ac.uk>
+ *
+ * Hacked by Peter Breitenlohner, peb@mppmu.mpg.de,
+ * to remove trailing empty fields. Oct 5, 96.
+ *
+ * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
+ * - added Native Language Support
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <getopt.h>
+#include <pwd.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "c.h"
+#include "env.h"
+#include "closestream.h"
+#include "islocal.h"
+#include "nls.h"
+#include "setpwnam.h"
+#include "strutils.h"
+#include "xalloc.h"
+#include "logindefs.h"
+
+#include "ch-common.h"
+
+#ifdef HAVE_LIBSELINUX
+# include <selinux/selinux.h>
+# include "selinux-utils.h"
+#endif
+
+#ifdef HAVE_LIBUSER
+# include <libuser/user.h>
+# include "libuser.h"
+#elif CHFN_CHSH_PASSWORD
+# include "auth.h"
+#endif
+
+struct finfo {
+ char *full_name;
+ char *office;
+ char *office_phone;
+ char *home_phone;
+ char *other;
+};
+
+struct chfn_control {
+ struct passwd *pw;
+ char *username;
+ /* "oldf" Contains the users original finger information.
+ * "newf" Contains the changed finger information, and contains
+ * NULL in fields that haven't been changed.
+ * In the end, "newf" is folded into "oldf". */
+ struct finfo oldf, newf;
+ unsigned int
+ allow_fullname:1, /* The login.defs restriction */
+ allow_room:1, /* see: man login.defs(5) */
+ allow_work:1, /* and look for CHFN_RESTRICT */
+ allow_home:1, /* keyword for these four. */
+ changed:1, /* is change requested */
+ interactive:1; /* whether to prompt for fields or not */
+};
+
+/* we do not accept gecos field sizes longer than MAX_FIELD_SIZE */
+#define MAX_FIELD_SIZE 256
+
+static void __attribute__((__noreturn__)) usage(void)
+{
+ FILE *fp = stdout;
+ fputs(USAGE_HEADER, fp);
+ fprintf(fp, _(" %s [options] [<username>]\n"), program_invocation_short_name);
+
+ fputs(USAGE_SEPARATOR, fp);
+ fputs(_("Change your finger information.\n"), fp);
+
+ fputs(USAGE_OPTIONS, fp);
+ fputs(_(" -f, --full-name <full-name> real name\n"), fp);
+ fputs(_(" -o, --office <office> office number\n"), fp);
+ fputs(_(" -p, --office-phone <phone> office phone number\n"), fp);
+ fputs(_(" -h, --home-phone <phone> home phone number\n"), fp);
+ fputs(USAGE_SEPARATOR, fp);
+ printf( " -u, --help %s\n", USAGE_OPTSTR_HELP);
+ printf( " -V, --version %s\n", USAGE_OPTSTR_VERSION);
+ printf(USAGE_MAN_TAIL("chfn(1)"));
+ exit(EXIT_SUCCESS);
+}
+
+/*
+ * check_gecos_string () --
+ * check that the given gecos string is legal. if it's not legal,
+ * output "msg" followed by a description of the problem, and return (-1).
+ */
+static int check_gecos_string(const char *msg, char *gecos)
+{
+ const size_t len = strlen(gecos);
+
+ if (MAX_FIELD_SIZE < len) {
+ warnx(_("field %s is too long"), msg);
+ return -1;
+ }
+ if (illegal_passwd_chars(gecos)) {
+ warnx(_("%s: has illegal characters"), gecos);
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * parse_argv () --
+ * parse the command line arguments.
+ * returns true if no information beyond the username was given.
+ */
+static void parse_argv(struct chfn_control *ctl, int argc, char **argv)
+{
+ int index, c, status = 0;
+ static const struct option long_options[] = {
+ { "full-name", required_argument, NULL, 'f' },
+ { "office", required_argument, NULL, 'o' },
+ { "office-phone", required_argument, NULL, 'p' },
+ { "home-phone", required_argument, NULL, 'h' },
+ { "help", no_argument, NULL, 'u' },
+ { "version", no_argument, NULL, 'V' },
+ { NULL, 0, NULL, 0 },
+ };
+
+ while ((c = getopt_long(argc, argv, "f:r:p:h:o:uvV", long_options,
+ &index)) != -1) {
+ switch (c) {
+ case 'f':
+ if (!ctl->allow_fullname)
+ errx(EXIT_FAILURE, _("login.defs forbids setting %s"), _("Name"));
+ ctl->newf.full_name = optarg;
+ status += check_gecos_string(_("Name"), optarg);
+ break;
+ case 'o':
+ if (!ctl->allow_room)
+ errx(EXIT_FAILURE, _("login.defs forbids setting %s"), _("Office"));
+ ctl->newf.office = optarg;
+ status += check_gecos_string(_("Office"), optarg);
+ break;
+ case 'p':
+ if (!ctl->allow_work)
+ errx(EXIT_FAILURE, _("login.defs forbids setting %s"), _("Office Phone"));
+ ctl->newf.office_phone = optarg;
+ status += check_gecos_string(_("Office Phone"), optarg);
+ break;
+ case 'h':
+ if (!ctl->allow_home)
+ errx(EXIT_FAILURE, _("login.defs forbids setting %s"), _("Home Phone"));
+ ctl->newf.home_phone = optarg;
+ status += check_gecos_string(_("Home Phone"), optarg);
+ break;
+ case 'v': /* deprecated */
+ case 'V':
+ print_version(EXIT_SUCCESS);
+ case 'u':
+ usage();
+ default:
+ errtryhelp(EXIT_FAILURE);
+ }
+ ctl->changed = 1;
+ ctl->interactive = 0;
+ }
+ if (status != 0)
+ exit(EXIT_FAILURE);
+ /* done parsing arguments. check for a username. */
+ if (optind < argc) {
+ if (optind + 1 < argc) {
+ warnx(_("cannot handle multiple usernames"));
+ errtryhelp(EXIT_FAILURE);
+ }
+ ctl->username = argv[optind];
+ }
+}
+
+/*
+ * parse_passwd () --
+ * take a struct password and fill in the fields of the struct finfo.
+ */
+static void parse_passwd(struct chfn_control *ctl)
+{
+ char *gecos;
+
+ if (!ctl->pw)
+ return;
+ /* use pw_gecos - we take a copy since PAM destroys the original */
+ gecos = xstrdup(ctl->pw->pw_gecos);
+ /* extract known fields */
+ ctl->oldf.full_name = strsep(&gecos, ",");
+ ctl->oldf.office = strsep(&gecos, ",");
+ ctl->oldf.office_phone = strsep(&gecos, ",");
+ ctl->oldf.home_phone = strsep(&gecos, ",");
+ /* extra fields contain site-specific information, and can
+ * not be changed by this version of chfn. */
+ ctl->oldf.other = strsep(&gecos, ",");
+}
+
+/*
+ * ask_new_field () --
+ * ask the user for a given field and check that the string is legal.
+ */
+static char *ask_new_field(struct chfn_control *ctl, const char *question,
+ char *def_val)
+{
+ int len;
+ char *buf = NULL; /* leave initialized to NULL or getline segfaults */
+ size_t dummy = 0;
+
+ if (!def_val)
+ def_val = "";
+
+ while (true) {
+ printf("%s [%s]:", question, def_val);
+ __fpurge(stdin);
+
+ putchar(' ');
+ fflush(stdout);
+
+ if (getline(&buf, &dummy, stdin) < 0)
+ errx(EXIT_FAILURE, _("Aborted."));
+
+ /* remove white spaces from string end */
+ ltrim_whitespace((unsigned char *) buf);
+ len = rtrim_whitespace((unsigned char *) buf);
+ if (len == 0) {
+ free(buf);
+ return xstrdup(def_val);
+ }
+ if (!strcasecmp(buf, "none")) {
+ free(buf);
+ ctl->changed = 1;
+ return xstrdup("");
+ }
+ if (check_gecos_string(question, buf) >= 0)
+ break;
+ }
+ ctl->changed = 1;
+ return buf;
+}
+
+/*
+ * get_login_defs()
+ * find /etc/login.defs CHFN_RESTRICT and save restrictions to run time
+ */
+static void get_login_defs(struct chfn_control *ctl)
+{
+ const char *s;
+ size_t i;
+ int broken = 0;
+
+ /* real root does not have restrictions */
+ if (geteuid() == getuid() && getuid() == 0) {
+ ctl->allow_fullname = ctl->allow_room = ctl->allow_work = ctl->allow_home = 1;
+ return;
+ }
+ s = getlogindefs_str("CHFN_RESTRICT", "");
+ if (!strcmp(s, "yes")) {
+ ctl->allow_room = ctl->allow_work = ctl->allow_home = 1;
+ return;
+ }
+ if (!strcmp(s, "no")) {
+ ctl->allow_fullname = ctl->allow_room = ctl->allow_work = ctl->allow_home = 1;
+ return;
+ }
+ for (i = 0; s[i]; i++) {
+ switch (s[i]) {
+ case 'f':
+ ctl->allow_fullname = 1;
+ break;
+ case 'r':
+ ctl->allow_room = 1;
+ break;
+ case 'w':
+ ctl->allow_work = 1;
+ break;
+ case 'h':
+ ctl->allow_home = 1;
+ break;
+ default:
+ broken = 1;
+ }
+ }
+ if (broken)
+ warnx(_("%s: CHFN_RESTRICT has unexpected value: %s"), _PATH_LOGINDEFS, s);
+ if (!ctl->allow_fullname && !ctl->allow_room && !ctl->allow_work && !ctl->allow_home)
+ errx(EXIT_FAILURE, _("%s: CHFN_RESTRICT does not allow any changes"), _PATH_LOGINDEFS);
+}
+
+/*
+ * ask_info () --
+ * prompt the user for the finger information and store it.
+ */
+static void ask_info(struct chfn_control *ctl)
+{
+ if (ctl->allow_fullname)
+ ctl->newf.full_name = ask_new_field(ctl, _("Name"), ctl->oldf.full_name);
+ if (ctl->allow_room)
+ ctl->newf.office = ask_new_field(ctl, _("Office"), ctl->oldf.office);
+ if (ctl->allow_work)
+ ctl->newf.office_phone = ask_new_field(ctl, _("Office Phone"), ctl->oldf.office_phone);
+ if (ctl->allow_home)
+ ctl->newf.home_phone = ask_new_field(ctl, _("Home Phone"), ctl->oldf.home_phone);
+ putchar('\n');
+}
+
+/*
+ * find_field () --
+ * find field value in uninteractive mode; can be new, old, or blank
+ */
+static char *find_field(char *nf, char *of)
+{
+ if (nf)
+ return nf;
+ if (of)
+ return of;
+ return xstrdup("");
+}
+
+/*
+ * add_missing () --
+ * add not supplied field values when in uninteractive mode
+ */
+static void add_missing(struct chfn_control *ctl)
+{
+ ctl->newf.full_name = find_field(ctl->newf.full_name, ctl->oldf.full_name);
+ ctl->newf.office = find_field(ctl->newf.office, ctl->oldf.office);
+ ctl->newf.office_phone = find_field(ctl->newf.office_phone, ctl->oldf.office_phone);
+ ctl->newf.home_phone = find_field(ctl->newf.home_phone, ctl->oldf.home_phone);
+ ctl->newf.other = find_field(ctl->newf.other, ctl->oldf.other);
+ printf("\n");
+}
+
+/*
+ * save_new_data () --
+ * save the given finger info in /etc/passwd.
+ * return zero on success.
+ */
+static int save_new_data(struct chfn_control *ctl)
+{
+ char *gecos;
+ int len;
+
+ /* create the new gecos string */
+ len = xasprintf(&gecos, "%s,%s,%s,%s,%s",
+ ctl->newf.full_name,
+ ctl->newf.office,
+ ctl->newf.office_phone,
+ ctl->newf.home_phone,
+ ctl->newf.other);
+
+ /* remove trailing empty fields (but not subfields of ctl->newf.other) */
+ if (!ctl->newf.other || !*ctl->newf.other) {
+ while (len > 0 && gecos[len - 1] == ',')
+ len--;
+ gecos[len] = 0;
+ }
+
+#ifdef HAVE_LIBUSER
+ if (set_value_libuser("chfn", ctl->username, ctl->pw->pw_uid,
+ LU_GECOS, gecos) < 0) {
+#else /* HAVE_LIBUSER */
+ /* write the new struct passwd to the passwd file. */
+ ctl->pw->pw_gecos = gecos;
+ if (setpwnam(ctl->pw, ".chfn") < 0) {
+ warn("setpwnam failed");
+#endif
+ printf(_
+ ("Finger information *NOT* changed. Try again later.\n"));
+ return -1;
+ }
+ free(gecos);
+ printf(_("Finger information changed.\n"));
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ uid_t uid;
+ struct chfn_control ctl = {
+ .interactive = 1
+ };
+
+ sanitize_env();
+ setlocale(LC_ALL, ""); /* both for messages and for iscntrl() below */
+ bindtextdomain(PACKAGE, LOCALEDIR);
+ textdomain(PACKAGE);
+ close_stdout_atexit();
+
+ uid = getuid();
+
+ /* check /etc/login.defs CHFN_RESTRICT */
+ get_login_defs(&ctl);
+
+ parse_argv(&ctl, argc, argv);
+ if (!ctl.username) {
+ ctl.pw = getpwuid(uid);
+ if (!ctl.pw)
+ errx(EXIT_FAILURE, _("you (user %d) don't exist."),
+ uid);
+ ctl.username = ctl.pw->pw_name;
+ } else {
+ ctl.pw = getpwnam(ctl.username);
+ if (!ctl.pw)
+ errx(EXIT_FAILURE, _("user \"%s\" does not exist."),
+ ctl.username);
+ }
+ parse_passwd(&ctl);
+#ifndef HAVE_LIBUSER
+ if (!(is_local(ctl.username)))
+ errx(EXIT_FAILURE, _("can only change local entries"));
+#endif
+
+#ifdef HAVE_LIBSELINUX
+ if (is_selinux_enabled() > 0) {
+ char *user_cxt = NULL;
+
+ if (uid == 0 && !ul_selinux_has_access("passwd", "chfn", &user_cxt))
+ errx(EXIT_FAILURE,
+ _("%s is not authorized to change "
+ "the finger info of %s"),
+ user_cxt ? : _("Unknown user context"),
+ ctl.username);
+
+ if (ul_setfscreatecon_from_file(_PATH_PASSWD) != 0)
+ errx(EXIT_FAILURE,
+ _("can't set default context for %s"), _PATH_PASSWD);
+ }
+#endif
+
+#ifdef HAVE_LIBUSER
+ /* If we're setuid and not really root, disallow the password change. */
+ if (geteuid() != getuid() && uid != ctl.pw->pw_uid) {
+#else
+ if (uid != 0 && uid != ctl.pw->pw_uid) {
+#endif
+ errno = EACCES;
+ err(EXIT_FAILURE, _("running UID doesn't match UID of user we're "
+ "altering, change denied"));
+ }
+
+ printf(_("Changing finger information for %s.\n"), ctl.username);
+
+#if !defined(HAVE_LIBUSER) && defined(CHFN_CHSH_PASSWORD)
+ if (!auth_pam("chfn", uid, ctl.username)) {
+ return EXIT_FAILURE;
+ }
+#endif
+
+ if (ctl.interactive)
+ ask_info(&ctl);
+
+ add_missing(&ctl);
+
+ if (!ctl.changed) {
+ printf(_("Finger information not changed.\n"));
+ return EXIT_SUCCESS;
+ }
+
+ return save_new_data(&ctl) == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
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